MAX6391

The MAX6391/MAX6392 microprocessor (P) supervisory ircuits provide sequenced logic reset outputs for multicomponent r dual-voltage systems. Each device can onitor two supply voltages and time-sequence two reset utputs to control the order in which system components re turned on and off. The MAX6391/MAX6392 increase ystem reliability and reduce circuit complexity and cost ompared to separate ICs or discrete components.

The MAX6391/MAX6392 monitor V_CC as the master eset supply. Both RESET1 and RESET2 are asserted henever V_CC drops below the selected factory-fixed eset threshold voltage. RESET1 remains asserted as ong as V_CC is below the threshold and deasserts 40ms (min) after V_CC exceeds the thresholds.

RESET IN2 is monitored as the secondary reset supply nd is adjustable with an external resistive-divider network. ESET2 is asserted whenever either V_CC or ESET IN2 is below the selected thresholds. RESET2 emains asserted 140ms (min) or a capacitoradjustable ime period after V_CC and RESET IN2 xceed their thresholds. RESET2 is always deasserted fter RESET1 during system power-up and is always sserted before RESET1 during power-down.

The MAX6391 includes two internal pullup resistors for ESET1 and RESET2 (the open-drain outputs can be xternally connected to the desired pullup voltages).

The MAX6392 includes an active-low manual reset nput (MR) that asserts bothRESET1 (push-pull) and ESET2 (open drain).

The MAX6391/MAX6392 are available in small 8-pin OT23 packages and are specified over the -40 to 85 extended temperature range.