lt3755-2 Linear Technology Corporation, lt3755-2 Datasheet - Page 19

• Manufacturer Part Number: lt3755-2
• Description: Lt3755/lt3755-1/lt3755-2 40vin, 75vout Led Controllers Features
• Manufacturer: Linear Technology Corporation

Typical applicaTions
100
84
80
96
92
88
0.0
V
IN
= 12V
0.2
Efficiency vs Load
0.4
8V TO
LOAD (A)
40V
V
IN
0.6
C
4.7µF
IN
INTV
V
500mA/DIV
0.8
OUT
0V TO 5V
L1: COILTRONICS DR127-220
M1: VISHAY SILICONIX SI7850DP
D1: DIODES INC. PDS5100
M2: VISHAY SILICONIX SI2308DS
RT1: MURATA NCP18WM1045
10V/DIV
37551 TA02c
2A/DIV
CC
100k
R1
1M
R2
187k
= 50V
PWM
C
0.01µF
I
LED
SS
I
L1
1.0
Waveforms for 50W LED Driver with
50W White LED Headlamp Driver
V
16.9k
IN
R
28.7k
375kHz
100k
NTC
RT1
T
= 12V
PWM Disconnect NFET
SHDN/UVLO
V
CTRL
OPENLED
PWM
SS
RT
V
REF
C
R
10k
C
C
0.001µF
C
LT3755-2
50µs/DIV
V
GND
IN
PWMOUT
SEE SUGGESTED LAYOUT, FIGURE 5
INTV
SENSE
GATE
ISN
22µH
ISP
FB
LT3755/LT3755-1/LT3755-2
L1
CC
C
4.7µF
VCC
37551 TA02b
120
100
M1
80
60
40
20
R
0.015
0
SENSE
25
V
D1
(ISP-ISN)
R
0.1
LED
for NTC Resistor Divider
45
1A
Threshold vs Temperature
TEMPERATURE (°C)
65
R3
1M
R4
23.7k
M2
37551 TA02a
50W
LED
STRING
85
C
4.7µF
OUT
105
37551 TA02d
125

37551fd