Datasheet

DS1831/A/B
2 of 14
3.3V reset or for all reset outputs by the master pushbutton. The DS1831A replaces one reference
comparator and the master pushbutton with watchdog and the DS1831B replaces the 3.3V PBRST with a
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
IN
5V
5V Power Supply Input MPBRST Master Pushbutton (DS1831)
TD
WD
Watchdog Time Delay Select (DS1831A)
RST
5V
5V Reset Open Drain Output
NMI2
Non-maskable Interrupt 2 (DS1831)
WDS
Watchdog Status Output (DS1831A)
TOL
5V
Selects 5V Input Tolerance
NMI1
Non-maskable Interrupt 1
TD
5V
Selects 5V Reset Time Delay
PBRST
3.3V
3.3V Reset Pushbutton
PBST
Pushbutton Status Output (DS1831B)
PBRST
5V
5V Reset Pushbutton TD
3.3V
Select 3.3V Reset Time Delay
IN1 Sense Input 1 TOL
3.3V
Selects 3.3V Input Tolerance
IN2
ST
Sense Input 2 (DS1831)
Watchdog Strobe Inputs
(DS1831A)
RST
3.3V
3.3V Reset Open Drain Output
GND Ground IN
3.3V
3.3V Power Supply Input
DS1831 BLOCK DIAGRAM Figure 1
RST
3.3V
V
CC
TOLERANCE
BIAS
IN
5
V
+
-
TIME
DELAY
1.25V T.C.
REFERENCE
TOL
5V
GROUND
V
CC
TOLERANCE
BIAS
IN
3.3V
TOL
3.3V
TIME
DELAY
Level
Sense
&
MPBRST
+
-
100k
TD
5V
TD
3.3V
100k
PBRST
3.3V
PBRST
5V
100k
+
-
+
-
IN1
IN2
NMI1
NMI2
RST
5V