Datasheet

LTC3876
40
3876f
APPLICATIONS INFORMATION
Figure 11. Design Example: 4.5V to 14V Input, VDDQ 1.5V/20A and VTT 0.75V/±10A Output,
400kHz, DCR, Step-Down Converter
• Keep small-signal components connected noise-sensi-
tive pins (give priority to SENSE
+
/SENSE
–
, V
OUTSENSE1
+
/
V
OUTSENSE1
–
, V
FB2
, RT , ITH, V
RNG
pins) on the left hand
side of the IC as close to their respective pins as pos-
sible. This minimizes the possibility of noise coupling
into these pins. If the LTC3876 can be placed on the
bottom side of a multilayer board, use ground planes
to isolate from the major power components on the top
side of the board, and prevent noise coupling to noise
sensitive components on the bottom side.
13.7k
3876 F11a
0.1µF
0.1µF
1µF
470pF
C
IN1
: SANYO 16SVP180M
C
IN2:
MURATA GRM32DR61E106KA12L
C
OUT2
,C
OUT4
: SANYO 2R5TPE330M9
C
OUT1
, C
OUT3
: MURATA GRM31CR60J107ME39L
DB1, DB2: CENTRAL SEMI CMDSH-3
L1: WÜRTH 7443330047
L2: WÜRTH 7443340047
MT1, MB2: INFINEON BSC0901NS
MB1: INFINEON BSC010NE2LS
MT2: INFINEON BSC050NE2LS
4700pF
L1
0.47µH
C
OUT3
100µF
C
OUT4
330µF
VTT
0.75V
±10A
DB2
MT2
MB2
LTC3876
2.2
2.2
30.1k
VTTR
±50mA
1
100k
12.7k
100k
V
IN
1µF
0.1µF
4.7µF
0.1µF
0.01µF
120pF
1500pF
L1
0.47µH
C
OUT2
330µF
w2
C
OUT1
100µF
VDDQ
1.5V
20A
V
IN
4.5V TO 14V
20k
SENSE1
–
SENSE1
+
BOOST1
TG1
SW1
SENSE2
+
BOOST2
TG2
SW2
DRV
CC1
INTV
CC
DRV
CC2
EXTV
CC
DB1
MT1
5.9K
2.74K
SENSE2
–
BG1 BG2
VTTRVCC
PGND
V
OUTSENSE1
+
VDDQSNS
V
OUTSENSE1
–
PGOOD VTTR
VTTSNS
TRACK/SS1
ITH1
DTR1
V
RNG1
ITH2
CVCC
PHASMD
MODE/PLLIN
CLKOUT
V
RNG2
SGND
RUN
RT
PGOOD
MB1
1µF
C
IN2
10µF
w3
C
IN1
180µF
w2
2.2µF
LOAD CURRENT (A)
0.1
EFFICIENCY (%)
POWER LOSS (W)
90
100
110
3876 F11b
60
50
40
80
70
4.0
4.5
1.5
0.5
1.0
0
3.0
3.5
2.5
2.0
FORCED
CONTINUOUS
MODE
DISCONTINUOUS
MODE
V
IN
= 12V
V
DDQ
= 1.5V