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.