The Kynix Components

This article will introduce the process of using AD590 to design a high-precision digital thermometer. AD590 is a commonly used T/I converter. It is a current output type two-end temperature sensor made by AD company using the relationship between PN junction forward current and temperature. When the measured temperature is constant, it is equivalent to a constant current source. AD590 has the characteristics of high measurement accuracy, good linearity and strong interchangeability. When the power supply voltage changes between 5 to 15V, the output current changes less than 1μA. CatalogI. AD590 Introduction1.1 AD590 Function and Structure1.2 AD590 Performance Characteristics1.3 AD590 Working PrincipleII. Design of Digital Display Thermometer2.1 AD590 Internal Circuit2.2 Design of Temperature Measurement Circuit2.3 A/D Conversion and Display Circuit DesignIII. ConclusionFAQOrdering & Quantity I. AD590 Introduction 1.1 AD590 Function and Structure AD590 is a current-type temperature sensor that uses current as an output to indicate temperature. According to the different characteristics, AD590 uses the suffix I, J, K, L, M to divide gears. AD590L and AD590M are generally used in precision temperature measurement circuits. The appearance structure is shown in Figure 1 below. It is packaged in a metal round shell with 3 pins, where pin 1 is the positive terminal of the power supply "+"; pin 2 is the current output terminal "-"; 3 The pin is the ground terminal of the tube shell and is generally not used. The circuit symbol is shown in Figure 2 below.Figure 1 The metal round shell package structure of AD590Figure 2 The circuit symbol of AD590 1.2 AD590 Performance Characteristics(1) Wide working voltage range: 4～30V;(2) Wide temperature measurement range: -55～+150℃;3) Linear current output: 1μA/K,(4) Excellent linearity: the non-linear error in the temperature measurement range is less than ±0.3℃ (AD590M);(5) Laser fine-tuning makes the calibration temperature reach: ±0.5℃ (AD590M);(6) Maximum forward voltage: +44V;(7) Maximum reverse voltage: -20V;(8) Storage temperature: -65～+175℃. 1.3 AD590 Working PrincipleWhen the measured temperature is constant, AD590 is equivalent to a constant current source. Connect it to a 5-30V DC power supply, and connect a 1kΩ constant-value resistor in series at the output end. The measured temperature is proportional, and there will be a voltage signal of 1mV/K across the resistor. Its basic circuit is shown as in Fig. 3.Figure 3 The core circuit of the temperature sensing partFigure 3 is the core circuit of the temperature sensing part of the integrated PN junction sensor using the ΔUBE characteristic. Among them, T1 and T2 play a constant current role, which can be used to make the collector currents I1 and I2 of the left and right branches equal; T3 and T4 are transistors for temperature sensing. The materials and processes of the two tubes are exactly the same, but T3 is essentially It is made up of n transistors in parallel, so its junction area is n times that of T4. The emission junction voltages UBE3 and UBE4 of T3 and T4 are connected in series with the reverse polarity to the resistor R, so the upper end voltage of R is ΔUBE. Therefore, the current I1 is: 　　I1=ΔUBE/R=(KT/q)(lnn)/R For AD590, n=8, in this way, the total current of the circuit will be proportional to the thermodynamic temperature T, and lead this current to the load resistance RL to get an output voltage proportional to T. Due to the use of constant current characteristics, the output signal is not affected by the power supply voltage and wire resistance. The resistor R in Figure 3 is a thin-film resistor formed on a silicon board. The resistor has been laser-corrected for its resistance value, so an I value of 1μA/K can be obtained at the reference temperature. II. Design of Digital Display Thermometer 2.1 AD590 Internal Circuit Figure 4 shows the internal circuit of AD590. VT1 to VT4 in the figure are equivalent to VT1 and VT2 in Figure 3, and VT9 and VT11 are equivalent to VT3 and VT4 in Figure 3. R5 and R6 are low temperature coefficient resistors made by thin film technology. The function of VT6 is to balance the collector voltage of VT7 and VT8.Figure 4 The internal circuit of AD590 VT5, VT12 and VT10 are start-up circuits, and VT5 is a constant bias diode. VT10 is not connected to the substrate, but is connected to R3 to isolate the substrate capacitance and prevent the substrate capacitance from affecting the frequency stability. VT6 can also be used to prevent damage to the circuit when the power supply is reversed. R1 and R2 are emitter feedback resistors, which can be used to increase impedance. VT1～VT4 are connection methods designed for thermal effects. C1 and R4 are used to prevent parasitic oscillation. The design of the circuit makes the emitter currents of VT9, VTl0, and VT11 equal, and they are also 1/3 of the total current I of the entire circuit.The launch junction area ratio of VT9 and VT11 is 8:1, and the launch junction area of VT10 and VT11 is equal. The emitter junction voltages of VT9 and VT11 are connected in series with opposite polarity to the resistors R5 and R6, so: △UBE=(R6-2R5)I/3, from the above formula, we can see that increasing R5 and decreasing R6 will make △ UBE decreases, but the effect of changing R5 on △UBE is more significant because the coefficient in front of it is larger. In the production process, laser correction R5 is used for coarse adjustment, and R6 is corrected for fine adjustment, and finally its output current l is 1μA/K.2.2 Design of Temperature Measurement Circuit Because AD590 is a current output device, when designing a temperature measurement circuit, first convert current into voltage. When the temperature increases by 1K, the current of the AD590 increases by 1μA. When the output current of AD590 passes through a 10kΩ resistor, the voltage drop on this resistor is 10mV, which is converted into 10mV/K. In order to make this resistance accurate to 0.1%, a 9.6kΩ resistor and a 1kΩ precision potential can be used,. The device is connected in series, and a precise 10kΩ resistance is obtained by adjusting the precision potentiometer. Figure 5 shows a current→voltage and absolute→Celsius temperature scale conversion circuit, in which the operational amplifier A1 is connected to the form of a voltage follower to increase the input impedance of the signal. The function of the operational amplifier A2 is to convert the absolute temperature scale into a Celsius temperature scale, input a constant voltage (such as 1.365V) to the non-inverting input terminal of A2, and then adjust RP2 to amplify this voltage to 2.730V. In this way, the voltage between the output terminals of A1 and A2 is the voltage corresponding to the converted Celsius temperature scale.Figure 5 Current→Voltage and Absolute→Celsius Temperature Conversion Circuit Put AD590 into the ice-water mixed solution at 0℃, adjust RP1 so that the output voltage of A1 is 2.730V, adjust RP2 so that the output voltage of A2 is also 2.730V, so the voltage between the two output terminals of A1 and A2: 2.730-2.730 =0V, which corresponds to 0°C.2.3 A/D Conversion and Display Circuit Design There are two schemes for designing A/D conversion and display circuits: (1) Realize with A/D converter MC14433 First, the output current of AD590 is converted into voltage. Since this signal is an analog signal, it is necessary to convert this signal into a digital signal for digital display. The conversion circuit using MC14433 is shown in Figure 6. The function of this circuit is to convert analog signals into digital signals through the A/D converter MC14433 to control the display circuit. Among them, MC14511 is a decoding/latch/drive circuit, its input is BCD code, and its output is a seven-segment decoding. The LED digital display is driven by the MC14433 bit selection signals DS1～DS4 through the Darlington array MC1413, and the DS1 and Q2 terminals of the MC14433 control the display of "+" and "-" temperature. When DS1=1 and Q2=1, the display is positive; when Q2=0, the display is negative.Figure 6 Block diagram of A/D conversion and digital display circuit (2) Realize with ICL7106 A/D conversion and LCD display circuit block diagram using ICL7106 is shown in Figure 7. Among them, ICL7106 is a 3 and a half display A/D conversion circuit, which contains a liquid crystal display drive circuit, which can be used for A/D conversion and LCD display drive.Figure 7 A/D conversion and LCD display circuit block diagramIII. ConclusionAD590 has the advantages of excellent linearity, stable performance, high sensitivity, no compensation, small heat capacity, strong anti-interference ability, remote temperature measurement and convenient use. It can be widely used in various temperature measurement and control fields such as refrigerators, air conditioners, granaries, ice storages, and industrial equipment. The digital display thermometer designed in this article based on AD590 has been applied in many fields.FAQHow does AD590 works?The temperature sensor AD590 is a current-type sensor. Temperature variations are converted into current conversion. The simplest processing is passing a resistor (10K) after the output to convert the current to a voltage, which can then be deduced using the detecting voltage.What is operating voltage of AD590?The AD590 is electrically durable: it withstands a forward voltage of up to 44 V and a reverse voltage of 20 V.What is the sensitivity of AD590?With an AD590 having a sensitivity of 1mv/C (using a 1 Kohm resistor) at 300K the voltage produced is 0.3 volts. To achieve resolution of 1/2C with this transducer the voltages must be measured to 0.5 mv. This is possible when using a 4 3/4 digit DMM.What is AD590?AD590 is a temperature sensor, the current output sensitivity is 1μA/℃, the standard output value is 298.2μA at 25℃, and the working voltage range is 4~30V.What are the characteristics of AD590 temperature sensor?Single function (only temperature measurement), small temperature measurement error, low price, fast response speed, long transmission distance, small size, micro power consumption, etc. It is suitable for remote temperature measurement and temperature control without non-linear calibration. The peripheral circuit is simple.How to detect the quality of AD590?AD590 has a current of 273 mA at 0°. Because 2113 is a Wen sensitive resistor 5261, it means that it is greatly affected by the surrounding temperature 4102. It is very difficult to measure without relying on 1653 other tools. Give you some suggestions.When the ambient temperature rises by one degree, the current of AD590 increases by 1uA. What you have to do is to work with AD590 simultaneously with the help of a high-precision temperature test instrument. After AD590 series 10K resistance, measure its voltage, that is to say, it should be 2.73V at 0°, and 2.98V at room temperature 25°.For higher accuracy, it is recommended that you use the electronic building block software Ardunio for measurement, and put the corresponding data into MATLAB for linear regression. The better the linearity, the more stable the measurement.AD590 is not a high-precision temperature testing device. If high-precision testing is required, other components are recommended.What is the difference between AD590 and PT100?AD590 is a current-type temperature sensor. It converts temperature changes into current conversion. The simplest processing is to pass a resistor (10K) after the output to convert the current into a voltage, and then through the detection voltage, the current at this time can be deduced. Use the relationship between current and temperature in the sensor data to calculate the current temperature.PT100 is a resistance type temperature sensor, which converts temperature changes into resistance changes. The simplest process is to place Pt100 in a bridge, use the voltage difference at the midpoint of the bridge arm, and use a differential amplifier circuit (instrument amplifier circuit) Amplify the voltage, use the amplifier gain and bridge structure data, and use the detected voltage to inversely calculate the current resistance value, and use the relationship between resistance and temperature in the PT100 data sheet to calculate the current temperature.Is AD590 a thermocouple or a thermal resistance?It is neither a thermocouple nor a thermal resistance. The main principle is to detect the temperature according to the temperature change, the output current change, and the current size.

