AL9910 13W T8: 240mA @ 59V Max, 230 VAC in

This application note describes the principles and design equations required for the design of a high brightness LED lamp using the AL9910. The equations are then used to demonstrate the design of a universal, offline, high power factor (PF) using a Valley Fill circuit, 13W LED lamp suitable for use as the replacement for T8 fluorescent tube. A complete design including the electrical diagram, component list and performance measurements are provided.

The AL9910/A high voltage PWM LED driver-controller provides an efficient solution for offline high brightness LED lamps from rectified line voltages ranging from 85VAC up to 277VAC. The AL9910 drives external MOSFETs at switching frequencies up to 300kHz, with the switching frequency determined by a single resistor. The AL9910 topology creates a constant current through the LEDs providing constant light output. The output current is programmed by one external resistor and is ultimately determined by the external MOSFET chosen and therefore allows many low current LEDs to be driven as well as a few high current LEDs.