DC1381A - Schematic

1
2
3
4
5
A
6
7
8
REVISION HISTORY
This circuit is proprietary to Linear Technology and supplied
for use with Linear Technology parts.
Customer Notice: Linear Technology has made a best effort to
design a circuit that meets customer-supplied specifications;
however, it remains the customer's responsibility to verify proper
and reliable operation in the actual application, Component
substitution and printed circuit board layout may significantly
affect circuit performance or reliability. Contact Linear
Applications Engineering for assistance.
ECO
REV
R39
200K
DESCRIPTION
3
INTVCC
R1
200K
*
DATE
PROD
APPROVED
05/14/09
OPTIONAL DCR SENSING:
NOTE: WHEN DCR SENSING IS IMPLEMENTED, SHORT R10 AND R17,
DO NOT STUFF R8,R9,R20 AND R21
E1
PGOOD1
A
E16
PGOOD2
R26
VOUT2
C2 10pF
TRACK1
OPT
VOUT1
JP5
E10
SS
TRACK
R2
3
TRACK1
35.7K
R3
11.5K
1
R4
R5
R6
182K 1%
0
C1
2
INTVCC
E2
57.6K
1%
0.1uF
C19
[1]
VIN
JP3
R34
OPT
RUN1
OFF
2
RUN2
OFF
3
R35
[1]
5
1
2
ON
R36
OPT
29
JP4
1
2
ON
6
3
7
C28
ITH1
PGOOD2
4700pF
R37
[1]
OPT
C29
8
OPT
33
PGOOD1
TRACK/SS1
TG1
FREQ
SW1
PLLIN/MODE
BOOST1
SGND
3
CLKOUT PHASE
13
R16
120
4
47pF
PHSMD
R22
VOUT2
C22
4.7uF
10V
R18
102K
1%
0
C18
2
3
TRACK2
[1]
C13
47uF
50V
10V
+
BG2 SHT 2
18
17
16
4
D3
R15 2.2
15
0.1uF
TG2 SHT 2
-A
LTC3857EUH
R32
OPT
VOUT2
GND
R33
OPT
C
L2 7.2uH
*
VOUT2
R17
CDEP105-7R2M
SW2 SHT 2
0.008
J5
VOUT2
C20
10uF
16V
C27
R20
0
R21
0
*
*
GND
E6
E13
4
COUT2
+ 68uF
10V
COUT4
+ OPT
J6
VOUT2
8.5V / 3A
GND
GND
R23
1
0
CONTRACT NO.
0.1uF
APPROVALS
R35
R37
APPROVED
OPT
OPT
DESIGNER
ENGINEER
DATE
10/26/07
TECHNOLOGY
1630 McCarthy Blvd.
Milpitas, CA 95035
Phone: (408)432-1900
Fax: (408)434-0507
D
TITLE
SCH, LTC3857EUH / LTC3858EUH, LOW QUIESCENT CURRENT
DUAL OUTPUT SYNCHRONOUS BUCK CONVERTER
SIZE
CAGE CODE
[2]
DWG NO
REV
3
DC1381A
-B
LTC3858EUH
1
66.5K
12.7K
[2] FOR REGULATION VIN > 9V
2
[2]
E14
CHECKED
U1
J4
SNS2+
Q4
BSZ097N04LS
DRAWN MI
ASSY
4.7uF
50V
OPT
CMDSH-4E
Q3
BSZ097N04LS
4.7uF
50V
VIN
4.5V - 36V
SNS2-
VIN
INTVCC
C16
C7
R31
INTVCC
C23
R25
10K
1%
D
EXTVCC
OPTIONAL DCR
SENSING
4.7uF
C12
0.1uF
C17
SS
OPT
97.6K1%
VIN
C11
J3
VIN
100pF
R19
976K
1%
C21
TRACK
4
R14 0
VIN
SNS1+
OPTIONAL DCR
SENSING
SNS2+
JP6
R24
CMDSH-4E
19
1000pF
