LM117K

Overview

The LM117K is a three-terminal adjustable positive voltage regulator manufactured by Texas Instruments. It provides an output voltage range from 1.2 V to 37 V with a maximum load current of 1.5 A. The device features a TO-39 metal can package and operates within a temperature range of -55°C to 125°C. Key electrical specifications include a line regulation of 0.04% per volt and a load regulation of 1%. It supports a maximum input voltage of 40 V and includes comprehensive protection against short circuits, thermal overload, and safe operating area limits.

Feature Summary

• Provides adjustable positive output voltage ranging from 1.2 V to 37 V using only two external resistors
• Delivers up to 1.5 A load current with integrated short-circuit, thermal overload, and safe operating area protection
• Maintains superior line and load regulation compared to standard fixed regulators
• Operates reliably across an extended industrial temperature range of -55°C to 125°C

Applications

• Adjustable power supply designs requiring precise voltage control
• Linear regulation in industrial equipment and instrumentation
• Constant current sources when configured with a resistor between the adjust and output terminals
• Power management systems needing robust overload protection

Procurement Notes

Verify that the specific part number matches the required tolerance and package variant, as the LM117 family includes multiple grades. Confirm RoHS compliance status if environmental regulations apply to your assembly process. Ensure the supplier provides authentic documentation from Texas Instruments or authorized distributors to avoid counterfeit components. Check for any specific handling requirements related to the metal can package during surface mount or through-hole integration.

Selection Notes

Select the LM117K when high current capability up to 1.5 A is required alongside adjustable output voltage. Consider its TO-39 package for applications needing robust thermal dissipation and mechanical stability. Evaluate the need for extended temperature operation down to -55°C, which distinguishes it from commercial-grade variants. Compare line and load regulation specs against fixed regulator alternatives to ensure performance meets circuit sensitivity requirements.

Part Context

The LM117K belongs to the LM117/LM317 family of three-terminal adjustable regulators produced by Texas Instruments. This series is widely recognized for its reliability and ease of use in linear power supply applications. The K suffix typically denotes a specific package configuration, often associated with the TO-39 metal can format, suitable for demanding environments. It shares core functionality with other members like the LM317 but may differ in packaging and specific qualification standards.

Replacement Considerations

LM317K