LTC3856 LINER [Linear Technology], LTC3856 Datasheet - Page 10

• Manufacturer Part Number: LTC3856
• Description: 2-Phase Synchronous Step-Down DC/DC Controller with Diffamp
• Manufacturer: LINER [Linear Technology]

LTC3856
pin FuncTions
INTV
control circuits are powered from this voltage. Decouple
this pin to PGND with a minimum of 4.7µF low ESR tan-
talum or ceramic capacitor.
V
to PGND with a capacitor (0.1µF to 1µF).
BG1, BG2 (Pins 31, 27/Pins 23, 19): Bottom Gate Driver
Outputs. These pins drive the gates of the bottom N-chan-
nel MOSFETs between INTV
PGND1, PGND2 (Pins 32, 26) TSSOP Package: Power
Ground Pin. Connect this pin closely to the sources of the
bottom N-channel MOSFETs, the (–) terminal of CV
the (–) terminal of C
BOOST1, BOOST2 (Pins 33, 24/Pins 24, 18): Boosted
Floating Driver Supplies. The (+) terminal of the boot-
strap capacitors connect to these pins. These pins swing
from a diode voltage drop below INTV
INTV
SGND/PGND (Exposed Pad Pin 33) QFN Package: Signal
Ground and Power Ground. Connect this pin closely to
0
IN
(Pin 30/Pin 22): Main Input Supply. Decouple this pin
CC
CC
.
(Pin 29/Pin 21): Internal 5V Regulator Output. The
IN
.
CC
(TSSOP/QFN)
and PGND.
CC
up to V
CC
IN
and
+
the sources of the bottom N-channel MOSFETs, the (–)
terminal of CV
components and compensation components should also
connect to this ground.
TG1, TG2 (Pins 35, 23/Pins 25, 17): Top Gate Driver
Outputs. These are the outputs of floating drivers with
a voltage swing equal to INTV
switch nodes voltages.
SW1, SW2 (Pins 36, 22/Pins 26, 16): Switch Node
Connections to Inductors. Voltage swing at these pins
is from a Schottky diode (external) voltage drop below
ground to V
CLKOUT (Pin 37/Pin 27): Clock output with phase change-
able by PHASMD to enable usage of multiple LTC3856 ICs
in multiphase systems.
PLLIN (Pin 38/Pin 28): External Synchronization Pin. A
clock on the pin synchronizes the internal oscillator with
the clock on this pin.
SGND (Exposed Pad Pin 39) TSSOP Package: The exposed
pad must be soldered to the PCB.
IN
CC
.
and the (–) terminal of C
CC
superimposed on the
IN
. All small-signal
3856f