Linear Technology LT3956 Series Manual page 17

Typical applicaTions
V
IN
9V TO
C1
45V
4.7µF 1M
187k
INTV
CC
100k
35.7k
300kHz
0.1µF
L1: COILCRAFT MSS1038-683
D1: ON SEMICONDUCTOR MBRS3100T3
M1: ZETEX ZXM6IP03F
Q1: ZETEX FMMT493
28V /0V to 28V SEPIC SuperCap Charger with Input Current Limit
IN
V
200m
IN
28V
≤ 1.2A
ISP
1µF
V
IN
EN/UVLO
LT3956
PWMOUT
VMODE
10k
INTV
CC
PWM
RT
V
C
28.7k
C2
375kHz
4.7µF
10nF
3956 TA04a
Buck-Boost Mode LED Driver
L1
D1
68µH
V SW
IN
ISP
EN/UVLO
V
REF
LT3956
ISN
CTRL
619k
FB
10k
VMODE
PGND
PWM
SS
RT
PWMOUT
V GND INTV
C CC
3.4k
INTV
CC
10nF
4.7µF
C4
L1A
10µF
33µH
1:1
C1
ISN
10µF
SW
PGND
536k
FB
25k
1M
CTRL
40.2k INTV
14k
V
REF
SS
2k
GND
Q1
30.1k
L1: WÜRTH ELEKTRONIK 744871330
D1: ON SEMI MBRS36OT
Q1: MMBTA42
C1, C3, C4: TAIYO-YUDEN GMK 3I6BJ106
V
OUT
1µF
4.7µF
100V
35V
V
IN
680m
24V
LED STRING
350mA
750
M1
V
Q1
IN
1k
3956 TA03a
D1
V
OUT
0V TO 28V
L1B
C3
10µF
1M
CC
59k
LT3956
Efficiency vs V
IN
100
96
92
88
84
80
0 10 20 30
V (V)
IN
Input and Output Current
vs Output Voltage
3.0
2.5
2.0
OUTPUT
1.5
1.0
INPUT
0.5
0
0 5 10 15 20
V (V)
OUT
40 50
3956 TA03b
25 30
3956 TA04b
3956f