Datasheet

LTC3618
9
3618fc
For more information www.linear.com/LTC3618
MODE/SYNC (Pin 24/Pin 3): Mode Selection.
1. Tying the MODE pin to SV
IN
or SGND enables pulse-
skipping mode or forced continuous mode respectively
for V
DDQ
only. The default operation mode for V
TT
is
forced continuous mode. The input to the MODE/SYNC
pin should be a digital signal.
2. When a clock signal is applied to this pin, the switching
frequency synchronizes to this clock signal and forced
continuous mode is selected for V
DDQ
.
pin FuncTions
(FE/UF)
PGND (Exposed Pad Pin 25/ Exposed Pad Pin 25): Power
Ground. The exposed pad connects to the sources of the
power N-channel MOSFETs. The PGND pin is common
for both channels. The exposed pad must be soldered
to the PCB for electrical connection and rated thermal
performance. Refer to the Operation and Applications
Information sections for more information.
FuncTional block DiagraM
IDEAL
DIODE
TRACK/SS1
SOFT-START
OR
V
REF
INTERNAL/
EXTERNAL
COMPENSATION
ITH-VOLTAGE
LIMIT
MODE/SYNC
FB1
PGOOD1
RT
RUN2
RUN1
PHASE
FB2
R
R
PGOOD2
ERROR
AMPLIFIER
SW2
PV
IN2
PV
IN1
SW1
PGND
SV
IN
VTTR
SGND
UNDERVOLTAGE
LOCKOUT
OVERVOLTAGE
LOCKOUT
SLOPE
COMPENSATION
NMOS
CURRENT SENSE
PMOS
CURRENT SENSE
CONTROLLER LOGIC
GATE DRIVER
–
+
–
+
–
+
–
+
SHUTDOWN
CLK2
CLK1
ITH1
0A
VDDQIN
PGOOD
WINDOW-
COMPARATOR
V
DDQ
ERROR
AMPLIFIER
DUPLICATE FOR V
TT
REVERSE
CURRENT
COMPARATOR
PMOS
CURRENT
COMPARATOR
DELAY
PLL
OSCILLATOR
AND PHASE
SELECTOR
ITH2
3618 FD
+–
+
–