Linear Technology LT3956 Series Manual page 20

LT3956
Typical applicaTion
Buck Mode 1A LED Driver with High Dimming Ratio and Open LED Reporting
V
IN
24V TO
80V
1M
V
IN
EN/UVLO
61.9k
V
REF
30.1k
PWMOUT
CTRL
LT3956
10k
INTV
CC
100k
VMODE
PWM
SS
0.1µF RT
V GND INTV
28.7k
C CC
375kHz
47k
2.2nF
relaTeD parTs
PART NUMBER DESCRIPTION
LT3756/LT3756-1/ 100V , 100V
IN
LT3756-2
LT3755/LT3755-1/ 40V , 75V
IN OUT
LT3755-2
LT3474 36V, 1A (I
LED
LT3475 Dual 1.5A (I
LT3476 Quad Output 1.5A, 36V, 2MHz High Current LED Driver
with 1000:1 Dimming
LT3477 3A, 42V, 3MHz Boost, Buck-Boost, Buck LED Driver
LT3478/LT3478-1 4.5A, 42V, 2.5MHz High Current LED Driver with
3000:1 Dimming
0 Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 FAX: (408) 434-0507
●
ISP
750 0.1
1A
ISN
FB
M1
Q1
6 WHITE LEDs
20W
1k
L1
33µH
SW
D1
C1
1µF
2
PGND
INTV
CC
D1: DIODES INC B1100/B
L1: WÜRTH 74456133
4.7µF
M1: VISHAY SILICONIX Si5435BDC
Q1: ZETEX FMMT493
Q2: ZETEX FMMT593
3956 TA07a
C1: TDKC3226X7R2A105K
C2: TDKC3225X7RIE475K
, Full Featured LED Controller
OUT
, Full Featured LED Controller
), 2MHz, Step-Down LED Driver
), 36V, 2MHz Step-Down LED Driver
LED
www.linear.com
●
C2
200k 200k
4.7µF
5
200k
Q2
20k
V
IN
COMMENTS
V : 6V to 100V, V
IN OUT(MAX)
I < 1µA, 3mm × 3mm QFN-16 and MS16E Packages
SD
V : 4.5V to 40V, V
IN OUT(MAX)
I < 1µA, 3mm × 3mm QFN-16 and MS16E Packages
SD
V : 4V to 36V, V
IN OUT(MAX)
I < 1µA, TSSOP16E Package
SD
V : 4V to 36V, V
IN OUT(MAX)
I < 1µA, TSSOP20E Package
SD
V : 2.8V to 16V, V
IN OUT(MAX)
I < 10µA, 5mm × 7mm QFN Package
SD
V : 2.5V to 25V, V
IN OUT(MAX)
QFN and TSSOP20E Packages
V : 2.8V to 36V, V
IN OUT(MAX)
I < 3µA, TSSOP16E Package
SD
Efficiency vs V
IN
100
96
92
88
84
80
20 30 40 50 60
V (V)
IN
= 100V, True Color PWM Dimming = 3000:1,
= 60V, True Color PWM Dimming = 3000:1,
= 13.5V, True Color PWM Dimming = 400:1,
= 13.5V, True Color PWM Dimming = 3000:1,
= 36V, True Color PWM Dimming = 1000:1,
= 40V, Dimming = Analog/PWM, I
= 42V, True Color PWM Dimming = 3000:1,
LT 0510 • PRINTED IN USA
 LINEAR TECHNOLOGY CORPORATION 2010
70 80
3956 TA06b
< 1µA,
SD
3956f