The HV9906DB4 provides a constant current of 750mA. It contains all circuitry necessary to demonstrate the features of the HV9906 second order power supply controller. A power converter of the demo board consists of an input buck-boost stage and an output buck stage. The output voltage polarity is negative. Due to its unique quadratic input-tooutput DC voltage transfer ratio, the converter can operate directly off AC line to produce low-voltage output without need for electrolytic capacitors. The HV9906 is designed for optimally controlling this type of power converter or other types of two-stage multiconverters.