PFC uses a two-phase, interleaved boost-type conversion architecture

The PFC uses a two-phase, interleaved boost-type conversion architecture, and a high power factor is achieved by adjusting the peak current value with respect to the rectified input voltage. The inrush current at the start-up is digitally controlled and the bulk capacitor is pre-charged using a switching MOSFET. It incorporates the digital inrush current concepts demonstrated in another IXYS reference design, the IXRD1002 High Power Digital Inrush Current Controller.

The input voltage of the PFC ranges from 105 to 140VAC while the output voltage is at 400V. The maximum output power is 1.06kW with the load current at 2.65A. The 3 switches needed in this design are realised using IXYS’ latest 650 Ultra Junction Power MOSFETs, the IXTH34N65X2 and IXTH80N65X2. This reference design consists of a microcontroller module and main power board. Designed as an add-on device, the MCU module includes two 8-bit MCUs that generate the gate control signals to maintain current balance between the two interleaved conversion phases. It also enables a high efficiency in a wide range of loads, keeps the output voltage stable, and provides overload and overvoltage protection functions.

“This reference design demonstrates the incorporation of low cost MCUs into the power control loop, which significantly improves the efficiency and reliability of power systems through the whole power range. This also demonstrates the depth of IXYS products that enable our customer to get the total solution from us for power systems designs,” commented Steve Darrough, VP of Marketing.

Well suited for high power (1kW and above) AC/DC converters with active PFCs, the IXRD1004 provides a platform for developing a number of power management solutions such as electric vehicle chargers, air conditioning systems, high-power LED lighting, and wielding equipment.