BU4918F-TR

Supervisors Overview

The BU4918F-TR is a CMOS voltage detector IC from ROHM Semiconductor, designed for high-accuracy power supply monitoring. It features a fixed under-voltage detection threshold of 1.8V with a precision of ±1%. The device operates within a reset active voltage range of 0.7V to 7V and supports a maximum supply voltage of 7V. It consumes low current, typically 550nA in operation and 300nA in standby. The component utilizes a 4-pin SOP package and functions without manual reset or watchdog timer capabilities.

Supervisors Feature Summary

• CMOS technology ensures low current consumption for battery-powered applications
• Fixed detection voltage provides stable monitoring without external adjustment
• Compact surface-mount packaging facilitates space-constrained circuit designs

Supervisors Applications

• Microprocessor system reset circuits
• Battery voltage monitoring
• Power supply supervision in portable devices

Supervisors Procurement Notes

Verify the specific suffix F-TR against the manufacturer's latest datasheet to confirm package type and tape-and-reel specifications. Confirm end-of-life status as some sources indicate last-time-buy conditions. Ensure compatibility with existing PCB footprints for the 4-pin SOP format before procurement.

Supervisors Selection Notes

Select this component when a fixed 1.8V threshold is required for system reset. Compare output drive capabilities and hysteresis characteristics against alternative supervisors if noise immunity is critical. Verify that the CMOS output type matches the input requirements of the downstream logic circuitry.

Supervisors Part Context

This part belongs to the BU49xx series of standard voltage detectors. The series offers various detection voltages from 0.9V to 4.8V in 0.1V increments. The BU4918F-TR specifically addresses applications needing a 1.8V reference point within this lineup.

Supervisors Replacement Considerations

BD5218G-1 is listed as a similar specification replacement. Note differences in package (SSOP5 vs SOP4) and output type (Open Drain vs CMOS). Verify pinout compatibility and electrical parameter alignment before substitution.