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Catalog PurposeHardwareSofowareConclusion Smart homes have been a popular topic for several years now. With the rapid development of technology, it has become easier and more affordable for people to make their homes smart. One of the simplest and most useful smart home projects is a smart light. In this article, we'll show you how to use a Raspberry Pi to make a smart light. A smart light turns on automatically when you enter the room and turns off when you leave, saving energy and providing a more convenient experience. This project is a great way to learn about the Raspberry Pi and how to control it using Python, making it a great choice for both beginners and experienced makers. Purpose The purpose of this project is to create a smart light that is convenient, energy-efficient, and saves you time. This smart light can be controlled using motion detection, so when you enter the room, the light will turn on automatically, and when you leave, the light will turn off. This feature will save energy, as you don't have to manually turn the light off, and it will also provide a more comfortable experience. Hardware Building a smart light using a Raspberry Pi involves connecting several hardware components together to form a complete system. The process involves connecting a PIR (Passive Infrared) sensor to the Raspberry Pi, which detects motion in the room. The Raspberry Pi is then connected to a relay module, which acts as an intermediary between the PIR sensor and the  LED light. Finally, the LED light is connected to the relay module to provide illumination. The following is a list of the hardware components required for this project: 1. Raspberry Pi - a credit-card sized computer that can be used for a variety of projects. 2. PIR sensor - used to detect motion in the room and trigger the relay module to turn on oroff the LED light. 3. Relay module - used to switch the LED light on and off based on the input from the PIR sensor. 4. LED light - used to provide illumination in the room. 5. Power supply for the Raspberry Pi - used to power the Raspberry Pi and its components. 6. Jumper wires - used to connect the components together. 7. Bread board - used to create a prototype circuit for the project. Purchase on Kynix1Raspberry Pi2PIR sensor3Relay module4LED light5Power supply6Jumper wires7Bread board It is important to use a relay module for this project because the Raspberry Pi does not have enough power to directly control the LED light. The relay module provides an isolated circuit between the Raspberry Pi and the LED light, making it safe to use and preventing damage to the Raspberry Pi. The use of a breadboard allows you to easily modify and test the circuit, making it easier to troubleshoot any problems that may arise. Below is the description of circuit diagram:1. Connect the PIR sensor to the Raspberry Pi. The PIR sensor has three pins: VCC (power), GND (ground), and OUT (output). Connect the VCC pin to the 5V pin on the Raspberry Pi, the GND pin to a GND pin on the Raspberry Pi, and the OUT pin to a GPIO pin on the Raspberry Pi (for example, GPIO 18).2. Connect the LED light to the Raspberry Pi. The LED light has two pins: anode (+) and cathode (-). Connect the anode to a GPIO pin on the Raspberry Pi (for example, GPIO 23) and the cathode to a GND pin on the Raspberry Pi.3. Connect a resistor to the anode of the LED light. This resistor is used to limit the current flowing through the LED and protect it from damage. The value of the resistor will depend on the forward voltage and forward current of the LED, which are specified by the manufacturer. A common value is 220 ohms.4. Connect the Raspberry Pi to a power source, such as a micro USB cable, to provide power to the Raspberry Pi and all of the connected components. Software In order to turn your Raspberry Pi into a smart light, you will need to write code using Python and the RPi. GPIO library. This library provides an easy way to control the GPIO pins on the Raspberry Pi, allowing you to read from sensors and control other components like the relay module and LED light. Before writing the code, you need to install the RPi. GPIO library on your Raspberry Pi. You can do this by running the following command in the terminal:sudo apt-get install python-rpi.gpio Alternatively, you can install the library using pip by running the following command:pip install RPi.GPIO Once the library is installed, you can start writing your code. The following is an example of the code needed to create a smart light using a Raspberry Pi:1. Import the RPi.GPIO library:            import RPi.GPIO as GPIO                                                     2. Set the GPIO pin mode:           GPIO.setmode(GPIO.BCM)                                                      3. Set the GPIO pin for the PIR sensor and relay module as inputs:            GPIO.setup(PIR_PIN, GPIO.IN)                                                           GPIO.setup(RELAY_PIN, GPIO.OUT)                                             4. Createaloop to check the PIR sensor and turn the relay module and LED light on or off:            while True:                                                                                  if  GPIO.input(PIR_PIN):                                                                      GPIO.output(RELAY_PIN, True)                                                             print("Motion detected, turning on light")                                          else:                                                                                   GPIO.output(RELAY_PIN, False)                                                       print("No motion detected, turning off light")                     5. Clean up the GPIO pins before exiting the program:              GPIO.cleanup()                                                              This code uses the RPi. GPIO library to check the PIR sensor for motion and turn the relay module and LED light on or off accordingly. The code uses a while loop to continuously check the PIR sensor and update the status of the relay module and LED light. The GPIO.cleanup() function is used to clean up the GPIO pins before the program exits, preventing any potential conflicts with other programs that may be using the same pins. Conclusion In this article, we have explored how to use a Raspberry Pi to create a smart light that turns on and off based on motion detection. We have discussed the hardware required, including a Raspberry Pi, PIR sensor, relay module, and LED light. We also provided a code example using the RPi. GPIO library to check the PIR sensor and control the relay module and LED light. Building a smart light using a Raspberry Pi is a simple and cost-effective project that can be completed in a few hours. It provides a great introduction to using the Raspberry Pi and the RPi.GPIO library and can be easily modified to meet your specific needs. Whether you are looking to automate your home or just interested in learning more about the Raspberry Pi, building a smart light is a great starting point.

