LT1123CZ#TRPBF

Overview

The LT1123CZ#TRPBF is a low dropout regulator driver designed for use with discrete PNP power transistors to form cost-effective regulators. It features a fixed 5V output trimmed to ±1% and operates with a quiescent current of 700µA. The device provides line regulation of 1mV and load regulation of 5mV. It guarantees an output current of up to 4A when paired with the MJE1123 pass transistor, achieving dropout voltages below 0.75V. The unit includes thermal limiting and foldback drive current protection.

Feature Summary

• Integrated bandgap reference and error amplifier for precise voltage control
• Driver circuit capable of sinking base current for external PNP transistors
• Built-in thermal limit and current foldback protection mechanisms

Applications

• Low dropout linear regulator circuits using discrete PNP pass elements
• Battery backup systems requiring stable 5V outputs
• Industrial equipment power supplies

Procurement Notes

Verify that the specific ordering suffix matches the required package type, as the datasheet indicates variations such as TO-92 or SOT-223. Confirm RoHS compliance status through official manufacturer documentation before finalizing procurement decisions.

Selection Notes

Select this component when designing inexpensive regulators requiring a fixed 5V output. Ensure the external PNP transistor can handle the required output current and that the input voltage range supports the necessary dropout characteristics for the application.

Part Context

This part belongs to the LT1123 family of low dropout regulator drivers manufactured by Analog Devices Inc. It serves as a control element rather than a complete standalone regulator, necessitating an external power transistor to achieve higher current capabilities.

Replacement Considerations

LT1123CST#PBF