1700 V switcher IC for space-saving in 800 V BEVs

Power Integrations has recently unveiled five new reference designs centered around its 1700 V InnoSwitch™3-AQ flyback switcher IC tailored for 800 V automotive applications. These designs, ranging from 16 W to 120 W power levels, make use of both wound and low-profile planar transformers, catering to various automotive needs like DC-DC bus conversion, inverter emergency power, battery management, and auxiliary system power supplies. The highlight of these designs is the incorporation of the new wide-creepage InSOP™-28G package, which enables 1000 VDC support on the primary side while ensuring adequate creepage and clearance between pins in pollution degree 2 environments.

Mike Stroka, a product marketing engineer at Power Integrations, emphasized the significance of the InSOP™-28G package, stating, “The new package, with its wide 5.1 mm drain-to-source pin creepage distance, meets the crucial demand for improved safety and reliability in high-voltage applications. It offers ample isolation to eliminate conformal coating, streamlining the manufacturing process and reducing associated qualification efforts. The InnoSwitch3-AQ IC, featuring a 1700 V silicon-carbide (SiC) switch, is particularly well-suited for 800 V vehicles, simplifying production while enhancing overall system performance and dependability.”

All the reference designs are isolated flyback converters based on the 1700 V-rated CV/CC InnoSwitch3-AQ switcher ICs. Power Integrations offers three reference design kits (RDKs) and two design example reports (DERs) to cater to different application needs:

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

The SiC-based CV/CC InnoSwitch3-AQ power supply switcher ICs, rated at 1700 V, can deliver up to 120 W of output power. These highly integrated ICs significantly reduce the power supply bill of materials (BOM) count by up to 50 percent, resulting in space savings, improved system reliability, and simplified component sourcing. The devices can start up with as little as 30 V on the drain pin without external circuitry, meeting critical functional safety requirements. They also come equipped with various protection features such as input under-voltage, output over-voltage, and over-current limiting. With power consumption below 15 mW at no load, the ICs incorporate synchronous rectification and a valley switching, discontinuous/continuous conduction mode (DCM/CCM) flyback controller capable of achieving over 91 percent efficiency.