For PFC control, the FL7921R uses a controlled on-time technique to provide a regulated DC output voltage. Innovative technology in the device reduces input-current distortion at the zero-crossing point to reduce harmonic distortion. The PFC function is always on regardless of the PWM stage’s status, ensuring that a high power factor is maintained even in light-load conditions.
For PWM operation, the FL7921R provides several functions to enhance performance, including valley detection, green-mode operation and high-/low-line over-power compensation.
The FL7921R is featured in a Fairchild reference design, RD-570, for a 100W smart LED lamp, which operates from a universal input-voltage range of 90V to 305V AC, and has an output of 50V/2A. The design achieves efficiency of 91.56% at an output voltage of 47V when operating from a 50Hz mains input at 230V AC.
- Brown-out protection
- Over-current protection
- Open-loop protection
- Over-temperature protection
- Adjustable over-temperature threshold using external temperature sensor
- Medium- to high-power LED lighting drivers
Orderable Part Number: FEBFL7921RMX_L65U100A