The AL9901, high-voltage PWM LED driver provides an efficient solution for offline, high-brightness LED lamps for rectified line voltages ranging from 85VAC up to 305VAC. The AL9901 has an internal MOSFET that allows switching frequencies up to 300kHz, with the switching frequency determined by an external single resistor. The AL9901 topology creates a constant current through the LEDs providing constant light output. The output current is programmed by one external resistor.
The LED brightness can be varied by both Linear and PWM dimming, using the AL9901’s LD and PWM pins respectively. The PWM input operates with a duty ratio of 0-100% and a frequency of up to several kHz.
The AL9901 is available in the thermally enhanced U-DFN6040-12 and SO-16 packages. The SO-16 is compliant to high voltage spacing rules for 230VAC mains applications.
• LED Offline Lamps
• High Voltage DC-DC LED Driver
• Signage and Decorative LED Lighting
• Back Lighting of Flat Panel Displays
• General Purpose Constant Current Source
• >90% Efficiency
• Universal Rectified 85 to 305VAC Input Range
• Internal MOSFET Up to 650V, 2A
• High Switching Frequency Up to 300kHz
• Internal Voltage Regulator Removes Start-Up Resistor
• 7.5V Regulated Output
• Tighter Current Sense Tolerance Better Than 5%
• LED Brightness Control with Linear and PWM Dimming