PT6901 High Power LED Driver DESCRIPTION PT6901 is an open loop current mode control high brightness LED driver IC. PT6901 can be programmed to operate in either constant frequency or constant off-time mode. The frequency can be programmable set as 30KHz~300KHz. The PT6901 is ideally suited for buck LED drivers. It exports PWM signal to control the external MOS. The PT6901 supply voltage input range is from 8V to 12V, and the output current can be programmed between a few milliamps and up to more than 1.0A. PT6901 can drive a single or multiple series LEDs, and provide reliability constant current output by detecting LED peak current. FEATURES • Constant-current driver • >85% Efficiency • Constant frequency or constant off-time operation • 8V to 12V input range • LED string from one to hundreds diodes • Applications from a few mA to more than 1A LED driver • PWM low-frequency dimming and linear dimming The functions of linear and PWM dimming are included. PT6901 provides a low-frequency PWM dimming input that can accept an external control signal with a duty cycle of 0~100% and a frequency between 100Hz and a few KHz. Output current to LED string can be programmed to any value between 0 to its maximum value at the PWM dimming control input of PT6901. Also, a 0~240mV linear dimming input can be used for linear dimming of the LED current. APPLICATIONS • • • • DC/DC or AC/DC LED driver Backlight LED driver Constant-Current driver Charger BLOCK DIAGRAM Tel: 886-66296288‧Fax: 886-29174598‧ http://www.princeton.com.tw‧2F, 233-1, Baociao Road, Sindian, Taipei 23145, Taiwan PT6901 TYPICAL APPLICATION Typical 220V AC application for a string of 6 HB LEDs V1.5 2 August, 2009 PT6901 ORDER INFORMATION Valid Part Number PT6901-SA Package Type 8 Pins, SOP, 150MIL Top Code PT6901-SA PIN CONFIGURATION PIN DESCRIPTION Pin Name CS GND GD VIN PWMD VDD LD RF V1.5 Description Senses LED string current with an external sense resistor. When the voltage of CS pin exceeds the lower of either the internal 240mV or the voltage of LD pin, the GD output goes low. IC Ground. IC output drives the gate of external MOSFET. Input supply voltage 8V-12V DC. Low frequency PWM dimming pin, also enable pin. When PWMD pin is floating or is pulled to GND, IC operates in shut-down mode. When PWMD pin is pulled to high, IC operates normally. Internal regulated voltage. The voltage acts as power supply of internal control circuit, also provides a supply voltage for external circuit. The current source capability is limited less than 10mA. Linear dimming. If the voltage at the LD pin is less than 240mV, the LD pin voltage sets the current sense threshold. Oscillator frequency control. The PT6901 operates in constant frequency mode when a resistor is connected between RF and GND. The PT6901 operates in constant off-time mode when a resistor is connected between RF and GD. 3 Pin No. 1 2 3 4 5 6 7 8 August, 2009 PT6901 IMPORTANT NOTICE Princeton Technology Corporation (PTC) reserves the right to make corrections, modifications, enhancements, improvements, and other changes to its products and to discontinue any product without notice at any time. PTC cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a PTC product. No circuit patent licenses are implied. Princeton Technology Corp. 2F, 233-1, Baociao Road, Sindian, Taipei 23145, Taiwan Tel: 886-2-66296288 Fax: 886-2-29174598 http://www.princeton.com.tw V1.5 4 August, 2009