MAX6971 19-3808 Rev 1 10/07 16-Port, 36V Constant-Current LED Driver General Description Features The MAX6971 serial-interfaced LED driver provides 16 25Mb, Industry-Standard, 4-Wire Serial Interface open-drain, constant-current-sinking LED driver outputs 3V to 5.5V Logic Supply rated at 36V. The MAX6971 operates from a 3V to 5.5V supply. The MAX6971 supply and the LEDs supply or 16 Constant-Current LED Outputs Rated at 36V supplies can power up in any order. The constant-cur- Up to 55mA Continuous Current per Output rent outputs are programmed together to up to 55mA using a single external resistor. The MAX6971 operates Output Current Programmed by Single Resistor with a 25Mb, industry-standard, 4-wire serial interface. 3% Current Matching Between Outputs The MAX6971 uses the industry-standard, shift-register- plus-latch-type serial interface. The driver accepts data 6% Current Matching Between ICs shifted into a 16-bit shift register using data input DIN High-Dissipation, 24-Pin Packages and clock input CLK. Input data appears at the DOUT output 16 clock cycles later to allow cascading of multi- -40C to +125C Temperature Range ple MAX6971s. The latch-enable input, LE, loads the 16 bits of shift register data into a 16-bit output latch to set which LEDs are on and which are off. The output- enable, OE, gates all 16 outputs on and off, and is fast Ordering Information enough to be used as a PWM input for LED intensity control. PART TEMP RANGE PIN-PACKAGE For applications requiring LED fault detection, refer to MAX6971AUG -40C to +125C 24 TSSOP the MAX6983, which automatically detects open-circuit MAX6971ANG -40C to +125C 24 Narrow PDIP LEDs. For safety-related applications requiring a watchdog timer, refer to the MAX6983, which includes a fail-safe feature that blanks the display if the serial interface Typical Application Circuit and Selector Guide appear at becomes inactive for more than 1s. end of data sheet. The MAX6971 is one of a family of 12 shift-register-plus- latch-type LED drivers. The family includes 8-port and 16-port types, with 5.5V- or 36V-rated LED outputs, with Pin Configuration and without open-circuit LED detection and watchdog. All versions operate from a 3V to 5.5V supply, and are TOP VIEW specified over the -40C to +125C temperature range. GND 1 24 V+ DIN 2 23 SET Applications CLK 3 22 DOUT LE 4 21 OE Variable Message Signs MAX6971AUG OUT0 5 20 OUT15 MAX6971ANG Marquee Displays OUT1 6 19 OUT14 Point-of-Order Signs OUT2 7 18 OUT13 Traffic Signs OUT3 8 17 OUT12 Gaming Features OUT4 9 16 OUT11 OUT5 10 15 OUT10 Architectural Lighting OUT6 11 14 OUT9 OUT7 12 13 OUT8 TSSOP/PDIP Maxim Integrated Products 1 For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxims website at www.maxim-ic.com. EVALUATION KIT AVAILABLE16-Port, 36V Constant-Current LED Driver ABSOLUTE MAXIMUM RATINGS Voltage with respect to GND. Continuous Power Dissipation (T = +70C) A V+ ............................................................................-0.3V to +6V 24-Pin TSSOP (derate 12.2mW/C over +70C) ..........975mW OUT .....................................................................-0.3V to +40V 24-Pin PDIP (derate 13.3mW/C over +70C)............1067mW DIN, CLK, LE, OE, SET ................................-0.3V to (V+ + 0.3V) Operating Temperature Range .........................-40C to +125C DOUT Current ..................................................................10mA Junction Temperature......................................................+150C OUT Sink Current .............................................................60mA Storage Temperature Range .............................-65C to +150C Total GND Current ...........................................................960mA Lead Temperature (soldering, 10s) .................................+300C Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. ELECTRICAL CHARACTERISTICS (Typical Operating Circuit, V+ = 3V to 5.5V, T = T to T , unless otherwise noted. Typical values are at V+ = 5V, T = +25C.) A MIN MAX A (Note 1) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Operating Supply Voltage V+ 3.0 5.5 V Output Voltage V 36 V OUT Standby Current All logic inputs at V+ or GND, DOUT (Interface Idle, All Output Ports I 5.7 8 mA + unloaded High Impedance, R = 360) SET Standby Current (Interface Running, All Output f = 5MHz, OE = V+, DIN and LE = V+ CLK I 6 8.5 mA + Ports High Impedance, or GND, DOUT unloaded R = 360) SET Supply Current All logic inputs at V+ or GND, (Interface Idle, All Output Ports I 18 25 mA + DOUT unloaded Active Low, R = 360) SET Input High Voltage 0.7 x V V IH DIN, CLK, LE, OE V+ Input Low Voltage 0.3 x V V IL DIN, CLK, LE, OE V+ Hysteresis Voltage V 0.8 V I DIN, CLK, LE, OE Input Leakage Current I , I -1 +1 A IH IL DIN, CLK, LE, OE V + Output High-Voltage DOUT V I = 4mA V OH SOURCE - 0.5V Output Low Voltage V I = 4mA 0.5 V OL SINK V+ = 3V to 5.5V, V = 0.8V to 2.5V, OUT Output Current OUT I 37 50 61 mA OUT R = 360 SET Output Leakage Current OUT I OE = V+ 1 A LEAK Note 1: All parameters tested at T = +25C. Specifications over temperature are guaranteed by design. A 2 MAX6971