PM8908TR

Overview

The PM8908TR is a monolithic step-down switching regulator designed primarily for DDR termination applications. It operates from an input voltage range of 1 V to 3.5 V and provides a single adjustable output voltage between 0.5 V and 2 V with ±1% accuracy over temperature variations. The device utilizes a constant-on-time (COT) control loop for excellent load and line transient performance. It features integrated MOSFETs, two programmable switching frequencies of 0.6 MHz or 1 MHz, and external tracking support. Protection mechanisms include positive and negative overcurrent protection, over/undervoltage protection, and overtemperature protection.

Feature Summary

• High-efficiency monolithic buck converter architecture with integrated MOSFETs
• Constant-on-time control loop ensuring robust load and line transient response
• Integrated thermal compensation for current sense precision
• Comprehensive protection suite including overcurrent, overvoltage, undervoltage, and overtemperature safeguards

Applications

• DDR memory termination power supplies
• Low voltage point-of-load conversion
• Embedded systems requiring precise low-voltage regulation

Procurement Notes

Verify component status as the PM8908 series is listed as obsolete in public records. Confirm availability through authorized distributors or secondary market sources. Ensure compatibility with existing PCB footprints and design specifications before procurement. Check for alternative components if long-term supply stability is required for production.

Selection Notes

Select this component when designing DDR termination circuits requiring high efficiency and compact size. The QFN20 package offers a small footprint suitable for space-constrained designs. Consider the input voltage range and output adjustment capabilities to ensure alignment with system requirements. Evaluate the need for external tracking and specific switching frequency settings during the design phase.

Part Context

The PM8908 is part of STMicroelectronics' portfolio of specialized power management ICs. It belongs to the category of monolithic buck converters tailored for specific memory interface applications. The TR suffix indicates tape and reel packaging. This component addresses the demand for efficient, low-profile power solutions in modern electronic devices.

Replacement Considerations

Publicly confirmed substitute part numbers are not available in the provided documentation. Designers should consult official replacement guides or contact STMicroelectronics directly for qualified alternatives due to the obsolete status of this specific model.