LT8500 48-Channel LED PWM Generator with 12-Bit Resolution and 50MHz Cascadable Serial Interface FEATURES DESCRIPTION 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 con- n 6-Bit (64 Steps) PWM Correction trols are programmable via a simple serial data interface. (50% of Programmed PWM Width) Three banks of 16-channels each can be configured such n Up to 6.1kHz PWM Frequency (PWMCK = 25MHz) that 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 inter- n Diagnostic Information: Sync Error/Open LED Flags face during status read back. The 50MHz cascadable serial n 56-Pin (6mm 6mm 0.78mm) TLA QFN Package data interface includes buffering and skew-balancing, mak- ing the chip suitable for PWM intensive applications such APPLICATIONS as large screen LCD dynamic backlighting and mono-, n Large Screen Display LED Backlighting multi- and full-color LED displays. The LT8500 is also n Mono-, Multi-, Full-Color LED Displays ideally suited to control three LT3595A LED drivers. n LED Billboards and Signboards All registered trademarks and trademarks are the property of their respective owners. n Motor Control n Industrial Control n Automated Test Equipment n Robotics TYPICAL APPLICATION 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 Rev C 1 Document Feedback For more information www.analog.comLT8500 ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION (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 PWM2 A1 A40 A39 A38 A37 A36 A35 A34 A33 A32 A31 PWM12 Operating Junction Temperature Range PWM24 A2 A30 PWM7 PWM1 B1 B16 PWM5 (Note 2) .................................................. 40C to 125C PWM22 A3 A29 PWM6 PWM21 B2 B15 PWM8 Storage Temperature Range .................. 65C to 150C PWM23 A4 A28 LDIBLANK PWM27 B3 B14 SDI PWM26 A5 A27 PWMCK PWM28 B4 B13 SDKO 57 PWM25 V A6 A26 CC GND PWM32 B5 B12 SCKI PWM31 A7 A25 SDO B6 B11 OPENLED PWM30 PWM20 A8 A24 PWM33 PWM19 B7 B10 PWM35 PWM29 A9 A23 PWM34 PWM18 B8 B9 PWM45 PWM17 A10 A22 PWM36 PWM40 A11 A12 A13 A14 A15 A16 A17 A18 A19 A20 A21 PWM46 TJ PACKAGE 56-LEAD PLASTIC TLA QFN (6mm 6mm) T = 125C, = 35C/W, = 5C/W JMAX JA JC EXPOSED PAD (PIN 57) IS GND, MUST BE SOLDERED TO PCB ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LT8500ETJ PBF LT8500ETJ TRPBF LT8500TJ 40C to 125C 56-Lead (6mm 6mm) Plastic TLAQFN LT8500ITJ PBF LT8500ITJ TRPBF LT8500TJ 40C to 125C 56-Lead (6mm 6mm) Plastic TLAQFN Consult ADI Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container. Tape and reel specifications. Some packages are available in 500 unit reels through designated sales channels with TRMPBF suffix. Rev C 2 For more information www.analog.com PWM39 PWM3 PWM37 PWM4 PWM38 PWM13 PWM44 PWM14 PWM915 PWM43 PWM42 PWM16 PWM41 PWM9 PWM48 PWM10 PWM47 PWM11