µP Supervisory Circuits Feature Manual Reset And Watchdog Timer

The MAX6821 through MAX6825 microprocessor supervisory circuits offer reset thresholds capable of monitoring system voltages from 1.8V to 5V. Whenever a supply voltage falls below the reset threshold, the reset output asserts and remains asserted for at least 140 ms after the voltage exceeds the reset threshold. Nine factory preset thresholds of 4.63V, 4.38V, 3.08V, 2.93V, 2.63V, 2.32V, 2.19V, 1.67V, and 1.58V are available. Other features include a watchdog timer (MAX6821/MAX6824) that detects code execution error and a manual reset input (MAX6821/MAX6823/MAX6825) that allows for a reset without the power supply falling below the reset threshold. The devices are available with three reset output options, which include an active-low, push-pull output (MAX6823/MAX6825), an active-high, push-pull output (MAX6821/MAX6824/MAX6825), and an active-low, open-drain output (MAX6822). All devices are available in five-pin, SOT23 packages. Prices start at $1.15 each/2,500.