I DescriptionThis blog introduces a temperature acquisition and alarm system based on AT89S52 microcontroller and DS18B20 temperature sensor.Here, we have described the following in detail: scheme design, component selection, hardware structure and software design, etc.CatalogI DescriptionII Introduction2.1 Introduction to temperature measurement system2.2 Introduction to DS18B202.3 DS18B20 Temperature measurement systemIII System scheme structure designIV Selection of main components4.1 Processor4.2 Digital temperature sensor DS18B20V System hardware design5.1 Power module5.2 Temperature acquisition module5.3 Display module5.4 Alarm module5.5 Button moduleVI System software design6.1 Instructions6.2 Initialization sequence6.3 Bus write timing6.4 Bus read timing6.5 Temperature acquisition programVII Experimental testVIII ConclusionFAQOrdering & QuantityII Introduction2.1 Introduction to temperature measurement systemTemperature measurement systems are widely used in the following fields:grain storage;medical care;transportation;smart homes and greenhouses;power telecommunication systems; …Moreover, the system with an alarm function can also reduce the risk of temperature accidents.At present, the temperature values collected by the temperature measuring device are still mainly analog signals. However, the microprocessor can only process digital signals, and A/D conversion is required first. This makes the device structure complex and low precision. However, the emergence of digital temperature sensors can solve this problem.2.2 Introduction to DS18B20The new digital temperature sensor represented by DS18B20 integrates temperature acquisition and A/D conversion directly outputs digital signals and has a simple interface circuit with the single-chip microcomputer.DS18B20 has the features of a single bus, small size, high resolution, strong anti-interference, etc. It has applications in the measurement of highway subgrade temperature field and bearing temperature detection in frozen soil areas.Moreover, the sensor has a unique 64-bit serial number, and multiple devices can be connected to a single signal line to achieve long-distance, multi-point distributed temperature measurement.2.3 DS18B20 Temperature measurement systemThis blog uses 51 single-chip microcomputers as the processing core, uses DS18B20 to form a temperature measurement module, plus a button module, a display module, and an alarm module, etc., to design a digital temperature collection alarm system suitable for multiple occasions. It is designed to realize multiple functions of synchronous collection, display, alarm, and control of specified temperature. The temperature measurement alarm system has passed the simulation test of the PROTUS simulation platform and successfully verified its function with the circuit board. The device runs stably, with a good temperature measurement effect and small error.III System scheme structure designThe system includes the following parts:The core AT89S52 microcontroller and its peripheral circuits;Temperature measurement module (DS18B20 digital temperature sensor);Power module;Display module (drive circuit, multi-digit LED digital tube);Button module;Alarm module (buzzer; LED light-emitting diode).We can take a look at details shown in Figure 1.Figure 1. Block Diagram of temperature measurement systemWhen we use the DS18B20 intelligent temperature sensor, it outputs digital signals without processing and conversion. As long as the read and write a sequence of DS18B20 is strictly followed, the real-time temperature can be accurately read.Even though the system has high precision and relatively complicated procedures, the circuit is simple and small, which is conducive to the intelligentization and lightweight of the system. With multiple DS18B20s connected to a single bus, the microcomputer can communicate with multiple DS18B20s with only one data line. In this way, it can also meet the requirements of multi-point temperature measurement.IV Selection of main components4.1 ProcessorThe system processor uses an AT89S52 single-chip microcomputer. AT89S52 is a high-performance, low-power 8-bit CMOS microprocessor from At-mel. Its 8K system programmable FLASH memory makes its download circuit simple and can realize online programming in serial and parallel mode.There are 3 16-bit timer/counters inside the AT89S52 chip, 1 full-duplex serial port, 4 I/O ports, and 256bytes RAM, which is convenient for program debugging.4.2 Digital temperature sensor DS18B20The DS18B20 temperature sensor is a one-line smart digital temperature sensor produced by DALLAS Semiconductor. In addition, DS18B20 is also the world's first temperature sensor supporting a "single-wire bus" interface. It has the characteristics of long transmission distance, small size, and simple interface.The DS18B20 is mainly composed of the following components:Temperature sensor, configuration register;64-bit ROM;High and low alarm triggers TH and TL.Among them, lithography ROM is the key to realizing multi-point temperature measurement.After the temperature measurement is converted, it is output in the form of 16-bit sign-extended two's complement and stored in the DS18B202 8-bit RAMs.V System hardware designThe hardware circuit of the system is mainly composed of the following 5 modules:Temperature measurement module, power supply module, display module, alarm module and button module. The overall circuit schematic diagram is shown as in Fig. 2.AT89S52 single-chip microcomputer is connected to a 11.0592MHz crystal oscillator circuit to provide an external clock, and the reset terminal RESET is connected to the watchdog circuit to form a minimal single-chip system.The system can achieve the following functions:DS18B20 collects temperature, and the microcontroller is responsible for the communication and control of the sensor;The display module displays the processed temperature value in real time;The alarm module monitors the temperature range. When the temperature exceeds the upper and lower limits, LED diodes and buzzers are used to generate alarm signals to remind users to take measures;The button module sets the alarm value as required to improve the practicality.5.1 Power moduleThe circuit uses +5V working voltage to supply power for the single-chip, acquisition, and alarm circuits. In addition, an independent power module needs to be added during hardware production.5.2 Temperature acquisition moduleDS18B20 utilizes the characteristic of a single bus line, connects the temperature output end DQ and P0.3 mouth through a 4.7kΩ pull-up resistor. The single-chip microcomputer initializes the sensor and completes the temperature collection through the wire. The GND of the sensor is grounded, and VDD can be powered by a data line or an external power supply. In order to improve the anti-interference ability, this design uses an external power supply mode.Figure 2. Hardware circuit structure5.3 Display moduleIn order to save the hardware interface, a dynamic scanning display scheme is adopted. Dynamic scanning is a cyclic shift method that uses the persistence of the human eye to achieve the effect of continuous display.This design uses a 6-digit 8-segment common cathode digital tube with a decimal point to display the temperature value. Among them, the first digit is the positive and negative sign digit, the second, third, fourth, and fifth digits respectively display the hundreds, tens, ones and decimal places of the temperature, and the last digit displays the temperature unit ℃.The P2 port of the single-chip microcomputer (P2.0 ~ P2.7 total 8 bits corresponding to 8 fields) is connected with the segment selection common signal line of the nixie tube through the driver chip 74LS245. P3. 