LTC2902
TYPICAL PERFOR A CE CHARACTERISTICS
COMPX Pull-Up Current
vs V2 (COMPX Held at 0V)
20
18
16
PULL-UP CURRENT (µA)
T
A
= 25°C
COMPX PROPAGATION DELAY (µs)
14
12
10
8
6
4
2
0
1
1.5
2
2.5
3
3.5
V2 (V)
4
4.5
5
RST Pull-Up Current vs V2
(LTC2902-1)
20
18
PULL-UP CURRENT (mA)
T
A
= 25°C
16
PULL-UP CURRENT (µA)
14
12
10
8
6
4
2
0
2
2.5
3
3.5
V2 (V)
4
4.5
5
2902 G23
V
RT33
V
RT30
V
RT25
PI FU CTIO S
COMP3 (Pin 1):
Comparator Output 3. Nondelayed, active
high logic output with weak pull-up to V2. Pulls high when
V3 is above reset threshold. May be pulled greater than V2
using external pull-up.
COMP1 (Pin 2):
Comparator Output 1. Nondelayed, active
high logic output with weak pull-up to V2. Pulls high when
V1 is above reset threshold. May be pulled greater than V2
using external pull-up.
V3 (Pin 3):
Voltage Input 3. Select from 2.5V, 1.8V, 1.5V
or ADJ. See Table 1 for details.
V1 (Pin 4):
Voltage Input 1. Select from 5V or 3.3V. See
Table 1 for details. The greater of (V1, V2) is also V
CC
for
the chip. Bypass this pin to ground with a 0.1µF (or
greater) capacitor.
CRT (Pin 5):
Reset Delay Time Programming Pin. Attach
an external capacitor (C
RT
) to GND to set a reset delay time
of 4.6ms/nF. Leaving the pin open generates a minimum
delay of approximately 50µs. A 47nF capacitor will gener-
ate a 216ms reset delay time.
U W
COMPX Propagation Delay vs
Input Overdrive Above Threshold
250
T
A
= 25°C
200
150
100
V1, V2
50
V3, V4
0
1000
10
100
INPUT OVERDRIVE ABOVE THRESHOLD (mV)
2902 G22
2902 G21
RST Pull-Up Current vs V2
(LTC2902-2)
6
5
4
3
2
1
0
2
2.5
3
3.5
V2 (V)
4
4.5
5
2902 G24
T
A
= 25°C
V
RT33
V
RT30
V
RT25
U
U
U
2902f
7
LINEAR [ LINEAR INTEGRATED SYSTEMS ]
