Patent ID: 8952670
Filing Date: 2015-02-10
Classification: H02M,H03K

Abstract:
1. A voltage conversion circuit for a driver having a voltage input terminal and a voltage output terminal to receive an input voltage and to provide an output voltage, respectively, the voltage conversion circuit comprising: a high voltage transistor connected between the voltage input terminal and a switching node; a first low voltage transistor and a second low voltage transistor connected in series between the switching node and the voltage output terminal; an inductor connected between the switching node and a ground terminal; a controller connected to the high voltage transistor and the second low voltage transistor, operative to provide a first signal and a second signal to switch the high voltage transistor and the second low voltage transistor, respectively, to thereby charge and discharge the inductor to generate the output voltage; and a protection circuit connected to an electrode of the first low voltage transistor that is connected to the second low voltage transistor, to apply a voltage to the electrode when the second low voltage transistor is off; wherein the first low voltage transistor is on when the second low voltage transistor is on; wherein the protection circuit comprises a switch connected between a bias source and the electrode and controlled by an inversion signal of the second signal.