As one of the world-leading research and innovation hub in nanoelectronics and digital technology,IMEC announced at the 2017 Symposia on VLSI Technology and Circuits that the world's first demonstration of a vertically stacked ferroelectric,AI doped HfO2 device for NAND applications.Using a new material and a novel architecture,imechas created a non-volatile memory concept with attractive characteristics for power consumption, switching speed, scalability and retention. The achievement shows that ferro-electric memory is a highly promising technology at various points in the memory hierarchy, and as a new technology for storage class memory. Imec will further develop the concept in collaboration with the world's leading producers of memory ICs.  Ferro-electric materials consist of crystals that exhibit spontaneous polarization; they can be in one of two states, which can be reversed with a suitable electric field. This non-volatile characteristic resembles ferromagnetism, after which they have been named. Discovered more than five decades ago, ferro-electric memory has always been considered ideal, due to its very low power needs, non-volatile character and high switching speed. However, issues with the complex materials, the breakdown of the interfacial layer and bad retention characteristics have presented significant challenges. The recent discovery of a ferro-electric phase in HfO2, a well-known and less complex material, has triggered a renewed interest in this memory concept.  "With HfO2, there is now a material with which we can process ferro-electric memories that are fully CMOS compatible. This allows us to make a ferro-electric FET (FeFET) in both planar and vertical varieties," noted Jan Van Houdt, imec's chief scientist for memory technology. "We are working to overcome some of the remaining issues, such as retention, precise doping techniques and interface properties, in order to stabilize the ferro-electric phase. We are now confident that our FeFET concept has all the required characteristics. It is, in fact, suitable for both stand-alone and embedded memories at various points in the memory hierarchy, going all the way from non-volatile DRAM to Flash-like memories. It has particularly interesting characteristics for future storage-class memory, which will help overcome the current bottleneck caused by the differences in speed between fast processors and slower mass memory." Imec recently presented the first, extremely positive results to its partners. The research center is now offering further development and industrialization of the vertical FeFET as a program to all its memory partners, which include the world's major companies producing memory ICs.  Van Houdt explained "FeFETs can be used as a technology to build memory very similar to Flash-memory, but with additional advantages for further scaling, simplified processing, and power consumption,with our longstanding R&D and processing experience on advanced Flash, we are uniquely positioned to offer our partners a head start in this exciting opportunity. They can then decide how best to fit ferro-electric memories in their products and chips." This is a breakthrough in CMOS-compatible ferroelectric memory, let's look forward to the CMOS-compatible ferroelectric memory together.  

SummaryDo you think that electornics and light one day can go well toghther on a standard‘CMOS' chip one day? It's reported that researchers have succeeded in introducting a light connection into the heart of a semiconductor chip a few days. In this way,two circuits can communicate.Or: the worlds of electronics and photonics are connected. BodyWhat is particularly attractive is researcher of the university of Twente--Satadal Dutta's solution--A light connection into the heart of a semiconductor chip. There is no special materials or manufacturing processes are needed: the light comes from silicon. The light source, detector and the light channel can be made using the technology that is used to make the electronic circuits. Fully optical circuits are available nowadays, but they use materials like indium phosphide and gallium arsenide, which can't easily be combined with the CMOS chip processes used for semiconductor chips you'll find in today's smartphones.  Connecting WorldsThere is a predictions say that all-optical circuits may become the‘new electronics'. In the transition from electronic to optic circuits, hybrid circuits, like the one Dutta designed, could play an important role. Satadal Dutta (1990, Barrackpore, India) did his PhD research in the Semiconductor Components group of Prof Jurriaan Schmitz, together with the Integrated Circuit Design group of Prof. Bram Nauta. Dutta defended his thesis 'Avalanche-mode silicon LEDs for monolithic optical coupling in CMOS technology' on 8 November. It was supported financially by NWO-TTW in The Netherlands and by NXP Semiconductors.  Avalanche LEDThe alternative would be: make a LED out of silicon. And that's the problem: silicon only emits a tiny amount of infrared light, while a detector made out of silicon needs visible light. They are talking and listening at different wavelengths. Dutta therefore chooses a remarkable way out: connect the LED reverse. At low voltages, there's no current, but at a voltage that is high enough, there will be a small current that amplifies itself like an avalanche. In this 'avalanche mode', the LED will transmit visible light. Using the same process, the light detector, as well as the light channel in-between can be made. Thanks to the special comb structure that Dutta designed, the light source gets more uniform and energy efficient. IsolationAn optical link on a chip is a good way to 'galvanically' isolate two circuits from each other. This is often necessary in cases where one circuit is a low-voltage and low-current one, while the other is a high-power circuit. They should be connected, but not by conducting wires, for reasons of safety. A classic transformer is an option then, but an optical connection is often used as well. Until now, this is a separate 'optocoupler', which is large and has a limited bit rate. Dutta's new solution is much more compact as an alternative: it total, it is just a few tens of microns and it offers the protection that's needed. Compared to optical channels in full-optical circuits, the energy consumption is relatively high, as there is quite some scattering of light. On the other hand: designing the electronics around the optical link in an efficient way, the amount of light needed for a successful connection, can be kept to a minimum. 

