Datasheet

LT3763
10
3763fa
For more information www.linear.com/LT3763
BG (Pin 1): BG is the bottom FET gate drive signal that
controls the state of the external low side power FET. The
driver pull-up impedance is 2.2Ω, and pull-down imped
-
ance is 1Ω. Do not force any voltage on this pin.
INTV
CC
(Pin 2): The INTV
CC
pin provides a regulated 5V
output for charging the BOOST capacitor. INTV
CC
also pro-
vides the power for the digital and switching subcircuits.
Do not force any voltage on this pin. Bypass with at least
a 22µF capacitor to ground. INT
V
CC
is current-limited to
50mA. Shutdown operation disables the output voltage
drive.
V
IN
(Pin 3): Input Supply Pin. Must be locally bypassed
with at least a 4.7µF low ESR capacitor to ground as close
as possible to the exposed pad of the package.
EN/UVLO (Pin 4): Enable Pin. The EN/UVLO pin acts as
an enable pin and turns on the internal current bias core
and sub-regulators at 1.705V and turns off at 1.52V. The
pin does not have any pull-up or pull-down, requiring a
voltage bias for normal operation. Full shutdown occurs
at approximately 0.5V. If unused, the Enable pin may be
tied to V
IN
.
V
REF
(Pin 5): Buffered 2V Reference Capable of 0.5mA
Drive. Bypass with at least 1µF capacitor to ground.
IVINN (Pin 6): IVINN is the inverting input of the input
current sense amplifier. This pin connects to the drain of
the high side N-channel power FET and the input current
sense resistor.
IVINP (Pin 7): IVINP is the noninverting input of the input
current sense amplifier. This pin connects to the input
supply V
IN
and the input current sense resistor.
IVINMON (Pin 8): IVINMON is the buffered output of the
input current sense amplifier. This pin enables monitoring
of the averaged supply current with an output voltage of
20 • (V
IVINP
– V
IVINN
). The capacitive loading to this pin
should be less than 1nF.
FAULT (Pin 9): Output Voltage Fault Detection Pin for
Shorted or Open LEDs. Internal comparators pull down
this pin when the FB pin voltage is lower than 0.25V or
higher than 1.16V and when the inductor current is less
than ten percent of the maximum value. This pin should
be pulled up to INTV
CC
with a resistance higher than 10k.
FBIN (Pin 10): The FBIN pin enables peak power tracking
for solar powered chargers and other similar applications
by controlling the output current of the system based on
the input voltage. This pin should be tied to V
REF
if this
feature is not used.
FB (Pin 11): The feedback pin is used for voltage regula
-
tion and overvoltage protection. The feedback voltage is
regulated to 1.206V. When the feedback voltage exceeds
1.515V, the overvoltage lockout prevents switching.
pin FuncTions