LT3746 32-Channel 20mA LED Driver with Buck Controller FeaTuresDescripTion n 6V to 55V Power Input Voltage Range The LT®3746 integrates a 32-channel LED driver with a 55V n 32 Independent LED Outputs up to 30mA/13V buck control er. The LED driver lights up to 30mA/13V of n 6-Bit Dot Correction Current Adjustment LEDs in series per channel, and the buck control er gener- n 12-Bit Grayscale PWM Dimming ates an adaptive bus voltage supplying the paral el LED n 0.5µs Minimum LED On Time strings. Each channel has individual 6-bit dot correction n Adaptive LED Bus Voltage for High Efficiency current adjustment and 12-bit grayscale PWM dimming. n Cascadable 30MHz Serial Data Interface Both dot correction and grayscale are accessible via a n Full Diagnostic and Protection: Individual Open/Short serial data interface in TTL/CMOS logic. LED and Overtemperature Fault The LT3746 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 The 30MHz ful y-buffered, skew-balanced, cascadable Large Screen Display LED Backlighting n serial data interface makes the chip extremely suitable Mono-, Multi-, Ful -Color LED Displays n for large screen LCD dynamic backlighting and mono-, LED Bil boards and Signboards multi-, ful -color LED displays. L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. Typical applicaTion32-Channel LED Driver, 1MHz Buck, 3 LEDs 10mA to 30mA per Channel, 500Hz 12-Bit Dimming VIN 13V TO 42V 0.47µF 4.7µF VIN CAP EN EN/UVLO GATE 100k 22µH 33mΩ VCC 3V TO 5.5V VCC 80.6k 10µF SYNC GND C1 2 × 47µF . RT ISP LT3746 10k SS ISN 46.4k 10nF FB ISET LED00 TSET 60.4k LED01 32.4k LED02 ... 2.048MHz CLOCK PWMCK LED29 LED30 LED31 SCKI SCKO TTL/CMOS SDI SDO TTL/CMOS LDI LDO 3746 TA01 3746fa For more information www.linear.com/3746 1 Document Outline Description Typical Application Absolute Maximum Ratings Pin Configuration Electrical Characteristics Pin Functions Block Diagram Applications Information Typical Application Related Parts
