AAT3532 Datasheet, PDF (2/8 Pages) Advanced Analogic Technologies – MicroPower™ Microprocessor Reset Circuit

AAT3532
MicroPower™ Microprocessor Reset Circuit
Pin Descriptions
Pin #
1
Symbol
PBRST
2
TD
3
TOL
4
GND
5
RST
6
RST
7
ST
8
VCC
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.
Pin Programming Selections
TD Pin
GND
Float
V_CC
Min
62.5ms
250ms
500ms
Timeout
Typ
150ms
600ms
1200ms
Max
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
2
PBRST ¹
TD ²
TOL ³
GND ⁴
SOP-8
(Top View)
8 _VCC
7 _ST
6 _RST
5 _RST
3532.2005.12.1.2