BU4909F-TR

Supervisors Overview

The BU4909F-TR is a CMOS voltage detector manufactured by ROHM Semiconductor, designed for monitoring power supply voltages in electronic circuits. It operates within a supply voltage range of up to 7 V and features a detection threshold of 900 mV with an accuracy of ±1%. The device consumes a typical static current of 300 nA and supports operation across a temperature range of -40°C to +125°C. Packaged in a compact SOP-4 format, it provides a CMOS output without manual reset or watchdog timer functions.

Supervisors Feature Summary

• CMOS output interface for direct logic compatibility
• High precision voltage detection with ±1% accuracy
• Ultra-low static current consumption for battery efficiency
• Wide operating temperature range suitable for industrial environments

Supervisors Applications

• Portable battery-powered devices requiring low quiescent current
• Microprocessor power supply monitoring systems
• Industrial control equipment operating in extreme temperatures
• Automotive electronics (non-critical safety applications)

Supervisors Procurement Notes

Verify the specific suffix 'TR' indicates tape and reel packaging when sourcing. Confirm RoHS compliance status through official manufacturer documentation as regulatory requirements may vary by region. Check for obsolescence notices since this component has been marked as end-of-life in some distributor databases. Ensure the SOP-4 package dimensions match your PCB footprint requirements before finalizing procurement decisions.

Supervisors Selection Notes

Select this component when a low-voltage threshold near 1 V is required for precise power management. Consider the CMOS output type if interfacing directly with standard logic families without additional pull-up resistors. Evaluate the 300 nA static current against system power budgets for battery-operated applications. Verify that the absence of a watchdog timer meets the system's fault recovery requirements.

Supervisors Part Context

This part belongs to the BU49xx series of voltage detectors from ROHM Semiconductor, which offers various threshold voltages for different power rail monitoring needs. The BU4909F variant specifically targets low-voltage detection applications. The series is known for its compact packaging options and high integration levels, making it suitable for space-constrained designs in consumer and industrial electronics.

Supervisors Replacement Considerations

BD5209G-1 is listed as a recommended replacement with similar specifications. Note that BD5209G-1 uses an SSOP5 package compared to the SOP4 package of the BU4909F-TR, requiring PCB layout adjustments. The replacement offers open-drain output instead of CMOS, potentially necessitating external pull-up components.