LT3517
TYPICAL APPLICATIONS
Low Side Current Sensing Load Dump Protected Buck-Boost Mode LED Driver
L1
6.8μH
D1
V
IN
8V TO 16V
C5
0.22μF
R1
3.92M
SHDN
V
IN
SW
FB
R2
124k
PWM
PWM
TGEN
LT3517
ISP
V
R
REF
SENSE
330mΩ
CTRL
SYNC
C1
2.2μF
C2
4.7μF
ISN
TG
D1: DIODES DFLS160
M1
L1: TOKO B992AS-6R8N
V
R
SS
T
GND
C
C1: KEMET C0806C225K4RAC
C2: KEMET C1206C475K3RAC
C3: MURATA GRM21BR71H104KA01B
C4: MURATA GRM219R71H333KAQ01B
C5: MURATA GRM21BR71H224KA01B
M1: ZETEX ZXMP6A13FTA
300mA
R3
R
T
10k 6.04k
2MHz
C4
33nF
C3
0.1μF
3517 TA05a
LEDs: LUXEON I (WHITE)
Efficiency
5000:1 PWM Dimming at 100Hz
90
80
70
60
50
40
30
20
V
= 12V
IN
CTRL = V
REF
PWM
5V/DIV
I
LED
200mA/DIV
I
L
1A/DIV
3517 TA05b
500ns/DIV
V
= 12V
IN
f
I
= 2MHz
OSC
LED
= 300mA
0
20
40
60
80
100
PWM DUTY CYCLE (%)
3517 TA05c
Load Dump Response
V
V
10V/DIV
ISP
10V/DIV
IN
V
ISP
15V TO 40V
V
15V TO 40V
IN
V
REF GND
REF GND
ISP
I
I
200mA/DIV
LED
V
IN
1A/DIV
L
3517 TA05d
5ms/DIV
Raises From 15V to 40V in 5ms.
V
IN
3517fa
15
Linear [ Linear ]
