Datasheet

LTC3853
36
3853fa
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 2008
LT 1210 REV A • PRINTED IN USA
RELATED PARTS
PART NUMBER DESCRIPTION COMMENTS
LTC3850/LTC3850-1/
LTC3850-2
Dual Output Synchronous Step-Down DC/DC Controller R
SENSE
or DCR Current Sensing
Phase Lockable Fixed 250kHz to 780kHz Frequency,
4V ≤ V
IN
≤ 30V, 0.8V ≤ V
OUT
≤ 5.25V
LTC3860 Dual Output Synchronous Step-Down DC/DC Controller with
Diff Amp, DCR Current Sense, Polyphase and Three-State
Output Drive
Operates with Power Blocks, DRMOS Devices or External
MOSFETs 3V ≤ V
IN
≤ 24V, t
ON(MIN)
= 20ns
LTC3855 Dual Output Synchronous Step-Down DC/DC Controller with
Diff Amp, Polyphase and DCR Temperature Compensation
Phase Lockable Fixed Frequency 250kHz to 770kHz,
4.5V ≤ V
IN
≤ 38V, 0.8V ≤ V
OUT
≤ 12V
LTC3829 3-Phase, Single Output Synchronous Step-Down DC/DC
Controller with Diff Amp, Polyphase and DCR Temperature
Compensation
Phase Lockable Fixed 250kHz to 770kHz Frequency,
4.5V ≤ V
IN
≤ 38V, 0.8V ≤ V
OUT
≤ 5V
LTC3856 2-Phase, Single Output Synchronous Step-Down DC/DC
Controller with Diff Amp, Polyphase and DCR Temperature
Compensation
Phase Lockable Fixed Frequency 250kHz to 770kHz,
4.5V ≤ V
IN
≤ 38V, 0.8V ≤ V
OUT
≤ 5V
LTC3851A/LTC3851A-1
Single Output Synchronous Step-Down DC/DC Controller
R
SENSE
or DCR Current Sensing
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
TG1 TG2
BOOST1,2,3
SW1
SW2
BG1 BG2
SENSE1
+
SENSE2
+
SENSE1
–
SENSE2
–
V
FB1
V
FB2
V
FB3
I
TH1
I
TH2
I
TH3
V
IN
INTV
CC
DRV
CC12
LTC3853
MODE/PLLIN
20k
1%
FREQ/PLLFLTR
ILIM
PGND
PGOOD12
SGND
TK/SS1
SENSE3
–
SENSE3
+
SW3
TG3
BG3
RUN1
RUN2
RUN3
PGOOD3
EXTV
CC
100Ω*
100Ω*
2.55k
4.7µF
10k
INTV
CC
V
OUT1
2.5V
40A
V
OUT1
0.002Ω
5%
V
OUT1
V
IN
6.5V TO 14V
C
ITH1
R
ITH1
1000pF*
660µF
4V
×3
R
ITH1
= 3.9k, C
ITH1
= 10nF, C
P1
= 470pF • 3
SHORT TK/SS1, TK/SS2 AND TK/SS3 TOGETHER
C
P1
180µF
16V
C
SS1
0.33µF
1000pF
1000pF*
1000pF*
100Ω*
100Ω*
0.78µH
0.78µH
0.78µH
C
B1,2,3
0.1µF
SW1,2,3
D
B1,2,3
100Ω*
+
3853 TA05
100Ω*
43.2k
1%
0.002Ω
5%
47pF
0.002Ω
5%
*THESE FILTER COMPONENTS NEED TO BE CLOSE TO THE IC
TYPICAL APPLICATION
Three Phase 2.5V Output High Current Step-Down Converter with R
SENSE