MAXIM MAX708EPA+

MAX705–MAX708/MAX813L microprocessor (µP) supervisory circuits reduce the complexity and component count required to monitor power-supply and battery functions in microprocessor systems. These devices significantly improve system reliability and accuracy compared to separate ICs or discrete components.

The MAX705/MAX706/MAX813L provide four functions:

1. Reset output during power-up, power-down, and brownout conditions.
2. An independent watchdog output that goes low if the watchdog input is not toggled within 1.6 seconds.
3. A 1.25V threshold detector for power-fail warning, low-battery detection, or monitoring power supplies other than +5V.
4. An active-low manual reset input.

The MAX707/MAX708 are identical to the MAX705/MAX706, except the watchdog timer is replaced with an active-high reset output. The MAX813L is identical to the MAX705, except it provides RESET instead of RESET.

Two power-supply voltage monitoring levels are available: the MAX705/MAX707/MAX813L assert a reset pulse when the supply voltage falls below 4.65V, while the MAX706/MAX708 assert a reset pulse when the supply voltage falls below 4.40V. All four devices are available in 8-pin DIP, SO, and µMAX packages.

Integrated supervisory functions significantly improve system reliability while reducing board space

µMAX Package RESET guaranteed valid at VCC = 1V — 200ms reset pulse width — Debounced TTL/CMOS-compatible manual reset input — Active-high reset output (MAX707/MAX708/MAX813L) Precision power-supply voltage monitoring — 4.65V (MAX705/MAX707/MAX813L) — 4.40V (MAX706/MAX708) Voltage monitoring for power-fail or low-battery warning

• Computers
• Controllers
• Intelligent instruments
• Critical µP power supply monitoring