DC1470A - Schematic

5
4
3
2
1
REVISION HISTORY
ECO
REV
1
3
VIN
DESCRIPTION
PRODUCTION
APPROVED
DATE
WALKER B.
10-02-09
*
R17 0
D
D
PVIN
4
E1
3
VREF
4
CTRL_T
6
CTRL_H
7
CTRL_L
R19
432K
R20
100K
R21
OPT
C7
2nF
R4
100K
R22
OPT
CTRL_H
E4
CTRL_L
E5
18
PWM
E6
17
CTRL_SEL
E7
16
SYNC
E8
SW
1
2
3
C18
470uF
CTRL_SEL
SYNC
SS
PWMGH 19
PWMGL 22
15
RT
VCH 14
VCL 13
10
GND
GND
GND
29
21
GND
FB
8
1
B
C19
OPT
C5
470uF
C6
470uF
C13
OPT
C14
OPT
+
2
D2
DFLS240
8
7
5
6
4
2
C27
10uF
C21
470uF
R15
10
R16
10
C
LEDE11
8
7
5
6
4
Q5
IS+
E13
Q6
R25
Si7234DP
OPT
IS-
R23
3.01K
C23
470uF
+
+
C22
OPT
R7
51K
R8
51K
+
C20
OPT
Si7234DP
C15
33nF
C8
1uF
R14
100K
(400kHz)
+
SENSE+ 11
20
R13
100K
+
VCC_INT
GND
R12
100K
VOUT*
24
Q3
RJK0330DPB
Q4
OPT
4
LG 26
9
R11
OPT
0.0025
E10
PWM
GND
R10
100K
R3
C4
22uF
6.3V
SENSE- 12
R9
100K
L1
1.3uH
3
R18
24.9K
VCC_INT
3
E2
GND
1
EN/UVLO
6V - 36V
E12
1
2
C11
100uf,50V
50CE100LX
C3
0.22uF
D1
PMEG4002EB
VCC_INT 27
4.7uF
1
2
3
EN/UVLO
VIN
E9
+
4.7uF
5
6
7
8
LT3743EUFD
28
C
2
U1
C2
1uF
50V
CBOOT 25
R2
374K
23
R1
124K
HG
E3
5
GND
RJK0305DPB
R26
OPT
R27
0
C1
C12
C16
C17
Q2
*
6V - 36V
Q1
1
VIN
5
6
7
8
VIN
*
C25
470uF
C24
OPT
E14
R24
2K
C9
5.6nF
B
R5
51K
C10
5.6nF
C26
R6
10k
1.2nF
* See Quick Start Guide
CUSTOMER NOTICE
A
CONTRACT NO.
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.
APPROVALS
ENG.
4
3
WALKER B. TITLE: SCHEMATIC
HIGH CURRENT SYNCHRONOUS
STEP-DOWN LED DRIVER WITH THREE-STATE CONTROL
SIZE
A
THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
5
TECHNOLOGY
PCB DES. ANTONINA K.
DATE:
2
1630 McCarthy Blvd.
Milpitas, CA 95035
Phone: (408)432-1900
Fax: (408)434-0507
LTC Confidential-For Customer Use Only
IC NO.
REV
LT3743EUFD
3
DEMO CIRCUIT 1470A
Friday, December 04, 2009
SHEET
1
1 OF 1
A