Patent ID: 7489531

Claim:
An inverter comprising: first and second input terminals adapted to receive a substantially direct current (DC) voltage source; an inverter output terminal: a series arrangement of a first inverter transistor and a second inverter transistor, the series arrangement being coupled between the first and second input terminals, wherein the first inverter transistor is coupled to the second inverter transistor at the inverter output terminal; a driver circuit coupled to the first and second inverter transistors and operable to commutate the inverter transistors in a substantially complementary manner and at a drive frequency, the driver circuit including a current-sense input and a frequency control input; a primary current sensing circuit coupled between the second inverter transistor and the current-sense input of the driver circuit, comprising a current-sensing resistor coupled between the second inverter transistor and circuit ground, wherein circuit ground is coupled to the second input terminal; and an auxiliary current sensing circuit, coupled between the second inverter transistor and the frequency control input of the driver circuit, wherein the auxiliary current sensing circuit is operable, in response to a condition wherein the current flow through the inverter transistors exceeds a predetermined peak limit, to provide an auxiliary signal to the frequency control input of the driver circuit, thereby increasing the drive frequency and reducing the current flow through the inverter transistors, comprising: a resistor coupled between the current-sensing resistor and a first node; a voltage-breakdown device coupled between the first node and a second node; and a diode having an anode coupled to the second node and a cathode coupled to the frequency control input of the driver circuit.