LM3411M5-5.0/NOPB

Overview

The LM3411M5-5.0/NOPB is a precision secondary shunt regulator and driver manufactured by Texas Instruments, designed specifically for driving optoisolators in isolated feedback systems. It provides a fixed regulation voltage of 5 V with an initial tolerance of ±1% at standard grade. The device integrates an internally compensated operational amplifier, a bandgap reference, and an NPN output transistor capable of sourcing up to 15 mA. It operates within an ambient temperature range of -40°C to 85°C and is housed in a compact 5-pin SOT-23 surface-mount package.

Feature Summary

• Provides precise secondary regulation for isolated DC-DC switching regulators
• Integrates an open-emitter NPN output transistor optimized for direct optocoupler drive
• Includes an accessible compensation pin for loop stability adjustment
• Features internal feedback resistors eliminating the need for external trimming

Applications

• Secondary controller for isolated flyback PWM switching regulators
• High-precision fixed-output regulators when used with LDOs
• Precision monitoring applications requiring accurate voltage sensing
• Feedback isolation circuits in power supply designs

Procurement Notes

Verify that the specific suffix M5 corresponds to the required tape and reel packaging configuration as defined in the manufacturer's orderable addendum. Confirm that the NOPB designation ensures compliance with RoHS standards and absence of specified hazardous materials. Ensure the selected grade meets the necessary initial tolerance specifications for the target application.

Selection Notes

Select this component when high-precision secondary regulation is required for isolated power supplies without using trim pots or precision external resistors. The integrated op-amp allows for local compensation via the COMP pin, simplifying circuit design. Consider the 5-V fixed version for standard logic levels and ensure the 15 mA output current capability matches the optocoupler drive requirements.

Part Context

This part belongs to the LM3411 family of precision shunt regulators. Unlike adjustable references, these devices are factory-trimmed for specific fixed voltages (3.3 V or 5 V) to simplify system design. The family is characterized by low quiescent current and robust overcurrent protection, making it suitable for space-constrained applications where board area is limited.

Replacement Considerations

LM3411AIDBVR: Offers improved ±0.5% initial tolerance compared to the standard grade.