LT1640AH LINER [Linear Technology], LT1640AH Datasheet - Page 5

• Manufacturer Part Number: LT1640AH
• Description: Negative Voltage Hot Swap Controller
• Manufacturer: LINER [Linear Technology]

BLOCK DIAGRA
PIN
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.
UV (Pin 3): Analog Undervoltage Input. When UV is
pulled below the 1.223V high to low threshold, an under-
voltage condition is detected and the GATE pin will be
immediately pulled low. The GATE pin will remain low
until UV rises above the 1.243 low-to-high threshold.
The UV pin is also used to reset the electronic circuit
breaker. If the UV pin is cycled low and high following the
trip of the circuit breaker, the circuit breaker is reset and
a normal power-up sequence will occur.
V
the lower potential of the power supply.
SENSE (Pin 5): Circuit Breaker Sense Pin. With a sense
resistor placed in the supply path between V
SENSE, the circuit breaker will trip when the voltage
across the resistor exceeds 50mV. Noise spikes of less
than 2 s are filtered out and will not trip the circuit
breaker.
EE
U
(Pin 4): Negative Supply Voltage Input. Connect to
FUNCTIONS
UV
OV
U
REF
U
–
+
–
+
W
V
EE
50mV
SENSE
–
+
–
+
EE
and
GENERATOR
REFERENCE
GATE DRIVE
V
If the circuit breaker trip current is set to twice the normal
operating current, only 25mV is dropped across the
sense resistor during normal operation. To disable the
circuit breaker, V
GATE (Pin 6): Gate Drive Output for the External
N-Channel. The GATE pin will go high when the following
start-up conditions are met: the UV pin is high, the OV pin
is low and (V
high by a 45 A current source and pulled low with a
50mA current source.
DRAIN (Pin 7): Analog Drain Sense Input. Connect this
pin to the drain of the external N-channel and the V
of the power module. When the DRAIN pin is below V
the PWRGD or PWRGD pin will toggle. In some condi-
tions, the DRAIN pin is pulled below V
damaged if the reverse DRAIN pin current is limited to
50mA.
V
pin to the higher potential of the power supply inputs and
the V
ranges from 10V to 80V.
CC
LOGIC
GATE
AND
DD
V
DD
AND
(Pin 8): Positive Supply Voltage Input. Connect this
+
pin of the power module. The input supply voltage
V
REF
SENSE
CC
V
+
+
–
EE
V
EE
PG
– V
DRAIN
LT1640AL/LT1640AH
and SENSE can be shorted together.
–
EE
OUTPUT
DRIVE
) < 50mV. The GATE pin is pulled
1640A BD
PWRGD/PWRGD
EE
. The part is not
–
5
pin
PG
,