Datasheet

LTC3859A
39
3859af
Typical applicaTions
Figure 13. High Efficiency Wide Input Range Dual 12V/3.3V Converter
3859A F13
LTC3859A
SENSE1
–
SENSE1
+
PGOOD1
TG1
SW1
BOOST1
BG1
V
BIAS
PGND
INTV
CC
TG2
BOOST2
SW2
BG2
SENSE2
+
SENSE2
–
TG3
SW3
BOOST3
BG3
SENSE3
–
SENSE3
+
V
FB1
I
TH1
TRACK/SS1
FREQ
PLLIN/MODE
SGND
RUN1
RUN2
RUN3
V
FB2
I
TH2
TRACK/SS2
V
FB3
I
TH3
SS3
C1
1nF
100k
C
B1
0.1µF
D1
D2
C
BIAS
10µF
C
INT1
4.7µF
C2
1nF
MTOP1
MBOT1
C1
10µF
L1
8.8µH
R
SENSE1
9mΩ
C
OUT1
47µF
V
OUT1
12V
3A
MTOP2
MBOT2
C2
10µF
L2
3.2µH
R
SENSE2
6mΩ
C
OUT2
150µF
V
OUT2
3.3V
5A
C
B2
0.1µF
MTOP3
MBOT3
L3
1.2µH
R
SENSE2
2mΩ
C3
1nF
D3
C
B3
0.1µF
C
IN
220µF
V
IN
2.5V TO 38V
(START-UP ABOVE 5V)
* V
OUT3
IS 15V WHEN V
IN
< 15V,
FOLLOWS V
IN
WHEN V
IN
> 15V
C
OUT3
220µF
R
B1
475k
33pF
V
OUT1
R
A1
34k
R
B2
215k
15pF
V
OUT2
R
A2
68.1k
C
ITH1A
100pF
C
ITH1
680pF
R
ITH1
10k
C
ITH2A
150pF
C
ITH2
820pF
C
SS2
0.1µF
R
ITH2
15k
R
B3
787k
OPT
V
OUT3
R
A3
68.1k
C
ITH3A
820pF
INTV
CC
C
ITH3
0.01µF
C
SS3
0.1µF
R
ITH3
3.6k
C
SS1
0.1µF
MTOP1, MTOP2: VISHAY Si7848DP
MBOT1, MBOT2: VISHAY Si7848DP
MTOP3: BSC027NO4LS
MBOT3: BSCO1BN04LS
L1: SUMIDA CDEP105-8R8M
L2: SUMIDA CDEP105-3R2M
L3: WÜRTH 744325120
C
OUT1
: KEMET T525D476MO16E035
C
OUT2
: SANYO 4TPE150M
C
IN
, C
OUT3
: SANYO 50CE220LX
D1, D2: CMDH-4E
D3: BAS140W
V
OUT3
15V*
OV3
100k
EXTV
CC