Industry White Papers

Simplified Product Safety Certification through Hardware-based Motor Fault Protection with BridgeSwitch

August 31, 2020 by Power Integrations

Learn about safety standards for domestic appliances, how hardware-based motor fault protection works with BridgeSwitch, and see the test results gathered with a reference design.

BridgeSwitch is a half-bridge motor driver IC, which incorporates two N-channel power FREDFETs with low and high-side drivers in a low-profile surface-mount package. Typical applications include high-voltage single or three-phase brushless DC (BLDC) motor drives in domestic appliances such as dishwashers, refrigerators, or fans. Each of the power switches comes with its own cycle-by-cycle current limit protection. This unique function not only protects the device but also provides protection for the inverter and the motor during abnormal operating conditions.

 

 

Traditionally, fault protection relies on observing the motor by means of monitoring its currents or temperature through sense circuits connected to a microcontroller. Because, in this case, safe operation of the appliance during a fault condition depends on the microcontroller running control software, international safety standards require compliance certification of the software. This is a time consuming and costly process.

In contrast, hardware-based motor fault protection does not rely on a microcontroller executing software. Thus, it simplifies the safety approval process either for an initial product release or for possible subsequent product updates.