HV9906

The Supertex HV9906 allows the development of the smallest possible, most reliable, offline and wide DC/DC conversion range converters for driving LEDs and other applications. The HV9906 combines internally all the components required to operate directly from the rectified AC line with a feedback mechanism that eliminates filters & compensation components, and which can close the loop with feedback from a discontinuous waveform (eg. LED current).

The HV9906 is capable of driving multiconverters, which have been shown to provide the best performance to component count trade off for wide conversion range applications like offline converters. Applicable multiconverters include bucking & boosting topologies, in isolated & non-isolated configurations, as well as power factor correcting topologies from <1W up to 150W.

Proper choice of external components will allow the programming of currents from <1mA to several amps and will allow stepping up or stepping down from the input without the need to change components. For example, the same HV9906 converter nominally regulating to 60VDC output may operate from 12VDC, or from rectified AC input to 265VRMS.

The HV9906 utilizes a programmable inversely proportional fast feed forward algorithm to calculate output on time and a novel Integrating Lock Loop (IL2) feedback with programmable threshold differential sensing. The sensed feedback may be positive or negative with respect to ground and the signal may be discontinuous. In some topologies this control method permits the elimination of the bulky input filter capacitor (a small high voltage ceramic or film capacitor is required to maintain a high frequency path). This algorithm when used with certain multiconverters such as the flyback-buck, with a fixed load, results in near constant frequency with only a small dither which helps meet FCC requirements.