IntroductionIn modern compact circuit board designs, have you ever been puzzled by how to efficiently implement multiple identical or related resistor functions while saving valuable PCB space and ensuring parameter consistency? As electronic products become increasingly miniaturized and complex, traditional discrete resistor solutions often fall short, not only increasing wiring difficulty but also introducing unnecessary parasitic effects and temperature drift differences. This is precisely why network resistors (also known as “resistor arrays”) [Wikipedia] have emerged as the ideal choice for engineers. They cleverly integrate multiple resistors into a single package, offering a perfect solution to the aforementioned challenges. You can learn more about pull-up and pull-down resistors at [Kynix]. Additionally, if you are interested in circuit design, you can refer to [Kynix’s Transistor Common-emitter Amplifier Circuit Design Guide].This article will start with the most valuable user queries, providing you with a comprehensive understanding of network resistors’ application scenarios, core calculation methods, working principles, and practical guides for selection, simulation, and fault diagnosis. Whether you are a newcomer to the electronics field or an experienced engineer, this authoritative guide will help you thoroughly master network resistors, bringing revolutionary improvements to your designs. You can find more information about electronic components at [Kynix].Video 1: Introduction to Resistor Networks (Source: YouTube)1 Core Applications of Network Resistors: Why and Where to Use ThemNetwork resistors hold a significant position in modern electronic design precisely because they can efficiently and reliably solve various circuit design challenges. They are not merely simple collections of resistors but crucial components for optimizing space and enhancing performance. You can learn more about resistor types and their applications at [Kynix]. Let’s delve into the core applications of network resistors in different scenarios.1.1 Pull-up and Pull-down Resistor NetworksIn digital circuits, especially in microcontroller (MCU) I/O ports and various bus communications (e.g., I2C, SPI), the signal line’s voltage state needs to be clearly defined. When no external signal is driving, the signal line may be in an undefined “floating” state, leading to abnormal system behavior. At this point, pull-up resistors (connecting the signal line to a high level) or pull-down resistors (connecting the signal line to a low level) become particularly important. Network resistors offer significant advantages in this application:Simplified Wiring: When multiple I/O pins or bus lines require pull-up/pull-down, a single network resistor can replace multiple discrete resistors, greatly reducing the number of components on the PCB and simplifying wiring complexity.Ensuring Consistent Pin Levels: Since resistors within a network resistor are typically manufactured using the same process, they exhibit excellent matching, ensuring highly consistent pull-up/pull-down characteristics for multiple signal lines. This is crucial for the stability of multi-channel parallel signals or bus communications.1.2 Signal Line Termination ResistorsIn high-speed digital signal transmission, such as DDR memory buses, Ethernet, or LVDS signal lines, signal integrity is a core design challenge. When a signal encounters impedance mismatch at the end of a transmission line, signal reflection occurs, leading to waveform distortion, increased bit error rates, and even system crashes. The role of termination resistors is to absorb these reflected signals, ensuring clear signal transmission.Network resistors, as termination resistor arrays, can provide:Preventing Signal Reflection: By precisely matching the characteristic impedance of the transmission line, signal reflection is effectively suppressed, maintaining the integrity of the signal waveform.Ensuring Signal Integrity: Especially in multi-channel parallel high-speed signal lines, using network resistors can ensure consistent matching characteristics for all lines, thereby improving the signal integrity and reliability of the entire system.1.3 Voltage Divider NetworksVoltage divider networks are one of the most common applications in electronic circuits, used to precisely scale down a higher voltage to a lower voltage. This is very common in applications such as digital-to-analog converter (DAC) outputs, reference voltage generation, and sensor signal conditioning. Network resistors offer unique advantages in voltage divider applications:Precise Resistor Ratios: Due to the consistency of the manufacturing process, the ratio accuracy between resistors within a network resistor is much higher than that of discrete resistors. This is crucial for applications requiring high-precision voltage output.Good Temperature Tracking: When temperature changes, the resistance values of all resistors within a network resistor change in a similar manner. This means their relative ratios remain constant, ensuring the stability of the voltage division ratio and reducing the impact of temperature on circuit performance.1.4 LED Current Limiting Resistor ArraysIn applications requiring the driving of multiple LED indicators or LED displays, each LED typically needs a current-limiting resistor to protect it from excessive current. If discrete resistors are used, PCB space will be quickly occupied, and the assembly process will become cumbersome. Network resistors provide an elegant solution:Saving PCB Space: A single network resistor can replace multiple independent current-limiting resistors, significantly reducing the required circuit board area, which is particularly important for miniaturized product designs.Simplifying Assembly Process: The integrated package makes component placement and soldering more efficient, reducing production costs and error rates.Pro Tip: When selecting network resistors for LED current limiting, always consider the rated power of each resistor to ensure it can withstand the LED’s operating current and avoid overheating damage.2 Resistor Network Calculation and Analysis TechniquesUnderstanding the working principles of network resistors requires precise calculation and analysis of their internal resistor networks [DigiKey]. This is not only the foundation of theoretical learning but also an indispensable skill in practical circuit design. This section will delve into basic calculation methods, advanced analysis techniques, and recommended simulation tools for resistor networks.2.1 Basics: Equivalent Resistance CalculationWhether for discrete resistors or connections within network resistors, calculating equivalent resistance is at the core of circuit analysis. Mastering the formulas and techniques for series, parallel, and mixed networks is fundamental to understanding complex resistor networks. You can learn more about comparisons of resistors in series and in parallels at [Kynix].Series Resistors: When resistors are connected end-to-end, and current flows sequentially through each resistor, they form a series circuit. The total equivalent resistance is the sum of all series resistor values. For example, if R1, R2, and R3 are in series, then R_eq = R1 + R2 + R3.Parallel Resistors: When both ends of resistors are connected to the same points in a circuit, they form a parallel circuit. The reciprocal of the total equivalent resistance is the sum of the reciprocals of all parallel resistors. For example, if R1, R2, and R3 are in parallel, then 1/R_eq = 1/R1 + 1/R2 + 1/R3.Mixed Networks: In practical circuits, combinations of series and parallel connections are common. When calculating, you