PT6718 18-Channel Constant Current Sink for LED Driver DESCRIPTION The PT6718 is a 18-channel current sink driver for LED clusters. It contains a serial buffer and data latches which convert serial input data into parallel output format. At output stage, sixteen regulated current ports are designed to provide uniform and constant current sinks for driving LEDs. The output current is determined by an external resistor and the brightness control code, both set by users. PT6718 can used to control LEDs intensity with output enables as PWM input function.PT6718 provides users with great flexibility and performance. Users may adjust the output current from 3mA to 45mA which gives users flexibility in controlling the light intensity of LEDs. The PT6718 guarantees to endure maximum 17V at the output port. FEATURES • • • • • 18-channel constant current sink output Output current invariant to load voltage change Serial data in/parallel data out Constant output current range: 3~45mA Output current accuracy: - ICs skew: < 3%(max) - Bits skew: < 2.5%(max) • 3~5.5V supply voltage • 25 MHz clock frequency • Package: SOP24 APPLICATION • LED display/ RGB cluster control BLOCK DIAGRAM Tel: 886-66296288‧Fax: 886-29174598‧ http://www.princeton.com.tw‧2F, 233-1, Baociao Road, Sindian, Taipei 23145, Taiwan PT6718 ORDER INFORMATION Valid Part Number PT6718-S Package Type 24 Pins, SOP Top Code PT6718-S PIN CONFIGURATION PIN DESCRIPTION Pin Name GND SDI CLK /LE OUT[0:17] REXT VDD V1.0 Description Ground terminal. Serial input of data shift register. Clock input of shift register, data is sampled at the rising edge of CLK. Input terminal of latch enable. Data is latched when /LE is low. And data on shift register goes through when /LE is high. Open-drain, constant-current sink outputs. External resistor terminal for setting up all output current. Supply voltage terminal. 2 Pin No. 1 2 3 4 5~22 23 24 May 2012