LM5642MTC

Overview

The LM5642MTC is a high-voltage, dual synchronous buck converter controller manufactured by Texas Instruments. It features two current-mode regulators operating 180 degrees out of phase at a normal switching frequency of 200 kHz. The device supports an input voltage range of 4.5 V to 36 V and delivers up to 20 A per output channel. Output voltages are adjustable from 1.3 V to 32.4 V with a maximum duty cycle of 98.9%. It operates within a temperature range of -40°C to +125°C and is housed in a TSSOP-28 package.

Feature Summary

• Dual synchronous buck topology with 180-degree phase shifting for reduced input ripple
• Oscillator synchronization capability for multi-phase or parallel system integration
• High-voltage operation supporting wide input supply ranges up to 36 V
• Current-mode control architecture ensuring fast transient response

Applications

• Point-of-load regulation for high-current digital processors
• Industrial power distribution systems requiring dual independent rails
• Telecommunications infrastructure equipment power supplies
• Server and storage subsystem voltage translation

Procurement Notes

Verify the manufacturer designation as Texas Instruments, which acquired National Semiconductor. Confirm the suffix /NOPB indicates lead-free and RoHS compliance. Ensure the TSSOP-28 package matches the design footprint. Check humidity sensitivity classification for proper storage and reflow profiles. Validate that the specific revision level aligns with the intended application requirements.

Selection Notes

Select this component when dual isolated outputs are required from a single high-voltage source. The 180-degree phase shift reduces input capacitor stress compared to non-interleaved designs. Consider the 200 kHz fixed frequency for passive component sizing. Evaluate thermal performance given the TSSOP-28 package limitations for high current loads. Ensure external MOSFETs support the voltage and current ratings derived from the 20 A specification.

Part Context

This part belongs to the LM5642 family of high-voltage synchronous buck controllers. It was originally developed by National Semiconductor before being integrated into Texas Instruments' portfolio. The LM5642X variant offers an extended temperature range. These devices are designed for applications demanding efficient, compact power solutions with synchronized operation capabilities.

Replacement Considerations

The LM5642MH is a pin-compatible alternative within the same family. Verify electrical specifications and package dimensions before substitution. Cross-reference datasheet revisions to ensure feature parity.