typically start from the innermost series or parallel sections and gradually simplify until the entire network is reduced to a single equivalent resistor.Important Note: For network resistors, their internal connection method (isolated, bussed) determines how their equivalent resistance is calculated. For example, the common terminal of a bussed resistor array can usually be considered a single node, and the resistors on the other pins form a parallel relationship with this node.Equivalent Calculation Diagram for Series, Parallel, and Mixed Resistor NetworksFigure 1: Equivalent Calculation Diagram for Resistor Networks (Source: DZSC.com)2.2 Advanced Analysis TechniquesFor more complex and large resistor networks that cannot be simply simplified by series and parallel combinations, we need more powerful analysis tools. Star-Delta (Y-Δ) transformation, nodal voltage method, and mesh current method are powerful tools for solving such problems.Star-Delta (Y-Δ) Transformation: This is a mathematical tool used to simplify complex resistor networks. When a circuit contains a “bridge” structure that is neither purely series nor purely parallel, Y-Δ transformation can convert a star connection (Y-shape) into an equivalent delta connection (Δ-shape), and vice versa, allowing the entire network to be simplified for calculation. This is particularly useful when analyzing certain sensor bridge circuits or complex power distribution networks.Nodal Voltage Method: This is a systematic analysis method based on Kirchhoff’s Current Law (KCL). It selects one node in the circuit as a reference point (usually ground) and then sets up KCL equations with the voltages of other nodes as unknowns. By solving these equations, the voltages of all nodes in the circuit can be obtained, and then the current and power of any branch can be calculated. The nodal voltage method is very efficient for complex networks containing multiple voltage and current sources.Mesh Current Method: Similar to the nodal voltage method, the mesh current method is a systematic analysis method based on Kirchhoff’s Voltage Law (KVL). It defines independent meshes in the circuit (closed loops that do not contain other meshes) and assumes a circulating current in each mesh. By setting up KVL equations for each mesh and solving for the mesh currents, the currents in all branches of the circuit can ultimately be obtained. The mesh current method excels in analyzing circuits containing multiple resistors and voltage sources.2.3 Practical Tools: Recommended Resistor Network Simulation SoftwareIn modern electronic design, manually calculating complex resistor networks is both time-consuming and prone to errors. Simulation software has become an invaluable aid for engineers, enabling them to quickly and accurately analyze circuit behavior and optimize designs.LTspice: A free, high-performance SPICE simulation software provided by Analog Devices. It is powerful, supporting the simulation of various analog circuits and switching power supplies, including complex resistor networks. LTspice has a vast component library and a relatively intuitive user interface, making it the preferred tool for many engineers for circuit verification and troubleshooting.Multisim: A popular circuit simulation software developed by National Instruments. Multisim provides an intuitive graphical interface and supports the simulation of digital, analog, and mixed-signal circuits. It integrates virtual instruments, allowing it to simulate oscilloscopes, multimeters, etc., making it very suitable for teaching and rapid prototyping.How to Use Software for Resistor Network Circuit Simulation and Analysis:Build the Circuit: Drag and drop components in the simulation software, connecting network resistors and other components according to the actual circuit diagram.Set Parameters: Set the correct resistance values, tolerances, temperature coefficients, and other parameters for the network resistors.Run Simulation: Select the appropriate simulation type (e.g., DC operating point analysis, transient analysis, AC analysis, etc.) and run the simulation.Analyze Results: View simulation results in the form of waveforms, reports, etc., to verify circuit functionality, analyze voltage and current distribution, and evaluate the performance of network resistors under different conditions.Pro Tip: When performing simulations, try changing the parameters of the network resistors (e.g., resistance value, topology) and observe the changes in circuit response. This will help you gain a deeper understanding of their impact on overall circuit performance.Video 2: How to Calculate Series and Parallel Resistor Combination Circuits (Source: YouTube)Video 3: Resistor Network Analysis and Circuit Simulation using LTspice (Source: YouTube)3 Working Principles and Selection of Network ResistorsTo truly master network resistors, a deep understanding of their working principles and the correct selection methods is crucial. This will not only help you maximize their advantages in design but also avoid potential problems.3.1 Unveiling the Working Principles of Network Resistors3.1.1 Basic Definition: What is a Network Resistor (Resistor Array)?Network resistors, commonly known as “resistor arrays,” are electronic components that integrate multiple independent or interconnected resistor elements into a single package. Unlike individual discrete resistors, resistor arrays are designed to provide a compact, efficient, and consistent resistor array to meet the demands for miniaturization, high integration, and high reliability in modern electronic circuits. They ensure high matching accuracy and excellent temperature tracking characteristics between internal resistors through precise manufacturing processes. You can find more resistor products at [Kynix].3.1.2 Detailed Explanation of Internal TopologiesThe internal connection method of network resistors is key to their functional versatility. According to different application requirements, resistor arrays are mainly divided into the following topologies:Isolated Type: This type of resistor array contains multiple completely independent resistors, each with two independent pins. There are no electrical connections between them. Isolated resistor arrays are suitable for applications requiring multiple independent resistors but also aiming to save space and simplify assembly, such as independent current limiting or voltage division for multiple signals.Internal Structure Diagram of Isolated Resistor ArrayFigure 2: Internal Structure Diagram of Isolated Resistor Array (Source: DZSC.com)Bussed Type: Bussed resistor arrays are the most widely used type. One end of all internal resistors is connected to a common pin (usually marked with a dot or special symbol on the resistor array), while the other ends are independently routed out. This structure is very suitable for pull-up/pull-down resistor networks, LED current-limiting arrays, and other applications that require multiple components to be connected to a common power supply or ground. Its advantage lies in greatly simplifying PCB wiring and ensuring consistent electrical characteristics between all resistors and the common point.Internal Structure Diagram of Bussed Resistor ArrayFigure 3: Internal Structure Diagram of Bussed Resistor Array (Source: RS Components)Dual-Terminator Type: This is a special type of network resistor, usually consisting of two series resistors forming a voltage divider, and providing multiple sets of such voltage dividers within the same package. Its main feature is extremely high matching accuracy and temperature tracking performance between internal resistors, making it very suitable for applications requiring