LM317H

Voltage Regulators - Linear, Low Drop Out (LDO) Regulators Overview

The LM317H is a three-terminal adjustable positive linear voltage regulator manufactured by National Semiconductor, now part of Texas Instruments. It provides an output current capability of up to 1.5 A with an adjustable output voltage range from 1.25 V to 37 V. The device features a maximum input voltage of 40 V and operates within a temperature range of -40°C to +125°C. Key electrical specifications include a typical line regulation of 0.01% per volt and a load regulation of 0.1%. It incorporates internal protections for overcurrent, thermal overload, and safe operating area (SOA).

Voltage Regulators - Linear, Low Drop Out (LDO) Regulators Feature Summary

• Adjustable output voltage ranging from 1.25 V to 37 V using only two external resistors.
• Internal circuitry includes current limiting, thermal shutdown, and safe operating area protection.
• Delivers a guaranteed output current of 1.5 A across the full operating temperature range.

Voltage Regulators - Linear, Low Drop Out (LDO) Regulators Applications

• Local card regulation in distributed computing systems.
• On-board regulation for power supplies.
• Programmable output precision regulators.

Voltage Regulators - Linear, Low Drop Out (LDO) Regulators Procurement Notes

Verify the manufacturer designation on the component marking, as National Semiconductor was acquired by Texas Instruments. Confirm the specific suffix indicates the TO-3 metal can package. Ensure the datasheet version matches the production lot date code to verify compliance with current RoHS standards and material declarations.

Voltage Regulators - Linear, Low Drop Out (LDO) Regulators Selection Notes

Select this component when a robust, high-current adjustable regulator is required for industrial or wide-temperature applications. The TO-3 metal case offers superior thermal dissipation compared to plastic packages. Consider the input-output differential voltage to ensure adequate headroom for regulation while managing power dissipation through appropriate heatsinking.

Voltage Regulators - Linear, Low Drop Out (LDO) Regulators Part Context

The LM317H belongs to the LM317 family of three-terminal adjustable regulators. This series is widely recognized for its versatility and reliability in power management designs. The 'H' suffix typically denotes the metal can package variant, distinguishing it from plastic encapsulated versions like the LM317T. It serves as a direct replacement for fixed regulators in many legacy designs requiring variable voltage outputs.

Voltage Regulators - Linear, Low Drop Out (LDO) Regulators Replacement Considerations

• LM317H/NOPB