Abstract: A cascoded switch system is disclosed. The cascoded switch system includes JFET and a MOSFET coupled in series between a drain terminal and a source terminal. The system further includes a drive circuit comprising a JFET driver configured to receive an input signal and to output a JFET-drive signal to a capacitor coupled in series with the gate of the JFET, a switch coupled between the gate of the JFET and the source terminal and configured to be responsive to the input signal, and a comparator to compare a JFET gate voltage against a threshold. The drive circuit further includes a MOSFET driver circuit to drive the MOSFET in a MOSFET on-state during an on-state of the input signal, and drive the MOSFET in one of a MOSFET off-state and the MOSFET on-state in response to a comparison signal from the comparator during an off-state of the input signal.

Abstract: A cascoded switch system includes a JFET, a MOSFET, and a cascode-drive circuit comprising (i) a drain-sense circuit to compare a drain voltage against a drain threshold, (ii) a logic gate to assert a cascode-on signal based on an input signal on-state or the drain voltage being less than the drain threshold, and to assert a cascode-off signal based on an input signal off-state and the drain voltage being greater than the drain threshold, (iii) a JFET drive circuit to drive the JFET on in response to the cascode-on signal, and with a negative voltage in response to the cascode-off signal, (iv) a comparator to compare the JFET gate voltage against a threshold, and (v) a MOSFET drive circuit to force the MOSFET on in response to the cascode-on signal, and force the MOSFET on or off based on the comparator output and in response to the cascode-off signal.

Abstract: Switching circuits, half-bridge power converters, and methods for operating a switching circuit including a switching transistor coupled to a load. The method includes applying, with a driver, a gate voltage to the switching transistor. The method also includes generating, with a feedback capacitor, a feedback current based on a change in a voltage sensed at a drain terminal of the switching transistor when the switching transistor turns on. The method further includes applying the feedback current to the driver to limit the gate voltage applied to the switching transistor. The method also includes adjusting, with a controller, a switching slew rate of the switching transistor by draining an amount of the feedback current.

Abstract: Switching circuits, half-bridge power converters, and methods for operating a switching circuit including a switching transistor coupled to a load. The method includes applying, with a driver, a gate voltage to the switching transistor. The method also includes generating, with a feedback capacitor, a feedback current based on a change in a voltage sensed at a drain terminal of the switching transistor when the switching transistor turns on. The method further includes applying the feedback current to the driver to limit the gate voltage applied to the switching transistor. The method also includes adjusting, with a controller, a switching slew rate of the switching transistor by draining an amount of the feedback current.