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 VCC 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 VCC returns to an in-tolerance condition, the reset signal is kept in theactive state for a minimum of 130 ms 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 130 ms minimum.

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