MinE-CAP IC reduces input bulk capacitor size by up to 40 per cent
According to Power Integrations, the MinE-CAP ICs “dramatically reduce” the input bulk capacitor size, reduce in-rush current by up to 95 per cent and eliminate NTC thermistors and associated losses.
The ICs are 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, the MinE-CAP IC can reduce adapter size by up to 40 per cent. The MinE-CAP also reduces in-rush current making NTC thermistors unnecessary, increasing system efficiency and reducing heat dissipation.
Power Integrations’ product marketing director, Chris Lee, believes: “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”.
Designers can implement it to use predominantly low voltage rating capacitors for a large portion of the energy storage, shrinking the volume of those components linearly with voltage.
“USB PD has driven a major market push towards small 65W chargers and many companies have concentrated on increasing switching frequency to reduce the size of the flyback transformer,” observed Lee. “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 RDS on of PowiGaN GaN transistors to actively and automatically connect and disconnect segments of the bulk capacitor network depending on AC line voltage conditions.
Using MinE-CAP allows designers to 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 which are protected by the MinE-CAP until needed at low AC line. This shrinks the input bulk capacitors without compromising output ripple, operating efficiency, or requiring redesign of the transformer, says Power Integrations.
In contrast to conventional power conversion methods which reduce power supply size by increasing switching frequency to allow the use of a smaller transformer, the MinE-CAP IC can reduce the overall power supply, using fewer components and without risking higher EMI and the increased transformer/clamp dissipation challenges associated with high frequency designs, explains Power Integrations. Applications include smart mobile chargers, appliances, power tools, lighting and automotive.
The MinE-CAP MIN1072M ICs are available now in a miniature MinSOP-16A package.