This ensures there is no sign of flicker or strobing across the entire dimming range, while still maintaining a high power factor.
The AL5822 has been designed and tested to comply with the Title 24 building code requirement of less than 30% flicker. The device has been demonstrated to suppress over 97% of ripple while still achieving a power factor of greater than 0.9. By monitoring the current flowing through the LEDs, the AL5822 compensates for ripple by adjusting the drive voltage for the external MOSFET. This control loop keeps the MOSFET operating in the saturation region to deliver a constant current.
With support for various pre-stage circuits, the chip can work with a number of drivers, such as the AL1665 single stage PFC flyback buck/boost controller, also from Diodes Incorporated. The device doesn’t require magnetic discrete components, minimizing the overall bill of materials. It operates over an input voltage range of 24Vac to 305Vac. Safety features include LED short-circuit, over-temperature, and over-current protection.