MAX691ACSE

MAX691ACSE is Maxim Integrated’s microprocessor supervisory device. It combines a voltage monitor, a reset output, and a watchdog timer to protect microcontrollers and digital logic from brown-out and watchdog failures. On power-up, it holds the MCU in reset for a defined delay; if the supply drifts low or the watchdog expires (unless refreshed by the MCU), the reset output is asserted. A manual reset input allows an immediate external reset. These parts ensure proper MCU initialization and robust operation in embedded systems and are offered in small single‑supply packages. For exact electrical characteristics, thresholds, timing, and packaging details, consult the MAX691ACSE datasheet and the MAX691 family documentation, since variants differ.

Equivalent parts (voltage supervisor with watchdog/reset) include:
- Analog Devices: ADM690/ADM691 (and related ADM69x family)
- Texas Instruments: TLV803/TLV803B; TPS3800/TPS3808 series
- Microchip: MCP1316/MCP1317 (watchdog/reset variants)
- ON Semiconductor: NCP301/NCP302 (and similar NCP series)
Note: match the same Vcc range, reset delay, and watchdog features; pinout/package may differ.

Here are the typical features of the MAX691ACSE (microprocessor supervisory with watchdog):
- Wide supply range: 2.7V to 5.5V operation
- Power-on reset (POR) that asserts during power-up/power-down and brown-out
- Manual reset input (active-low)
- Watchdog timer with programmable timeout (external capacitor) and periodic WDI servicing
- If watchdog is not serviced in time, RESET is asserted to reset the processor
- RESET output: active-low, open-drain
- Power-fail/brown-out detection to ensure reset during supply dips
- Low quiescent current in normal operation
- Industrial temperature range (typical -40°C to +85°C)
Note: Exact pinout and timing ranges depend on package/variant; verify against the specific datasheet revision for your application.

Pin count: 8 pins (8-pin package).
Function: MAX691ACSE is a microprocessor supervisory circuit with a watchdog timer. It monitors the supply voltage and generates a reset to a microcontroller on power-up/power-down and/or watchdog timeout, ensuring proper system reset behavior.

Manufacturer: Maxim Integrated (now part of Analog Devices, Inc.).
What kind of company: A fabless semiconductor company that designs and markets analog and mixed‑signal integrated circuits.

Applications of MAX691ACSE:
- Microprocessor/microcontroller reset supervision and power-on reset
- Watchdog timer to detect software hangs and reset the CPU
- Brown-out/power-fail detection with reset generation
- Manual reset input for external control
- Embedded systems in consumer electronics, communications, and industrial automation, including battery-powered equipment requiring reliable reset with low quiescent current

The MAX691ACSE comes in an 8-pin SOIC (Small-Outline Integrated Circuit) surface-mount package.