4.1V threshold voltage detector for power-rail monitoring
The ROHM BD4741G-TR is a single-channel voltage detector from the BD47xx family, designed to assert a reset signal when the monitored supply drops below 4.1V. The Active Low, Open Drain output pulls low on a fault condition, and an external pull-up resistor sets the logic-high level to match the downstream microcontroller or logic supply. Housed in a 5-pin SC-74A (SOT-753) surface-mount package, it suits compact PCB layouts where board space is constrained. The -40°C to 75°C operating temperature range covers most indoor commercial and industrial environments, but does not extend to the 105°C or 125°C ratings found on some BD47xx family siblings.
Open Drain output and reset timing flexibility
The Open Drain output allows the reset signal to be shared on a common bus with other open-drain reset sources, and the pull-up resistor value can be chosen to tune the rise time. This is useful in multi-voltage systems where the reset signal must be valid before the core supply is fully stable. The part monitors a single voltage rail; for systems needing multiple thresholds, a second BD4741G-TR or a multi-channel supervisor would be required. The 4.1V threshold is well-suited for 5V rails where a drop below ~4.1V indicates an impending brown-out.
The 5-SSOP supplier package designation corresponds to the SC-74A / SOT-753 footprint.