LK112M55TR

Overview

The LK112M55TR is a low-noise, low-dropout linear voltage regulator manufactured by STMicroelectronics. It provides a fixed output voltage of 5.5 V with a maximum output current of 150 mA. The device operates within an input voltage range of 2.5 V to 14 V and features a typical dropout voltage of 350 mV at full load. It includes integrated shutdown control, overcurrent protection, and thermal overload protection. The regulator maintains a quiescent current of 250 µA and offers a power supply rejection ratio (PSRR) of 55 dB at 400 Hz. It is housed in a compact SOT-23-5 package and functions reliably across a temperature range of -40°C to +125°C.

Feature Summary

• Integrated shutdown control for efficient power management
• Low noise performance suitable for sensitive analog circuits
• Built-in overcurrent and thermal overload protection mechanisms

Applications

• Battery-powered portable devices requiring low quiescent current
• RF modules and sensor interfaces needing stable low-noise power
• Embedded systems utilizing microcontrollers with shutdown capabilities

Procurement Notes

Verify the specific suffix TR indicates tape-and-reel packaging when sourcing. Confirm RoHS compliance status through official manufacturer documentation or authorized distributor certificates. Ensure the ordering part number matches the exact 5.5 V output variant to avoid functional mismatches. Cross-reference datasheet revisions for any updates to pin configurations or electrical characteristics prior to final procurement decisions.

Selection Notes

Select this component when a fixed 5.5 V output is required with minimal external components. Consider the SOT-23-5 package constraints for PCB layout and thermal dissipation. Evaluate the 150 mA current limit against peak load requirements. The shutdown pin allows for system-level power control, making it suitable for applications requiring extended battery life through active sleep modes.

Part Context

This component belongs to the LK112S series of low-dropout regulators from STMicroelectronics. The series is designed for general-purpose linear regulation tasks where size and efficiency are critical. The LK112M55TR specifically targets applications needing a precise 5.5 V rail with integrated safety features. It complements other variants in the family that offer different fixed output voltages while sharing the same footprint and protection architecture.

Replacement Considerations

Direct substitutes include other LK112 series variants with compatible packages, such as LK112M50TR for 5.0 V output or LK112SM18TR for 1.8 V output, provided the voltage requirement differs. Verify pin compatibility and thermal performance before swapping. No direct cross-brand replacements are confirmed in public documentation without detailed parameter matching.