APEC week: NXP and Hitachi collaborate on SIC power stage for vehicle traction inverters

Author: EIS Release Date: Mar 28, 2022

NXP and Hitachi have co-designed a gate driver evaluation board for Hitachi’s 1.2kV RoadPak SiC mosfet half-bridges.

 

Hitachi RoadPak SiC mosfet half bridgeThe half-bridges are ~75 x 70mm and come in 580, 780 and 980A versions which are liquid-cooled – one side having a pin-fin array (just visible right) which has to be sealed into a water-glycol filled cooling manifold. Junction to fluid resistance is typically 114K/kW. Inside, the mosfets come from Cree/Wolfspeed.

 

“Hitachi Energy’s RoadPak power module delivers excellent heat dissipation, low stray inductances, and long-term ruggedness to withstand the challenging automotive environment,” said NXP. “It can support applications from e-buses and electric passenger vehicles to high-performance Formula-E race cars.”

 

NXP FRDMGD31RPEVM SiC mosfet driver boardThe driver evaluation board, called FRDMGD31RPEVM, is shaped to mount directly on the non-heatsink side of the power module and match up with its drive and sense pins. NXP has built it around a pair of single-channel MC33GD3160 driver ICs which include a galvanic isolation barrier (creepage >7.8mm) and are suitable for SiC mosfets and silicon IGBTs up to 1,700V, delivering up to ±15A to the gate.

 

MC33GD3160 is programmable via an SPI interface and includes over-temperature and de-saturation protection. It can detect and react against short-circuits in 1.4µs via the ‘de-sat’ circuit, according to NXP, and it “autonomously manages faults and reports power device and gate driver status via pins and the SPI interface”. Sadly its full data sheet is not pubic.

 

Integrated self-test, control and protection functions are aimed at traction inverters meeting the requirements of ASIL-C or ASIL-D functional safety. Qualification is to AEC-Q100 grade 1.

 

An  NXP evaluation kit includes the evaluation board, a KL25Z MCU board (FRDM-KL25Z) and a 3.3 to 5.0V translator board (KITGD316xTREVB) plus a cable and a quick start guide. There is enough hardware to link a PC running NXP’s ‘FlexGUI’ software to registers on the gate drivers. Note, another version of the eval board, also called FRDMGD31RPEVM, has a different (GD3100) driver IC. The kit does not include the necessary mosfet power module, dc link capacitor nor inductor.