Low-Voltage, SOT23 µP Supervisors with Power-

Fail In/Out, Manual Reset, and Watchdog Timer

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5

Pin Description

PIN

MAX6701(A)

MAX6702(A)

MAX6703(A)

MAX6704

MAX6705(A)

MAX6706(A)

MAX6707(A)

MAX6708

NAME

FUNCTION

11

1

1

MR

Active-Low, Manual Reset Input, Internal 50k

Pull low to force a reset. Reset remains active as long as MR is

low and the reset timeout period after MR goes high. Leave

when MR is low (MAX6701(A)/MAX6702(A)/MAX6703(A)/

MAX6705(A)/ MAX6706(A)/MAX6707(A) only).

22

2

2

Supply Voltage for MAX6701–MAX6708 and Input for Primary

.

3

3

3

3

GND

Ground

—

4

4

4

PFI

Power-Fail Voltage Monitor Input. High-impedance input for

internal power-fail comparator. Connect this pin to an external

resistive-divider network to set the reset threshold voltage;

—

55

5

PFO

Power-Fail Monitor Output. Open drain or push-pull active low.

PFO goes low when PFI is less than 0.62V.

66

6

—

WDI

Watchdog Input. If WDI remains high or low for longer than the

watchdog timeout period, the internal watchdog timer runs out and

WDO is asserted. WDO is asserted low after each watchdog

overflow and remains low until the watchdog timer is cleared (the

reset output is not affected). The internal watchdog timer clears

reset is asserted, or WDI sees a rising or falling edge. The

watchdog timer remains cleared until the reset output is

deasserted. On the MAX6704, RESET pulse asserts for the reset

timeout period after each watchdog timeout overflow. The

watchdog timer cannot be disabled.

——

—

6

N.C.

No Connection. Not internally connected.

77

7

7

RESET

Active-Low Reset Output (Open Drain or Push-Pull). RESET

selected reset threshold (or RST_IN1/ RST_IN2 for the

MAX6701(A)/MAX6702(A)/MAX6703(A), MR is pulled low, or the

watchdog triggers a reset (MAX6704 only). RESET remains low for

the reset timeout period after the reset conditions are terminated.