4.2V threshold supervisor for automotive and industrial rails
The ROHM BD52E42G-MTR is a single-channel voltage detector (supervisor IC) from the automotive-grade BD52Exx series. It monitors a single supply rail and asserts an active-low reset when the voltage drops below the 4.2V threshold. The open-drain output lets you wire-OR multiple reset signals or pull it up to a different logic voltage.
Open-drain output and package options
The open-drain output (active-low reset) means the reset signal is pulled low when the monitored voltage falls below 4.2V. That's a small footprint for dense PCB layouts.