0~P3.5 of P3 port are connected with the bit selection signal line of the digital tube to realize bit selection control.5.4 Alarm moduleIn order to increase the safety factor, the alarm circuit adopts an alarm method with sound and light double guarantee. This includes a buzzer and 2 LEDs of different colors.The collected temperature is constantly compared with the set temperature threshold:When the temperature is higher than the upper limit threshold, the buzzer of port P3.7 sends out a high-frequency alarm signal, and the red LED light of port P0.6 is lit at the same time to give high temperature alarm.When the temperature is lower than the lower limit threshold, the buzzer sends out a low-frequency alarm signal, and at the same time lights up the blue LED light of port P0.7 to give a low-temperature alarm.5.5 Button moduleWe can realize human-computer interaction through buttons, adjust the temperature threshold, and make the system suitable for more occasions. This module is composed of two parts, one part is the control button (K1～K4), the other part is the indicator light, which occupies the port P1.0～P1.5 of the single-chip microcomputer. For details, we can see Figure 3 below.When K1 is pressed, the red light is on, indicating that the upper limit setting state is entered, and the temperature is adjusted through the buttons K2 (+) and K3 (-). At the same time, the display module displays the temperature value setting synchronously. After the adjustment is completed, press K1 again to exit.The lower limit temperature value adjustment (K4) process is consistent with the upper limit.VI System software designThe DS18B20 hardware circuit is simple, and relatively complicated software design must be used to provide reasonable logic timing to ensure reliable and accurate work. DS18B20 mainly includes 3 kinds of operations: initialization, bus read, and bus write. These three operations must strictly follow the timing requirements. In the following, we will conduct an in-depth analysis of these three aspects.6.1 InstructionsAccording to the communication protocol of DS18B20, the sensor must use the ROM instruction and memory RAM instruction provided by it to operate. And these two kinds of instructions appear in the program in the hexadecimal form of 8bit word length. Commonly used codes and specific meanings are shown in Table 1 and Table 2.Each temperature conversion generally goes through three steps: reset operation, send ROM command, send RAM command, and then read the temperature.6.2 Initialization sequenceInitialization is one of the basic operations at the bottom of the DS18B20, which is equivalent to establishing a communication bridge between the microcontroller and the sensor to prepare for the subsequent operations. The initialization pulse includes the reset pulse sent by the CPU and the response pulse sent by the sensor. The initialization pulse sequence is shown in Figure 3.Figure 3. DS18B20 initialization sequenceThe host first sends out a reset pulse (low-level signal) of 480-960μs and then releases the bus to enter the receiving mode (RX). When DS18B20 detects the rising edge when the bus is released, it waits for 15-60μs, and then sends out a low-level response pulse with a delay of 60-240μs. At this time, the DQ of the sensor is set to 1, and the host is also set to 1, and the initialization process is completed. At this time, the sensor is in a state where it can be read and written6.3 Bus write timingWriting data to DS18B20 is the basic operation of sending instructions and data. The right shift operation is used to realize bit-by-bit writing with low bit in front and high bit in back. It mainly includes two timings: writing "0" and writing "1".The write sequence starts when the host pulls down the bus for more than 1μs, and sends the signal to be sent to the DQ within 15μs, waiting for the sensor to sample it, and the sensor completes the data collection within 45μs.During data collection, if the bus is high, write logic "1"; otherwise, write logic "0".It can be seen from the write sequence in Figure 4 that one write cycle requires at least 60 μs, and there must be an interval greater than 1 μs between two write cycles.Figure 4. Write time sequence of DS18B206.4 Bus write timingWriting data to DS18B20 is the basic operation of sending instructions and data. The right shift operation is used to realize bit-by-bit writing with low bit in front and high bit in back. It mainly includes two timings: writing "0" and writing "1".The write sequence starts when the host pulls down the bus for more than 1μs, and sends the signal to be sent to the DQ within 15μs, waiting for the sensor to sample it, and the sensor completes the data collection within 45μs. During data collection, if the bus is high, write logic "1"; otherwise, write logic "0".It can be seen from the write sequence in Figure 4 that one write cycle requires at least 60 μs, and there must be an interval greater than 1 μs between two write cycles.Figure 5. Read time sequence of DS18B206.5 Temperature acquisition programTake the temperature acquisition program as an example to briefly explain the source code:　　Void Convert_18B20(Void)　　{RST_18B20();　　WR_18B20(0xcc);　　WR_18B20(0x44);}　　Int Read_18B20(Void)　　{RST_18B20();　　WR_18B20(0xcc);　　WR_18B20(0xbe);　　Temp_8[0]= RD_18B20;　　Temp_8[1]= RD_18B20;　　return(Temp_8);}VII Experimental testThe test temperature value is shown in Table 3.The system error is less than 0.5, and the test results show that the system has high accuracy and strong practicability.VIII ConclusionThis article designs a temperature acquisition alarm system based on AT89S52 single-chip microcomputer and DS18B20 digital temperature sensor, and details the software and hardware design. The design has the advantages of simple structure, high precision and good stability, and is suitable for the following fields: granary, electric machine room, bearing, air conditioner, refrigerator, industry and agriculture, etc.The DS18B20 single bus and multi-point temperature measurement feature strengthens its scalability and has a broad market prospect.FAQWhat is DS18B20 temperature sensor?The DS18B20 is a 1-wire programmable temperature sensor from maxim integrated. It is widely used to measure temperature in hard environments like in chemical solutions, mines or soil etc. The constriction of the sensor is rugged and also can be purchased with a waterproof option making the mounting process easy.How does the DS18B20 work?It works on the principle of direct conversion of temperature into a digital value. Is DS18B20 a thermistor?A thermistor is a thermal resistor - a resistor that changes its resistance with temperature. ... Thermistors have some benefits over other kinds of temperature sensors such as analog output chips (LM35/TMP36 ) or digital temperature sensor chips (DS18B20) or thermocouples.How accurate is DS18B20?The DS18B20 reads with an accuracy of ±0.5°C from -10°C to +85°C and ±2°C accuracy from -55°C to +125°C.What is ds1820?The DS18B20 is one type of temperature sensor and it supplies 9-bit to 12-bit readings of temperature. ... The communication of this sensor can be done through a one-wire bus protocol which uses one data line to communicate with an inner microprocessor.How do I connect my DS18B20 to my Raspberry Pi?Once you've connected the DS18B20, power up your Pi and log in, then follow these steps to enable the One-Wire interface:1.At the command prompt, enter sudo nano /boot/config.txt , then add this to the bottom of the file:2.dtoverlay=w1-gpio.3.Exit Nano, and reboot the Pi with sudo reboot.What is the working principle of DS18B20?The DS18B20 Digital Thermometer provides 9 to 12-bit (configurable) temperature readings which indicate the temperature of the device. It communicates over a 1-Wire bus that by definition requires only one data line (and ground) for communication with a central microprocessor. In addition it can derive power directly from the data line (“parasite power”), eliminating the need for an external power supply.The core functionality of the DS18B20 is its direct-to-digital temperature sensor. The resolution of the temperature sensor is user-configurable to 9, 10, 11, or 12 bits, corresponding to increments of 0.5°C, 0.25°C, 0.125°C, and 0.0625°C, respectively. The default resolution at power-up is 12-bit.Where to use DS18B20 Sensor?The DS18B20 is a 1-wire programmable Temperature sensor from maxim integrated. It is widely used to measure temperature in hard environments like in chemical solutions, mines or soil etc. The constriction of the sensor is rugged and also can be purchased with a waterproof option making the mounting process easy. It can measure a wide range of temperature from -55°C to +125° with a decent accuracy of ±5°C. Each sensor has a unique address and requires only one pin of the MCU to transfer data so it a very good choice for measuring temperature at multiple points without compromising much of your digital pins on the microcontroller.How connect DS18B20 to Arduino?First plug the sensor on the breadboard the connect its pins to the Arduino using the jumpers in the following order: pin 1 to GND; pin 2 to any digital pin (pin 2 in our case); pin 3 to +5V or +3.3V, at the end put the pull-up resistor.On an ATMega328P, why is a DS18B20 temperature sensor returning incorrect temperature values?Several possibilities:1. If it is just reading a little high, it might be caused by “self heating”. Add a heat sink and/or make measurements less frequently.2. Especially if the values are really whacky, it might be code with errors or mis-wiring. Use a published sketch to check operation.3. The DS18B20 might be defective. Try another.4. It’s accurate to 0.5ºC. Are you expecting it to be more accurate (like down to the LSB of the read value)?

