automotive2024

EV DC Fast Charger: ONSEMI SiC Diodes + ST STM32 Achieve 97.5% Peak Efficiency

EV Charging Infrastructure Company (Suzhou)

ONSEMISTSiC Diodes & MOSFETsSTM32 Microcontrollers

Challenge

An EV charging infrastructure company designing a 120kW DC fast charger needed to achieve ENERGY STAR certification while operating reliably in outdoor environments from -25°C to +55°C — with required Surge protection to IEC 61851-23 standards.

Solution

ONSEMI FFSP3065A SiC Schottky barrier diodes (650V, 30A) in the Vienna PFC stage. ST STM32G474 mixed-signal MCU handles power stage control, digital protection, and Modbus TCP communication. CoreWin FAE provided IEC 61851-23 compliance documentation andEMC pre-scan verification.

Key Outcomes

Charger peak efficiency: 97.5% across full load range
ENERGY STAR certified (efficiency >97% at 50% load)
Full IEC 61851-23 compliance with first-pass EMC certification
Operating range: -30°C to +60°C verified