Hybrid cars drive TranSiC switch development
Strong demands from potential customers in the automotive industry are pushing power electronics start-up TranSiC to improve the power ratings and performance of its SiC transistors.
That s why the Swedish company has developed two additional SiC bipolar junction transistor (BJT) products, and began distributing engineering samples on May 5.
“We are seeing a large interest from companies active in development of power electronic systems for hybrid electric vehicles,” Martin Domeij, TranSiC s chief technical officer told compoundsemiconductor.net. “These customers are looking for voltage ratings in the range of 900 V to 1200 V and chip currents exceeding 10 A.”
Hybrid vehicles stand to gain from the higher switching efficiency that SiC provides compared to silicon, and its ability to operate at higher temperatures. TranSiC claims to be the first company to offer normally-off switches, which automotive electronic engineers prefer, made from SiC.
TranSiC s latest products move towards these customers needs' with one 600 V, 20 A BJT, and by adding a separate Schottky diode to the company's original 1200 V, 6 A device. In the combined package, the externally-sourced freewheeling diode helps improve switching performance and protects the BJT from damage caused by inductive capacitance.
For the 600 V, 20 A transistor, TranSiC has retained an epitaxial structure similar to its original BJT but has increased the overall die size to increase the power rating. Consequently the 20 A chip measures 3.2 mm x 3.6 mm, whereas the 6 A chip measures just 2.4 mm x 2.4 mm.
Although these two devices are currently being offered to interested customers by Domeij and his colleagues, final product designs will be based on the feedback that they gain. Consequently TranSiC s plan to move its SiC BJTs into production will take up to a year to fully crystallize.
Domeij says that the company s next move will be to produce a 1200 V and 20 A device as it tries to more fully meet its customers' desired specifications.