G690/G691 are microprocessor (µP) supervisory circuits used to monitor the power supplies in µP and digital systems. They provide excellent circuit reliability and low cost by eliminating external components and adjustments when used with +5V, +3.3V, +3.0V- pow- ered circuits. These circuits perform a single function: they assert a reset signal whenever the VCC supply voltage declines below a preset threshold, keeping it asserted for at least 140ms after VCC has risen above the reset threshold. Reset thresholds suitable for operation with a variety of supply voltages are available. The G691L has an open-drain output stage, while the G690 have push-pull outputs. The G691L’s open-drain RESET output requires a pull-up resistor that can
The G690 and G691 are microprocessor supervisory circuits that monitor +3 V, +3.3 V and +5 V power‑supply rails. They provide a reset output when VCC falls below a preset threshold and hold the reset low for at least 140 ms after VCC recovers. The G690 variants use push‑pull outputs (active‑low G690L, active‑high G690H) while the G691L uses an open‑drain output requiring a pull‑up resistor.
The devices are offered in 3‑pin SOT89, SOT23 and SC70 packages, operate from –40 °C to +105 °C, and draw very low supply current (typical 10 µA). Detailed electrical characteristics, absolute maximum ratings, and typical operating curves are provided for each threshold and package option.
| Supply Current (typical) | 10 µA |
|---|---|
| Operating Temperature Range | -40 °C to +105 °C |
| Package Types | SOT89, SOT23, SC70 |
G690L and G690H provide push‑pull outputs (active‑low and active‑high), while G691L provides an open‑drain output.
It monitors +3 V, +3.3 V, and +5 V power‑supply rails.