BU4221F-TR

Overview

The BU4221F-TR is a CMOS voltage detector IC from ROHM Semiconductor, designed for low-voltage monitoring applications. It features an adjustable output delay time and operates within a supply voltage range of 0.9 V to 7 V. The device provides a detection threshold of 2.1 V with high accuracy of ±1.0%. It consumes ultra-low current, typically 550 nA, and supports an operating temperature range from -40°C to +125°C. The component utilizes a SOP-4 package and offers an open-drain output type without manual reset or watchdog timer functions.

Feature Summary

• CMOS technology ensures ultra-low current consumption for extended battery life in portable devices.
• Adjustable output delay time allows customization of reset timing via external components.
• High detection voltage accuracy of ±1.0% guarantees reliable system supervision under varying conditions.

Applications

• Portable electronic devices requiring low-power voltage supervision
• Battery-operated equipment needing precise under-voltage detection
• General-purpose supervisory circuits in consumer electronics

Procurement Notes

Verify the specific suffix 'F' indicates the SOP-4 package variant, distinct from other package options like SSOP or VSOF. Confirm availability status as this part may be subject to lifecycle changes such as NRND or EOL. Ensure compatibility with existing PCB footprint designs utilizing the SOP-4 form factor before procurement.

Selection Notes

Select this component when a fixed 2.1 V detection threshold is required alongside adjustable delay functionality. Consider the SOP-4 package constraints for space-limited designs. Evaluate the open-drain output capability against load requirements. Compare power consumption specifications against alternative detectors if ultra-low standby current is critical for the application.

Part Context

This part belongs to the BU42xx series of CMOS voltage detectors, characterized by adjustable delay times and high accuracy. The series includes various threshold voltages and package options to suit different monitoring needs. The BU4221F-TR specifically targets applications requiring a 2.1 V detection point in a compact surface-mount format.

Replacement Considerations

BD5211G-1TR is listed as a same-pinout replacement option with similar electrical characteristics, though it uses an SSOP-5 package instead of SOP-4. Verify pinout compatibility and package dimensions before substitution.