DS1831/A/B

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3.3V reset or for all reset outputs by the master pushbutton. The DS1831A replaces one reference

last reset status output.

TOL and TD inputs allow user configuration of the DS1831 for multiple applications. The TOL inputs

configure the tolerance for the specified output and the TD inputs configure the reset time delays.

PIN DESCRIPTION

5V Power Supply Input

MPBRST

Master Pushbutton (DS1831)

Watchdog Time Delay Select (DS1831A)

5V Reset Open Drain Output

NMI2

Non-maskable Interrupt 2 (DS1831)

WDS

Watchdog Status Output (DS1831A)

Selects 5V Input Tolerance

NMI1

Non-maskable Interrupt 1

Selects 5V Reset Time Delay

3.3V Reset Pushbutton

PBST

Pushbutton Status Output (DS1831B)

5V Reset Pushbutton

Select 3.3V Reset Time Delay

IN1

Sense Input 1

Selects 3.3V Input Tolerance

IN2

ST

Sense Input 2 (DS1831)

Watchdog Strobe Inputs

(DS1831A)

3.3V Reset Open Drain Output

GND

Ground

3.3V Power Supply Input

DS1831 BLOCK DIAGRAM Figure 1

TOLERANCE

BIAS

+

-

TIME

DELAY

1.25V T.C.

REFERENCE

GROUND

TOLERANCE

BIAS

TIME

DELAY

Level

Sense

&

MPBRST

+

-

100k

100k

100k

+

-

+

-

IN1

IN2

NMI1

NMI2