LM338K Voltage Regulator: Complete Guide with Datasheet, Circuit, and Alternatives

The LM338K is a versatile and powerful 5 A adjustable voltage regulator, widely recognized for its flexibility and durability. This article explores into its key features, practical applications, and how it can be effectively implemented in various electronic systems. With an adjustable output range from 1.2V to 32V, the LM338K proves requisite in projects requiring precise voltage control, from DIY electronics to industrial power management. Equipped with over-temperature protection and current limiting, the LM338K ensures reliable performance even under challenging conditions, making it a top choice for your robust and adaptable power solutions.

Catalog

Pinout of LM338K

LM338K Design Insights

Visual Symbol for LM338K

Physical Footprint for LM338K

3D Modeling of LM338K

Exploration of LM338K

The LM338K navigates a wide voltage spectrum from 1.2 V to 32 V, capably managing currents surpassing 5 A. Its adaptability is unveiled through the simple use of two resistors for output adjustment, which eases its incorporation into a variety of systems.

Industrial systems benefit from its design, blending efficiency akin to advanced power supplies. Telecommunications systems find it suitable due to its versatility. Domestic electronics appreciate its seamless integration.

In power management fields you can frequently incorporate the LM338K into their systems. Its stability and ease of utilization make it a preferred choice for those seeking reliable power solutions. Its sturdy design confronts fluctuating loads with grace, making it exceptionally useful.

Specifications of LM338K

Type	Parameter
Mount	Through Hole
Mounting Type	Through Hole
Package / Case	TO-204AA, TO-3
Number of Pins	2
Weight	6.40101g
Operating Temperature	0°C ~ 125°C
Packaging	Tube
Tolerance	5%
JESD-609 Code	e3
Part Status	Obsolete
Moisture Sensitivity Level (MSL)	1 (Unlimited)
Number of Terminations	2
ECCN Code	EAR99
Terminal Finish	Tin (Sn)
Power Rating	50W
Terminal Position	BOTTOM
Terminal Form	PIN/PEG
Number of Functions	1
Base Part Number	LM338
Pin Count	2
Number of Outputs	1
Voltage - Input (Max)	35V
Output Voltage	32V
Output Type	Adjustable
Max Output Current	5A
Output Configuration	Positive
Max Output Voltage	32V
Number of Regulators	1
Min Input Voltage	4.2V
Protection Features	Over Current, Over Temperature
PSRR	75dB ~ 60dB (120Hz)
Reference Voltage	1.29V
Dropout Voltage	3V
Dropout Voltage1-Nom	3V
Min Output Voltage	1.2V
Power Supply Rejection Ratio (PSRR)	75dB
Min Current Limit	7A
Load Regulation-Max (%)	1%
Height	8.7mm
Length	39.5mm
Width	26.2mm
REACH SVHC	No SVHC
Radiation Hardening	No
RoHS Status	ROHS3 Compliant
Lead Free	Lead Free

Features of LM338K

Feature	Description
Peak Output Current	Guaranteed 7 A
Output Current	Guaranteed 5 A
Adjustable Output Voltage	Down to 1.2 V
Line Regulation	Typically 0.005 %/V
Load Regulation	Typically 0.1 %
Thermal Regulation	Guaranteed
Current Limit	Constant with temperature
Package Type	Standard 3-lead transistor package

Circuit Schematics with LM338K

Applications of LM338K

The LM338K serves in crafting adjustable power supplies, delivering precise constant current, and efficiently charging batteries. Its wide application stems from its sturdy build and versatile voltage regulation.

Adjustable Power Supplies

The LM338K is chief in creating versatile power supply systems. Its ability to manage high voltage and current enhances stability while minimizing noise, boosting electronic system performance. Commonly used in labs and workshops, these systems benefit from the reliability of equipment. You can value the precise voltage adjustments, reflecting the device’s precision and reliability.

Constant Current Regulation

In contexts such as LED lighting and motor control, regulating constant current is active. The LM338K provides stable current, safeguarding sensitive components and improving system efficiency. Reliable current regulation helps ensure long-term stability, preventing fluctuations that might lead to system failures.

