LTC3865/LTC3865-1
38
3865fb
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900
●
FAX: (408) 434-0507
●
www.linear.com
© LINEAR TECHNOLOGY CORPORATION 2010
LT 0810 REV B • PRINTED IN USA
RELATED PARTS
PART NUMBER DESCRIPTION COMMENTS
LTC3850/LTC3850-1
LTC3850-2
Dual 2-Phase, High Effi ciency Synchronous Step-Down DC/DC
Controllers, R
SENSE
or DCR Current Sensing and Tracking
Phase-Lockable Fixed 250kHz to 780kHz Frequency,
4V ≤ V
IN
≤ 30V, 0.8V ≤ V
OUT
≤ 5.25V
LTC3855 Dual, Multiphase Synchronous Step-Down DC/DC Controller
with Diffamp and DCR Temperature Compensation
Phase-Lockable Fixed 250kHz to 770kHz Frequency,
4.5V ≤ V
IN
≤ 38V, t
ON(MIN)
= 90ns
LTC3860 Dual, Multiphase Synchronous Step-Down DC/DC Controller
with Diffamp and Three-State Output Drive
Operates with Power Blocks, DRMOS Devices or External
MOSFETs, 3V ≤ V
IN
≤ 24V, t
ON(MIN)
= 20ns
LTC3853 Triple Output, Multiphase Synchronous Step-Down DC/DC
Controller, R
SENSE
or DCR Current Sensing and Tracking
Phase-Lockable Fixed 250kHz to 750kHz Frequency,
4V ≤ V
IN
≤ 24V, V
OUT3
Up to 13.5V
LTC3854 Small Footprint Wide V
IN
Range Synchronous Step-Down
DC/DC Controller, R
SENSE
or DCR Current Sensing
Fixed 400kHz Operating Frequency 4.5V ≤ V
IN
≤ 38V,
0.8V ≤ V
OUT
≤ 5.25V, 2mm × 3mm QFN-12, MSOP-12
LTC3878/LTC3879 No R
SENSE
Constant On-Time Synchronous Step-Down
DC/DC Controller, No R
SENSE
Required
Very Fast Transient Response, t
ON(MIN)
= 43ns, 4V ≤ V
IN
≤ 38V,
0.8V ≤ V
OUT
≤ 0.9V
IN
, SSOP-16, MSOP-16E, 3mm × 3mm QFN-16
LTC3775 High Frequency, Synchronous Voltage Mode Step-Down
DC/DC Controller
Fast Transient Response, t
ON(MIN)
= 30ns, 4V ≤ V
IN
≤ 38V,
0.6V ≤ V
OUT
≤ 0.8V
IN
, MSOP-16E, 3mm × 3mm QFN-16
Figure 18. High V
IN
, 3.6V/10A, 2V/10A Converter With External Sense Resistors Synchronized at 400kHz
TYPICAL APPLICATION
D3
CMDSH-3
D4
CMDSH-3
0.1µF
HAT2266H
HAT2266H
L1
2.2µH
PLLIN
400kHz
0.004
HAT2266H
HAT2266H
1800pF
100pF
1nF
1nF
C
IN1
22µF
50V
C
OUT1
220µF
s2
C
OUT1
, C
OUT2
: SANYO 4TPE 220µF
L1: TOKO FDA1055-2R2M
L2: TOKO FD1055-1R2M
49.9k
1%
100
100
17.8k
1%
10k
1%
V
OUT1
3.6V
10A
0.1µF
L2
1.2µH
0.004
2200pF
100pF
C
OUT2
220µF
s2
14.7k
1%
10k
1%
V
OUT2
2V
10A
TG1 TG2
BOOST1 BOOST2
SW1 SW2
BG1
BG2
SGND
PGND
FREQ
SENSE1
+
SENSE2
+
VID21
SENSE1
–
SENSE2
–
V
OSENSE1
V
OSENSE2
I
TH1
I
TH2
V
IN
PGOOD INTV
CC
TK/SS1 TK/SS2
V
IN
7V TO 36V
3865 F18
EXTV
CC
0.1µF
0.1µF
121k
LTC3865
3.3µF
50V
3.3µF
50V
MODE/PLLIN
I
LIM
RUN2RUN1
VID22
VID12
VID11
100
100
23.2k
1%
4.7µF
C
IN2
1µF
2.2Ω
+
+
+
