LM3431MHX

Overview

The LM3431MHX is a 3-channel constant current LED driver with an integrated boost controller, designed for automotive applications. It operates within an input voltage range of 4.5 V to 36 V and supports a maximum switching frequency of 1100 kHz. The device features peak current control mode and delivers up to 0.7 A output current. Packaged in a 28-pin TSSOP (PDSO28) with a thermal slug, it functions reliably across temperatures from -40°C to 125°C.

Feature Summary

• Integrates three linear current controllers with a single boost switching controller for compact design
• Configurable output current ranging from 20 mA to 150 mA per channel using external resistors
• Operates without requiring a microcontroller for basic LED driving functionality

Applications

• Automotive LED backlight panels
• Space-critical lighting designs
• High-efficiency LED illumination systems

Procurement Notes

Verify the specific suffix (e.g., NOPB) against the manufacturer's official documentation to confirm lead-free status and exact package variant. Ensure the supplier provides valid traceability for automotive-grade components. Cross-reference the datasheet revision date to guarantee compatibility with current design specifications and regulatory requirements.

Selection Notes

Select this component when designing multi-channel LED drivers requiring integrated power management. It is suitable for applications needing precise current regulation without complex digital control. Consider the thermal performance of the TSSOP package and the 1100 kHz switching frequency for EMI management in dense layouts.

Part Context

Manufactured by National Semiconductor, now part of Texas Instruments, the LM3431 series addresses the need for efficient, high-density LED driving solutions. This specific model combines linear and switching technologies to optimize efficiency and size for automotive and industrial backlighting applications.

Replacement Considerations

Consult official substitution guides for equivalents such as the LM3431AQMHX/NOPB. Verify that alternative parts maintain identical pinout, thermal characteristics, and automotive qualification standards before implementation.

FAQ

Does the LM3431MHX require a microcontroller to operate?

No, the regulators serve as stand-alone LED drivers configurable via external resistors, eliminating the need for a microcontroller.

What is the maximum switching frequency of the LM3431MHX?

The maximum switching frequency is 1100 kHz.