Datasheet

LTC3523/LTC3523-2
7
3523fb
BLOCK DIAGRAM
16
SHDN1
V
IN
1.8V TO 5.5V
2
+
PWM
LOGIC
AND
DRIVERS
SHUTDOWN
AND
V
BIAS
ANTI-RING
L1
4.7μH
V
IN1
3
PGOOD1
15
10
V
BAT
9
V
IN2
SW1
V
OUT
C
IN
47μF
C
C2
C
OUT
10μF
V
OUT
STEP-UP
1.8V TO 5.25V
V
OUT
STEP-DOWN
0.615V TO 5.5V
1.2V
R1
R2
C
OUT
10μF
R4
R3
MODE
g
m
ERROR
AMPLIFIER
ZERO CURRENT
COMP
C
C1
R
Z
C
C1
GND3
R
Z
5
4
FB1
STEP-UP
STEP-DOWN
SHARED
MODE
1
SW2
0.66V
GND2
L2
4.7μH
8
FB2
3523 BD
BULK CONTROL
SIGNALS
CURRENT
SENSE
I
ZERO
COMP
SHDN
MODE
OSC
SLP
+
+
PWM/I
LIM
COMP
PWM/I
LIM
COMP
I
LIM
REF
SLOPE COMPENSATION
PWM
LOGIC
AND
DRIVERS
V
OUT
LIMIT
COMP
MODE
OSC
I
LIM
REF
0A
SHUTDOWN
AND
V
BIAS
SHDN
+
–
+
––
++
SLP
+
–
1.2V
–9%
FB1
OSC
0.6V
1.2V
1V
SLP
+
–
+
–
+
–
–
MODE
MODE
START-UP
SOFT-START
AND
THERM REG
g
m
ERROR
AMPLIFIER
MODE
START-UP
SOFT-START
AND
THERM REG
OSCILLATOR REFERENCE
THERMAL SHDN
11
PGOOD2
13
14
SHDN2
0.6V
–9%
FB2
+
–
SLOPE COMPENSATION
+
–
+
–
0.6V
12
GND2
7
GND1
6