Datasheet

DS1831/A/B
6 of 14
TIMING DIAGRAM—5V OR 3.3V PUSHBUTTON RESET Figure 5
OPERATION—PUSHBUTTON STATUS
The DS1831B provides a master pushbutton status open drain output. The PBST output indicates the
status of the most recent reset condition. If the last reset was generated by the master pushbutton input it
would maintain a low condition until cleared by another event (except the master pushbutton) generating
a reset. Once cleared it will remain high until the master pushbutton is pulled low generating a reset
condition. The
PBST output is open drain and will require a pull-up resistor on the output to maintain a
valid condition. The value of the pull up resistor is not critical in most cases but must be set low enough
to pull the output to a high state. A common value used is 10kW (see Figure 6).
DS1831B APPLICATION EXAMPLE Figure 6
V
IH
V
IL
t
PDLY
t
PB
t
RST
PBRST
5V
(or PBRST
3.3V
)
RST
5V
(or RST
3.3V
)
V
OH
V
IL
5V Supply
PBRST
5V
GND
NMI2
IN1
NMI1
V
SENSE1
IN2
MPBRST
V
SENSE2
V
CC
10kW
DS1831B
RST
5V
TD
5V
IN
5V
TOL
5V
PBST
IN
3.3V
RST
3.3V
TOL
3.3V
TD
3.3V
3.3V Supply
V
CC
10
k
W
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9