TRACK2
E15
SW2
TG2
SNS2-
E3
14V MAX
BOOST2
ITH2
EXTVCC
EXTVCC
BG2
TRACK/SS2
VFB2
E9
12
3300pF
C14
3
60
SGND
C15
2
90
R41
OPT
15K
20
ILIM
11
JP8
1
R40
OPT
C
EXTVCC
BG1
SHT 2
INTVCC
SNS2+
28
INTVCC
21
SNS2-
INTVCC
GND
E5
OPT
D2
R13 2.2
24
GND
E12
SNS1-
25
VIN
INTVCC
B
R30
0.1uF
PGND
CLKOUT
9
4
3.3V / 5A
J2
R29
OPT
Q2
BSZ097N04LS
26
22
GND
R28
OPT
+ C5
OPT
C10
27
23
RUN2
BSZ097N04LS
14
BG1
RUN1
E17
CLKOUT
Q1
4
5
6
7
8
30
VIN
TG1 SHT 2
+ COUT1
220uF
4V
1
2
3
PLLIN / MODE
8.2K C4
COUT3
100uF
6.3V
1
2
3
R11
VOUT1
0.005
5
6
7
8
0
J1
VOUT1
100pF
1
2
3
E4
VOUT1
*
R10
5
6
7
8
C3 22pF
B
5
6
7
8
R7
1000pF
L1 3.2uH
CDEP105-3R2M
VIN
1
2
3
BURST MODE
E11
SW1 SHT 2
C26
32
6
*
C6
SNS1+
5
PULSE SKIP
*
U1
31
100K
4
R38
OPT
VFB1
3
INTVCC
CCM
R9
0
1
2
R27
R8
0
SNS1-
2.2uF
JP2
1
SNS1-
MODE
10
INTVCC
SNS1+
INTVCC
3
Friday, August 21, 2009
4
5
6
SCALE: NONE
FILENAME: 1381A-3.DSN
7
SHEET
1
8
OF
2
This circuit is proprietary to Linear Technology and supplied
for use with Linear Technology parts.
Customer Notice: Linear Technology has made a best effort to
design a circuit that meets customer-supplied specifications;
however, it remains the customer's responsibility to verify proper
and reliable operation in the actual application, Component
substitution and printed circuit board layout may significantly
affect circuit performance or reliability. Contact Linear
Applications Engineering for assistance.
REVISION HISTORY
ECO
VIN
REV
DESCRIPTION
3
C24
C25
OPT
OPT
DATE
PROD
APPROVED
05/14/09
5
6
7
8
VIN
Q5
OPT
4
1
2
3
TG1
5
6
7
8
SW1
Q6
OPT
4
1
2
3
BG1
VIN
5
6
7
8
SHT 1
Q7
OPT
4
1
2
3
TG2
5
6
7
8
SW2
Q8
4
OPT
1
2
3
BG2
5
6
7
8
VIN
Q1X
4
OPT
1
2
3
TG1
5
6
7
8
SW1
X6
1
1
X5
X7
1
1
1
X1
1
X2
Represents
Tooling Holes
4
REPRESENTS STAND OFFS
1
2
3
BG1
Q2X
OPT
X4
on PCB
VIN
5
6
7
8
SHT 1
1
2
3
DRAWN MI
CHECKED
5
6
7
8
SW2
APPROVED
Q4X
OPT
4
1
2
3
BG2
CONTRACT NO.
APPROVALS
4
TG2
Q3X
OPT
ENGINEER
DESIGNER
DATE
10/26/07
TECHNOLOGY
1630 McCarthy Blvd.
Milpitas, CA 95035
Phone: (408)432-1900
Fax: (408)434-0507
TITLE
SCH, LTC3857EUH / LTC3858EUH, LOW QUIESCENT CURRENT
DUAL OUTPUT SYNCHRONOUS BUCK CONVERTER
SIZE
CAGE CODE
DWG NO
REV
3
DC1381A
Friday, August 21, 2009
SCALE: NONE
FILENAME: 1381A-3.DSN
SHEET
2
OF
2