Datasheet

LTC3869/LTC3869-2
31
38692fa
For more information www.linear.com/LTC3869
applicaTions inForMaTion
Figure 14. DCR Sense Efficiency vs R
SENSE
Efficiency
Figure 13. High Efficiency Dual 400kHz 1.8V/1.2V Step-Down Converter
LOAD CURRENT (A)
0
85
EFFICIENCY (%)
POWER LOSS (W)
90
161412108642
80
75
70
95
4
3
2
1
0
5
3869 F14
1.2V R
SENSE
1.2V DCR SENSE
1.8V R
SENSE
1.8V DCR SENSE
V
IN
= 12V
MODE = CCM
DCR SENSE APP: SEE FIGURE 16
R
SENSE
APP: SEE FIGURE 19
EFFICIENCY
POWER LOSS
D3
D4
M1
M2
0.1µF
40.2k
1%
L1
0.56µH
3.09k
1%
1nF
150pF
0.1µF
0.1µF
82µF
25V
C
OUT1
330µF
×2
L1, L2: VISHAY IHLP4040DZ-01, 0.56µH
M1, M3: RENESAS RJK0305DPB
M2, M4: RENESAS RJK0330DPB
20k
1%
12.1k
1%
V
OUT1
1.8V
15A
M3
M4
0.1µF
L2
0.56µH
1nF
150pF
C
OUT2
330µF
×2
20k
1%
4.99k
1%
100k
1%
V
OUT2
1.2V
15A
TG1 TG2
BOOST1 BOOST2
SW1 SW2
BG1
BG2
SGND
PGND
FREQ
SENSE1
+
SENSE2
+
SENSE1
–
SENSE2
–
V
FB1
V
FB2
I
TH1
I
TH2
V
IN
PGOOD INTV
CC
TK/SS1 TK/SS2
V
IN
4.5V TO
20V
3869 F13
EXTV
CC
0.1µF
0.1µF
LTC3869
MODE/PLLIN
I
LIM
RUN1
RUN2
3.09k
1%
4.7µF
1µF
2.2Ω
+
+
10µF
25V
×2
+
20k
1%