LTC3890
Typical applicaTion
High Efficiency Dual 12V/3.3V Step-Down Converter
+
SENSE1
INTV
CC
C1
1nF
R
B1
100k
100k
100k
–
PGOOD1
SENSE1
R
A1
6.98k
V
PGOOD2
BG1
FB1
C
100pF
R
ITH1A
MBOT1
R
SENSE1
9mΩ
V
12V
3A
OUT1
C
470pF
ITH1
ITH1
SW1
34.8k
L1
8µH
C
OUT1
BOOST1
ITH1
180µF
C
LTC3890
TRACK/SS1
C
SS1
0.01µF
B1
0.47µF
TG1
MTOP1
D1
I
LIM
V
IN
PHSMD
CLKOUT
PLLIN/MODE
V
IN
12.5V TO 60V
C
IN
220µF
INTV
CC
C
INT
SGND
4.7µF
PGND
V
EXTV
CC
OUT1
RUN1
RUN2
FREQ
R
FREQ
D2
41.2k
TG2
MTOP2
C
0.47µF
C
SS2
0.01µF
B2
L2
4.7µH
R
BOOST2
SW2
SENSE2
10mΩ
TRACK/SS2
ITH2
V
3.3V
5A
OUT2
R
ITH2
34.8k
C
1000pF
ITH2
C
C
OUT2
ITH2A
MBOT2
BG2
470µF
100pF
V
FB2
R
A2
–
+
SENSE2
31.6k
R
MTOP1, MTOP2, MBOT1, MBOT2: RJK0651DPB
L1: COILCRAFT SER1360-802KL
B2
C2
1nF
100k
L2: COILCRAFT SER1360-472KL
SENSE2
C
C
: 16SVP180MX
: SANYO 6TPE470M
OUT1
OUT2
D1, D2: DFLS1100
3890 TA08
relaTeD parTs
PART NUMBER
DESCRIPTION
COMMENTS
LTC3891
60V, Low I , Synchronous Step-Down DC/DC Controller
PLL Fixed Frequency 50kHz to 900kHz, 4V ≤ V ≤ 60V,
IN
Q
with 99% Duty Cycle
0.8V ≤ V
≤ 24V, TSSOP-20E, 3mm × 4mm QFN-20
OUT
LTC3857/LTC3857-1/ Low I , Dual Output 2-Phase Synchronous Step-Down
PLL Fixed Frequency 50kHz to 900kHz, 4V ≤ V ≤ 38V,
IN
Q
LTC3858/LTC3858-1 DC/DC Controllers with 99% Duty Cycle
0.8V ≤ V
≤ 24V, I = 50µA/170µA
OUT Q
LTC3834/LTC3834-1/ Low I , Single Output Synchronous Step-Down
PLL Fixed Frequency 140kHz to 650kHz, 4V ≤ V ≤ 36V,
IN
Q
LTC3835/LTC3835-1 DC/DC Controllers with 99% Duty Cycle
0.8V ≤ V
≤ 10V, I = 30µA/80µA
OUT Q
LTC3810
100V Synchronous Step-Down DC/DC Controller
Constant On-Time Valley Current Mode, 4V ≤ V ≤ 100V,
IN
0.8V ≤ V
≤ 0.93V , SSOP-28
IN
OUT
LTC3859A
Low I , Triple Output Buck/Buck/Boost Synchronous
Outputs (≥5V) Remain in Regulation Through Cold Crank,
2.5V ≤ V ≤ 38V, V Up to 24V, V Up to 60V
Q
DC/DC Controller with Improved Burst Mode Operation
IN
OUT(BUCKS)
OUT(BOOST)
3890fb
LT 0412 REV B • PRINTED IN USA
LinearTechnology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
40
●
●
LINEAR TECHNOLOGY CORPORATION 2010
(408) 432-1900 FAX: (408) 434-0507 www.linear.com
Linear Systems [ Linear Systems ]
