Four-channel supervisor for multi-rail systems
It asserts an active-low reset output when any monitored voltage falls below its threshold, and holds reset for a minimum of 140 ms after all rails recover, with an option to extend the timeout via an external capacitor. The open-drain output allows wired-OR connection to other reset sources.
Threshold voltages are set via external resistor dividers, giving the designer flexibility to monitor non-standard rail voltages (e.g., 1.2 V, 2.5 V, 3.3 V, 5 V) without being locked to fixed factory-trimmed levels. The reset timeout defaults to 140 ms, which covers most power-supply ramp and oscillator start-up sequences; adding a capacitor to the CT pin extends it proportionally. For a system with a slow-start power module or a large bulk capacitance, plan the timeout margin so the supervisor does not falsely hold the system in reset while the rails are still settling.