This blog provides you with a basic overview of the STM32F7 Series, including its specifications, datasheet, frequently asked questions, etc., to help you quickly understand what STM32F7 Series are.We will be glad to find that this blog can be useful for STM32F7 Series lover.CatalogSTM32F7 AdvantageSTM32F7x0 Value lineSTM32F7x2STM32F7x3STM32F7x5STM32F7x6STM32F7x7STM32F7x9STM32H7 ManufacturerComponent DatasheetFAQSTM32F7 AdvantageSTMicro STM32F7 SeriesThe STM32F7 microcontrollers are based on an Arm® Cortex® -M7 core offering from 216 MHz / 462 DMIPS. Thanks to an L1 cache, the series delivers the maximum possible theoretical performance of the Cortex-M7 core.The STM32F7 series includes advanced and foundation lines as well as the STM32F7x0 value line.STM32F7 series of very high-performance MCUs with Arm® Cortex®-M7 coreTaking advantage of ST’s ART Accelerator™ as well as an L1 cache, STM32F7 microcontrollers deliver the maximum theoretical performance of the Cortex-M7 core, regardless if code is executed from embedded Flash or external memory: 1082 CoreMark /462 DMIPS at 216 MHz fCPU.Smart architecture with new peripheral setThe STM32F7 series unleashes the Cortex-M7 core:AXI and multi-AHB bus matrixes for interconnecting core, peripherals and memoriesUp to 16 Kbytes +16 Kbytes of I-cache and D-cacheUp to 2 Mbytes of embedded Flash memory, with Read-While-Write capability on certain devicesTwo general-purpose DMA controllers and dedicated DMA controllers for Ethernet (on some variants), high-speed USB On-The-Go interfaces and the Chrom-ART graphic accelerator (on some variants)Peripheral speed is independent from CPU speed (dual clock support) allowing system clock changes without any impact on peripheral operationsEven more peripherals, such as two serial audio interfaces (SAI) with SPDIF output support, three I²S half-duplex interfaces with SPDIF input support, two USB OTG interfaces with dedicated power supply and Dual-mode Quad-SPI Flash memory interfaceLarge SRAM with a scattered architecture:Up to 512 Kbytes of universal data memory, including up to 128 Kbytes of Tightly-Coupled Memory for Data (DTCM) for time critical data handling (stack, heap...)16 Kbytes of Tightly-Coupled Memory for Instructions (ITCM) for time-critical routines4 Kbytes of backup SRAM to keep data in the lowest power modesProtected code execution feature (PC-ROP) on some variantsOn-chip USB high-speed PHY on some variantsPower efficiency7 CoreMark/mW at 1.8 V100 µA typical current consumption in Stop mode with all context and SRAM savedCompatibilityCortex-M7 is backwards compatible with the Cortex-M4 instruction setSTM32F7 series is pin-to-pin compatible with the STM32F4 series** Note: see datasheet for the specific case of 64- and 100-pin packagesSTM32F7 Series Advanced LinesSTM32F7 Series Foundation LinesSTM32F7 Series Value LinesSTM32F7x0 Value lineThe STM32F730 and STM32F750 Value lines provide the performance of the Arm® Cortex®-M7 core (with floating point unit) running at up to 216 MHz at a low cost by reducing embedded Flash to the essentials. The STM32F7x0 Value lines represent the lowest price point for the STM32F7 Series ever.PerformanceThe STM32F7x0 line, with a 216 MHz fCPU, achieves 1082 CoreMark / 462 DMIPS performance when executing from Flash memory, with 0-wait states thanks to ST's ART Accelerator. The FPU and DSP instructions broaden the addressable applications. Because of the L1 cache (I/D up to 8 Kbytes + 8 Kbytes), external memory can be used without sacrificing performance.Power efficiencyST’s 90 nm process, ART Accelerator™ and dynamic power scaling enables the power consumption in Run mode and executing from Flash memory to be at 7 CoreMark / mW at 1.8 V.In Stop mode, power consumption is typically 100 µA.The maximum junction temperature supported is up to 125 °C, allowing to leverage the full core and peripherals performance even when the ambient temperature increases.GraphicsThe STM32F750 line includes an LCD-TFT controller interface with dual-layer support that takes advantage of the Chrom‑ART Accelerator™. This graphics accelerator creates content twice as fast as the core alone. As well as efficient 2-D raw data copy, additional functions are supported by the Chrom-ART Accelerator such as image format conversion or image blending (image mixing with some transparency). As a result, the Chrom-ART Accelerator boosts graphics content creation and saves the processing bandwidth of the MCU core for other applications.IntegrationAudio: Two dedicated audio PLLs, three half-duplex I²S interfaces and a new serial audio interface (SAI) supporting time-division multiplex (TDM) mode.Up to 25 communication interfaces (including four USARTs in addition to four UARTs running at up to 12.5 Mbit/s, up to six SPIs running at up to 50 Mbit/s, up to four I²C interfaces with a new optional digital filter capability, up to two CAN, up to two SDMMC, USB 2.0 full-speed device/host/OTG controller with an optional on-chip PHY and a USB 2.0 high-speed/full-speed device/host/OTG controller (with on-chip high-speed PHY), optional SPDIF-IN and optional HDMI-CEC.Analog: Two 12-bit DACs, three 12-bit ADCs reaching 2.4 Msample/s or 7.2 Msample/s in Interleaved mode.Up to eighteen 16- and 32-bit timers running at up to 216 MHz.Easily extendable memory range using the flexible memory controller with 32-bit parallel interface, and supporting Compact Flash, SRAM, PSRAM, NOR, NAND and SDRAM memories or using the Dual-mode Quad-SPI Flash memory interface to allow code execution from an external serial Flash memory.An analog true random number generator.SecurityThe STM32F7x0 line comes with the proprietary code read-out-protection feature and integrates a crypto processor providing hardware acceleration for AES-128 and -256 encryption.The STM32F7x0 line integrates a crypto/hash processor providing hardware acceleration for AES-128, -192 and -256 encryption, with support for GCM and CCM, Triple DES, and hash (MD5, SHA-1 and SHA-2) algorithms.The STM32F7x0 Value line provides 64 Kbytes of Flash memory and 320 Kbytes of SRAM including up to 64 Kbytes of Tightly-Coupled Memory for Data (DTCM), 16 Kbytes of Tightly-Coupled Memory for Instructions (ITCM), and 4-Kbyte Backup RAM, in LQFP64, LQFP100, LQFP144 ,UFBGA 176-and TFBGA216 pin packages.STM32F7x2The STM32F7x2 line offers the performance of the Cortex-M7 core (with floating point unit) running up to 216 MHz while reaching similar lower static power consumption (Stop mode) versus the STM32F427/429/437/439 lines.Performance: At 216 MHz fCPU, the STM32F7x2 delivers 1082 CoreMark / 462 DMIPS performance executing from Flash memory, with 0-wait states thanks to ST’s ART Accelerator. The FPU and DSP instructions enlarge the range of addressable applications. External memory can be used with no performance penalty thanks to the L1 cache (I/D 8 Kbytes + 8 Kbytes).Power efficiency: ST’s 90 nm process, ART Accelerator and dynamic power scaling enables the power consumption in Run mode and executing from Flash memory to be at 7 CoreMark / mW at 1.8 V. In Stop mode, power consumption is typically 100 µA.Integration:Audio: Two dedicated audio PLLs, three half-duplex I²S interfaces and a new serial audio interface (SAI) supporting time-division multiplex (TDM) mode.Up to 21 communication interfaces (including four USARTs in addition to four UARTs running at up to 12.5 Mbit/s, up to five SPIs running at up to 50 Mbit/s, three I²C interfaces with a new optional digital filter capability, one CAN, two SDIO, USB 2.0 full-speed device/host/OTG controller with on-chip PHY.USB 2.0 high-speed/full-speed device/host/OTG controller with dedicated DMA (with on-chip full-speed PHY and ULPI).Analog: Two 12-bit DACs, three 12-bit ADCs reaching 2.4 Msample/s or 7.2 Msample/s in Interleaved mode.Up to eighteen 16- and 32-bit timers running at up to 216 MHz.Easily extendable memory range using the flexible memory controller (on packages with than 100 pins) with 32-bit parallel interface, and supporting Compact Flash, SRAM, PSRAM, NOR, NAND and SDRAM memories or using the Dual-mode Quad-SPI Flash memory interface to allow code execution from external serial Flash memory.An analog true random number generator.The STM32F7x2 line comes with the