Switcher IC delivers reliability and space-saving benefits

Power Integrations has released five new reference designs targeting 800V automotive applications based on its 1700V InnoSwitch3-AQ flyback switcher ICs. Spanning power levels from 16W to 120W, the designs uses wound and low-profile planar transformers and target automotive applications such as DC-DC bus conversion, inverter emergency power, battery management and power supplies for auxiliary systems. The designs feature the company's new wide-creepage InSOP-28G package, which supports 1000VDC on the primary side while providing appropriate creepage and clearance between pins in pollution degree two environments.

"The new InSOP-28G package, with its wide 5.1mm drain-to-source pin creepage distance, addresses the critical need for enhanced safety and reliability in high-voltage applications," said Mike Stroka, product marketing engineer at Power Integrations. "It provides sufficient isolation that conformal coating can be eliminated, saving a manufacturing process step and associated qualification effort. The InnoSwitch3-AQ IC, featuring a 1700V SiC switch, is an ideal solution for 800V vehicles, simplifying manufacturing while enhancing overall system performance and reliability."

Available from the company's website, the following reference designs are all isolated flyback converters based on the 1700 V-rated CV/CC InnoSwitch3-AQ switcher ICs. The three reference designs kits (RDKs) and two design example reports (DERs) are:

• RDK-994Q – 35W ultra-low-profile traction inverter gate-drive or emergency power supply with 40-1000VDC input and 24V output;
• RDK-1039Q – 18W power supply with planar transformer for traction inverter gate driver or emergency power supply;
• RDK-1054Q – 120W power supply with planar transformer, designed to shrink or eliminate heavy, bulky 12V batteries;
• DER-1030Q – 20W four-output power supply – one emergency power supply (EPS) with 24.75V output and three gate-drive power supplies with 25.5V output;
• DER-1045Q – 16W four-output power supply – one 14V EPS output and three gate-drive outputs with split with +18V/-5V rails.

The company's 1700V-rated SiC-based CV/CC InnoSwitch3-AQ switching power supply ICs deliver up to 120W of output power. The highly integrated ICs reduce power supply BOM count by as much as 50%, saving space, enhancing system reliability and easing component sourcing challenges. Devices start up with as little as 30V on the drain pin without external circuitry, which is often a critical requirement for functional safety. Additional protection features include input under-voltage, output over-voltage and over-current limiting. Power consumption is less than 15mW at no-load. The ICs also include synchronous rectification and a valley switching, DCM/CCM flyback controller capable of delivering greater than 91% efficiency.