BD4939G-TR

Overview

The BD4939G-TR is a standard CMOS voltage detector IC from ROHM Semiconductor, designed for monitoring power supply voltages in electronic circuits. It features a fixed detection threshold of 3.9V with a typical accuracy of ±1%. The device operates within a supply voltage range of 1.2V to 10V and consumes a typical quiescent current of 900nA. It provides a reset delay timer of 100µs and utilizes an SSOP-5 package. The output type is CMOS, suitable for direct interfacing with microcontrollers or logic circuits requiring a reset signal.

Feature Summary

• High accuracy detection voltage with ±1% tolerance
• Ultra-low current consumption for battery-powered applications
• CMOS output interface compatible with digital logic
• Integrated reset delay timer for stable system initialization

Applications

• Microcontroller reset circuits
• Logic circuit supervision
• Battery-operated device power management

Procurement Notes

Verify the component status as End-of-Life (EOL) before procurement. Confirm that the SSOP-5 package dimensions match your PCB footprint. Ensure the 3.9V detection threshold aligns with your system's power rail requirements. Check for RoHS compliance documentation if required by your manufacturing standards. Consider lead times due to potential discontinuation.

Selection Notes

Select this component when a precise 3.9V detection threshold is required with CMOS output compatibility. It is suitable for designs prioritizing low static current consumption. Verify that the 100µs reset delay meets your system's timing constraints. Ensure the operating temperature range of -40°C to +105°C fits your environmental specifications. Compare against newer recommended alternatives if long-term supply stability is critical.

Part Context

The BD4939G-TR belongs to the BD49xxx series of voltage detectors from ROHM Semiconductor. This series is characterized by high accuracy and low current consumption. The BD4939 variant specifically sets the detection voltage at 3.9V. It is part of a broader family including N-channel open drain outputs (BD48xxx) and CMOS outputs (BD49xxx). The series supports detection voltages from 2.3V to 6.0V in 0.1V increments.

Replacement Considerations

The BD5239G-1 is listed as a replacement with the same package and similar detection voltage. Verify pinout compatibility and electrical characteristics before substitution.