proprietary code Read-out-protection featureThe STM32F7x2 line provides variants from 256 to 512 Kbytes of Flash memory and up to 256 Kbytes of SRAM including up to 64 Kbytes of Tightly-Coupled Memory for Data (DTCM), 16 Kbytes of Tightly-Coupled Memory for Instructions (ITCM), and 4 Kbytes of Backup RAM, in 64- to 176-pin packages.STM32F7x3The STM32F7x3 line offers the performance of the Cortex-M7 core (with floating point unit) running up to 216 MHz while reaching similar lower static power consumption (Stop mode) versus the STM32F427/429/437/439 lines.Performance: At 216 MHz fCPU, the STM32F7x3 delivers 1082 CoreMark / 462 DMIPS performance executing from Flash memory, with 0-wait states thanks to ST’s ART Accelerator. The FPU and DSP instructions enlarge the range of addressable applications. External memory can be used with no performance penalty thanks to the L1 cache (I/D 8 Kbytes + 8 Kbytes).Power efficiency: ST’s 90 nm process, ART Accelerator and dynamic power scaling enables the power consumption in Run mode and executing from Flash memory to be at 7 CoreMark / mW at 1.8 V. In Stop mode, power consumption is typically 100 µA.Integration:Audio: Two dedicated audio PLLs, three half-duplex I²S interfaces and a new serial audio interface (SAI) supporting time-division multiplex (TDM) mode.Up to 21 communication interfaces (including four USARTs in addition to four UARTs running at up to 12.5 Mbit/s, up to five SPIs running at up to 50 Mbit/s, three I²C interfaces with a new optional digital filter capability, one CAN, two SDIO, USB 2.0 full-speed device/host/OTG controller with an on-chip PHY and a USB 2.0 high-speed/full-speed device/host/OTG controller (with on-chip high-speed PHY).Analog: Two 12-bit DACs, three 12-bit ADCs reaching 2.4 Msample/s or 7.2 Msample/s in Interleaved mode.Up to eighteen 16- and 32-bit timers running at up to 216 MHz.Easily extendable memory range using the flexible memory controller with 32-bit parallel interface, and supporting Compact Flash, SRAM, PSRAM, NOR, NAND and SDRAM memories or using the Dual-mode Quad-SPI Flash memory interface to allow code execution from external serial Flash memory.An analog true random number generator.The STM32F7x3 line comes with the proprietary code Read-out-protection featureThe STM32F7x3 line provides variants from 256 to 512 Kbytes of Flash memory and up to 256 Kbytes of SRAM including up to 64 Kbytes of Tightly-Coupled Memory for Data (DTCM), 16 Kbytes of Tightly-Coupled Memory for Instructions (ITCM), and 4-Kbyte Backup RAM, in 100- to 176-pin packages.STM32F7x5The STM32F745 line offers the performance of the Cortex-M7 core (with floating point unit) running up to 216 MHz while reaching similar lower static power consumption (Stop mode) versus the STM32F427/429/437/439 lines.Performance: At 216 MHz fCPU, the STM32F745 delivers 1082 CoreMark / 462 DMIPS performance executing from Flash memory, with 0-wait states thanks to ST’s ART Accelerator. The DSP instructions and the floating point unit enlarge the range of addressable applications. External memory can be used with no performance penalty thanks to the L1 cache(I/D 4 Kbytes + 4 Kbytes).Power efficiency: ST’s 90 nm process, ART Accelerator and dynamic power scaling enables the power consumption in Run mode and executing from Flash memory to be at 7 CoreMark / mW at 1.8 V. In Stop mode, power consumption is typically 100 µA, which is similar to the STM32F427/429/437/439 lines.Graphics: As compared to the STM32F746/756 lines, the STM32F745 doesn’t embed the LCD-TFT controller interface. However, the STM32F745 embeds the Chrom‑ART Accelerator™. This graphics accelerator performs content creation twice as fast as the core alone. As well as efficient 2-D raw data copy, additional functions are supported by the Chrom-ART Accelerator such as image format conversion or image blending (image mixing with some transparency). As a result, the Chrom-ART Accelerator boosts graphics content creation and saves the processing bandwidth of the MCU core for the rest of the application. The STM32F745 can then be used to drive displays using a standard serial interface.Integration:Audio: Two dedicated audio PLLs, three half-duplex I²S interfaces and a new serial audio interface (SAI) supporting time-division multiplex (TDM) mode.Up to 25 communication interfaces (including four USARTs in addition to four UARTs running at up to 12.5 Mbit/s, six SPIs running at up to 50 Mbit/s, four I²C interfaces with a new optional digital filter capability, two CAN, SDIO, USB 2.0 full-speed device/host/OTG controller with an on-chip PHY and a USB 2.0 high-speed/full-speed device/host/OTG controller, on-chip full-speed PHY and ULPI, Ethernet MAC, SPDIF-IN and HDMI-CEC).Analog: Two 12-bit DACs, three 12-bit ADCs reaching 2.4 MSPS or 7.2 MSPS in Interleaved mode.Up to 18 timers: 16- and 32-bit running at up to 216 MHz.Easily extendable memory range using the flexible memory controller with 32-bit parallel interface, and supporting Compact Flash, SRAM, PSRAM, NOR, NAND and SDRAM memories or using the Dual-mode Quad-SPI to allow code execution from external serial Flash memory.An analog true random number generator.The STM32F745 line provides from 512 Kbytes to 1 Mbyte of Flash memory, 320-Kbyte SRAM, 16-Kbyte ITCM RAM, 4-Kbyte Backup RAM and 100- to 176-pin packages.STM32F7x6The STM32F746/756 lines offer the performance of the Cortex-M7 core (with floating point unit) running up to 216 MHz while reaching similar lower static power consumption (Stop mode) versus the STM32F427/429/437/439 lines.Performance: At 216 MHz fCPU, the STM32F746/756 lines deliver 1082 CoreMark /462 DMIPS performance executing from Flash memory, with 0-wait states thanks to ST’s ART Accelerator. The DSP instructions and the floating point unit enlarge the range of addressable applications. External memory can be used with no performance penalty thanks to the L1 cache (I/D 4 Kbytes + 4 Kbytes).Power efficiency: ST’s 90 nm process, ART Accelerator and dynamic power scaling enables the power consumption in Run mode and executing from Flash memory to be at 7 CoreMark / mW at 1.8 V. In Stop mode, power consumption is typically 100 µA, which is similar to the STM32F427/429/437/439 lines.Graphics: The new LCD-TFT controller interface with dual-layer support takes advantage of the Chrom‑ART Accelerator™. This graphics accelerator creates content twice as fast as the core alone. As well as efficient 2-D raw data copy, additional functions are supported by the Chrom-ART Accelerator such as image format conversion or image blending (image mixing with some transparency). As a result, the Chrom-ART Accelerator boosts graphics content creation and saves the processing bandwidth of the MCU core for the rest of the application.Integration:Audio: Two dedicated audio PLLs, three half-duplex I²S interfaces and a new serial audio interface (SAI) supporting time-division multiplex (TDM) mode.Up to 25 communication interfaces (including four USARTs in addition to four UARTs running at up to 12.5 Mbit/s, six SPIs running at up to 50 Mbit/s, four I²C interfaces with a new optional digital filter capability, two CAN, SDIO, USB 2.0 full-speed device/host/OTG controller with an on-chip PHY and a USB 2.0 high-speed/full-speed device/host/OTG controller, on-chip full-speed PHY and ULPI, Ethernet MAC, SPDIF-IN and HDMI-CEC).Analog: Two 12-bit DACs, three 12-bit ADCs reaching 2.4 MSPS or 7.2 MSPS in Interleaved mode.Up to 18 timers: 16- and 32-bit running at up to 216 MHz.Easily extendable memory range using the flexible memory controller with 32-bit parallel interface, and supporting Compact Flash, SRAM, PSRAM, NOR, NAND and SDRAM memories or using the Dual-mode QuadSPI to allow code execution from external serial Flash memory.An analog true random number generator.The STM32F756 line integrates a crypto/hash processor providing hardware acceleration for AES-128, -192 and -256 encryption, with support for GCM and CCM, Triple DES, and hash (MD5, SHA-1 and SHA-2) algorithms.The STM32F746 and STM32F756 portfolio provides from 512 Kbytes to 1 Mbyte of Flash memory, 320-Kbyte SRAM, 16-Kbyte ITCM RAM, 4-Kbyte Backup RAM and 100- to 216-pin packages as small as 4.5 x 5.5 mm in a CSP form factor.STM32F7x7The