onsemi (Ansemi)

SOIC-16

taping

2500

The FAN9611 interleaved dual-channel Boundary Conduction Mode (BCM) Power Factor Correction (PFC) controller operates two parallel boost power supply units with 180° phase difference. Interleaving extends the maximum practical power level of the control technique from approximately 300 W to over 800 W. Unlike continuous conduction mode (CCM) technology, which typically uses higher power levels, BCM provides intrinsic zero-current switching of the boost diode, allowing the use of cheaper diodes without loss of efficiency. Additionally, input and output filters can be smaller due to ripple current cancellation and efficient switching frequency doubling. These converters operate at a variable frequency that depends on the load and instantaneous input/output voltage. The switching frequency is limited between 16.5 kHz and 525 kHz. The pulse width modulator (PWM) implements voltage mode control and input voltage feedforward. When configured for PFC applications, the slow voltage regulation loop produces constant on-time operation over the line cycle. This PWM approach, combined with BCM operation of the boost converter, provides automatic power factor correction. The controller provides 10 V/7.5 V bias UVLO, input undervoltage protection, overcurrent, open loop feedback, output overvoltage and redundant latching overvoltage protection. Also, the output power limit of this converter is independent of the input RMS voltage. Synchronization between power stages is maintained under all operating conditions.