PT6911 AC/DC Wide Input Range Buck LED Driver DESCRIPTION The PT6911 is ideally suited for AC/DC buck LED driver with external MOSFET. Since the PT6911 includes a 12V~450V linear regulator which allows it to work from a wide range of input voltages without the need for an external low voltage supply. Besides, the PT6911 operates in hysteretic control mode; the controller achieves good output current regulation without the need for any loop compensation. The PT6911 delivers constant current within high accuracy to a wide variety and number of series connected LEDs. The PT6911 includes PWM dimming and linear dimming functions. The PWM dimming input 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 by PWM dimming. Also, a 0.1~1.2V linear dimming input can be used for linear dimming of the LED current. FEATURES • • • • • • Wide Input Voltage: 12V ~ 450V DC Hysteretic controller ±5% Output Current Accuracy Low Stand-by Power Dissipation Soft Start PWM Low-frequency Dimming and Linear Dimming • Thermal Shutdown 160℃ Typical • SOP-8 Package APPLICATIONS • AC/DC LED Driver • LED Bulbs • Constant-Current driver BLOCK DIAGRAM Tel: 886-66296288‧Fax: 886-29174598‧ http://www.princeton.com.tw‧2F, 233-1, Baociao Road, Sindian, Taipei 23145, Taiwan PT6911 TYPICAL APPLICATION ORDER INFORMATION Valid Part Number PT6911-S Package Type 8 Pins, SOP, 150MIL Top Code PT6911-S PIN CONFIGURATION PIN DESCRIPTION Pin Name VIN PWMD NC CS LD GND GD VDD V1.3 Description Input supply voltage, 12V~450V DC. Low frequency PWM dimming pin, also enable pin. When PWMD pin is floating or is pulled to GND, IC operates in stand-by mode. When PWMD pin is pulled to high, IC operates normally. No connection. Current sense pin. Linear dimming with 0.1~1.2V DC input to set the current sense threshold voltage. IC ground. IC output drives external MOSFET. Internal regulated voltage output pin. It must be bypassed with a low ESR capacitor to GND. 2 Pin No. 1 2 3 4 5 6 7 8 August 2011