LT3745EUJ-1#TRPBF

LT3745-1 16-Channel 50mA LED Driver with Buck Controller DESCRIPTION FEATURES 6V to 55V Power Input Voltage Range 16 Independent LED Outputs Up to 75mA/36V ±4% LED Current Matching at 50mA (Typ ±1%) 6-Bit Dot Correction Current Adjustment 12-Bit Grayscale PWM Dimming 0.5µs Minimum LED On-Time Adaptive LED Bus Voltage for High Efficiency Cascadable 30MHz LVDS Serial Data Interface Full Diagnostic and Protection: Individual Open/Short LED and Overtemperature Fault n 40-Lead 6mm × 6mm QFN Package n n n n n n n n The LT®3745-1 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 generates 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 LVDS logic. A ±4% LED current matching and a 0.5µs minimum LED on-time can be achieved at 50mA per channel. n The LT3745-1 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, cascadable LVDS serial data interface makes the chip extremely suitable for large screen LCD dynamic backlighting and mono-, multi-, full-color LED displays. The LT3745 uses a TTL/CMOS serial data interface instead of LVDS. APPLICATIONS Large Screen Display LED Backlighting Mono-, Multi-, Full-Color LED Displays n LED Billboards and Signboards n n L, LT, LTC, LTM, 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. Protected by U.S. Patents, including 8058810 TYPICAL APPLICATION 16-Channel LED Driver, 1MHz Buck, 10 LEDs, 25mA to 75mA per Channel, 500Hz 12-Bit Dimming VIN 42V TO 55V 4.7µF 0.47µF VIN EN EN/UVLO CAP GATE 47µH 100k VCC 3V TO 3.6V 10µF VCC 267k GND SYNC 46.4k SS ISN ISET TSET 32.4k 2.048MHz LVDS CLOCK LVDS PWMCK+ PWMCK– SCKI+ SCKI– SDI+ SDI– LDI .. .. . .. .. . .. .. . .. .. . .. .. . .. .. . FB 10nF 60.4k 10k ISP LT3745-1 47µF ×2 . .. RT 25mΩ LED00 LED01 LED02 .. . LED13 LED14 LED15 SCKO+ SCKO– SDO+ SDO– LVDS 37451 TA01 37451f 1 LT3745-1 RT SS FB ISN ISP CAP GATE VIN TSET TOP VIEW ISET 40 39 38 37 36 35 34 33 32 31 EN/UVLO 1 30 SYNC LED07 2 29 LED08 LED06 3 28 LED09 LED05 4 27 LED10 41 GND LED04 5 LED03 6 26 LED11 25 LED12 LED02 7 24 LED13 LED01 8 23 LED14 LED00 9 22 LED15 SCKI– 10 21 SCKO– SCKO+ SDO– SDO+ PWMCK– PWMCK+ VCC LDI 11 12 13 14 15 16 17 18 19 20 SDI+ VIN ........................................................................... 57V CAP.......................................................... VIN – 8V to VIN GATE...............................................................CAP to VIN LED00 to LED15, ISP, ISN..........................................40V ISP..................................................ISN – 1V to ISN + 1V FB, RT, TSET, ISET........................................................ 2V VCC................................................................ –0.3V to 4V SCKI+, SCKI–, SCKO+, SCKO –, SDI+, SDI–, SDO+, SDO –, LDI, PWMCK+, PWMCK–, SYNC, SS, EN/UVLO.............................................. –0.3V to VCC Operating Junction Temperature Range (Notes 2, 3) LT3745E-1..........................................–40°C to 125°C LT3745I-1...........................................–40°C to 125°C Storage Temperature Range...................–65°C to 125°C PIN CONFIGURATION SDI– (Note 1) SCKI+ ABSOLUTE MAXIMUM RATINGS UJ PACKAGE 40-LEAD (6mm × 6mm) PLASTIC QFN TJMAX = 125°C, θJA = 34°C/W, θJC = 2.5°C/W EXPOSED PAD (PIN 41) IS GND, MUST BE SOLDERED TO PCB ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LT3745EUJ-1#PBF LT3745EUJ-1#TRPBF LT3745UJ-1 40-Lead (6mm × 6mm) Plastic QFN –40°C to 125°C LT3745IUJ-1#PBF LT3745IUJ-1#TRPBF LT3745UJ-1 40-Lead (6mm × 6mm) Plastic QFN –40°C to 125°C Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container. Consult LTC Marketing for information on nonstandard lead based finish parts. For more information on lead free part marking, go to: http://www.linear.com/leadfree/ For more information on tape and reel specifications, go to: http://www.linear.com/tapeandreel/ ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VIN = 12V, VCC = 3.3V, VEN/UVLO = 1.5V, VFB = 1.5V, VISP = VISN = 0V, RT = 105k, RISET = 60.4k, CCAP = 0.47µF to VIN, unless otherwise noted. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS Supply VIN VIN Operating Voltage IVIN VIN Supply Current VCC VCC Operating Voltage IVCC VCC Supply Current (Note 4) l 6 VEN/UVLO = 0V No Switching 0.2 0.4 l VEN/UVLO = 0V LED Channel Off, 30MHz Data Off LED Channel On, 30MHz Data Off LED Channel On, 30MHz Data On 55 3 0.25 11 16 19 V 2 0.55 µA mA 3.6 V mA mA mA mA 37451f 2 LT3745-1 ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VIN = 12V, VCC = 3.3V, VEN/UVLO = 1.5V, VFB = 1.5V, VISP = VISN = 0V, RT = 105k, RISET = 60.4k, CCAP = 0.47µF to VIN, unless otherwise noted. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS VCC UVLO Threshold VCC Rising VCC Falling 2.76 2.58 2.86 2.68 2.96 2.78 V V EN/UVLO Shutdown Threshold UVLO Threshold IVCC