STM32F767/777 lines offer the performance of the Cortex-M7 core (with double-precision floating point unit) running up to 216 MHz while reaching similar lower static power consumption (Stop mode) versus the STM32F427/429/437/439 lines.Performance: At 216 MHz fCPU, the STM32F767/777 lines deliver 1082 CoreMark /462 DMIPS performance executing from Flash memory, with 0-wait states thanks to ST’s ART Accelerator. The DSP instructions and the floating point unit enlarge the range of addressable applications. External memory can be used with no performance penalty thanks to the L1 cache (I/D 16 Kbytes + 16 Kbytes).Power efficiency: ST’s 90 nm process, ART Accelerator and dynamic power scaling enables the power consumption in Run mode and executing from Flash memory to be at 7 CoreMark / mW at 1.8 V. In Stop mode, power consumption is typically 100 µA, which is similar to the STM32F427/429/437/439 lines.Graphics: The new LCD-TFT controller interface with dual-layer support takes advantage of the Chrom‑ART Accelerator™. This graphics accelerator creates content twice as fast as the core alone. As well as efficient 2-D raw data copy, additional functions are supported by the Chrom-ART Accelerator such as image format conversion or image blending (image mixing with some transparency). As a result, the Chrom-ART Accelerator boosts graphics content creation and saves the processing bandwidth of the MCU core for the rest of the application. In addition the STM32F767/777 lines embed a JPEG hardware accelerator for fast JPEG encoding and decoding off-loading the CPU which remains available for other tasks.Integration:Audio: Two dedicated audio PLLs, three half-duplex I²S interfaces, a new serial audio interface (SAI) supporting time-division multiplex (TDM) mode and a DFSDM (Digital filters for sigma-delta modulators or MEMS microphone)Up to 28 communication interfaces including four USARTs in addition to four UARTs running at up to 12.5 Mbit/s, six SPIs running at up to 50 Mbit/s, four I²C interfaces with a new optional digital filter capability, three CAN, two SDIO, USB 2.0 full-speed device/host/OTG controller with an on-chip PHY and a USB 2.0 high-speed/full-speed device/host/OTG controller, on-chip full-speed PHY and ULPI, Ethernet MAC, SPDIF-IN, HDMI-CEC, and MDIO slave.Analog: Two 12-bit DACs, three 12-bit ADCs reaching 2.4 or 7.2 MSPS in Interleaved mode. Up to 18 timers: 16- and 32-bit running at up to 216 MHz. Easily extendable memory range using the flexible memory controller with 32-bit parallel interface, and supporting Compact Flash, SRAM, PSRAM, NOR, NAND and SDRAM memories or using the Dual-mode Quad-SPI to allow code execution from external serial Flash memory. An analog true random number generator.The STM32F777 line integrates a crypto/hash processor providing hardware acceleration for AES-128, -192 and -256 encryption, with support for GCM and CCM, Triple DES, and hash (MD5, SHA-1 and SHA-2) algorithms.The STM32F767 and STM32F777 portfolio provides from 1 to 2 Mbytes of Flash memory, 512-Kbyte SRAM including up to 128 Kbytes of Tightly-Coupled Memory for Data (DTCM), 16-Kbyte ITCM RAM, 4-Kbyte Backup RAM and 100- to 216-pin packages.STM32F7x9The STM32F769/779 lines offer the performance of the Cortex-M7 core (with double precision floating point unit) running up to 216 MHz while reaching similar lower static power consumption (Stop mode) versus the STM32F427/429/437/439 lines.Performance: At 216 MHz fCPU, the STM32F769/779 lines deliver 1082 CoreMark /462 DMIPS performance executing from Flash memory, with 0-wait states thanks to ST’s ART Accelerator. The DSP instructions and the floating point unit enlarge the range of addressable applications. External memory can be used with no performance penalty thanks to the L1 cache (I/D 16 Kbytes + 16 Kbytes).Power efficiency: ST’s 90 nm process, ART Accelerator and dynamic power scaling enables the power consumption in Run mode and executing from Flash memory to be at 7 CoreMark / mW at 1.8 V. In Stop mode, power consumption is typically 100 µA, which is similar to the STM32F427/429/437/439 lines.Graphics: The new LCD-TFT controller interface with dual-layer support takes advantage of the Chrom‑ART Accelerator™. This graphics accelerator creates content twice as fast as the core alone. As well as efficient 2-D raw data copy, additional functions are supported by the Chrom-ART Accelerator such as image format conversion or image blending (image mixing with some transparency). As a result, the Chrom-ART Accelerator boosts graphics content creation and saves the processing bandwidth of the MCU core for the rest of the application. The STM32F769/779 lines embed a JPEG hardware accelerator for fast JPEG encoding and decoding off-loading the CPU which remains available for other tasks. The STM32F769/779 lines also embed a MIPI-DSI interface allowing the drive of DSI display technology which are commonly found in the mobile market.Integration:Audio: Two dedicated audio PLLs, three half-duplex I²S interfaces, a new serial audio interface (SAI) supporting time-division multiplex (TDM) mode and a DFSDM (Digital filters for sigma-delta modulators or Mems Microphone)Up to 28 communication interfaces including four USARTs in addition to four UARTs running at up to 12.5 Mbit/s, six SPIs running at up to 50 Mbit/s, four I²C interfaces with a new optional digital filter capability, three CAN, two SDIO, USB 2.0 full-speed device/host/OTG controller with an on-chip PHY and a USB 2.0 high-speed/full-speed device/host/OTG controller, on-chip full-speed PHY and ULPI, Ethernet MAC, SPDIF-IN, HDMI-CEC, MDIO slave.Analog: Two 12-bit DACs, three 12-bit ADCs reaching 2.4 MSPS or 7.2 MSPS in Interleaved mode. Up to 18 timers: 16- and 32-bit running at up to 216 MHz.Easily extendable memory range using the flexible memory controller with 32-bit parallel interface, and supporting Compact Flash, SRAM, PSRAM, NOR, NAND and SDRAM memories or using the Dual-mode Quad-SPI to allow code execution from external serial Flash memory.An analog true random number generator.The STM32F779 line integrates a crypto/hash processor providing hardware acceleration for AES-128, -192 and -256 encryption, with support for GCM and CCM, Triple DES, and hash (MD5, SHA-1 and SHA-2) algorithms.The STM32F769 and STM32F779 portfolio provides from 1Mbyte to 2 Mbyte of Flash memory, 512-Kbyte SRAM including up to 128 Kbytes of Tightly-Coupled Memory for Data (DTCM), 16-Kbyte ITCM RAM, 4-Kbyte Backup RAM and 100- to 216-pin packages including a WLCSP* form factor as small as 5.6 x 6.1 mm.Note: * while the “regulator off” feature is available in the STM32F7x9 LQFP and BGA package variants upon activation via a dedicated input, the feature is not available on standard WLCSP product variants. However, two specific WLCSP “regulator off” devices are available, STM32F778 (with crypto/hash accelerator) and STM32F768 (without crypto/hash accelerator), operating at 180 MHz maximum CPU frequency.STM32H7 ManufacturerSTMicroelectronics is a Swiss-domiciled multinational electronics and semiconductor manufacturer headquartered in Geneva, Switzerland.STMicroelectronics is a world leader in providing the semiconductor solutions that make a positive contribution to people's lives, today and into the future.Component DatasheetSTM32F7 DatasheetFAQWhy is STM32 So Popular?The STM32 series of microcontrollers from ST Microelectronics is a popular, and very large, family of ARM-based 32-bit microcontrollers. ... While the STM32 microcontrollers are quite versatile and highly configurable, it is this very fact that makes them hard to initialize.Where is STM32 Used?There are various types and varieties of STM32 Microcontrollers available and they belong to the ARM-architecture family of Microcontrollers. These microcontrollers are used in a variety of applications, from simple printers to complex circuit boards in vehicles.How Do I Start STM32?Getting started with STM32 step-by-stepStep 1: Pre-requisites: In this part, user must install all required software tools and make sure it has board for further development.Step 2: LED blinking using STM32CubeMx and NUCLEO-L476RG development board.Step 3: UART interface on NUCLEO-L476RG and L475 IoT Node Discovery board.