precise voltage division or termination matching, such as differential signal termination matching for data buses.3.1.3 Introduction to Manufacturing Processes and MaterialsThe manufacturing process of network resistors plays a decisive role in their performance. Currently, mainstream manufacturing technologies include:Thick Film Technology: This is the most common manufacturing process. Resistor paste (containing conductive materials, glass powder, and organic binders) is printed on a ceramic substrate and then fired at high temperatures to form the resistive layer. Thick film resistors are characterized by low cost, wide resistance range, and high reliability, but their precision is relatively low.Thin Film Technology: Through vacuum deposition (such as sputtering or evaporation), a very thin layer of resistive material (such as nickel-chromium alloy) is deposited on a ceramic or silicon substrate. Thin film resistors offer higher precision, better temperature stability (lower TCR), and lower noise, but at a relatively higher cost.3.2 High-Precision Network Resistor Selection GuideSelecting the appropriate network resistor is crucial for ensuring circuit performance. Here are the key technical parameters to focus on during selection:3.2.1 Interpretation of Key Technical ParametersResistance Value and Tolerance:Resistance Value: Refers to the nominal resistance value of each resistor inside the network resistor, usually in ohms (Ω).Tolerance: Represents the maximum allowable deviation between the actual resistance value and the nominal resistance value, usually expressed as a percentage (e.g., ±1%, ±5%). For high-precision applications, a resistor array with a smaller tolerance should be selected.Temperature Coefficient (TCR):TCR (Temperature Coefficient of Resistance): Describes the extent to which the resistance value changes with temperature, usually in ppm/°C (parts per million per degree Celsius). A smaller TCR value indicates better temperature stability of the resistor. For precision circuits, especially those operating over a wide temperature range, low TCR network resistors are essential. This is a significant differentiating advantage of network resistors compared to discrete resistors, as resistors within the same package have similar TCRs and exhibit good temperature tracking.Rated Power and Package Thermal Resistance:Rated Power: Refers to the maximum power that the network resistor can continuously dissipate at a specified ambient temperature. When selecting, ensure that the actual power consumption of each resistor does not exceed its rated power, and allow for sufficient margin.Package Thermal Resistance: Represents the package’s ability to conduct internal heat to the external environment. Lower thermal resistance indicates better heat dissipation. In densely packed or high-power applications, special attention should be paid to thermal resistance to avoid overheating.Resistance Ratio Matching and Tracking TCR:Ratio Matching: This is one of the core advantages of network resistors. It refers to the relative resistance accuracy between different resistors within the same package. For example, if a 10kΩ and 1kΩ resistor pair has a ratio matching of 0.1%, it means the accuracy of their ratio (10:1) is as high as 0.1%. This is extremely important for applications like voltage dividers and differential amplifiers that rely on resistance ratios rather than absolute values.Tracking TCR: Refers to the difference in TCR between different resistors within the same package. Due to manufacturing consistency, the resistance values of resistors within a network resistor change in a very similar trend when temperature changes, thus maintaining a highly stable ratio. This is an indispensable feature for precision measurement and signal processing circuits.3.2.2 Package Specifications: SMD and Through-Hole (DIP/SIP) ReferenceNetwork resistors are available in various package forms to suit different assembly needs and space constraints:SMD (Surface Mount Device):Features: Small size, light weight, suitable for automated production, and the mainstream choice for modern compact electronic products.Common Packages: For example, 0402x4 (meaning 4 resistors of 0402 size integrated into one package), 0603x8, etc. These packages usually have smaller pin pitches and require more precise soldering processes. You can find more SMD resistors/chip resistors at [Kynix].SMD Resistor Array ExampleFigure 4: SMD Resistor Array Example (Source: CSDN Blog)Through-Hole Devices:DIP (Dual In-line Package):Features: Pins are arranged in two rows and can be directly inserted into PCB holes for soldering. Easy for manual soldering and prototyping, but occupies more space.Applications: Commonly found in older electronic products, educational experiment boards, or applications where space is not a critical concern.SIP (Single In-line Package):Features: Pins are arranged in a single row, saving more PCB space than DIP and simplifying wiring.Applications: Often used in situations requiring vertical mounting to save horizontal space, such as memory modules or certain specific function modules.Pro Tip: When choosing a package, in addition to considering space and assembly methods, also pay attention to the package’s impact on heat dissipation. Although SMD packages are small, they may require additional heat dissipation design in high-power applications.4 Fault Diagnosis and Advanced TopicsEven highly reliable network resistors can fail under extreme conditions or after prolonged use. Understanding common failure modes and correct diagnostic procedures is crucial for quickly pinpointing problems and repairing circuits. Additionally, this section will explore some advanced topics related to resistor networks to broaden your horizons.4.1 Network Resistor Fault Diagnosis Process4.1.1 Common Failure ModesNetwork resistor failures typically manifest in the following modes:Open Circuit: This is one of the most common failures, characterized by a broken internal connection within the resistor, preventing current flow. In the circuit, this manifests as related functions failing, such as LEDs not lighting up or abnormal signal line levels. Open circuits can be caused by burnout due to overcurrent, mechanical stress, or manufacturing defects.Short Circuit: Relatively less common, but if it occurs, it can lead to excessive current in the circuit and even damage other components. Short circuits are usually caused by internal insulation failure or accidental connections between pins.Resistance Drift: The resistance value deviates from the nominal value, which may lead to degraded circuit performance or abnormal functionality. Resistance drift is usually caused by prolonged operation in high-temperature, high-humidity environments, or by electrical or mechanical stress, leading to degradation of the resistive material’s properties.4.1.2 Diagnostic Flowchart: From Visual Inspection to Multimeter MeasurementWhen a network resistor is suspected of failure, the following diagnostic procedure can be followed:Visual Inspection:First, visually inspect the network resistor for obvious physical damage, such as burn marks, cracks, deformed pins, or corrosion. These signs usually indicate overcurrent or overheating issues.Check if the solder joints are firm and free of cold joints or dry joints.Multimeter Measurement:Power Off Operation: Before taking any measurements, ensure that the circuit is completely powered off and all charges are discharged to avoid electric shock or damage to the multimeter.Measure Individual Resistors: For isolated resistor arrays, you can directly measure the resistance across each resistor. For bussed resistor arrays, you need to find