Circuit diagram of using a comparator to set the undersaturation protection threshold voltage of UAA4002 higher than 5.5V

A scheme is given to design an equivalent threshold voltage
of 10V. The threshold voltage detected in the figure is set at the reverse input end of the LM 339 comparator
. Under the parameters shown in the figure, the equivalent undersaturation protection threshold voltage is
10V. As long as the voltage on pin Kt is lower than iov, the output of the comparator is low level
, the voltage on pin RSD is approximately -4V, the desaturation protection function is deleted, once the voltage
on VCE exceeds 10V, compare The output of the controller changes state, the desaturation protection function is activated, and the fault is detected.