The ADM9690 is a power supply monitor that monitors the 5 V power supply and the microprocessor operation. It features a precision voltage monitor, selectable timeout, two reset outputs.
The ADM9690 is a voltage‑monitoring comparator and watchdog timer designed to supervise a 5 V microprocessor supply. It generates two reset outputs when the monitored voltage drops below the threshold or when the watchdog timer expires, providing power‑on reset and additional circuitry reset.
The device is offered in an 8‑lead SOIC package, operates from 4.3 V to 5.5 V, and features selectable watchdog timeout periods (0.75 ms to 25 ms) via SEL1/SEL2 pins. Detailed electrical specifications, absolute maximum ratings, pin functions, and typical performance curves are provided in the handbook.
| Operating Voltage Range (VCC) | 4.3 V – 5.5 V |
|---|---|
| Supply Current | 55 µA – 100 µA |
| Reset Voltage Threshold | 4.2 V – 4.42 V |
| Reset Threshold Hysteresis | 30 mV |
| RESET(2) Timeout Delay | 10 ms |
| Watchdog Timeout Period (SEL2=0, SEL1=0) | 0.75 ms – 1.28 ms |
| WDI Input Threshold (Logic Low) | 0.8 V |
| Output Voltage (RESET pins) | 0.1 V – 0.4 V |
The reset threshold is typically 4.4 V, with a specified range of 4.2 V to 4.42 V.
RESET(1) remains low for 50 ms after VMON rises above the reset threshold.
Four timeout periods are selectable: 0.75 ms, 1.5 ms, 12.5 ms, and 25 ms, set by SEL1 and SEL2 pins.
The device can tolerate VCC from –0.3 V to +6 V under absolute maximum ratings.