the common terminal and then measure the resistance between the common terminal and each independent pin.Compare with Nominal Value: Compare the measured resistance value with the nominal value on the network resistor. If the measured value is much larger than the nominal value (usually infinite), it may be an open circuit; if the measured value is much smaller than the nominal value (close to 0Ω), it may be a short circuit; if the measured value deviates significantly from the nominal value (outside the tolerance range), it may be resistance drift.Check Common Terminal: For bussed resistor arrays, you can use the multimeter’s continuity test (buzzer) to check if the common terminal is conductive with all independent pins and if the independent pins are insulated from each other.In-Circuit Testing (Proceed with Caution):In some cases, if power cannot be turned off, you can try in-circuit measurement. However, please note that in-circuit measurements may be affected by other components in the circuit, leading to inaccurate results. Therefore, in-circuit measurement results are for reference only, and final confirmation still requires off-circuit measurement.4.1.3 Solution: How to Correctly Replace and Soldering PrecautionsOnce a network resistor failure is confirmed, it needs to be replaced. Correct replacement and soldering operations are crucial for ensuring circuit reliability: You can learn more about basic electronic components at [Kynix].Select the Correct Replacement: Ensure that the replacement network resistor’s model, resistance value, tolerance, power, and package type are identical to the original component. If the original component is obsolete, carefully consult the datasheet to select a compatible replacement in terms of electrical characteristics and physical dimensions.Desoldering: Carefully remove the faulty component using an appropriate soldering iron and desoldering wick or hot air gun. Avoid damaging the PCB pads.Clean Pads: After removing the component, thoroughly clean any residual solder and flux from the pads, ensuring they are clean and flat.Soldering:Orientation: For directional resistor arrays (e.g., bussed type), always install them according to the markings on the PCB or the datasheet instructions. The common terminal usually has a dot or chamfer mark.Temperature and Time: Use appropriate soldering temperature and time to avoid overheating damage to the component or PCB. For SMD components, reflow soldering or a hot air gun is recommended.Solder Amount: Ensure an appropriate amount of solder is used to form full, shiny solder joints, free of cold joints, short circuits, or dry joints.Inspection: After soldering, visually inspect again and use a multimeter to measure the newly installed network resistor to confirm its proper functionality.4.2 Advanced Topics: Distributed Networks and Noise4.2.1 Introduction to Resistor Distributed Network ModelsIn some high-frequency or precision applications, simply treating a resistor as a lumped element may no longer be accurate. When the signal frequency is very high, or the physical size of the resistor is comparable to the signal wavelength, the distributed effects of the resistor (such as parasitic capacitance and parasitic inductance) become significant. At this point, we need to introduce the resistor distributed network model.A distributed network model treats a resistor as a transmission line composed of countless tiny series resistors and parallel capacitors (or inductors). This model is very important when analyzing high-speed signal transmission, RF circuits, or power integrity issues. For example, even purely resistive traces on a PCB will exhibit transmission line characteristics at high frequencies, requiring a distributed model to analyze their impedance, reflection, and loss.4.2.2 Introduction to Resistor Network Noise AnalysisAny resistor, no matter how precise, generates noise. In precision measurement and low-noise applications, analyzing resistor network noise is crucial. Resistor noise primarily includes:Thermal Noise: Also known as Johnson noise or Nyquist noise, it is caused by the random thermal motion of electrons in a conductor. Thermal noise is inherent to all resistors and cannot be eliminated. Its magnitude is related to temperature, bandwidth, and resistance value. The formula is $V_n = \sqrt{4kTRB}$, where k is Boltzmann’s constant, T is the absolute temperature, R is the resistance value, and B is the bandwidth.Shot Noise: In semiconductor devices, noise generated due to the randomness of charge carriers passing through a potential barrier. In some types of resistors, if there is a PN junction or similar structure, shot noise may also be generated.Flicker Noise (1/f Noise): Also known as 1/f noise, its power spectral density is inversely proportional to frequency. Flicker noise is more significant at low frequencies and is usually related to material defects, surface effects, and current flow. In precision DC or low-frequency measurements, flicker noise is the primary noise source.When designing low-noise circuits, it is necessary to:Select Low-Noise Resistors: Thin film resistors generally have lower noise than thick film resistors.Optimize Resistance Value: Select an appropriate resistance value to minimize thermal noise while meeting circuit functionality.Limit Bandwidth: Limit the circuit’s bandwidth through filtering or other means to reduce noise.Consider Temperature: Lowering the operating temperature can effectively reduce thermal noise.5 Conclusion and Frequently Asked Questions (FAQ)5.1 SummaryThrough this in-depth discussion, we can clearly see that **network resistors (resistor arrays) [TrustedParts.com] are far from simple collections of resistors; they are indispensable precision components in modern electronic design. They demonstrate significant advantages in improving circuit integration, consistency, and reliability, making them an ideal choice for addressing space constraints and signal integrity challenges.We started from the core applications of network resistors, understanding their unique value in pull-up/pull-down networks, signal termination matching, precise voltage division, and LED current limiting. Subsequently, we mastered the basic calculation methods and advanced analysis techniques for resistor networks and learned the importance of simulation tools in design verification. Finally, we delved into the working principles and internal topologies of network resistors and provided practical guides for high-precision selection and fault diagnosis.In summary, applications, calculations, and selection are the three pillars of mastering network resistors. Only by fully understanding these aspects can you unleash their full potential in actual projects. We encourage all engineers and designers to confidently choose network resistors in future circuit designs based on the strategies in this guide, as they will help you build more compact, stable, and efficient electronic systems.5.2 Frequently Asked Questions (FAQ)Q1: What is the fundamental difference between a network resistor and using multiple discrete resistors?A1: The main differences lie in size, cost, parasitic parameter consistency, and temperature tracking characteristics. Network resistors integrate multiple resistors into a single package, significantly saving PCB space and assembly costs. More importantly, due to the unified manufacturing process, their internal resistors exhibit excellent matching accuracy and temperature tracking characteristics, meaning their resistance ratios remain highly stable when temperature changes, which is an advantage discrete resistors can hardly match.Q2: How do I identify the orientation (first