Highly integrated components to enable easy design and reduced part count

In particular, power engineers working in the design of all-in-one PC power supplies, slim-pack PC adapters, LCD TVs, and LED lighting require dual-switch flyback systems to provide the high efficiency and energy savings required by government regulations that cannot be provided by LLC or single flyback solutions. To meet these demands, Fairchild Semiconductor’s FAN6920MR, a critical mode PFC and quasi-resonant current mode PWM controller, was developed to achieve over 90% efficiency and meet regulatory conditions of less than 300mW under no-load conditions to increase power savings.

The FAN6920MR combines a PFC controller and a Quasi-resonant PWM controller to enable a cost-reduction design by using fewer external components. The PFC uses Controlled on-time technology to provide a constant DC output voltage and achieve a natural power factor.
With innovative Total Harmonic Distortion (THD) optimization, the FAN6920MR can reduce input current distortion in the zero-crossing section to reduce total harmonic distortion.

In the PWM controller, the FAN6920 provides various features to enhance power system performance, such as increased low-load efficiency, green mode operation, internal 10ms soft start, and high/low line overvoltage compensation, including valley detect extended to the 12th valley cycle to reduce switching frequency.

Additionally, this product provides various protection features such as brownout, secondary open-loop and auto-recovery overcurrent, external auto-recovery protection, and internal overtemperature shutdown.

The FAN6920MR, available in a 16-pin SOP package, is similar to LCD TVs and LED streetlights