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LTC3407A Datasheet, PDF (6/16 Pages) Linear Technology – Dual Synchronous 600mA, 1.5MHz Step-Down DC/DC Regulator
LTC3407A
PIN FUNCTIONS
SW2 (Pin 7): Regulator 2 Switch Node Connection to the
Inductor. This pin swings from VIN to GND.
POR (Pin 8): Power-On Reset. This common-drain logic
output is pulled to GND when the output voltage is not
within ±8.5% of regulation and goes high after 216 clock
cycles when both channels are within regulation.
RUN/SS2 (Pin 9): Regulator 2 Enable and Soft-Start Input.
Forcing this pin to VIN enables regulator 2, while forcing it
to GND causes regulator 2 to shut down. Connect external
RC-Network with desired time-constant to enable soft-start
feature. This pin must be driven; do not float.
VFB2 (Pin 10): Output Feedback. Receives the feedback
voltage from the external resistive divider across the output.
Nominal voltage for this pin is 0.6V.
Exposed Pad (GND) (Pin 11): Power Ground. Connect to
the (–) terminal of COUT, and (–) terminal of CIN. Must be
soldered to electrical ground on PCB.
BLOCK DIAGRAM
MODE/SYNC 6
REGULATOR 1
VFB1 1
0.6V
+
ITH
EA
–
0.55V
–
UV
UVDET
+
+
OV
OVDET
0.65V
–
SHUTDOWN
SLOPE
COMP
–
EN
SLEEP
0.65V
+
BURST
S
Q
RS
LATCH
R
Q
SWITCHING
LOGIC
AND
BLANKING
CIRCUIT
BURST
CLAMP
–+
ICOMP
ANTI
SHOOT-
THRU
IRCMP
RUN/SS1 2
0.6V REF
OSC
RUN/SS2 9
OSC
VFB2 10
REGULATOR 2 (IDENTICAL TO REGULATOR 1)
6
PGOOD1
POR
COUNTER
PGOOD2
VIN
5Ω
4 SW1
11 GND
VIN
3 VIN
8 POR
5 GND
7 SW2
3407afa