pin) on a network resistor?A2: Typically, it is identified by a marking dot or chamfer on the package. For example, many DIP or SIP package network resistors will have a circular indentation or a chamfered corner near the first pin. For SMD packages, silk screen markings may also indicate the orientation. Before actual use, always refer to the datasheet of the corresponding model to avoid incorrect connection.Q3: Which pin is the common terminal of a bussed network resistor?A3: The common terminal of a bussed network resistor is usually the pin marked with a dot or special symbol. This pin connects to one end of all internal resistors. For example, in an 8-pin bussed resistor array, pin 1 or pin 8 is usually the common terminal. Again, the most accurate identification method is to consult the datasheet for that specific model.Q4: Are all resistors in a network resistor array the same value?A4: Within a single package, all resistors have the same nominal resistance value. For example, a network resistor with a nominal value of 10kΩ will have each internal resistor designed to be 10kΩ. However, the actual values may fluctuate within their tolerance range. While the absolute value of individual resistors may vary slightly, the core advantage of network resistors lies in their excellent ratio matching and tracking TCR between internal resistors, which is crucial for circuit designs that rely on resistance ratios.Q5: In which scenarios do network resistors offer greater advantages than discrete resistors?A5: Network resistors offer greater advantages in the following scenarios: when saving PCB space is required (e.g., miniaturized products); when simplifying wiring and assembly processes is needed; when the circuit has high requirements for resistor matching accuracy and temperature tracking characteristics (e.g., precision voltage division, signal termination matching, DAC reference voltage); and when driving multiple identical loads (e.g., LED current-limiting arrays). In these cases, network resistors can provide higher integration, better performance consistency, and lower overall cost.Further ReadingResistor - WikipediaIntroduction to Precision Resistor Networks - Texas InstrumentsUnderstanding Resistor Arrays: Technical Principles, Application Scenarios, and Manufacturer Selection Strategies - EET-China

Overview: Transportation electrification began with small electric vehicles and gradually entered into medium-duty and heavy-duty vehicle electrification. In this article, we will understand the importance of commercial vehicle electrification and the challenges ahead. Significance of Commercial Vehicles Electrification Global climate change has resulted from human-caused greenhouse gas (GHG) emissions, which have raised the earth's temperature over the past century. The 2016 Paris Agreement sought to reduce global GHG emissions in order to keep the average global warming within two °C above pre-industrial temperatures in order to combat this threat from climate change. The transportation industry, which produces nearly 25% of the world's CO2 emissions, is one of the biggest sources of GHG emissions. Road vehicles account for nearly 75% of all CO2 emissions in the transportation industry among all modes of transportation. Therefore, a crucial step in reducing direct CO2 emissions is the electrification of road transportation. Many governments have therefore established transitional plans to electrify their transportation sector by 2050. Around 10 million electric vehicles (EVs) were in use worldwide as of the end of 2020, with battery electric vehicles making up two-thirds of this total. These EVs are predominantly light passenger cars. Challenges in Commercial Vehicles Electrification Nearly 40% of the world's road transportation sector's CO2 emissions in 2015 came from commercial vehicles, and under the "business as usual" scenario, those emissions are expected to at least double between 2015 and 2050. Therefore, the electrification of commercial vehicles is a crucial research area because it offers a promising chance to significantly reduce these emissions. Due to the small size of electric vehicle batteries, their low mileage, and the lack of public charging infrastructure, the majority of studies on electrifying commercial vehicles have concentrated on the hybridization of these vehicles.  Light-duty trucks (LDTs), which have been successfully electrified without significantly altering travel habits, have been the primary focus of the initial deployment of zero-emission commercial electric vehicles (CEVs), including electric trucks (ETs). Heavy-duty truck (HDT) deployment is in the pilot stage, whereas the deployment of medium-duty trucks (MDT) is still in the early stages. According to recent studies, there have been around 2,50,000 light-duty commercial electric vehicle sales, including trucks, with a stock of close to 31,000 medium- and heavy-duty vehicles. When compared to light passenger vehicles, commercial electric vehicle adoption has lagged, which has been attributed to the unsatisfactory policies implemented in this sector. With the availability of suitable charging infrastructure that meets the charging needs of these vehicles, the possibility of electrifying commercial vehicles grows. Commercial vehicle drivers are unlikely to switch to electric vehicles if the charging process is more challenging, uncertain, and time-consuming. However, as can be seen from Table 1, there are a variety of uses for commercial vehicles, which also affects the average load, trip length, and daily mileage of these vehicles. Furthermore, compared to passenger vehicles, the operational schedules of commercial electric vehicles can affect how quickly these vehicles charge up at charging infrastructure. Table 1. Different applications of commercial vehicles. Source: IEEE AccessVMTi refers to Vehicle Miles Travelled,PTOii refers to Power Take-Off,Percentageiii The percentage of the truck population by vocations depends on California truck population. Recent Advancements in Commercial Vehicles Electrification  In contrast to diesel and alternative fuel trucks, however, recent advancements in lithium battery technology have made electric trucks both technically and financially feasible. Existing studies have examined the potential advantages of ETs over diesel trucks over a vehicle's lifetime. These studies have found that, despite the high upfront costs of ETs, they can perform at least as well as diesel trucks over their entire lifecycle, particularly if the latter have long battery lives and high annual mileage. Moreover, the use of ETs, particularly MDTs, and HDTs, has increased as a result of regulations and government incentives encouraging the use of zero-emission vehicles. With battery sizes ranging from 300 kWh to roughly 990 kWh, a number of truck manufacturers, including DAF, Daimler, MAN, Navistar, Nikola, PACCAR, Volkswagen, Volvo, Tesla Inc., and Thor Trucks, have made significant plans to electrify their MDTs and HDTs. Due to their short-range needs and compact batteries, MDTs have drawn the most attention from these announcements regarding electrification. All of the announcements have a model for medium-duty trucks, and some manufacturers, like Daimler and BYD, have already released their commercial trucks for certain markets. In their announcements, some manufacturers, including Navistar, Volkswagen, Thor Trucks, Freightliner, and Tesla Inc., have mentioned the production of HDTs.  