Datasheet

LT3745
1
3745f
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EN/UVLO
SYNC
RT
SS
V
CC
I
SET
T
SET
SCKI
SDI
LDI
SCKO
SDO
LDO
LED13
LED14
LED15
LED00
LED01
LED02
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LT3745
100k
V
IN
42V TO 55V
EN
V
CC
3V TO 5.5V
V
IN
CAP
0.47µF
GATE
GND
FB
ISP
ISN
4.7µF
267k
10k
C1
2 × 47µF
47µH 25mΩ
PWMCK
TTL/CMOS
2.048MHz CLOCK
TTL/CMOS
3745 TA01
10µF
46.4k
10nF
60.4k
32.4k
Typical applicaTion
DescripTion
16-Channel 50mA LED
Driver with Buck Controller
The LT
®
3745 integrates a 16-channel LED driver with a 55V
buck controller. The LED driver lights up to 75mA/36V of
LEDs in series per channel, and the buck controller gener-
ates an adaptive bus voltage supplying the parallel LED
strings. Each channel has individual 6-bit dot correction
current adjustment and 12-bit grayscale PWM dimming.
Both dot correction and grayscale are accessible via a
serial data interface in TTL/CMOS logic. A ±3% LED cur-
rent matching and a 0.5µs minimum LED on-time can be
achieved at 50mA per channel.
The LT3745 performs full diagnostic and protection
against open/short LED and overtemperature fault. The
fault status is sent back through the serial data interface.
The 30MHz fully-buffered, skew-balanced, cascadable
serial data interface makes the chip extremely suitable
for large screen LCD dynamic backlighting and mono-,
multi-, full-color LED displays.
16-Channel LED Driver, 1MHz Buck, 10 LEDs, 25mA to 75mA per Channel, 500Hz 12-Bit Dimming
FeaTures
applicaTions
n
6V to 55V Power Input Voltage Range
n
16 Independent LED Outputs Up to 75mA/36V
n
±3% LED Current Matching at 50mA (Typ ±1%)
n
6-Bit Dot Correction Current Adjustment
n
12-Bit Grayscale PWM Dimming
n
0.5µs Minimum LED On-Time
n
Adaptive LED Bus Voltage for High Efficiency
n
Cascadable 30MHz Serial Data Interface
n
Full Diagnostic and Protection: Individual Open/Short
LED and Overtemperature Fault
n
40-Lead 6mm × 6mm QFN Package
n
Large Screen Display LED Backlighting
n
Mono-, Multi-, Full-Color LED Displays
n
LED Billboards and Signboards
L, LT, LT C, LT M, Linear Technology and the Linear logo are registered trademarks and
True Color PWM is a trademark of Linear Technology Corporation. All other trademarks are the
property of their respective owners.

Summary of content (28 pages)