LT4356CDE-1-PBF LINER [Linear Technology], LT4356CDE-1-PBF Datasheet - Page 6

• Manufacturer Part Number: LT4356CDE-1-PBF
• Description: Overvoltage Protection Regulator and Inrush Limiter
• Manufacturer: LINER [Linear Technology]

LT4356-1
TYPICAL PERFORMANCE CHARACTERISTICS
unless otherwise noted.
PIN FUNCTIONS
A
output of the auxiliary amplifi er. It is capable of sinking
up to 2mA from 80V. The negative input of the amplifi er
is internally connected to a 1.25V reference.
EN (Pin 9/Pin 8): Open-Collector Enable Output. The EN
pin goes high impedance when the voltage at the OUT pin
is above (V
fully on. The state of the pin is latched until the OUT pin
voltage resets at below 0.5V and goes back up above 2V.
The internal NPN is capable of sinking up to 3mA of cur-
rent from 80V to drive an LED or opto-coupler.
Exposed Pad (Pin 13 DE Only): Exposed pad may be left
open or connected to device ground (GND).
FB (Pin 2/Pin 1): Voltage Regulator Feedback Input. Con-
nect this pin to the center tap of the output resistive divider
connected between the OUT pin and ground. During an
overvoltage condition, the GATE pin is servoed to main-
tain a 1.25V threshold at the FB pin. This pin is clamped
internally to 7V. Tie to GND to disable the OV clamp.
FLT (Pin 8/Pin 7): Open-Collector Fault Output. This pin
pulls low after the voltage at the TMR pin has reached
the fault threshold of 1.25V. It indicates the pass transis-
tor is about to turn off because either the supply voltage
has stayed at an elevated level for an extended period
of time (voltage fault) or the device is in an overcurrent
6
OUT
(Pin 11 DE Only): Amplifi er Output. Open collector
CC
– 0.7V), indicating the external MOSFET is
500
400
300
200
100
0
–50
Overvoltage Turn-Off Time
vs Temperature
–25
(DE/MS)
0
TEMPERATURE (°C)
OVERVOLTAGE CONDITION
V
25
FB
= 1.5V
50
75
100
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125
condition (current fault). The internal NPN is capable of
sinking up to 3mA of current from 80V to drive an LED or
opto-coupler.
GATE (Pin 4/Pin 3): N-Channel MOSFET Gate Drive Output.
The GATE pin is pulled up by an internal charge pump
current source and clamped to 14V above the OUT pin.
Both voltage and current amplifi ers control the GATE pin
to regulate the output voltage and limit the current through
the MOSFET.
GND (Pin 10/Pin 9): Device Ground.
IN
Amplifi er. This amplifi er can be used as a level detection
comparator with external hysteresis or linear regulator
controlling an external PNP transistor. This pin is clamped
internally to 7V. Connect to ground if unused.
OUT (Pin 3/Pin 2): Output Voltage Sense Input. This pin
senses the voltage at the source of the N-channel MOSFET
and sets the fault timer current. When the OUT pin volt-
age reaches 0.7V away from V
impedance.
SHDN (Pin 7/Pin 6): Shutdown Control Input. The LT4356-1
can be shutdown to a low current mode by pulling the
SHDN pin below the shutdown threshold of 0.6V. Pull
this pin above 1.7V or disconnect it and allow the inter-
+
(Pin 12 DE Only): Positive Input of the Auxiliary
4.0
3.5
3.0
2.5
2.0
1.5
1.0
–50
Overcurrent Turn-Off Time
vs Temperature
Specifi cations are at V
–25
0
TEMPERATURE (°C)
OVERCURRENT CONDITION
ΔV
25
SNS
= 120mV
50
75
CC
CC
100
, the EN pin goes high
= 12V, T
43561 G18
125
A
= 25°C
43561fd