Novel MinE-CAP device dramatically reduces the input bulk capacitor size, reduces in-rush current by up to 95%, eliminates NTC thermistors and associated losses
Power Integrations, a developer of high-voltage integrated circuits for energy-efficient power conversion, has announced the MinE-CAP IC for high power density, universal input AC-DC converters.
By halving the size of the high-voltage bulk electrolytic capacitors required in offline power supplies, it’s been possible for this IC to achieve a reduction in adapter size of up to 40%. The MinE-CAP device also dramatically reduces in-rush current making NTC thermistors unnecessary, increasing system efficiency and reducing heat dissipation.
Commenting Power Integrations’ product marketing director, Chris Lee said,“The MinE-CAP will be a game-changer for compact chargers and adapters. Electrolytic capacitors are physically large, occupy a significant fraction of the internal volume and often constrain form factor options – particularly minimum thickness – of adapter designs. The MinE-CAP IC allows the designer to use predominantly low voltage rated capacitors for a large portion of the energy storage, which shrinks the volume of those components linearly with voltage. USB PD has driven a major market push towards small 65 W chargers and many companies have concentrated on increasing switching frequency to reduce the size of the flyback transformer. MinE-CAP provides more volume saving than doubling the switching frequency, while actually increasing system efficiency.”
The MinE-CAP leverages the small size and low RDSon of PowiGaN gallium nitride transistors to actively and automatically connect and disconnect segments of the bulk capacitor network depending on AC line voltage conditions.
Designers using the MinE-CAP select the smallest high-line rated bulk capacitor required for high AC line voltages, and allocate most of the energy storage to lower voltage capacitors that are protected by the MinE-CAP until needed at low AC line. This approach has been found to dramatically shrink the size of input bulk capacitors without compromising output ripple, operating efficiency, or requiring redesign of the transformer.
Conventional power conversion solutions reduce power supply size by increasing switching frequency to allow the use of a smaller transformer, by contrast the MinE-CAP IC achieves just as significant overall power supply size reduction while using fewer components and avoiding the challenges of higher EMI and the increased transformer/clamp dissipation challenges associated with high-frequency designs. Applications include smart mobile chargers, appliances, power tools, lighting and automotive.
Housed in the miniature MinSOP-16A package, the devices work seamlessly with Power Integrations’ InnoSwitch family of power supply ICs with minimal external components. MinE-CAP MIN1072M ICs are now available.