MP4689DN-LF

Overview

The MP4689DN is a synchronous step-down DC/DC converter from Monolithic Power Systems. It integrates high-side and low-side N-channel power MOSFETs for efficient voltage regulation. The device operates with an input voltage range of 3V to 28V, delivering up to 3A of output current. It features fixed-frequency pulse-width modulation (PWM) operation at 500kHz. Internal compensation ensures stability with small ceramic capacitors. The converter includes comprehensive protection mechanisms such as over-current protection, thermal shutdown, and undervoltage lockout.

Feature Summary

• Integrated synchronous rectification with internal high-side and low-side MOSFETs
• Fixed-frequency PWM control architecture for stable transient response
• Comprehensive protection suite including thermal shutdown and over-current limiting

Applications

• Industrial point-of-load regulation
• Embedded system power supplies
• Communication equipment bias circuits

Procurement Notes

Verify the specific suffix 'DN-LF' against manufacturer documentation to confirm package type and lead-free status. Ensure compatibility with required input voltage ranges and load currents before integration. Cross-reference pinouts with official datasheets to prevent layout errors during PCB design.

Selection Notes

Select this component for applications requiring moderate current levels and fixed frequency operation. Evaluate thermal performance based on expected ambient temperatures and board copper area. Confirm that the output voltage setting resistors align with the desired regulation target within the specified input range.

Part Context

This part belongs to the MP46xx series of synchronous buck converters. It is designed for space-constrained applications where efficiency and simplicity are prioritized. The DN package offers a compact footprint suitable for dense PCB layouts. It serves as a solution for converting higher bus voltages to lower logic or analog supply rails.

Replacement Considerations

Direct replacements must match the 3A current rating, 28V max input, and 500kHz switching frequency. Verify pin-to-pin compatibility if substituting with other manufacturers' parts. Check for equivalent protection features and thermal characteristics to ensure system reliability remains unchanged.