DS1705

The DS1705/DS1706 3.3- or 5.0-Volt MicroMonitor monitors three vital conditions for a microprocessor: power supply, software execution, and external override. A precision temperature compensated reference and comparator circuit monitor the status of V_CC at the device and at an upstream point for maximum protection. When the sense input detects an out-of-tolerance condition a non-maskable interrupt is generated. As the voltage at the device degrades, an internal power fail signal is generated which forces the reset to an active state. When V_CC returns to an in-tolerance condition, the reset signal is kept in the active state for a minimum of 130ms to allow the power supply and processor to stabilize.

The second function the DS1705/DS1706 performs is pushbutton reset control. The DS1705/DS1706 debounces the pushbutton input and guarantees an active reset pulse width of 130ms minimum.

The third function is a watchdog timer. The DS1705/DS1706 has an internal timer that forces the WDO signal to the active state if the strobe input is not driven low prior to time-out.