Datasheet

4
LT1640L/LT1640H
1640lhfb
TYPICAL PERFOR A CE CHARACTERISTICS
UW
Gate Voltage vs Temperature
TEMPERATURE (°C)
12.0
GATE VOLTAGE (V)
13.0
14.0
15.0
12.5
13.5
14.5
–25 0 75
1640 G04
100–50 25 50
TEMPERATURE (°C)
–50
48
TRIP VOLTAGE (mV)
49
51
52
53
55
250
50
1640 G05
50
54
100
–25
75
TEMPERATURE (°C)
–50
GATE PULL-UP CURRENT (µA)
48
47
46
45
44
43
42
41
40
75
1640 G06
–25 10050250
V
GATE
= 0V
Gate Pull-Up Current
vs Temperature
Gate Pull-Down Current
vs Temperature
TEMPERATURE (°C)
–50
GATE PULL-DOWN CURRENT (mA)
49
52
55
75
1640 G07
46
43
40
–25 0
25
50
100
V
GATE
= 2V
PWRGD Output Low Voltage
vs Temperature (LT1640L)
TEMPERATURE (°C)
–50
PWRGD OUTPUT LOW VOLTAGE (V)
0.3
0.4
0.5
75
1640 G08
0.2
0.1
0
–25 25
0
50
100
I
OUT
= 1mA
TEMPERATURE (°C)
–50
2
OUTPUT IMPEDANCE (kΩ)
3
4
5
6
7
8
–25 2505075
1640 G09
100
V
DRAIN
– V
EE
> 2.4V
PWRGD Output Impedance
vs Temperature (LT1640H)
Circuit Breaker Trip Voltage
vs Temperature
pin which pulls the module’s enable pin low, forcing it off.
When V
DRAIN
drops below V
PG
, the PWRGD sink current
is turned off and a 6.5k resistor is connected between
PWRGD and DRAIN, allowing the module’s pull-up cur-
rent to pull the enable pin high and turn on the module.
OV (Pin 2): Analog Overvoltage Input. When OV is pulled
above the 1.223V low to high threshold, an overvoltage
condition is detected and the GATE pin will be immediately
pulled low. The GATE pin will remain low until OV drops
below the 1.203V high to low threshold.
PIN FUNCTIONS
UUU
PWRGD/PWRGD (Pin 1): Power Good Output Pin. This pin
will toggle when V
DRAIN
is within V
PG
of V
EE
. This pin can
be connected directly to the enable pin of a power module.
When the DRAIN pin of the LT1640L is above V
EE
by more
than V
PG
, the PWRGD pin will be high impedance, allowing
the pull-up current of the module’s enable pin to pull the
pin high and turn the module off. When V
DRAIN
drops
below V
PG
, the PWRGD pin sinks current to V
EE
, pulling
the enable pin low and turning on the module.
When the DRAIN pin of the LT1640H is above V
EE
by more
than V
PG
, the PWRGD pin will sink current to the DRAIN