LTC3878
26
3878fa
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900
●
FAX: (408) 434-0507
●
www.linear.com
LINEAR TECHNOLOGY CORPORATION 2009
LT 0710 REV A • PRINTED IN USA
relaTeD parTs
Typical applicaTion
PART NUMBER DESCRIPTION COMMENTS
LTC3879 No
R
SENSE
Constant On-Time Synchronous Step-Down
DC/DC Controller
Very Fast Transient Response, t
ON(MIN)
= 43ns, 4V ≤ V
IN
≤ 38V,
0.6V ≤ V
OUT
≤ 0.9V
IN
, MSOP-16E, 3mm × 3mm QFN-16
LTC3854 Small
Footprint Wide V
IN
Range Synchronous Step-Down
DC/DC Controller
Fixed 400kHz Operating Frequency 4.5V ≤ V
IN
≤ 38V,
0.8V ≤ V
OUT
≤ 5.25V, 2mm × 3mm QFN-12
LTC3851A
LTC3851A-1
No
R
SENSE
Wide V
IN
Range Synchronous Step-Down
DC/DC Controller
Phase-Lockable Fixed Operating Frequency 250kHz to 750kHz,
4V ≤ V
IN
≤ 38V, 0.8V ≤ V
OUT
≤ 5.25V, MSOP-16E, 3mm × 3mm
QFN-16, SSOP-16
LTC3775 High
Frequency Synchronous Step-Down DC/DC Controller Fixed Operating Frequency 250kHz to 1MHz, 4.5V ≤ V
IN
≤ 38V,
0.6V ≤ V
OUT
≤ 0.8V
IN
, 3mm × 3mm QFN-16
LTC3850/LTC3850-1
LTC3850-2
Dual
2-Phase, High Efficiency Synchronous Step-Down
DC/DC Controllers, R
SENSE
or DCR Current Sensing and
Tracking
Phase-Lockable
Fixed Operating Frequency 250kHz to 780kHz,
4V
≤ V
IN
≤ 30V, 0.8V ≤ V
OUT
≤ 5.25V
LTC3853 Triple
Output, Multiphase Synchronous Step-Down DC/DC
Controller, R
SENSE
or DCR Current Sensing and Tracking
Phase-Lockable Fixed Operating Frequency 250kHz to 750kHz,
4V
≤ V
IN
≤ 24V, V
OUT
Up to 13.5V
LTC3857/LTC3857-1 Low
I
Q
, Dual Output 2-Phase Synchronous Step-Down
DC/DC Controller with 99% Duty Cycle
Phase-Lockable Fixed Operating Frequency 50kHz to 900kHz,
4V≤ V
IN
≤ 38V, 0.8V ≤ V
OUT
≤ 24V, I
Q
= 50µA,
LTC3868/LTC3868-1 Low
I
Q
, Dual Output 2-Phase Synchronous Step-Down
DC/DC Controller with 99% Duty Cycle
Phase-Lockable Fixed Operating Frequency 50kHz to 900kHz,
4V≤ V
IN
≤ 24V, 0.8V ≤ V
OUT
≤ 14V, I
Q
= 170µA,
4.5V to 14V Input, 0.9V/25A Output at 300kHz
+
RUN/SS
LTC3878
BOOST
16
C
B
0.22µF
M1
SiR408DP
C
VCC
4.7µF
C
C1
680pF
C
C2
100pF
D
B
CMDSH-3
L1
0.26µH
C
OUT1
330µF
2.5V
s3
C
OUT2
100µF
6.3V
s2
+
C
IN1
10µF
16V
s4
C
IN2
180µF
16V
V
OUT
0.9V
25A
3878 TA08
V
IN
4.5V TO 14V
1
PGOOD
R
PG
100k
R2
93.1k
R
C
7.5k
R
FB1
20.0k
R1
10.0k
TG
152
V
RNG
SW
143
FCB PGND
134
I
TH
BG
125
SGND INTV
CC
116
I
ON
V
IN
107
V
FB
NC
98
R
ON
432k
R
FB2
2.49k
C
F
0.1µF
R
F
2.2Ω
M2
SiR892DP
s2
C
IN1
: TDK C3225X5R1E106MT s4
C
OUT1
: SANYO 2R5TPE330M9 s3
C
OUT2
: MURATA GRM31CR60J107ME39 s2
L1: PULSE PA0513.261NLT
C
SS
0.1µF
