lt3743 Linear Technology Corporation, lt3743 Datasheet - Page 11

• Manufacturer Part Number: lt3743
• Description: High Current Synchronous Step-down Led Driver With Three-state Control
• Manufacturer: Linear Technology Corporation

BLOCK DIAGRAM
9nF
34k
100nF
82.5k
2nF
SYNC
9nF
402k
133k
34k
V
IN
16
15
13
14
17
18
2
3
6
7
8
4
EN/UVLO
V
SYNC
RT
CTRL_H
CTRL_L
SS
CTRL_T
VCL
VCH
CTRL_SEL
PWM
REF
1.5V
+
+
+
–
CTRL BUFFER
(QFN Package)
2V REFERENCE
OSCILLATOR
5.5μA
CURRENT
MIRROR
90k
Figure 1. Block Diagram
–
+
COMPARATOR
PWM
g
g
R
I
COMPARATOR
OUT
REGULATOR
m
m
O
OPEN-LED
VOLTAGE
AMP
= 450μA/V
= 4M
= 40μA
AMP
R
S
Q
2.5Ω
2.5Ω
–
+
–
+
SYNCRONOUS
+
–
CONTROLLER
REGUALTOR
INTERNAL
UVLO
AND
1V
1.3V
3k
LOW SIDE
HIGH SIDE
DRIVER
DRIVER
PWMGH
PWMGL
V
SENSE
SENSE
CBOOT
CC_INT
SW
V
HG
LG
FB
IN
+
–
28
27
25
23
24
26
11
12
10
22
19
40.2k
10k
3743 F01
R
5mΩ
2.2μH
0.1μF
S
1mF
40μF
LT3743
V
IN
10μF
1mF
10A LED
11
V
3743f
OUT