Traditionally, the higher-efficiency and the lower-cost BCM PFC converters are limited to around 300W of maximum power level. Interleaving expands the power range of BCM control while the ripple current cancellation minimizes the high peak currents. By interleaving and keeping the two power stages precisely at 180 degrees out of phase timing under all the operating conditions, the new FAN9612 lowers conduction losses. These energy conservation benefits are integral in helping the customers meet the new ENERGY STAR and Climate Savers Computing Initiative requirements.
By the interleaving of power trains, the new FAN9612 is also able to decrease the input filter size and reduce the board space by as much as 10% when compared to the alternate solutions. This smaller system footprint decreases the overall cost of the solution and simplifies design, without compromising on the protection features.
The new FAN9612 includes the new set of features including:
Automatic phase disable to operate with only one channel under the light-load conditions, lessens power losses;
A low start-up and the operating current;
Valley switching technology lessens losses at MOSFET turn-on;
Over-current and the power-limit protection for each channel;
Two-level output over-voltage protection (OVP);
Input brownout protection and the line OVP;
Less restart timer frequency to avoid audible noise;
Maximum switching frequency clamp;
Programmable closed-loop soft-start, which minimizes output voltage overshoot at start-up;
Input voltage feed-forward function that minimizes output voltage variation versus line voltage.
The PFC controller portfolio:
The new FAN9612 improves the company’s large portfolio of PFC controllers that includes single-channel boundary-conduction mode controllers, stand-alone continuous conduction-mode controllers and also PFC+PWM combination (combo) controllers. With the industry adoption of the PFC as a means of decreasing energy waste at the point of distribution, the interleaved PFC is becoming a more sophisticated way of maximizing energy savings.
