Datasheet

LTC3838
39
3838fa
APPLICATIONS INFORMATION
Figure 13. Design Example: 4.5V to 26V Input, 1.2V/15A and 1.5V/15A Dual Outputs,
350kHz, DCR Sense, DTR Enabled, Step-Down Converter
100k
90.9k
82.5k
3838 F13a
0.1µF
0.1µF
0.01µF
22pF
220pF
L2
0.56µH
C
OUT3
100µF
w2
C
OUT4
330µF
w2
V
OUT2
1.5V
15A
15k
DB2
MT2
MB2
3.57k
+
LTC3838
2.2
2.2
10k 15k
100k
90.9k
82.5k
115k
V
IN
1µF
0.1µF
4.7µF
0.1µF
0.01µF
22pF
220pF
L1
0.56µH
C
OUT2
330µF
w2
C
OUT1
100µF
w2
V
OUT1
1.2V
15A
V
IN
4.5V TO 26V
15k
10k 10k
SENSE1
–
SENSE1
+
BOOST1
TG1
SW1
SENSE2
+
BOOST2
TG2
SW2
DRV
CC1
INTV
CC
DRV
CC2
EXTV
CC
DB1
MT1
3.57k
SENSE2
–
BG1 BG2
V
FB2
PGND
V
OUTSENSE1
+
V
OUTSENSE1
–
PGOOD1 PGOOD2
TRACK/SS1
ITH1
DTR1
V
RNG1
TRACK/SS2
ITH2
DTR2
PHASMD
MODE/PLLIN
CLKOUT
RUN2
V
RNG2
SGND
RUN1
RT
PGOOD1 PGOOD2
MB1
1µF
C
IN2
10µF
w3
+
C
IN1
220µF
+
C
IN1
: PANASONIC EEEFK1V221P
C
IN2
: TAIYO YUDEN GMK325BJ106MN-T
C
OUT2
, C
OUT4
: SANYO 2R5TPE330M9
C
OUT1
, C
OUT3
: MURATA GRM31CR60J107ME39L
DB1, DB2: CENTRAL SEMI CMDSH-4ETR
L1, L2: VISHAY IHLP4040DZERR56M01
MT1, MT2: RENESAS RJK0305DPB
MB1, MB2: RENESAS RJK0330DPB
LOAD CURRENT (A)
0.1
40
EFFICIENCY (%)
POWER LOSS (W)
50
60
70
80
100
110
3838 F13b
90
0
0.5
1.0
1.5
2.0
3.0
2.5
EFFICIENCY
V
IN
= 12V
V
OUT
= 1.2V
FORCED CONTINUOUS MODE
DISCONTINUOUS MODE
POWER
LOSS
LOAD CURRENT (A)
0.1
40
EFFICIENCY (%)
POWER LOSS (W)
50
60
70
80
100
110
3838 F13c
90
0
0.5
1.0
1.5
2.0
3.0
2.5
EFFICIENCY
V
IN
= 12V
V
OUT
= 1.5V
FORCED CONTINUOUS MODE
DISCONTINUOUS MODE
POWER
LOSS