Commercial power switching modules can be purchased that offer many options of shape, size, connection and performance for controlling several kilowatts of power at up to 600V. However, an off-the shelf device seldom offers a perfect match for the application and compromises in thermal, electrical and mechanical performance often have to be made.

GE Aviation has developed a semi-custom approach, which is analogous to a semi-custom ASIC, where the building blocks are proven and manufactured, awaiting only a final interconnect layer. The building blocks include matched transistors, sense resistors, isolating transformers, programmable ASICs, high heat conduction substrates and high current packaging.