BU4321FVE-TR

Overview

The BU4321FVE-TR is a CMOS voltage detector IC manufactured by ROHM Semiconductor, designed for monitoring power supply voltages with an adjustable output delay. It features a typical under-voltage detection threshold of 2.1 V and a precision of ±1%. The device operates within a reset active voltage range of 0.7 V to 7 V and supports a CMOS output type with a low active state. Key electrical parameters include a circuit current of 0.40 μA (ON) and 0.55 μA (OFF) at VDET=4.8 V, hysteresis voltage of VDET x 0.05, and L output currents of 3.3 mA (LowVol) and 6.5 mA (HighVol). It utilizes a 10.0 MΩ delay circuit resistance and functions in temperatures from -40°C to 125°C.

Feature Summary

• CMOS voltage detector with adjustable output delay time
• High detection precision of ±1% for the 2.1 V threshold
• Wide operating voltage range supporting 0.7 V to 7 V reset activation
• Low power consumption suitable for battery-operated systems

Applications

• Monitoring power supply voltages in portable electronic devices
• System reset generation in microcontroller-based applications
• Battery backup switching circuits
• Over/under voltage protection in consumer electronics

Procurement Notes

Verify the ordering part number BU4321FVE-TR against the specific package VSOF5 and RoHS compliance requirements. Confirm that the adjustable delay feature meets the timing specifications for the target application. Check the supply status as it may be subject to last-time-buy or end-of-life notices. Ensure the manufacturer is ROHM Semiconductor and the component matches the official datasheet specifications before procurement.

Selection Notes

Select this component when a precise 2.1 V detection threshold with high accuracy is required. The adjustable delay timer allows customization of reset timing without external components. Consider the VSOF5 package size for space-constrained designs. Compare performance metrics such as output current capabilities and hysteresis against alternative supervisors if system margins are tight.

Part Context

The BU4321FVE-TR belongs to the BU43xx series of low voltage detectors from ROHM Semiconductor. This series is characterized by CMOS technology and adjustable delay times, offering a balance between precision and flexibility. The FVE suffix indicates the VSOF5 package variant, which is distinct from other package options like SSOP5 found in similar series members.

Replacement Considerations

BD5221G-1 is a recommended replacement with the same pinout and comparable detection voltage.