DC976A - Schematic

5
4
3
2
PVIN
33V max
VIN
2.8V- 16V
R3
33.2K
R2
66.5K
R24
33.2K
R25
66.5K
R26
33.2K
R27
66.5K
R28
33.2K
R29
66.5K
C4
C1
4.7uF
50V
(OPT)
1uF
7 REF
37 VADJ1
GND
PVIN
C3
2.2uF
35V
C2
2.2uF
35V
E15
D
GND
E16
Vin 33
D
E2
E1
22nF
SHDN 18
C6
1
U1
LT3476EUHF
CAP1 3
LED1 2
PVIN
R1
0.1
LED1+
LED1-
E3
S1
E4
SW1
SW1
SW2
SW3
SW4
35 PWM1
34 PWM2
C14
(OPT)
R6
C15
(OPT)
R7
0
C16
(OPT)
R9
0
C17
(OPT)
R10
C10
1nF
C11
1nF
C12
1nF
0
0
C13
1nF
CAP3 9
LED3 8
LED2+
LED2-
E5
38 VC2
PVIN
R5
0.1
LED3-
LED3+
E7
C7
0.33uF
S4
DFLS140
0
D3
C8
0.33uF
S6
2
DFLS140
0
10uH
L3
D4
R8
0.1
LED4+
LED4-
E9
R23 **
S7
E10
C9
0.33uF
S8
L4
0
2
DFLS140
SW4 23
SW4 22
6 RT
C
SW3
PVIN
CAP4 10
LED4 11
12 VC4
10uH
L2
R22 **
S5
E8
10uH
B
SW4
CUSTOMER NOTICE
4
**
SW2
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
TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE.
THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
5
R21
1
13 VC3
** Remove for faster LED turn-off.
A
S3
E6
SW3 25
SW3 24
1 VC1
R11
21K
0.1
1
17 PWM3
16 PWM4
PWM4
R4
N/C
N/C
N/C
N/C
N/C
N/C
PWM3
PVIN
2
19
20
21
30
31
32
PWM2
E13 PWM3
D2
SW2 27
SW2 26
39 GND
E12 PWM2
E14 PWM4
B
CAP2 4
LED2 5
PWM1
PWM2
PWM3
PWM4
PWM1
10uH
1
14 VADJ4
2
DFLS140
L1
0
15 VADJ3
E11 PWM1
C5
0.33uF
S2
R20 **
SW1 29
SW1 28
36 VADJ2
C
D1
1
3
CONTRACT NO.
APPROVALS
DRAWN
DATE
HELEN
6/22/06
Walker Bai
6/22/06
CHECKED
APPROVED
ENGINEER
DESIGNER
Monday, August 28, 2006
2
TECHNOLOGY
1630 McCarthy Blvd.
Milpitas, CA 95035
Phone: (408)432-1900
Fax: (408)434-0507
A
TITLE
LT3476EUHF
Quadruple High Power LED Driver in Buck Mode
SIZE
CAGE CODE
SCALE:
FILENAME:
DWG NO
REV
A
DC976A
SHEET
1
1
OF
1
5
4
3
D
2
S1
Si2303BDS
3
D
S2
Q2
1
3
R13
2N7002
2
4.99K
PWM1
1
4.99K
2
S3
Si2303BDS
3
S4
Q3
Q4
1
R14
4.99K
3
R15
2N7002
2
4.99K
C
PWM2
1
C
2
Si2303BDS
3
Q5
S6
Q6
1
S5
4.99K
3
R17
2N7002
2
4.99K
PWM3
1
R16
2
S7
Si2303BDS
3
Q7
S8
Q8
1
4.99K
3
R19
4.99K
PWM4
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
TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE.
THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
A
4
B
2N7002
2
1
R18
5
1
Q1
R12
B
2
3
CONTRACT NO.
APPROVALS
DRAWN
DATE
HELEN
6/22/06
Walker Bai
6/22/06
CHECKED
APPROVED
ENGINEER
DESIGNER
Tuesday, July 25, 2006
2
TECHNOLOGY
1630 McCarthy Blvd.
Milpitas, CA 95035
Phone: (408)432-1900
Fax: (408)434-0507
A
TITLE
LT3476EUHF
Quadruple High Power LED Driver in Buck Mode
SIZE
CAGE CODE
SCALE:
FILENAME:
DWG NO
REV
A
DC976A
SHEET
1
2
OF
2