I DescriptionIn this blog, you will see how we use the LM5117 chip developed by TI to design a buck circuit. LM5117 chip has broad market prospects. That's because, this chip has the advantages of high frequency, high efficiency, low ripple, and simplified circuit design. Also, the power supply designed with LM5117 not only has good stability, but also high reliability. And these are the reasons why it is very suitable for occasions with high power requirements.CatalogI DescriptionII Introduction to LM5117 ChipIII Buck Circuit Design3.1 Design Requirements3.2 Design PrincipleIV Experimental ResultsV SummaryVI FAQOrdering & QuantityII Introduction to LM5117 ChipLM5117 is suitable for high-voltage or various input power buck regulator applications. And, these applications often need current mode control that simulates current ramps. The internal structure of the LM5117 chip is shown in Figure 1. Its main features are: 5.5V～65V wide voltage range output. The operating frequency can be set in the range of 55kHz～750kHz. Optional diode emulation mode to improve power efficiency under light load. 0.8V programmable output, voltage reference with 1.5% accuracy. With analog current monitor, real-time monitoring of current value. With discontinuous mode current protection. The current mode control of the simulated current ramp reduces the noise sensitivity of the pulse width modulation circuit.The following table briefly introduces the functions of all 20 pins of LM5117:Pin NumberPin FunctionPin 1UVLO is the under-voltage lockout pin. The voltage regulator is shut down below 0.4V, and the voltage regulator is in standby mode when it is greater than 0.4V and less than 1.25V. The voltage regulator above 1.25V works normally and stably.Pin 2DEMB is a diode emulation mode pin, which can be floated if not needed.Pin 3RES restarts the timer pin and can configure hiccup current-limiting mode.Pin 4SS can set the internal reference slope of the internal error amplifier.Pin 5RT sets the clock frequency and the maximum frequency can be configured to 750kHz, just connect a resistor between ground, and connect a capacitor to synchronize to the external frequency.Pin 6GroundPin 7VCCDIS is an optional input pin for disabling the regulator.Pin 8FB feedback pin is used to stabilize the set output, and the reference base is 0.8V.Pin 9COMP is the output of the internal error amplifierPin 10CM is the output of the current monitor, which can detect the average current value for programming.Pin 11feet RAMP is the PWM ramp signal.Pin 12CS is the current detection input pin.Pin 13GroundPin 14GroundPin 15Pin 15 is the bottom MOS output drive pin.Pin 16Pin 16 is the VCC power bias pinPin 17SW is the switch node of the buck regulator and provides a bootstrap loop.Pin 18HO is high bridge MOS drive outputPin 19HB is Gaoqiao bootstrap power inputPin 20VIN is the power supply voltage input source of VCC regulatorAnd the following part is the internal structure of LM5117:Figure 1. LM5117 Internal StructureIII Buck Circuit Design3.1 Design RequirementsDesign a step-down DC switching power supply with TI's step-down controller LM5117 chip as the core device. The circuit design reference diagram is shown in Figure 2. The rated input DC voltage UIN=16V, the rated output DC voltage Uo=5V, and the maximum output current is IOmax=3A. The specific parameter requirements are:1. Under the rated input voltage, the output voltage deviation |ΔU|=|5V-Uo|≤100mV;2. Peak-to-peak output noise ripple: UOPP≤50mV (UIN=16V, IO=IOmax);3. When the output Io is from 3A at full load to 0.6A at light load, load regulation rate: Si=|(UO light load/ UO full load)-1|×100%≤5%(UIN=16V);4. UIN changes to 17.6V and 13.6V, voltage adjustment rate:Sv={max(|Uo(17.6V)-Uo(16V)|, |Uo(16V)-Uo(13.6V)|)/ Uo(16V)}× 100%≤0.5%　　RL=Uo(16V)/ IOmax5. The power efficiency is greater than 85% (under rated conditions);6. The protection current value is set to 3.2A;7. With load port identification function, that is, Uo=R/1kΩ(V).　　Figure 2. Circuit Design Diagram3.2 Design PrincipleAccording to the design requirements in Section 3.1, this article designs a DC step-down circuit with a rated output of 5V/3A  as shown in Figure 3. The circuit uses a half-bridge structure to improve circuit efficiency. The following is a detailed analysis of the circuit:When Q1 turns on, the inductor L charges.When Q1 is off, Q2 conducts freewheeling to achieve the voltage reduction function.R1, R2 voltage division power supply undervoltage lockout pin UVLO, the voltage value of this pin is greater than 1.25V during normal operation.R3 and C6 provide chip startup power.D1 and C13 form a bootstrap circuit to provide the upper bridge Q1 drive.R7 and R8 are drive current limiting resistors.R4 is connected between RT and GND to provide the operating frequency. In this design, the switching frequency is set to 230kHz. According to the calculation formula provided in the manual, RT=5.2×109/ fsw-948Ω, and R4 can be calculated to be approximately 21.7kΩ.C7 is the current-limiting capacitor for restart hiccups, and C8 is the capacitor for setting the reference slope of the error amplifier.C12 is a PWM slope compensation capacitor to improve chip adjustment efficiency.R9 is a current sampling resistor, connected to pins 12 and 13. According to the internal structure diagram in Figure 1, this pin is the positive and negative input of the internal current sampling amplifier, which is amplified by 10 times.C14 is the input filter capacitor.R6 and C11 are the internal current monitor output filter circuit, this output can output the sampled current value for programming or display.R11 and R12 form an output voltage divider feedback circuit, which feeds back the voltage to pin 8 of the chip to stabilize the output voltage of 5V. Since the internal reference voltage value of the chip is 0.8V, the resistance value can be determined according to the formula (1+R11/R12)×0.8V=Uout. Because the design requires a stable output of 5V, the resistance values are set to 5.25kΩ and 1kΩ.C10, R5, and C9 are connected to the output of the feedback circuit and the internal error amplifier to form a loop compensation network.D2, D3, and R10 provide output power to the VCC pin, and use output feedback to supply power to reduce input high-voltage power supply efficiency loss.　　Figure 3. LM5117 Buck Circuit3.2.1 Short Circuit ProtectionThe circuit design needs to have a circuit protection function. According to the chip manual, there are two ways to realize this function:(1) Utilize UVLO foot to realize electric current protection. The current monitor CM determines the output current protection value. Determine the high and low levels of the UVLO pin according to the protection value. If the protection value is reached, set the undervoltage latch pin to a high level of 5V, and set it to 0 to make it work normally if it is below the protection value. Figure 4 is a schematic diagram of the protection realization principle.　　Figure 4. Utilize UVLO Pin to Realize Current Protection Sructure (2) Use current feedback closed-loop control to lock the PWM output to achieve protection. How to close the output and realize the purpose of current protection?According to Figure 1, the current is amplified by 10 times through the sampling circuit, and compared with 10UCS(th), the output of the R/S latch is determined with the PWM comparator.This method only needs to determine the current sampling resistance to achieve current protection. The sampling resistance is calculated according to the internal structure:　　R9=10Uch(th)/(10×3.2A)=10×0.12V/(10×3.2A)=37.5mΩ.Compared with the above solutions, it is found that the implementation of the second method is simpler. This design chooses the second scheme to realize the 3.2A protection function. The chip provides powerful peripheral functions, greatly improving the efficiency of circuit design.3.2.2 Resistance follow outputThe circuit design requires the realization of voltage follow resistance output, that is, it has the function of port recognition, and can realize Uo=R1kΩ(V) follow output: 1kΩ resistance value corresponds to 1V output, 2kΩ corresponds to 2V output, and 10kΩ corresponds to 10V output. According to the analysis of the circuit principle, the tracking function can be realized by adjusting the feedback voltage value.The design circuit structure is shown as in Fig. 5.The output voltage in the figure is finally output to the feedback FB pin after two stages of reverse amplification. According to the calculation relationship in the figure:Uout×{-(8kΩ/R)}×{-(1kΩ/1kΩ)}=0.8V is calculated;Uout=R is obtained to realize the tracking function.Figure 5. Resistance Follower Output Interface CircuitIV Experimental ResultsAccording to the design requirements, a step-down power supply circuit with DC 5V/3A output is produced. Besides, parameter tests can also be performed together. The results are shown in Table 1. According to Table 1 and the design requirements, the calculation method is provided, and the design output voltage deviation of 5V is less than 100mV. The load regulation rate of 0.69% is far less than the design requirement of 5%. The voltage regulation rate of 0.02% is sufficiently less than 0.5%. The circuit power can reach 88.6% when running at rated power. At the same time, the circuit has a 3.2A current protection action and a load port identification function. And this fuction can accurately track resistance changes from 1kΩ to 10kΩ.Ripple design is an important part of the circuit design. At the same time, reducing noise ripple is also one of the main features of this chip. The chip provides a COMP error compensation pin. According to the manual, it can be known that a reasonable setting of the compensation capacitor resistance value of this pin can greatly reduce the noise ripple. At the same time, you need to pay attention to the following points:　　1. The chip PCB design requirements are relatively high;　　2. The circuit is reasonably wired;　　3. The circuit is coated with copper;　　4. The chip heat dissipation, etc.So as to optimize the circuit performance.The circuit ripple test waveform is shown in Figure 6. It can be seen from the figure that the circuit ripple is controlled within 10mV, and the occasional noise ripple does not exceed 40mV. Therefore, the circuit designed in this way can fully meet the circuit design requirements.Table 1: LM5117 step-down power supply circuit test parametersFigure 6. Waveform of Ripple TestV SummaryAs a switching power supply step-down chip, LM5117 improves the stability of the switching power supply. It can directly drive dual-bridge MOS transistors. It also provides a wealth of expansion units, including current monitoring, with excellent performance. This design makes full use of the control function of the LM5117 chip. And it also realize a high-performance, high-efficiency and high-stability switching power supply.VI FAQWhat is lm5117?Synchronous buck controller What type of applications are LM5117 suitable for?High-voltage or various input power buck regulator applications. How many pins does LM5117 have?20 pins

