Datasheet

LTC3891
32
3891fa
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
[phone]
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FAX: [phone]
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www.linear.com
 LINEAR TECHNOLOGY CORPORATION 2010
LT 1012 REV A • PRINTED IN USA
RELATED PARTS
TYPICAL APPLICATION
PART NUMBER DESCRIPTION COMMENTS
LTC3890/LTC3890-1 60V, Low I
Q
, Dual Output 2-Phase Synchronous Step-
Down DC/DC Controller
Phase-Lockable Fixed Frequency 50kHz to 900kHz, 4V ≤ V
IN
≤ 60V,
0.8V ≤ V
OUT
≤ 24V, I
Q
= 50µA
LTC3857/LTC3857-1
Low I
Q
, Dual Output 2-Phase Synchronous Step-Down
DC/DC Controllers with 99% Duty Cycle
Phase-Lockable Fixed Frequency 50kHz to 900kHz, 4V ≤ V
IN
≤ 38V,
0.8V ≤ V
OUT
≤ 24V, I
Q
= 50µA
LTC3858/LTC3858-1
Low I
Q
, Dual Output 2-Phase Synchronous Step-Down
DC/DC Controllers with 99% Duty Cycle
Phase-Lockable Fixed Frequency 50kHz to 900kHz, 4V ≤ V
IN
≤ 38V,
0.8V ≤ V
OUT
≤ 24V, I
Q
= 170µA
LTC3868/LTC3868-1
Low I
Q
, Dual Output 2-Phase Synchronous Step-Down
DC/DC Controller with 99% Duty Cycle
Phase-Lockable Fixed Frequency 50kHz to 900kHz, 4V ≤ V
IN
≤ 24V,
0.8V ≤ V
OUT
≤ 14V, I
Q
= 170µA
LTC3834/LTC3834-1
Low I
Q
, Single Output Synchronous Step-Down DC/DC
Controller with 99% Duty Cycle
Phase-Lockable Fixed Frequency 140kHz to 650kHz, 4V ≤ V
IN
≤ 36V,
0.8V ≤ V
OUT
≤ 10V, I
Q
= 30µA
LTC3835/LTC3835-1
Low I
Q
, Single Output Synchronous Step-Down DC/DC
Controller with 99% Duty Cycle
Phase-Lockable Fixed Frequency 140kHz to 650kHz, 4V ≤ V
IN
≤ 36V,
0.8V ≤ V
OUT
≤ 10V, I
Q
= 80µA
LT3845A
60V, Low I
Q
, Single Output Synchronous Step-Down
DC/DC Controller
Adjustable Fixed Frequency 100kHz to 500kHz, 4V ≤ V
IN
≤ 60V,
1.23V ≤ V
OUT
≤ 36V, I
Q
= 120µA
LTC3859
Low I
Q
, Triple Output Buck/Buck/Boost Synchronous
DC/DC Controller
Outputs ≥ 4V Remain in Regulation Through Cold Crank, 2.5V ≤ V
IN
≤ 38V, V
OUT(BUCKS)
Up to 24V, V
OUT(BOOST)
Up to 60V, I
Q
= 55µA
LTC3824
Low I
Q
, Single Output Step-Down Controller, 100%
Duty Cycle
Fixed 200kHz to 600kHz, 4V ≤ V
IN
≤ 60V, 0.8V ≤ V
OUT
≤ V
IN
, I
Q
= 40µA,
MSOP-10E
0.1µF
C
IN
22µF
V
IN
9V TO 60V
V
OUT
INTV
CC
34.8k
470pF
100k
100k
MTOP, MBOT: Si7850DP
L1 COILCRAFT SER1360-802KL
C
OUT
: SANYO 10TPE330M
D1: DFLS1100
10.5k
3891 F14
2.2µF
D1
0.1µF
FREQ
ITH
SGND
SGND
LTC3891
V
IN
PGOOD
RUN
I
LIM
EXTV
CC
PLLIN/MODE
INTV
CC
PGND
L1
8µH
R
SENSE
10mΩ
BOOST
SW
BG
SENSE
+
SENSE
–
V
FB
TG
MTOP
MBOT
1nF
C
OUT
330µF
V
OUT
8.5V
3A
TRACK/SS
Figure 14. High Efficiency 8.5V Step-Down Converter