Datasheet LT3745 (Analog Devices)
| Manufacturer | Analog Devices |
| Description | 16-Channel 50mA LED Driver with Buck Controller |
| Pages / Page | 28 / 1 — FeaTures. DescripTion. 6V to 55V Power Input Voltage Range. 16 … |
| File Format / Size | PDF / 394 Kb |
| Document Language | English |
FeaTures. DescripTion. 6V to 55V Power Input Voltage Range. 16 Independent LED Outputs Up to 75mA/36V
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LT3745 16-Channel 50mA LED Driver with Buck Controller
FeaTures DescripTion
n
6V to 55V Power Input Voltage Range
The LT®3745 integrates a 16-channel LED driver with a 55V n
16 Independent LED Outputs Up to 75mA/36V
buck controller. The LED driver lights up to 75mA/36V of n
±3% LED Current Matching at 50mA (Typ ±1%)
LEDs in series per channel, and the buck controller gener- n
6-Bit Dot Correction Current Adjustment
ates an adaptive bus voltage supplying the parallel LED n
12-Bit Grayscale PWM Dimming
strings. Each channel has individual 6-bit dot correction n
0.5µs Minimum LED On-Time
current adjustment and 12-bit grayscale PWM dimming. n
Adaptive LED Bus Voltage for High Efficiency
Both dot correction and grayscale are accessible via a n
Cascadable 30MHz Serial Data Interface
serial data interface in TTL/CMOS logic. A ±3% LED cur- n Full Diagnostic and Protection: Individual Open/Short rent matching and a 0.5µs minimum LED on-time can be LED and Overtemperature Fault achieved at 50mA per channel. n 40-Lead 6mm × 6mm QFN Package The LT3745 performs full diagnostic and protection against open/short LED and overtemperature fault. The
applicaTions
fault status is sent back through the serial data interface. n Large Screen Display LED Backlighting The 30MHz fully-buffered, skew-balanced, cascadable n Mono-, Multi-, Full-Color LED Displays serial data interface makes the chip extremely suitable n LED Billboards and Signboards for large screen LCD dynamic backlighting and mono-, L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and multi-, full-color LED displays. True Color PWM is a trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners.
Typical applicaTion 16-Channel LED Driver, 1MHz Buck, 10 LEDs, 25mA to 75mA per Channel, 500Hz 12-Bit Dimming
VIN 42V TO 55V 0.47µF 4.7µF VIN CAP EN EN/UVLO GATE 100k 47µH 25mΩ VCC 3V TO 5.5V VCC 267k 10µF SYNC GND C1 . 2 × 47µF RT ISP LT3745 10k SS ISN 46.4k 10nF .. FB . .. .. ISET LED00 TSET 60.4k LED01 32.4k LED02 ... 2.048MHz CLOCK PWMCK LED13 LED14 LED15 SCKI SCKO TTL/CMOS SDI SDO TTL/CMOS LDI LDO 3745 TA01 3745f 1 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Timing Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Typical Application Package Description Typical Application Related Parts
FeaTures DescripTion
n
6V to 55V Power Input Voltage Range
The LT®3745 integrates a 16-channel LED driver with a 55V n
16 Independent LED Outputs Up to 75mA/36V
buck controller. The LED driver lights up to 75mA/36V of n
±3% LED Current Matching at 50mA (Typ ±1%)
LEDs in series per channel, and the buck controller gener- n
6-Bit Dot Correction Current Adjustment
ates an adaptive bus voltage supplying the parallel LED n
12-Bit Grayscale PWM Dimming
strings. Each channel has individual 6-bit dot correction n
0.5µs Minimum LED On-Time
current adjustment and 12-bit grayscale PWM dimming. n
Adaptive LED Bus Voltage for High Efficiency
Both dot correction and grayscale are accessible via a n
Cascadable 30MHz Serial Data Interface
serial data interface in TTL/CMOS logic. A ±3% LED cur- n Full Diagnostic and Protection: Individual Open/Short rent matching and a 0.5µs minimum LED on-time can be LED and Overtemperature Fault achieved at 50mA per channel. n 40-Lead 6mm × 6mm QFN Package The LT3745 performs full diagnostic and protection against open/short LED and overtemperature fault. The
applicaTions
fault status is sent back through the serial data interface. n Large Screen Display LED Backlighting The 30MHz fully-buffered, skew-balanced, cascadable n Mono-, Multi-, Full-Color LED Displays serial data interface makes the chip extremely suitable n LED Billboards and Signboards for large screen LCD dynamic backlighting and mono-, L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and multi-, full-color LED displays. True Color PWM is a trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners.
Typical applicaTion 16-Channel LED Driver, 1MHz Buck, 10 LEDs, 25mA to 75mA per Channel, 500Hz 12-Bit Dimming
VIN 42V TO 55V 0.47µF 4.7µF VIN CAP EN EN/UVLO GATE 100k 47µH 25mΩ VCC 3V TO 5.5V VCC 267k 10µF SYNC GND C1 . 2 × 47µF RT ISP LT3745 10k SS ISN 46.4k 10nF .. FB . .. .. ISET LED00 TSET 60.4k LED01 32.4k LED02 ... 2.048MHz CLOCK PWMCK LED13 LED14 LED15 SCKI SCKO TTL/CMOS SDI SDO TTL/CMOS LDI LDO 3745 TA01 3745f 1 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Timing Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Typical Application Package Description Typical Application Related Parts
