Datasheet

LTC3520
22
3520fa
TYPICAL APPLICATIONS
Dual 3.3V at 500mA and 1.2V at 600mA Supplies
with Power Good Output
3520 TA03a
SW1A
SW1B
V
OUT1
A
OUT
A
IN
V
C1
FB1
SS1
SV
IN
PV
IN3
PV
IN2
PV
IN1
PGND2SGNDPGND1
SW2
FB2
SS2
R
T
PWM1
PWM2
SD3
SD2
SD1
C3
22μF
1M
442k
309k
15k
470pF
10k
56pF
LTC3520
V
OUT
3.3V
500mA
1A FOR V
IN
≥ 3V
V
OUT
1.2V
600mA
V
IN
2.2V TO 4.2V
C1, C2, C3: TAIYO YUDEN CERAMIC JMK212BJ226MG-T
L1: TDK RLF7030T-4R7M3R4 4.7μH
L2: TDK RLF7030T-3R3M4R 3.3μH
27pF
C2
22μF
0.022μF
0.022μF
54.9k
100k
191k
301k
C1
22μF
Li-Ion
L2
3.3μH
L1
4.7μH
158k
BUCK-BOOST
PGOOD OUTPUT
150pF
PWM
BURST
ON
OFF
Typical Waveforms During Power-Up
SD1, SD2, SD3
5V/DIV
1ms/DIV
BUCK V
OUT
0.5V/DIV
BUCK-BOOST V
OUT
1.5V/DIV
A
OUT
(BUCK-BOOST PGOOD)
5V/DIV
3520 TA03b