MinE-CAP IC cuts power adapter size by up to 40%

Power Integrations has released the MinE-CAP IC for high power density, universal input AC/DC converters. This new IC type can reduce adapter size by up to 40% by shrinking the size of the high-voltage bulk electrolytic capacitors required in offline power supplies. The new device type also significantly reduces in-rush current by up to 95%, eliminating the need for NTC thermistors, said the company, which increases system efficiency and reduces heat dissipation.

In addition, the MinE-CAP IC also eliminates the challenges of higher EMI and increased transformer/clamp dissipation associated with high-frequency designs, compared to conventional power conversion solutions, said the company. Applications include smart mobile chargers and adapters, appliances, power tools, lighting, and automotive.

The MinE-CAP takes advantage of the small size and low RDSon of the PowiGaN gallium nitride (GaN) transistors to automatically connect and disconnect segments of the bulk capacitor network depending on AC line voltage conditions. This enables designers to select the smallest high-line rated bulk capacitor required for high AC line voltage, said the company, and allocate most of the energy storage to lower voltage capacitors, protected by the MinE-CAP, until needed at low AC line.

Shrinking the size of the input bulk capacitors doesn’t compromise output ripple and operating efficiency or require the redesign of the transformer, according to the company.

Chris Lee, production marketing director, Power Integrations calls the new device type 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,” he said in a statement. “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 IC is housed in a miniature MinSOP-16A package, and works with Power Integrations’ InnoSwitch family of power supply ICs with minimal external components. MinE-CAP MIN1072M ICs are available from Power Integrations and its franchised distributors. The devices are priced at $1.75 for 10 Ku.

Two initial design example reports (DERs) pair the MinE-CAP IC with Power Integrations’ InnoSwitch3-Pro PowiGaN IC, INN3370C-H302. The DER-626 example is a 65-W USB PD 3.0 power supply with 3.3 V – 21 V PPS output for mobile phone/laptop chargers and the DER-822 showcases a 60-W USB PD 3.0 power supply for USB PD/PPS power adapters using the INN3379C-H302.