Four-rail supervisor for multi-voltage boards
The DS1831S+ is a 4-channel voltage supervisor from the MicroMonitor™ family, monitoring up to four supply rails with thresholds at 3.3V, 5V, and two adjustable levels. It asserts an active-low, open-drain reset output when any monitored voltage falls below its threshold, holding the reset for a user-selectable timeout of 10ms, 100ms, or 1000ms minimum. Packaged in a 16-SOIC (0.154" body width, 3.90mm) for surface-mount assembly.
What the four monitored channels mean for your board
With four independent voltage monitors, the DS1831S+ covers the core rails of a mixed-voltage design — e.g., a 5V analog supply, 3.3V I/O, and two adjustable rails for a 1.8V core and 1.2V auxiliary. The open-drain outputs can be wire-ORed with other supervisors or pulled up to the lowest rail for a single system reset line. The adjustable thresholds use external resistor dividers, letting you set trip points anywhere within the supply range without changing the IC.