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FEB279_FAN9611/12 • Rev. 0.0.2

The following user guide supports the FAN9611/12 400W evaluation board for

interleaved boundary-conduction-mode power-factor-corrected supply. It should be used

in conjunction with the FAN9611/12 datasheet as well as the Fairchild application note

AN-6086 Design Considerations for Interleaved Boundary-Conduction Mode PFC using

to evaluate either the FAN9611 (10V turn-on threshold) or FAN9612 controller (12.5V

additional information.

1. Overview of the Evaluation Board

The FAN9611/12 interleaved dual Boundary-Conduction-Mode (BCM) Power-Factor-

Correction (PFC) controllers operate two parallel-connected boost power trains 180º out

of phase. Interleaving extends the maximum practical power level of the control

technique from about 300W to greater than 800W. Unlike the continuous conduction

mode (CCM) technique often used at higher power levels, BCM offers inherent zero-

current switching of the boost diodes (no reverse-recovery losses), which permits the use

of less expensive diodes without sacrificing efficiency. Furthermore, the input and output

filters can be smaller due to ripple current cancellation between the power trains and

doubling of effective switching frequency.

The advanced line feedforward with peak detection circuit minimizes the output voltage

variation during line transients. To guarantee stable operation with less switching loss at

light load, the maximum switching frequency is clamped at 525kHz. Synchronization is

maintained under all operating conditions.

Protection functions include output over-voltage, over-current, open-feedback, under-

voltage lockout, brownout, and redundant latching over-voltage protection. The

FAN9611/12 is available in a lead-free 16-lead SOIC package.

This FAN9611/12 evaluation board is a four-layer board designed for 400W (400V/1A)

rated power. Thanks to the phase management, the efficiency is maintained above 96%

at low-line and high-line, even down to 10% of the rated output power. Efficiency is