Power modules for driving two-phase switched reluctance motors

The FCAS20DN60BB and FCAS30DN60BB are the industry’s first SRM-SPM power modules for driving two-phase switched reluctance motors (SRM) in small motor applications, such as vacuum cleaners. SRMs are an attractive alternative to AC drives due to their high efficiency. The small motor industry is migrating from single-phase to two-phase SRMs due to their ability to startup under difficult load conditions and the lower components that these motors require.

Each SRM-SPM module integrates two HVICs, one LVIC, four NPT IGBTs, four fast recovery diodes (FRDs), two bootstrap diodes, a thermistor and various protection functions in a single package. By integrating 14 fully tested power components in a compact 45mm x 28mm SIP package, these products offer 40 percent space savings. This space conservation allows vacuum cleaner designers to incorporate the controller into the SRM assembly, and also improves design productivity and manufacturability. System reliability is further enhanced by incorporating protection features such as under-voltage lock-out and short circuit protection into this thermally efficient package.

The SRM-SPM products offer the following features: low-loss, efficient IGBTs and FRDs meet low electromagnetic interference (EMI) requirements; built-in HVICs offer a single-grounded power supply, which simplifies designs; built-in bootstrap diodes reduce external component count and simplify circuit layout; and built-in HVIC/LVIC offers high noise immunity and protection functions.

The power modules utilize lead-free (Pb-free) terminals and have been characterized for moisture sensitivity in accordance with the Pb-free reflow requirements of the joint IPC/JEDEC standard J-STD-020.