LTC3890-2
40
38902f
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900
●
FAX: (408) 434-0507
●
www.linear.com
© LINEAR TECHNOLOGY CORPORATION 2012
LT 1112 • PRINTED IN USA
RELATED PARTS
TYPICAL APPLICATION
High Efficiency Dual 12V/3.3V Step-Down Converter
PART NUMBER DESCRIPTION COMMENTS
LTC3891 60V, Low I
Q
, Synchronous Step-Down DC/DC Controller
with 99% Duty Cycle
PLL Fixed Frequency 50kHz to 900kHz, 4V ≤ V
IN
≤ 60V,
0.8V ≤ V
OUT
≤ 24V, TSSOP-20E, 3mm × 4mm QFN-20
LTC3857/LTC3857-1/
LTC3858/LTC3858-1
Low I
Q
, Dual Output 2-Phase Synchronous Step-Down
DC/DC Controllers with 99% Duty Cycle
PLL Fixed Frequency 50kHz to 900kHz, 4V ≤ V
IN
≤ 38V,
0.8V ≤ V
OUT
≤ 24V, I
Q
= 50µA/170µA
LTC3834/LTC3834-1/
LTC3835/LTC3835-1
Low I
Q
, Single Output Synchronous Step-Down
DC/DC Controllers with 99% Duty Cycle
PLL Fixed Frequency 140kHz to 650kHz, 4V ≤ V
IN
≤ 36V,
0.8V ≤ V
OUT
≤ 10V, I
Q
= 30µA/80µA
LTC3810 100V Synchronous Step-Down DC/DC Controller Constant On-Time Valley Current Mode, 4V ≤ V
IN
≤ 100V,
0.8V ≤ V
OUT
≤ 0.93V
IN
, SSOP-28
LTC3859A Low I
Q
, Triple Output Buck/Buck/Boost Synchronous
DC/DC Controller with Improved Burst Mode Operation
Outputs (≥5V) Remain in Regulation Through Cold Crank,
2.5V ≤ V
IN
≤ 38V, V
OUT(BUCKS)
Up to 24V, V
OUT(BOOST)
Up to 60V
MTOP2
SENSE1
+
SENSE1
–
V
FB1
TRACK/SS2
ITH2
V
FB2
SENSE2
–
SENSE2
+
ITH1
TRACK/SS1
I
LIM
PHASMD
CLKOUT
PLLIN/MODE
SGND
EXTV
CC
RUN1
RUN2
FREQ
PGOOD2
PGOOD1
BG1
C
ITH1A
100pF
C
ITH1
470pF
C
SS2
0.01µF
C
SS1
0.01µF
C
ITH2
1000pF
C
ITH2A
100pF
C1
1nF
C
OUT1
180µF
R
A1
6.98k
R
ITH1
34.8k
R
B1
100k
R
B2
100k
R
FREQ
41.2k
R
ITH2
34.8k
MTOP1, MTOP2, MBOT1, MBOT2: RJK0651DPB
L1: COILCRAFT SER1360-802KL
L2: COILCRAFT SER1360-472KL
C
OUT1
: 16SVP180MX
C
OUT2
: SANYO 6TPE470M
D1, D2: DFLS1100
D1
D2
LTC3890-2
R
SENSE1
9m
R
SENSE2
10m
L1
8µH
L2
4.7µH
MBOT1
TG1
MTOP1
V
OUT1
12V
3A
V
IN
12.5V TO 60V
38902 TA08
INTV
CC
100k
100k
C
B1
0.47µF
R
A2
31.6k
SW1
V
OUT2
3.3V
5A
SW2
BOOST1
C
B2
0.47µF
BOOST2
V
IN
INTV
CC
PGND
TG2
BG2
C
OUT2
470µF
C
INT
4.7µF
MBOT2
C2
1nF
V
OUT1
C
IN
100µF
2.2µF
x3
+
