Q&A - Being allergic to aluminum; the SA310 3-phase SiC module - Apex

July 2, 2020


Being allergic to aluminum; what can the SA310 3-phase SiC module do without heatsink? 


There can be use cases, for instance those where space is at a premium, that rule out the use of heatsinks to cool SA310 down. In those cases, SA310 has to vent off the heat, caused by internal power dissipation, through its own nickel-and-steel casing. The graph from SA310's datasheet below shows the limits with respect to supply voltage and current, and switching frequency, for the operating point of SA310 without a heatsink.




The higher the supply voltage or current or switching frequency, the lower the other two parameters have to be to keep internal power dissipation within safe levels (or, differently said: to keep SA310 case and junction temperature below their maximum ratings in the datasheet).

The graph immediately shows that supply current (which more or less equals output current) cannot be higher than 8.6A when SA310 has no heatsink. It also shows that output current, in case of a 600V supply voltage, is limited to 6A at a switching frequency of 10kHz, and to 4.5A and 2.3A at switching frequencies of 20kHz and 50kHz respectively. Other operating points can be found by staying within the areas bordered by supply voltage and current and the switching frequency curves.

The SA310 is an 80A peak, 650V brushless DC motor driver. This silicon carbide three-phase driver is designed for AC/DC converters, BLDC and PMSM motors, and power inverters, with  high efficiency and excellent switching capabilities at up to 500 kHz.