LTC3443 Linear Technology, LTC3443 Datasheet - Page 6

• Manufacturer Part Number: LTC3443
• Description: High Current Micropower 600kHz Synchronous Buck-Boost DC/DC Converter
• Manufacturer: Linear Technology

PI FU CTIO S
BLOCK DIAGRA
LTC3443
V
capacitor is placed from V
capacitor is recommended as close to the V
pins as possible.
6
OUT
U
MODE/SYNC = Low: Disable Burst Mode operation and
maintain low noise, constant frequency operation .
MODE/SYNC = External CLK : Synchronization of the
internal oscillator and Burst Mode operation disable. A
clock pulse width between 100ns and 2µs and a clock
frequency between 1.38MHz and 2.4MHz (twice the
desired frequency) is required to synchronize the IC.
(Pin 8): Output of the Synchronous Rectifier. A filter
f
OSC
U
+
= f
2.4V TO 5.5V
1 = Burst Mode
0 = FIXED FREQUENCY
SYNC
OPERATION
V
IN
U
/2
10
9
7
PV
V
MODE/SYNC
IN
IN
W
OUT
V
INTERNAL
2.4V
CC
4A
600kHz
SYNC
OSC
to GND. A ceramic bypass
3.2A
÷2
+
–
+
–
SW A
+
–
CURRENT
g
SUPPLY
m
LIMIT
UVLO
SW1
=
SW B
CURRENT LIMIT
SLEEP
100
1
AVERAGE
k
4
OUT
CONDUCTION
ANTICROSS
OPERATION
Burst Mode
5µs DELAY
CONTROL
DRIVERS
PHASING
OUTPUT
LOGIC
GATE
PWM
and GND
AND
AND
2
GND
COMPARATORS
SHUTDOWN
PGND
6
THERMAL
5
PGND
SW C
PWM
SW2
I
SENSE
AMP
PV
tor is recommended as close to the PV
as possible
V
V
network is connected from this pin to the FB pin to
compensate the loop. See the section “Compensating the
Feedback Loop” for guidelines.
FB (Pin 12): Feedback Pin. Connect resistor divider tap
here. The output voltage can be adjusted from 2.4V to
5.25V. The feedback reference voltage is typically 1.22V.
IN
C
–0.4A
IN
+
–
+
(Pin 11): Error Amp Output. A frequency compensation
–
–
SHUTDOWN
(Pin 10): Input Supply Pin. Internal V
SW D
(Pin 9): Power V
+
REVERSE
CURRENT
CLAMP
MODE
LIMIT
ERROR
AMP
CLAMP
+
–
IN
SHDN/SS
Supply Pin. A 10µF ceramic capaci-
V
1.22V
OUT
V
FB
C
12
11
8
1
R
C
SS
www.DataSheet4U.com
SS
V
IN
2.4V TO 5.25V
IN
R1
R2
V
and PGND pins
CC
OUT
3443 BD
for the IC.
sn3443 3443fs