Overview of the Evaluation Board

The FAN9611/12 interleaved dual Boundary-Conduction-Mode (BCM) Power-FactorCorrection (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 zerocurrent 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.

Key Features

◾ Low Total Harmonic Distortion, High Power Factor

◾ 180° Out-of-Phase Synchronization

◾ Automatic Phase Disable at Light Load

◾ 1.8A Sink, 1.0A Source, High-Current Gate Drivers

◾ Transconductance (gM) Error Amplifier for Reduced Overshoot

◾ Voltage-Mode Control with (VIN)2 Feed-forward

◾ Closed-Loop Soft-Start with Programmable Soft-Start Time for Reduced Overshoot

◾ Minimum Restart Timer Frequency to Avoid Audible Noise

◾ Maximum Switching Frequency Clamp

◾ Brownout Protection with Soft Recovery

◾ Non-Latching OVP on FB Pin and Second-Level Latching Protection on OVP Pin

◾ Open-Feedback Protection

◾ Over-Current and Power-Limit Protection for Each Phase

◾ Low Startup Current: 80µA Typical

◾ Works with DC, 50Hz to 400Hz AC Inputs