LM338T 5A Adjustable Voltage Regulator

LM338T 5A Adjustable Voltage Regulator is a high-current, adjustable linear voltage regulator designed for applications that require a stable and precise output voltage with load currents up to 5 amperes. This device is widely used in industrial power supplies, laboratory bench supplies, battery chargers, audio amplifiers, and high-power embedded systems due to its reliability, simplicity, and excellent electrical performance.

Overview and Core Function

• The LM338T 5A Adjustable Voltage Regulator allows the user to set the output voltage anywhere between 1.2 V and 32 V using only two external resistors.

• It belongs to the classic LM regulator family, but it is specifically optimized for high-current operation, making it suitable for demanding power applications.

• The TO-220 package enables efficient heat dissipation when mounted on an appropriate heatsink.

Key Electrical Characteristics

• Maximum output current: 5 A

• Output voltage range: 1.2 V to 32 V (depending on input voltage)

• Dropout voltage: typically around 2–3 V at full load

• Line regulation: excellent stability against input voltage variations

• Load regulation: maintains consistent output even with changing loads

These characteristics make the LM338T 5A Adjustable Voltage Regulator ideal for circuits that require clean and well-regulated DC power.

Built-in Protection Features

• Thermal shutdown: automatically limits output if the junction temperature becomes too high

• Current limiting: protects the device from overload and short-circuit conditions

• Safe operating area (SOA) protection: prevents damage during high voltage and high current operation

These protections significantly increase system reliability and reduce the need for external safety circuitry.

Typical Applications

• Adjustable bench and laboratory power supplies

• High-current battery chargers

• Motor control power stages

• Audio amplifier power rails

• Industrial and automation control systems

Because of its robustness, the LM338T 5A Adjustable Voltage Regulator is often chosen in professional designs where long-term stability is critical.

Design Advantages

• Simple circuit design with minimal external components

• High output current capability compared to standard LM317

• Proven architecture with wide industry acceptance

• Suitable for both commercial and educational electronics projects

Datasheet Summary

• Package: TO-220

• Input-to-output voltage differential: up to 40 V

• Reference voltage: typically 1.25 V

• Operating junction temperature range: 0 °C to 125 °C

• Manufacturer: Texas Instruments / National Semiconductor (original design)

The official datasheet provides detailed information on electrical characteristics, application circuits, thermal calculations, and protection behavior, making it easy for engineers and technicians to integrate this regulator into their designs.

Conclusion

remains a trusted solution for high-current adjustable voltage regulation. Its combination of simplicity, built-in protection, and strong electrical performance makes it a reliable choice for both professional engineers and advanced hobbyists.

LM338T 5A Adjustable Voltage Regulator Selection Notes

For more compatible parts, explore the components category at Electrolik. In addition, you can read more about voltage regulator to understand the circuit concept before choosing replacements.