LT8500 48-Channel LED PWM Generator with 12-Bit Resolution and 50MHz Cascadable Serial Interface Fea T Descrip T n 3V to 5.5V Input Voltage The LT 8500 is a pulse width modulation (PWM) genera- n 48 Independent PWM Outputs tor with 48 independent channels. Each channel has an n TTL/CMOS Logic 50MHz Serial Data Interface individually adjustable 12-bit (4096-step) PWM register n 12-Bit (4096 Steps) PWM Width Resolution and a 6-bit (64-step) 50% correction register. All controls n 6-Bit (64 Steps) PWM Correction are programmable via a simple serial data interface. Three (50% of Programmed PWM Width) banks of 16-channels each can be configured such that n Up to 6.1kHz PWM Frequency (PWMCK = 25MHz) they operate 120 out-of-phase with each other. n Phase-Shift Option Reduces Switching Noise The LT8500 features two diagnostic information flags: n Directly Controls Three LT3595A 16-Channel synchronization error and open LED. The flags are sent, LED Drivers with additional state information, on the serial data interface n Diagnostic Information: Sync Error/Open LED Flags during status read back. The 50MHz cascadable serial data n 56-Pin (5mm 9mm 0.75mm) QFN Package interface includes buffering and skew-balancing, making the chip suitable for PWM intensive applications such as large screen LCD dynamic backlighting and mono-, a T multi- and full-color LED displays. The LT8500 is also n Large Screen Display LED Backlighting ideally suited to control three LT3595A LED drivers. n Mono-, Multi-, Full-Color LED Displays L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear n LED Billboards and Signboards Technology Corporation. All other trademarks are the property of their respective owners. n Motor Control n Industrial Control n Automated Test Equipment n Robotics Typical a T 48 PWM OUTPUTS 48 PWM OUTPUTS 48 PWM OUTPUTS PWM 48:1 PWM 48:1 PWM 48:1 5-WIRE SDI SDO SDI SDO SDI SDO SERIAL SCKI SCK0 SCKI SCK0 SCKI SCK0 DATA INTERFACE LDIBLANK LDIBLANK LDIBLANK LT8500 (1) LT8500 (2) LT8500 (N) OSC PWMCK PWMCK PWMCK OPENLED OPENLED OPENLED DIAGNOSTIC CIRCUIT 8500 TA01a 8500f 1 ion pplica ions pplica ion uresLT8500 a Te Maxi Mu M r a T p in c F T (Note 1) TOP VIEW V ............................................................... 0.3V to 6V CC SDI, SCKI, PWMCK, OPENLED, LDIBLANK ......... 0.3V to Lesser of 6V and (V + 0.3V) CC 56 55 54 53 52 51 50 49 48 47 Operating Junction Temperature Range PWM1 1 46 PWM12 (Note 2) .................................................. 40C to 125C PWM24 2 45 PWM5 Storage Temperature Range .................. 65C to 150C PWM23 3 44 PWM6 PWM22 4 43 PWM7 PWM21 5 42 PWM8 PWM28 6 41 LDIBLANK PWM27 7 40 SDI PWM26 8 39 PWMCK PWM25 9 38 SCKO 57 PWM32 10 37 VCC GND PWM31 11 36 SCKI PWM30 12 35 SDO PWM29 13 34 OPENLED 33 PWM20 14 PWM33 PWM19 15 32 PWM34 PWM18 16 31 PWM35 PWM17 17 30 PWM36 18 PWM40 29 PWM45 19 20 21 22 23 24 25 26 27 28 UHH PACKAGE 56-LEAD (5mm 9mm) PLASTIC QFN T = 125C, = 35C/W, = 5C/W JMAX JA JC EXPOSED PAD (PIN 57) IS GND, MUST BE SOLDERED TO PCB o r Der i n F Ma T LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LT8500EUHH PBF LT8500EUHH TRPBF 8500 56-Lead (5mm 9mm) Plastic QFN 40C to 125C LT8500IUHH PBF LT8500IUHH TRPBF 8500 56-Lead (5mm 9mm) Plastic QFN 40C to 125C 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 non-standard lead based finish parts. For more information on lead free part marking, go to: