DESCRIPTION The ADM706P/ADM706R/ADM706S/ADM706T and the ADM708R/ADM708S/ADM708T microprocessor supervisory circuits are suitable for monitoring either 3 V or 3.3 V power supplies. The ADM706P/ADM706R/ADM706S/ADM706T provide power-supply monitoring circuitry that generate a reset output during power-up, power-down, and brownout conditions. The CC as low as 1 V. Independent watchdog monitoring circuitry is also provided. This is activated if the watchdog input has not been toggled within 1.6 seconds. In addition, there is a 1.25 V threshold detector for power-fail warning, low battery detection, or to monitor an additional power supply. An active low debounced MR input is also included. The ADM706R, ADM706S, and ADM706T are identical except for the reset threshold monitor levels, which are 2.63 V, 2.93 V, and 3.08 V, respectively. The ADM706P is identical to the ADM706R in that the reset threshold is 2.63 V. It differs only in that it has an active high reset output. The ADM708R/ADM708S/ FEATURES Precision supply voltage monitor 2.63 V (ADM706P, ADM706R, ADM708R) 2.93 V (ADM706S, ADM708S) 3.08 V (ADM706T, ADM708T) 100 A quiescent current 200 ms reset pulse width Debounced manual reset input (MR) Independent watchdog timer Reset output Active high (ADM706P) Active low (ADM706R, ADM706S, ADM706T) Both active high and active low (ADM708R, ADM708S, ADM708T) Voltage monitor for power-fail or low battery warning Guaranteed RESET valid with VCC = 1 V Superior upgrade for MAX706P/R/S/T, MAX708R/S/T APPLICATIONS Microprocessor systems Computers Controllers Intelligent instruments Critical microprocessor monitoring Battery-operated systems Portable instruments FUNCTIONAL BLOCK DIAGRAMS WATCHDOGTRANSITIONDETECTORWATCHDOGINPUT (WDI)POWER-FAILINPUT (PFI)POWER-FAILOUTPUT (PFO)WATCHDOGOUTPUT (WDO)RESET,(P = RESET)*ADM706P/ADM706R/ADM706S/ADM706TWATCHDOGTIMERRESETANDWATCHDOGTIMEBASERESETGENERATORMRVCC70AVCCVREF*1.25V06435-001 Figure 1. ADM706P/ADM706R/ADM706S/ADM706T 1.25VINPUT (PFI)* Specifications subject to change without notic