LTC3785 LINER [Linear Technology], LTC3785 Datasheet - Page 9

• Manufacturer Part Number: LTC3785
• Description: High Efficiency, Synchronous, 4-Switch Buck-Boost Controller
• Manufacturer: LINER [Linear Technology]

pin FuncTions
V
Boost Transition Comparator. Connect this pin to the drain
of the top N-channel MOSFET on the output side.
I
Range Input. This pin tied to SGND, INTV
sets the maximum average current sense threshold.
I
Average Current Sense Amplifier.
I
Average Current Sense Amplifier.
TRIM (Pin 15/Pin 12): Tie this pin to GND for normal
operation. Do not allow this pin to float.
EXTV
Internal LDO Connected to INTV
INTV
V
Connection in the Applications Information section. Do
not exceed 14V on this pin.
INTV
Dropout Regulator. The driver and control circuits are
powered from this voltage source. Must be bypassed to
power ground with a minimum of 4.7µF tantalum, ceramic,
or other low ESR capacitor.
V
citor should be tied between this pin and the signal
ground pin.
LIM
OSENSE
OSENSE
OUTSNS
IN
IN
whenever EXTV
(Pin 22/Pin 19): Main Supply Pin. A bypass capa-
(Pin 12/Pin 9): Input/Output Average Current Sense
CC
CC
CC
+
–
(Pin 21/Pin 18): Output of the Internal Linear Low
power, bypassing the internal LDO powered from
(Pin 20/Pin 17): External Power Input to an
(Pin 13/Pin 10): The (+) Input to the Input/Output
(Pin 14/Pin 11): The (–) Input to the Input/Output
(Pin 11/Pin 8): V
CC
is higher than 4.8V. See EXTV
OUT
(SSOP/QFN)
Sense Input to the Buck-
CC
. This LDO supplies
CC
or left floating,
CC
BG1, BG2 (Pins 23, 19/Pins 20, 16): High Current Gate
Drives for Bottom (Synchronous) N-Channel MOSFETs.
Voltage swing at these pins is from ground to INTV
PGND (Pin 24/Pin 21): Driver Power Ground. Connects
to C
BOOST1, BOOST2 (Pins 25, 18/Pins 22, 15): Bootstrapped
Supplies to the Top Side Floating Drivers. Capacitors
are connected between the BOOST and SW pins and
Schottky diodes are tied between the BOOST and INTV
pins. Voltage swing at the BOOST pins is from INTV
(V
TG1, TG2 (Pins 26, 17/Pins 23, 14): High Current Gate
Drives for Top N-Channel MOSFETs. These are the outputs
of floating drivers with a voltage swing equal to INTV
– 0.5V superimposed on the switch node voltage SW.
SW1, SW2 (Pins 27, 16/Pins 24, 13): Switch Node
Connections to Inductors. Voltage swing at these pins
is from a Schottky diode (external) voltage drop below
ground to V
PGOOD (Pin 28/Pin 25): Open-Drain Logic Output. PGOOD
is pulled to ground when the voltage on the V
within ±10% of its regulation window, after the internal
20µs power-bad mask timer expires.
IN
OUT
+ INTV
and R
CC
IN
).
.
SENSE
(–) terminal(s) of C
LTC3789
IN
.
FB
pin is not
CC
CC
9
3789f
.
CC
CC
to