800V SiC EV Designs Enhanced with eFuse Technology

Asahi Kasei Microdevices (AKM) and Silicon Austria Labs (SAL) have successfully completed a collaborative proof of concept involving the eFuse technology in 800V silicon carbide (SiC) designs. The eFuse board, developed and tested in partnership with SAL, is centered around the AKM current sensor, known for its ability to detect a current spike in under 100ns.

This breakthrough showcases the potential of eFuse technology to significantly enhance safety measures while simultaneously reducing material and maintenance costs for systems like on-board chargers (OBC) in automobiles, as highlighted by AKM.

The increasing adoption of SiC- and gallium nitride (GaN)-based power devices in electric vehicles and other high-voltage applications necessitates the replacement of traditional mechanical fuses, commonly used with conventional silicon (Si) power converters. This shift aims to swiftly deactivate the system upon detecting an overcurrent, safeguarding the devices and averting expensive maintenance procedures.

AKM's CZ39 series, a coreless current sensor boasting a rapid response time of 100 ns, is at the forefront of this technological advancement. Its swift responsiveness and high precision enable the accurate identification of overcurrent situations, facilitating prompt system shutdowns.

In a collaborative technical validation effort with SAL in Graz, AKM has developed the eFuse system, offering a solution to the limitations of conventional protection mechanisms reliant on mechanical fuses. This innovation delivers the necessary overcurrent and short circuit protection for high-voltage EV systems utilizing SiC- and GaN-based power devices, such as OBCs, while also streamlining the regulation of current in interconnected subsystems to reduce overall component count.

“Through this joint validation of technology, we have established a new benchmark for eFuse technology, leveraging AKM's expertise in conjunction with SAL's research capabilities to achieve this groundbreaking outcome. We anticipate that eFuse technology will play a pivotal role in the development of more compact and lightweight EV onboard chargers,” remarked Toshinori Takatsuka, General Manager of AKM's current sensor business.

“By harnessing the latest AKM current sensing technologies, we can enhance the response time of eFuses and fortify the protection of wide-bandgap power converters,” added Thomas Langbauer, Team Lead in the Power Electronics Division at SAL.

AKM is showcasing the fruits of their collaborative research with SAL at PCIM Europe 2024 in Nuremberg, Germany this week, while also engaging in discussions regarding future steps and potential advancements.

Sources: Silicon Austria Labs; Asahi Kasei