BU4921G-TR

Supervisors Overview

The BU4921G-TR is a CMOS voltage detector manufactured by ROHM Semiconductor, designed for power supply monitoring. It features a fixed detection threshold of 2.1 V with a precision of ±1%. The device operates within a reset active voltage range of 0.7 V to 7 V and draws a typical operating current of 400 nA at VDET=4.8V. It utilizes an SSOP-5 package and supports a temperature range from -40°C to +125°C. The output type is CMOS with a low active state, and it includes hysteresis defined as VDET x 0.05.

Supervisors Feature Summary

• CMOS output structure providing digital voltage supervision
• Fixed 2.1 V detection threshold ensuring precise monitoring
• Low power consumption suitable for battery-operated systems
• Integrated hysteresis to prevent output oscillation

Supervisors Applications

• Portable electronic devices requiring voltage supervision
• Battery-powered equipment monitoring
• General-purpose power supply support circuits

Supervisors Procurement Notes

Verify the NRND status before procurement, as this component is not recommended for new designs. Confirm that the SSOP-5 package and 2.1 V threshold align with existing system requirements. Ensure compatibility with the CMOS output logic levels. Check for availability of the recommended replacement BD5221G-1 if long-term supply stability is required.

Supervisors Selection Notes

Select this part when a fixed 2.1 V threshold is required without manual reset or watchdog functionality. The CMOS output is suitable for direct interfacing with digital logic. Consider the BD5221G-1 series if open-drain outputs or adjustable delays are needed for future designs. Verify thermal performance within the specified -40°C to +125°C range.

Supervisors Part Context

The BU4921G-TR belongs to the BU4921G standard voltage detector family from ROHM. It is classified under PMIC - Power Management ICs. The component is designated as Not Recommended for New Designs (NRND), indicating it is supported for existing customers but discontinued for new projects. It shares characteristics with other single-input voltage detectors in the series.

Supervisors Replacement Considerations

The BD5221G-1 is listed as a similar level replacement with the same package. It offers a comparable 2.1 V threshold but features an open-drain output instead of CMOS. Designers should verify output interface compatibility when transitioning to the BD5221G-1.