AAT3532
MicroPower™ Microprocessor Reset Circuit
Pin Descriptions
Pin #
1
2
3
4
5
Symbol
PBRST
TD
TOL
GND
RST
Function
Push-button reset input. A de-bounced active low input for manual reset. Guaranteed
to recognize inputs 20ms or greater.
Watchdog time delay set input. See Table 1 for watchdog timeout selections.
Tolerance set. Input selects 5% or 10% threshold detection.
IC ground connection.
Reset output (active high). Activated when either: V
CC
falls below the reset voltage
threshold; PBRST is forced low; ST is not strobed within the minimum timeout period;
or during power-up.
Reset output (active low, open drain). Inverse of RST.
Strobe input to watchdog timer. A pulse is required within the watchdog timeout period
to prevent RST and RST entering active state.
5V supply.
6
7
8
RST
ST
VCC
Pin Programming Selections
Timeout
TD Pin
GND
Float
V
CC
Min
Typ
Max
62.5ms
250ms
500ms
150ms
600ms
1200ms
250ms
1000ms
2000ms
Table 1: TD Pin Programming for Watchdog Timeout Selections.
TOL Pin
V
CC
GND
Tolerance
10%
5%
Table 2: Reset Voltage Threshold Programming Selections.
Pin Configuration
SOP-8
(Top View)
PBRST
TD
TOL
GND
1
8
V
CC
ST
RST
RST
1
2
2
7
3
6
4
5
2
3532.2005.12.1.2
AAT [ ADVANCED ANALOG TECHNOLOGY, INC. ]