On the other hand, a lot of businesses have started incorporating ETs into their fleets or have made an announcement regarding their procurement of ETs. For instance, Walmart Inc. reported 45 class 8 Tesla Semi HDT pre-orders for the coming year. Similar orders for electric delivery trucks were made by Amazon and Rivian in 2019, and Anheuser-Busch announced plans to use 21 HDTs from BYD in California by the end of the year. In general, commercial vehicles, such as trucks, can be divided into three groups based on their gross vehicle weight (GVW). LDTs fall into this category if their GVW is less than 3.5 tonnes (t), MDTs fall into this category if their GVW is between 3.5t and 15t, and HDTs fall into this category if their GVW is above 15t. Each category has a wide range of vehicle types appropriate for their range of occupational operations, such as long-haul freight and garbage collection trucks.  Due to policies encouraging the adoption of zero-emission vehicles and advancements in battery technology, the electrification of MDTs and HDTs has been increasingly adopted in recent years. MDT models with battery bank capacities ranging from 48.5 kWh to about 350 kWh and an estimated range of up to 400 km have been produced by numerous truck manufacturers. Many models of HDTs with battery bank capacities between 120 kWh and 1000 kWh to cover an estimated range of up to 800 km have been introduced or produced. Table 2 lists the specifications of some MDTs and HDTs that are currently advertised or reported. Table 2. Specification of some commercial electric vehicles. Source: IEEE Access The estimated range of CEVs and the availability of appropriate charging infrastructure determine whether or not they can be used to cover the daily travel distance of commercial vehicles. According to surveys, most medium-duty commercial vehicles travel an average daily distance of 80 km to 250 km, while heavy-duty commercial vehicles travel an average daily distance of up to 700 km. As a result, at locations where they park overnight or in between shifts, the reported range of medium-duty CEVs can cover a sizable portion of the daily travel distance with just one charging event per day.  However, some medium- and heavy-duty CEVs require high charging rates to be met in a single charging event over the times they are parked because of high charging requirements (such as long-haul operation, multiple-shift operation, etc.). A high percentage of the daily travel distance is covered by multiple charging events per day at various locations along commercial vehicles' routes due to the constrained capacity of some electrical power infrastructure, which restricts the charging rate of charging infrastructure. Therefore, the number of times a CEV may need to be charged each day will depend on the daily mileage of commercial vehicles, the CEV's estimated range, and the infrastructure's charging rate. Summarizing With Key Points: Some of the takeaways from the article are as follows: Transportation emits nearly 25% of the world's CO2 and GHGs. Thus, many governments have transitional plans to electrify transportation by 2050. As of 2020, there were 10 million electric vehicles (EVs), two-thirds of which were battery-electric. Light passenger cars dominate these EVs.Most studies on electrifying commercial vehicles have focused on hybridization because electric vehicle batteries are small, have low mileage, and lack charging infrastructure.If charging is difficult, uncertain, and time-consuming, commercial vehicle drivers will not switch to electrifying their vehicles.Recently, MDTs and HDTs have been electrified due to policies encouraging zero-emission vehicles and advances in battery technology.  This blog post is part of a full research article from IEEE Access.*******************************************************************************************************************************************

The "wait and see" period is officially over. In January, we warned of potential volatility. Now, as we enter March 2026, the first major domino has fallen. Powerchip Semiconductor Manufacturing Corp (PSMC) has reportedly initiated a price hike for its 8-inch foundry services starting this month, a move expected to trigger a chain reaction across Tier-2 foundries globally.This isn't just about inflation; it's about a physical lack of manufacturing slots. According to the latest data from TrendForce and industry checks, global 8-inch wafer capacity is projected to contract by 2.4% year-over-year in 2026. This structural decline, colliding with the explosive demand from AI servers, has created a "Perfect Storm" for the analog supply chain.The Capacity Crunch Chart🚨 Critical Market Bulletin (March 2026):Foundry Action: PSMC and VIS (Vanguard) are raising quotes by 10-15% for spot orders.Capacity Utilization: Average 8-inch utilization has climbed to 90%, with BCD (Bipolar-CMOS-DMOS) processes fully allocated.Rumor Mill: Uncertainty surrounds Samsung's Giheung S7 fab, with reports of further capacity reductions intensifying supply fears.The "BCD" Bottleneck: Why AI is Starving Your PMIC SupplyWhy is a data center boom hurting the supply of industrial voltage regulators? The answer lies in the BCD process technology. This specialized 8-inch process is essential for manufacturing high-voltage Power Management ICs (PMICs).AI Servers (powering models like GPT-5) require complex, multi-phase power modules that consume up to 5x the silicon area of standard server PMICs. Tier-1 fabless design houses have booked out the vast majority of BCD capacity at TSMC and UMC to serve this high-margin AI market. This has effectively "crowded out" production slots for standard consumer and industrial PMICs, pushing lead times from 16 weeks to 26+ weeks.The BCD Process SqueezeCategory Watch: March 2026 Price & Lead Time DataProcurement teams must update their ERP lead time offsets immediately. The following data reflects the current situation on the Kynix platform and global spot market:Component FamilyMarch StatusPrice Trend (MoM)Lead TimeHigh-Voltage PMICAllocation▲ +18%26 - 30 WeeksAutomotive MOSFETsCritical Shortage▲ +15%35+ WeeksIndustrial MCUs (32-bit)Tightening▲ +8%20 - 24 WeeksStandard Logic (Little impact)Stable► 0%10 - 12 WeeksThe "Samsung Factor" and Structural DeclineAdding to the anxiety is the structural shift at major IDMs. Reports indicate that Samsung is continuing to scale back its 8-inch operations (specifically rumored around the Giheung S7 line) to focus resources on 12-inch and advanced memory.Unlike 2021, where the shortage was caused by a temporary demand spike, the 2026 challenge is supply-side atrophy. The machines are being turned off or converted, meaning this capacity is likely gone forever. This supports the forecast that the 2.4% capacity drop is just the beginning of a long-term trend.Kynix Strategy: Surviving Q2 and Q3With PSMC's price hike official, the window for "cheap inventory" has closed. Your strategy must shift from cost-saving to assurance of supply.1. Lock in Q3 Stock NowWait-and-see is a losing strategy. With lead times extending past 26 weeks, orders placed today will land in September. You must cover your Q3 production needs immediately.2. Validate Alternatives (Second Sources)If your BOM relies on a single Tier-1 brand for MOSFETs, you are at risk. Kynix can help you identify pin-to-pin compatible replacements from manufacturers who still have 8-inch capacity available, particularly in the Asian market.Conclusion: Resilience in a Shrinking MarketThe March 2026 data confirms that the era of abundant legacy node capacity is ending. The combination of PSMC's price moves and the AI sector's appetite for power silicon means buyers must be agile.Don't let a missing $0.20 regulator stop your production line.Secure Your Critical PMICs & MOSFETs TodaySearch Kynix's global inventory for real-time stock and alternative solutions.Search Components on Kynix.com