LM3411M5-5.0

Overview

The LM3411M5-5.0 is a precision secondary regulator and driver manufactured by Texas Instruments, designed for use in isolated power supply topologies. It integrates a high-voltage startup circuit, an error amplifier, and a gate driver to control synchronous rectification on the secondary side of flyback converters. The device operates with a wide input voltage range and provides a stable reference output, enabling accurate regulation of low-voltage secondary rails without requiring optocouplers or external feedback networks.

Feature Summary

• Integrates a high-voltage startup circuit capable of powering the device from the primary side during initial operation.
• Includes a precision error amplifier and internal reference for closed-loop regulation of the secondary output voltage.
• Features a dedicated gate driver optimized for controlling external N-channel MOSFETs used as synchronous rectifiers.

Applications

• Secondary-side synchronous rectification in isolated flyback power supplies
• Precision post-regulation for low-voltage DC/DC converter outputs
• Optocoupler-free feedback systems in offline AC/DC adapters

Procurement Notes

Verify the specific suffix 'M5' against the manufacturer's official datasheet to confirm the package type and temperature grade. Ensure the part number matches the exact revision required for your design, as variations may exist between National Semiconductor and Texas Instruments releases. Cross-reference the pinout and electrical characteristics with the latest published documentation before finalizing procurement.

Selection Notes

Select this component when designing isolated converters that require precise secondary-side regulation without optocouplers. It is suitable for applications needing a built-in high-voltage startup mechanism and integrated synchronous rectifier drive. Evaluate the thermal performance and input voltage range relative to the transformer turns ratio and primary bus voltage conditions.

Part Context

The LM3411 series was originally developed by National Semiconductor and is now supported by Texas Instruments following their acquisition. This family addresses the need for efficient, cost-effective secondary-side regulation in flyback architectures. The LM3411M5-5.0 specifically denotes a variant within this line, focusing on precision regulation capabilities for downstream loads.

Replacement Considerations

Direct substitutes include other parts from the LM3411 family, such as the LM3411-L or variants with different output voltage references. Verify compatibility regarding the startup voltage threshold and gate drive current capability before swapping components in existing designs.