Datasheet

5
LTC1232
sn1232 1232fas
TYPICAL PERFOR A CE CHARACTERISTICS
UW
V
CC
Trip Point vs Temperature
Reset Active Time vs Temperature
Time-Out Period vs Temperature
V
CC
Trip Point vs Temperature
RST Output Voltage vs Supply Voltage
PI FU CTIO S
UU
U
TOL: Input to Select 5% or 10% Variation on V
CC
. When
TOL is connected to GND, the reset pulse generator forces
the reset outputs to active states as V
CC
falls below 4.75V
(4.62V typical). When TOL is connected to V
CC
, the reset
pulse generator forces the reset outputs to active states as
V
CC
falls below 4.5V (4.37V typical).
TD: Time-Out Delay. TD is a three-level input to select three
different time-out periods. The time-out period is set by
the TD input to be 150ms with TD connected to GND,
600ms with TD left floating, and 1.2 seconds with TD
connected to V
CC
.
V
CC
: 5V Supply Input. The V
CC
pin should be bypassed
with a 0.1µF capacitor.
GND: Ground Pin.
PB RST: Logic Input to be Directly Connected to a Push-
Button. The PB RST input requires an active low signal
which is debounced and timed for a minimum of 40ms.
When this condition is satisfied, the reset pulse generator
forces the reset outputs to active states. The reset outputs
remain in active states for a minimum of 250ms after
PB RST is released from logic low level.
LTC1232 • TPC01
TEMPERATURE (˚C)
–50
V
CC
TRIP POINT (V)
4.61
4.62
4.63
25 75
4.60
4.59
–25 0
50 100 125
4.58
4.57
TOL = GND
LTC1232 • TPC02
TEMPERATURE (˚C)
–50
V
CC
TRIP POINT (V)
4.36
4.37
4.38
25 75
4.35
4.34
–25 0
50 100 125
4.33
4.32
TOL = V
CC
LTC1232 • TPC03
TEMPERATURE (˚C)
–50
RESET ACTIVE TIME (ms)
648
672
696
25 75
624
600
–25 0
50 100 125
576
552
V
CC
= 5V
LTC1232 • TPC04
TEMPERATURE (˚C)
–50
WATCHDOG TIME-OUT PERIOD (ms)
648
672
696
25 75
624
600
–25 0
50 100 125
576
552
V
CC
= 5V
TD = NO CONNECTION
LTC1232 • TPC05
SUPPLY VOLTAGE (V)
0
RST OUTPUT VOLTAGE (V)
3
4
5
4
2
1
0
1
2
3
5
T
A
= 25°C
EXTERNAL PULL-UP = 10µA