Battery Charging

Battery charging systems leverage the LM338K's adjustable capabilities for precise charging cycle control. This optimizes battery charging efficiency and safety, enhancing battery lifespan. Advanced systems integrate features to detect state changes in charging, significantly improving efficiency and battery health.

Robust Design and Flexibility

The LM338K's durable design and voltage regulation adaptability make it suitable for various applications. It functions well under different environmental conditions, a valued trait in industries demanding robustness. Its flexibility has led to widespread use in fields that require high performance and dependability, you can often cite these features as reasons for selection in diverse projects.

Common LM338K Use Circuit Designs

Alternatives of LM338K

Parts	Description	Manufacturer
LM138AKSTEEL	1.2 V-32V Adjustable Positive Regulator, MBFM2, Metal Can, TO-3, 2 Pin	Texas Instruments
LM138K/883	IC VREG 1.2 V-32 V Adjustable Positive Regulator, MBFM2, Metal Can, TO-3, 2 Pin, Adjustable Positive Single Output Standard Regulator	National Semiconductor Corporation
LM338K STEEL/NOPB	1.2 V-32V Adjustable Positive Regulator, MBFM2, Green, Metal Can, TO-3, 2 Pin	Texas Instruments
LM138K-MIL/NOPB	1.2 V-32V Adjustable Positive Regulator, MBFM2, RoHS Compliant, Metal Can, TO-3, 3 Pin	Texas Instruments
M38510/11706SYA	IC VREG Adjustable Positive Regulator, Adjustable Positive Single Output Standard Regulator	Linear Technology
FT138AK	Adjustable Positive Standard Regulator, 1.2V Min, 32V Max, MBFM2, Metal Can, TO-3, 2 Pin	Force Technologies Ltd
FT338K	Adjustable Positive Standard Regulator, 1.2V Min, 32V Max, MBFM2, Metal Can, TO-3, 2 Pin	Force Technologies Ltd
LT338AK	IC VREG 1.2 V-32 V Adjustable Positive Regulator, MBFM2, Metal Can, TO-3, 3 Pin, Adjustable Positive Single Output Standard Regulator	Linear Technology
SG138AK/883B	Regulator, 1 Output, Bipolar	Microsemi Corporation
LM338MWC	1.2 V-32V Adjustable Positive Regulator, UUC, Wafer	Texas Instruments

LM338K Packaging

Manufacturer Details

STMicroelectronics intertwines its core design philosophy with sustainability in semiconductor solutions, weaving environmental stewardship with product safety and efficiency, reflecting on values and aspirations towards a sustainable future.

Dominant to STMicroelectronics' innovations is the pursuit of eco-conscious technology to minimize environmental harm. By emphasizing energy efficiency, components are crafted to lower power consumption across diverse applications. Industries like automotive and consumer electronics benefit, from seeing a reduction in carbon footprints. This trend mirrors a wider industry migration towards green solutions, demanding ongoing adaptation and ingenuity.

Datasheet PDF

LM338K Datasheets:

LMx38.pdf

Frequently Asked Questions [FAQ]

1. What operational conditions suit LM338K?

The LM338K thrives in temperatures ranging from 0 °C to 125 °C. This flexibility caters to a plethora of uses, from everyday consumer gadgets to rigorous industrial contexts. Maintaining consistent device temperature is key, shaping both its performance and lifespan, thus offering you sufficient possibilities.

2. Can you describe LM338K?

LM338K is a resilient three-terminal positive voltage regulator, delivering over 5 A between 1.2 V and 32 V. With just two resistors, it simplifies voltage management while mirroring the efficiency of advanced power systems. This straightforwardness appeals to those prioritizing reliable output, especially in space and budget-sensitive environments.

3. What kind of package does LM338K come in?

Encased in the Steel TO-3 transistor package, the LM338K is built for strength and effective heat management. This packaging is preferred for high-power tasks due to its superior thermal regulation, ensuring stability and prolonged reliability. Proper packaging selection is used for enhancing the safety and performance of any electronic component.