LT3967EFE#TRPBF Analog Devices

LT3967 1.3A Eight-Switch Matrix LED Dimmer with CRC-8 FEATURES DESCRIPTION n Eight Independent 15V/110m NMOS Switches The LT 3967 is an LED bypass switching device for dim- n Controls LED Dimming of Strings Up to 54V ming individual LEDs in a string using a common current 2 n I C Serial Interface with Programmable Address source. It features eight individually controlled floating 2 n I C Packet Error Checking with CRC-8 source 15V/110m NMOS switches. The eight switches n Programmable 256:1 (8-Bit) PWM Dimming can be connected in parallel and/or in series to bypass 2 n 11-Bit Precision Exponential Fade with current around LEDs in a string. The LT3967 uses the I C Programmable Time serial interface to communicate with a microcontroller. n Independent On/Off Control for Each Switch Each of the eight channels can be independently pro- n Programmable Shorted/Open LED Threshold with grammed to bypass the LED string in constant on or off, Fault Reporting or PWM dimming with or without fade transition. Using n Internal PWM Signal Generator the programmable fade option provides 11-bit resolution n Programmable Watchdog Timer exponential transition between PWM dimming states. The n Accurate V Referred Enable Pin IN LT3967 provides an internal clock generator and also sup- n User Defined Power-Up/Reset State of Switches ports an external clock source for PWM dimming. The n Thermally Enhanced TSSOP Package LT3967 reports fault conditions for each channel such as open LED and shorted LED. The four address pins allow 2 16 LT3967 devices to share the I C bus and define the APPLICATIONS power-up state of the switches. n Automotive LED Headlight Clusters All registered trademarks and trademarks are the property of their respective owners. n Large LED Displays n RGBW Color Mixing Lighting TYPICAL APPLICATION 1A Matrix LED Dimmer Powered by a Buck LED Driver 1F D1 D2 50V 10k INTV CC + LED V V IN IN ENH V BST IN DRN8 32V TO 36V 49.9k 22nF L1 255k SRC8 1F 2 33H + 50V DRN7 1A LED EN/UVLO SW 10F 100m V V DD DD 50V SRC7 V 10.2k OUT DRN6 2.2F 267k LT3967 SRC6 10k 22nF DRN5 ALERT FB 50V 10k LT3932 SCL SRC5 10k DRN4 10k SDA GND V REF SRC4 RTSYNC CLKIN 2.2F DRN3 3.3V CTRL ISP 0V SRC3 350kHz PWM ISN D1: NEXPERIA BAT46WJ WDI DRN2 D2: NXP PMEG4010CEJ INTV CC 1A 10nF L1: WURTH 74437349330 INTV SYNC/SPRD CLKIN CC UP TO 26V LED SRC2 ADDR1 DRN1 SS RT RP V PWMTG, FAULT, AND C 1M ADDR2 ISMON NOT USED ADDR3 287k 2.2F 350kHz 330pF SRC1 ADDR4 GND 10nF 3967 TA01 Rev 0 1 Document Feedback For more information www.analog.comLT3967 TABLE OF CONTENTS Features ............................................................................................................................ 1 Applications ....................................................................................................................... 1 Typical Application ............................................................................................................... 1 Description......................................................................................................................... 1 Absolute Maximum Ratings ..................................................................................................... 3 Pin Configuration ................................................................................................................. 3 Order Information ................................................................................................................. 3 Electrical Characteristics ........................................................................................................ 4 Typical Performance Characteristics .......................................................................................... 7 Pin Functions ...................................................................................................................... 9 Block Diagram ....................................................................................................................11 Applications Information .......................................................................................................12 Overview ............................................................................................................................................................... 12 Power-On Reset and Dimming Cycle Initialization ................................................................................................ 12 Operation in Shutdown Condition ......................................................................................................................... 12 Dimming without Fade Transition vs Dimming with Fade Transition ..................................................................... 13 2 LT3967 I C Registers............................................................................................................................................ 14 LT3967 Command Registers and Channel Control ............................................................................................... 14 2 I C Serial Interface ................................................................................................................................................ 14 The Start and Stop Conditions .............................................................................................................................. 17 2 I C Serial Port Data Transfer ................................................................................................................................. 17 2 LT3967 I C Commands and Write/Read Protocols ............................................................................................... 19 LT3967 Alert Response Protocol Using Alert Response Address (ARA) ............................................................... 23 Watchdog Timeout Reset ...................................................................................................................................... 24 RTSYNC Input Clock Fault Detection and Alert Assertion ...................................................................................... 24 LED/Overheat Fault Detection And Reporting ........................................................................................................ 24 Open LED Fault Detection and Alert Assertion ...................................................................................................... 25 Shorted LED Fault Detection and Alert Assertion .................................................................................................. 25 LED Fault Status Bit Clearance .............................................................................................................................. 25 Overheat Fault Detection and Alert Assertion ........................................................................................................ 25 Overheat Status Bits Clearance ............................................................................................................................. 25 Alert Deassertion .................................................................................................................................................. 25 Printed Circuit Board Layout ................................................................................................................................. 25 Typical Applications .............................................................................................................27 Package Description ............................................................................................................28 Typical Application ..............................................................................................................30 Related Parts .....................................................................................................................30 Rev 0 2 For more information www.analog.com