All CONCEPT drivers contain a Vce detector that measures the voltage across the IGBT or MOSFET after turn-on of the power component. If the power component is subject to excessive current or a short circuit, the forward voltage rises in response. This voltage rise as a function of the current is detected by the Vce detector, which then effectively protects the power component.
However, Vce detection is unable to protect the load reliably from short circuits and overcurrents. This is because an overcurrent level that is still permissible for the IGBT can already be critical for the connected motor or similar load. Moreover, a very strong rise of the IGBT forward voltage occurs only as a result of the desaturation effect. If the current remains below the desaturation threshold, no true short circuit occurs.
As a rule, the Vce detection should be considered as protection for the power component, and the load protection in the application should be assured via dedicated load-current measurement and regulation or other suitable measures.
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