The CD706P/ CD706R/ CD706S/ CD706T and the CD708R/ CD708S/ CD708T microprocessor supervisory circuits are suitable for monitoring either 3 V or 3.3 V power supplies. The CD706P/ CD706R/ CD706S/CD706T provide power supply monitoring circuitry that generate a reset output during power-up, power-down, and brownout conditions. The reset output remains operational with VCC as low as 1 V. Independent watchdog monitoring circuitry is also provided. This activates if the watchdog input does not toggle within 1.6 sec. In addition, there is a 1.25 V threshold detector for a power fail warning, low battery detection, or to monitor an additional power supply. An active low debounced MR input is also included.
The CD706R, CD706S, and CD706T are identical except for the reset threshold monitor levels, which are 2.63V, 2.93V,and 3.08 V, respectively. The CD706P is identical to the CD706R in that the reset threshold is 2.63 V. It differs only in that it has an active high reset output. The CD708R/CD708S/CD708T provide similar functio-nality as the CD706R/ CD706S/CD706T and only differ in that a watchdog timer function is not available. Instead, an active high reset output (RESET) is provided in addition to the active low (RESET ) output. All devices are available in narrow 8-lead MSOP and 8-lead SOP packages.