Power factor correction ICs assure high efficiency across entire load range

Power Integrations has introduced the HiperPFS-3 family of power factor correction ICs, which offer high power factor and high efficiency across the entire load range. Aimed at applications with continuous power demands up to 405W for universal input and 900W for high-line, the ICs feature efficiency levels of better than 95% from 10% load to full load and consume less than 60 mW under no-load conditions. A power factor of above 0.92 is easily achievable at 20% load. The highly-integrated HiperPFS-3 devices include the variable frequency CCM controller, high-voltage power MOSFET and a Qspeed(tm) low QRR boost diode. The new devices also employ an innovative means of controlling EMI without adversely affecting power factor at light loads. Poor system power factor at light load is caused by X capacitors that are used to reduce differential mode EMI being fed back to the AC line. HiperPFS-3 ICs incorporate a digital power factor-enhancing circuit that activates during light load conditions; this increases the compensation to overcome the reactance of X capacitors in the EMI filter, minimizing the phase angle difference between the input voltage and the current. Consequently, designers may increase the size of the X capacitors while minimizing or eliminating differential-mode chokes, thereby reducing EMI without degrading light load power factor performance. This results in a smaller, lower cost, EMI filter stage. Edward Ong, product marketing manager, Power Integrations, said: "Standby energy-use standards such as ErP Lot 6 have previously forced designers of PCs and other systems to include both a main PSU and standby power supply. The excellent light load efficiency of our new HiperPFS-3 ICs enables them to eliminate the standby power supply, saving components, design time, space and cost." Available for both high and low-line applications, HiperPFS-3 ICs cover a continuous output power up to 900W. Thermally efficient eSIP-16 packaging simplifies heat sink mounting.