Datasheet

LT3517
14
3517fg
For more information www.linear.com/LT3517
Low Side Current Sensing Load Dump Protected Buck-Boost Mode LED Driver
D1
L1
6.8µH
R
SENSE
330mΩ
SHDN
VC GNDRT SS
R
T
6.04k
2MHz
R3
10k
3517 TA05a
C3
0.1µF
C2
4.7µF
R1
3.92M
R2
124k
M1
C5
0.22µF
C1
2.2µF
C4
33nF
PWM
ISP
FB
ISN
TG
TGEN
V
REF
CTRL
SYNC
300mA
V
IN
8V TO 16V
V
IN
LT3517
SW
PWM
D1: DIODES DFLS160
L1: TOKO B992AS-6R8N
C1: KEMET C0806C225K4RAC
C2: KEMET C1206C475K3RAC
C3: MURATA GRM21BR71H104KA01B
C4: MURATA GRM219R71H333KAQ01B
C5: MURATA GRM21BR71H224KA01B
M1: ZETEX ZXMP6A13FTA
LEDs: LUXEON I (WHITE)
TYPICAL APPLICATIONS
5000:1 PWM Dimming at 100Hz
Efficiency
PWM
5V/DIV
I
L
1A/DIV
I
LED
200mA/DIV
500ns/DIV
V
IN
= 12V
f
OSC
= 2MHz
I
LED
= 300mA
3517 TA05b
PWM DUTY CYCLE (%)
0
20
EFFICIENCY (%)
30
40
50
60
70
80
90
20 40 60 80
3517 TA05c
100
V
IN
= 12V
CTRL = V
REF
V
ISP
REF GND
5ms/DIV
V
IN
Raises From 15V to 40V in 5ms.
3517 TA05d
V
IN
REF GND
I
L
1A/DIV
V
ISP
10V/DIV
V
IN
10V/DIV
I
LED
200mA/DIV
V
ISP
15V TO 40V
V
IN
15V TO 40V
Load Dump Response