catalogDescriptionCAD ModelBlock diagram FeaturesApplicationsDatesheetSpecificationManufacturerAdvantagesWhere and How to use TPS70950DBVRTPS70950DBVR vs TPS709-Q1FAQ DescriptionThe TPS70950DBVR of devices, produced by Texas Instruments, are ultra-low quiescent current devices and low dropout linear voltage regulator. To prevent any discharge current from the output to the input, the linear voltage regulator TPS70950DBVR provides reverse current protection. In addition, TPS709 series also boast current limit and thermal shutdown for power-sensitive applications which makes them an ideal choice for battery-powered and alwayson systems. so if you are looking for a voltage regulator that can operate reliably the TPS70950DBV device might be the right choice for you. The following is some detailed information, including whatever you want to know about this model' features, datesheets, cad model, advantages etc. If you're interested, you can read on. CAD ModelFeature: Symbol Feature: Footprint Feature: 3D Model Block diagramFigure：Block DiagramFeaturesInput Voltage Range:2.7 V to 30 VReverse Current ProtectionAvailable in Fixed-OutputVoltages:1.2 V to 6.5 V2 % AccuracyOverTemperatureSupports 200-mA Peak OutputLow Dropout: 245 mV at 50 mAPackages: SOT-23-5,SON-6,SOT-223-4Thermal Shutdown and Overcurrent Protection  ApplicationsSmoke and heat detectorsThermostatsMotion detectors (PIR, uWave, and so forth)Cordless power toolsAppliance battery packsElectricity metersWater meters DatasheetTPS70950DBVR datasheetSpecificationsProduct AttributeAttribute ValueAttributeAttribute ValueManufacturerTexas InstrumentsProduct CategoryLinear Voltage RegulatorsSeries  TPS709Product  Voltage RegulatorsType  Voltage Linear Regulator with EnablePackaging   Alternate PackagingUnit-Weight   0.000557 ozMounting-Style  SMD/SMTPackage-Case  SC-74A, SOT-753Operating-Temperature   -40°C ~ 125°CMounting-Type  Surface MountOutput-Type   FixedSupplier-Device-Package  SOT-23-5Voltage-Input  Up to 30VNumber-of-Outputs  1 OutputCurrent-Output   150mAVoltage-Output  5VRegulator-Topology  Positive FixedVoltage-Dropout-Typical   0.69V @ 150mANumber-of-Regulators   1 RegulatorCurrent-Limit-Min   200mAPd-Power-Dissipation   -ManufacturerTexas Instruments, a Texas-based semiconductor multinational corporation, is a global semiconductor company that designs, manufactures, tests and sells analog and embedded processing chips. Nearly 80,000 products from Texas Instruments help over 100,000 customers efficiently manage power, accurately sense and transmit data and provide the core control or processing in their designs, going into markets such as industrial, automotive, personal electronics, communications equipment and enterprise systems. AdvantagesThe TPS70950DBVR is an ultra-low quiescent current device designed for power sensitive applications. A  regulator is provided on TPS709 devices to allow operation with a voltage between 1.65V to 5.5V. The regulator output can be used to power other circuits, but the power dissipation cannot exceed the package limit. TPS709 series devices are packaged with SOT-23-6, operating temperature range from -40℃ to 85℃ Where and How to use TPS70950DBVR  TPS70950DBVR is a TI company's voltage regulator device, used in Electricity meters, Water meters, Cordless power tools and many other fields. The TPS70950DBVR can operate in the voltage range of 1.65V to 5.5V,  with a maximum current output of 200mA.The input voltage of the TPS70950DBVR regulator ranges from 2.7V to 30VDC, and the power dissipation depends on the input voltage and load conditions. power dissipation (PDISS) is equal to the product of the output current and the voltage drop across the output pass element, as shown in Eq:                                          PDISS = (VIN - VOUT) × IOUTthe following is its typical application circuit. TPS70950DBVR vs TPS709-Q1Differences: Voltage of the TPS70950DBVR ranges from 1.65V to 5.5V; voltage of the TPS709-Q1 ranges from 2.7V to 30V; operating environment temperature of TPS70950DBVR range from -40℃ to  85℃;operating environment temperature of TPS709-Q1 range from -40℃ to 125℃Similarities:  Both support 200mA peak output;  both have thermal-shutdown, current-limit, and reverse-current protections.  FAQWhat packaging is used for TPS70950DBVR?Reel tape (TR), Cute tape (CT), DiGi-Reel What is a Linear Voltage Regulators used for?A linear regulator is a device used to stabilize the output voltage, a linear regulator uses a transistor or FET operating in its linear region to produce a regulated output voltage by subtracting the excess voltage from the applied input voltage. A linear regulator uses a transistor or FET operating in its linear region to produce a regulated output voltage by subtracting the excess voltage from the applied input voltage. How to calculate the production cycle from the TPS70950DBVR chip physically?TPS stands for the number of transactions executed per second, which can be calculated based on the number of transactions completed during the test cycle.

This blog will introduce a chip with good electrical performance and low design cost: the LM5117 chip.  The LM5117 is a step-down dc-dc controller. The device is typically used to convert a higher dc-dc voltage to alower dc voltage. The Controller features adjustable 750 kHz switching frequency which results in a typical inductor size of 11.3 uH. And what about its pacakge? You can find that LM5117 is available in 2 package option(s): WQFN-24 and HTSSOP-20.CatalogLM5117 Documents And MediaLM5117 Pinout and FunctionsLM5117 Basic ParametersLM5117 FeaturesLM5117 ApplicationsLM5117 AdvantagesLM5117 Typical ApplicationLM5117 CAD CAE SymbolsLM5117 ManufacturerComponent DatasheetOrdering & Quantity LM5117 Documents and MediaUser GuidesAN-2103 LM5117 Evaluation Board (Rev. B)Featured ProductLM5117 Synchronous Buck ControllerDesign ResourcesLM5117 Design with WEBENCH® Power DesignerLM5117 Pinout and Functions　　Pin NumberPin FunctionsPin 1UVLO is the under-voltage lockout pin. The voltage regulator is shut down below 0.4V, and the voltage regulator is in standby mode when it is greater than 0.4V and less than 1.25V. The voltage regulator above 1.25V works normally and stably.Pin 2DEMB is a diode emulation mode pin, which can be floated if not needed.Pin 3RES restarts the timer pin and can configure hiccup current-limiting mode.Pin 4SS can set the internal reference slope of the internal error amplifier.Pin 5RT sets the clock frequency and the maximum frequency can be configured to 750kHz, just connect a resistor between ground, and connect a capacitor to synchronize to the external frequency.Pin 6GroundPin 7VCCDIS is an optional input pin for disabling the regulator.Pin 8FB feedback pin is used to stabilize the set output, and the reference base is 0.8V.Pin 9COMP is the output of the internal error amplifierPin 10CM is the output of the current monitor, which can detect the average current value for programming.Pin 11feet RAMP is the PWM ramp signal.Pin 12CS is the current detection input pin.Pin 13GroundPin 14GroundPin 15Pin 15 is the bottom MOS output drive pin.Pin 16Pin 16 is the VCC power bias pinPin 17SW is the switch node of the buck regulator and provides a bootstrap loop.Pin 18HO is high bridge MOS drive outputPin 19HB is Gaoqiao bootstrap power inputPin 20VIN is the power supply voltage input source of VCC regulatorLM5117 Basic ParametersApprox. price1ku | 1.85 US$Iout (Max)20 AIq (Typ)4.8 mANumber of Phases1Operating temperature range-40℃ to 125℃RatingCatalogRegulated outputs1Switching frequency (Max)750 kHzSwitching frequency (Min)50 kHzVin (Max)65 VVin (Min)5.5 VVout (Max)62 VVout (Min)0.8 VLM5117 FeaturesEmulated Peak Current Mode ControlWide Operating Range from 5.5 V to 65 VRobust 3.3-A Peak Gate DrivesAdaptive Dead-Time Output Driver ControlFree-Run or Synchronizable Clock up to 750 kHzOptional Diode Emulation ModeProgrammable Output from 0.8 VPrecision 1.5% Voltage ReferenceAnalog Current MonitorProgrammable Current LimitHiccup Mode Overcurrent ProtectionProgrammable Soft-Start and TrackingProgrammable Line Undervoltage LockoutProgrammable Switchover to External Bias SupplyThermal ShutdownLM5117 ApplicationsAutomotive InfotainmentIndustrial DC-DC Motor DriversAutomotive USB PowerTelecom ServerLM5117 AdvantagesThe LM5117 is a synchronous buck controller intended for step-down regulator applications from a high voltage or widely varying input supply. The control method is based upon current mode control utilizing an emulated current ramp. Current mode control provides inherent line feed-forward, cycle-by-cycle current limiting and ease of loop compensation. The use of an emulated control ramp reduces noise sensitivity of the pulse-width modulation circuit, allowing reliable control of very small duty cycles necessary in high input voltage applications. The operating frequency is programmable from 50kHz to 750 kHz. The LM5117 drives external high-side and low-side NMOS power switches with adaptive dead-time control. A user-selectable diodeemulation mode enables discontinuous mode operation for improved efficiency at light load conditions. A high voltage bias regulator that allows external bias supply further improves efficiency. The LM5117’s unique analog telemetry feature providesaverage output current information. Additional features include thermal shutdown, frequency synchronization, hiccup mode current limit, and adjustable line undervoltage lockout.LM5117 Typical ApplicationLM5117 CAD CAE SymbolsPackagePinsDownloadHTSSOP (PWP)20View optionsWQFN (RTW)24View optionsLM5117  ManufacturerTexas Instruments Inc. (TI)  is an American technology company that designs and manufactures semiconductors and various integrated circuits, which it sells to electronics designers and manufacturers globally. Its headquarters are in Dallas, Texas, United States. TI is one of the top ten semiconductor companies worldwide, based on sales volume. Texas Instruments's focus is on developing analog chips and embedded processors, which accounts for more than 80% of their revenue. TI also produces TI digital light processing (DLP) technology and education technology products including calculators, microcontrollers and multi-core processors. To date, TI has more than 43,000 patents worldwide.Component DatasheetLM5117 Datasheet