Achieve fast response overcurrent detection with optical isolators
Over-current or short-circuit conditions in an IGBT can occur due to a phase-to-phase short, a ground short, or a shoot through. Typically, an IGBT can survive short-circuit conditions up to 10 μs before failure. Within this time period, a fault must be generated as feedback to the microcontroller to trigger an immediate shutdown procedure within the system. One method is to detect the over-current directly from sensing the phase current using the sigma-delta modulator. Usually, a longer post-processing time of the sigma-delta modulator output data is required to achieve higher resolution of the measured phase current. As a result, over-current may not be detected quickly enough to shut down the entire control system. Learn more about how to achieve fast response overcurrent detection with Broadcom optical isolators.
