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LM338K Linear Voltage Regulator: Datasheet, Applications, Circuits

  • Contents

The LM338K are Adjustable 3-terminal Positive Voltage Regulators capable of supplying in excess of 5A over a 1.2V to 32V output range.

Catalog

Product Overview

LM338K CAD Models

LM338K Package Dimensions

LM338K Features

LM338K Product Attributes

LM338K Applications

LM338K Application Circuits

Alternate Parts

Component Datasheet

LM338 vs LM338K

Using Warnings

LM338K Manufacturer

FAQ


Product Overview

LM338K Voltage Regulator

LM338K Voltage Regulator

The LM338K is exceptionally easy to use and requires only 2 resistors to set the output voltage. The careful circuit design has resulted in outstanding load and line regulation comparable to many commercial power supplies. The LM138  family is supplied in a standard 3-lead transistor package. A unique feature of the LM138 family is time-dependent current limiting. The current limit circuitry allows peak currents of up to 12 A to be drawn from the regulator for short periods of time. This allows the LM138 to be used with heavy transient loads and speeds start-up under full-load conditions. Under sustained loading conditions, the current limit decreases to a safe value protecting the regulator. Also included on the chip are thermal overload protection and safe area protection for the power transistor. Overload protection remains functional even if the adjustment pin is accidentally disconnected.
The LM338  is capable of providing extremely good load regulation but a few precautions are needed to obtain maximum performance. In operation, the LM338 develops a nominal 1.25 V reference voltage, V(REF), between the output and adjustment terminal. 


LM338K CAD Models

LM338K CAD Models

LM338K CAD Models


LM338K Package Dimensions

LM338K Regulator Package Dimensions

LM338K Regulator Package Dimensions


LM338K Features

• Guaranteed 7 A peak output current
• Guaranteed 5 A output current
• Adjustable output down to 1.2 V
• Line regulation typically 0.005 %/V
• Load regulation typically 0.1 %
• Guaranteed thermal regulation
• Current limit constant with temperature
• Standard 3-lead transistor package


LM338K Product Attributes

Specifications

Values

Manufacturer:

STMicroelectronics

Product Category:

Linear Voltage Regulators

RoHS:

Details

Mounting Style:

Through Hole

Package/Case:

TO-3

Number of Outputs:

1 Output

Polarity:

Positive

Output Voltage:

1.2 V to 32 V

Output Current:

5 A

Output Type:

Adjustable

Input Voltage MAX:

35 V

Input Voltage MIN:

4.2 V

Minimum Operating Temperature:

0 C

Maximum Operating Temperature:

+ 125 C

Load Regulation:

0.5 %

Line Regulation:

0.03 %/V

Series:

LM338

Packaging:

Bulk

Brand:

STMicroelectronics

Height:

8.7 mm (Max)

Length:

39.5 mm (Max)

Product Type:

Linear Voltage Regulators

PSRR / Ripple Rejection - Typ:

75 dB

Factory Pack Quantity:

100

Subcategory:

PMIC - Power Management ICs

Width:

26.2 mm (Max)


LM338K Applications

Consumer Electronics, Aerospace, Defence, Military, Industrial, Power Management


LM338K Application Circuits

Constant 5-V Regulator

Constant 5-V Regulator

 

Regulator with line resistance in output lead
Regulator with Line Resistance in Output Lead

 

Regulator With Protection Diodes
Regulator With Protection Diodes

 

Slow Turnon 15-V Regulator
Slow Turnon 15-V Regulator

 

Adjustable Regulator with Improved Ripple Rejection
Adjustable Regulator with Improved Ripple Rejection

 

High Stability 10-V Regulator
High Stability 10-V Regulator

 

Digitally Selected Outputs
Digitally Selected Outputs

 

Light Controller
Light Controller

 

Precision Current Limiter
Precision Current Limiter


Alternate Parts

LM338KSTEEL/NOPB


Component Datasheet

LM338K PDF


LM338 vs LM338K

Specifications

LM338

LM338K

Pbfree Code

 No

*

Rohs Code

 No

 No

Part Life Cycle Code

Obsolete

Transferred

Ihs Manufacturer

SEMTECH CORP

SEAGATE MICROELECTRONICS LTD

Part Package Code

TO-204AA

*

Package Description

TO-3, TO-204/-3

TO-204/-3

Pin Count

2

*

Reach Compliance Code

unknown

unknown

ECCN Code

EAR99

EAR99

HTS Code

8542.39.00.01

8542.39.00.01

Samacsys Description

TO-3 5 AMP POSITIVE ADJUSTABLE VOLTAGE REGULATORS

*

Samacsys Manufacturer

SEMTECH

*

Adjustability

ADJUSTABLE

ADJUSTABLE

Dropout Voltage1-Nom

3 V

3 V

Input-Output Voltage Differential-Max

35 V

*

Input-Output Voltage Differential-Min

3 V

*

JESD-30 Code

O-MBFM-P2

*

JESD-609 Code

e0

*

Line Regulation-Max (%/V)

0.06

0.06

Load Regulation-Max(%)

1%

1%

Number of Functions

1

*

Number of Outputs

1

1

Number of Terminals

2

3

Operating Temperature TJ-Max

125 °C

125 °C

Output Current1-Max

5 A

5 A

Output Voltage1-Max

32 V

32 V

Output Voltage1-Min

1.2 V

1.2 V

Package Body Material

METAL

METAL

Package Code

TO-3

*

Package Equivalence Code

TO-204/-3

TO-204/-3

Package Shape

ROUND

*

Package Style

FLANGE MOUNT

*

Peak Reflow Temperature (Cel)

NOT SPECIFIED

*

Qualification Status

Not Qualified

Not Qualified

Regulator Type

ADJUSTABLE POSITIVE SINGLE OUTPUT STANDARD REGULATOR

*

Surface Mount

No

*

Technology

BIPOLAR

BIPOLAR

Terminal Finish

Tin/Lead (Sn/Pb)

*

Terminal Form

PIN/PEG

*

Terminal Position

BOTTOM

*

Time@Peak Reflow Temperature-Max (s)

NOT SPECIFIED

*

Base Number Matches

4

1


Using Warnings

Please check their parameters and pin configuration before replacing them in your circuit.


LM338K Manufacturer

STMicroelectronics is a French-Italian multinational electronics and semiconductor manufacturer headquartered in Geneva, Switzerland. It is commonly called ST, and it is Europe's largest semiconductor chip maker based on revenue. While STMicroelectronics corporate headquarters and the headquarters for EMEA region are based in Geneva, the holding company, STMicroelectronics N.V. is registered in Amsterdam, Netherlands.


FAQ

What is LM338K?

Adjustable 3-terminal Positive Voltage Regulator.

 

What does the LM138 have to be used with?

Heavy transient loads and speeds start-up under full-load conditions.

 

What types of protections are included on the LM338K?

Thermal overload protection and safe area protection.

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