Abstract: A desaturation detection circuit for use between the desaturation detection input of an optocoupler and the output of a power switching device, the desaturation detection circuit comprising: a threshold setting element having an input and an output, the input for connection to the output of a power switching device via one or more diode(s), the threshold setting element being arranged to set a threshold voltage at the input at which the threshold setting element will provide an output at the output of the threshold setting element when the input voltage is exceeded, and a detector having an input connected to the output of the threshold setting element and an output connectable to a desaturation detection input of an optocoupler, the detector being arranged to detect an output at the output of the threshold setting element and in response to provide a control signal at the output of the detector for the desaturation detection input to trigger a desaturation routine in the optocoupler.

Abstract: A semiconductor device driving unit to supply a drive signal to a gate of a semiconductor switching device, the semiconductor device driving unit comprising: a plurality of gate impedance circuits selectably connectable to the gate of the semiconductor switching device; and a selector to select one or more of the gate impedance circuits to connect to the semiconductor switching device. Also provided is a method of supplying a drive signal to a gate of a semiconductor switching device, the method comprising: selecting one or more of a plurality of gate impedance circuits to be connected to the gate of the semiconductor switching device based on one or more operating conditions and stored data relating to the one or more operating conditions; and connecting the selected one or more of the gate impedance circuits to the semiconductor switching device.

Abstract: A desaturation detection circuit for use between the desaturation detection input of an optocoupler and the output of a power switching device, the desaturation detection circuit comprising: a threshold setting element having an input and an output, the input for connection to the output of a power switching device via one or more diode(s), the threshold setting element being arranged to set a threshold voltage at the input at which the threshold setting element will provide an output at the output of the threshold setting element when the input voltage is exceeded, and a detector having an input connected to the output of the threshold setting element and an output connectable to a desaturation detection input of an optocoupler, the detector being arranged to detect an output at the output of the threshold setting element and in response to provide a control signal at the output of the detector for the desaturation detection input to trigger a desaturation routine in the optocoupler.

Abstract: A semiconductor device driving unit to supply a drive signal to a gate of a semiconductor switching device, the semiconductor device driving unit comprising: a plurality of gate impedance circuits selectably connectable to the gate of the semiconductor switching device; and a selector to select one or more of the gate impedance circuits to connect to the semiconductor switching device. Also provided is a method of supplying a drive signal to a gate of a semiconductor switching device, the method comprising: selecting one or more of a plurality of gate impedance circuits to be connected to the gate of the semiconductor switching device based on one or more operating conditions and stored data relating to the one or more operating conditions; and connecting the selected one or more of the gate impedance circuits to the semiconductor switching device.