Patent ID: 8203321

Claim:
A DrMOS, comprising: a high side power MOSFET coupled between a first voltage terminal and a phase node; a low side power MOSFET coupled between the phase node and a second voltage terminal; a driver circuit coupled to the high side and low side power MOSFETs to drive thereto in response to a control signal to thereby provide an output current, and a thermal balance circuit monitoring a temperature of the DrMOS to modulate the control signal to thereby regulate the output current; wherein the thermal balance circuit comprises: a thermal balance terminal; an element having a characteristic varying with the temperature of the DrMOS; a current source providing a first current for the element to generate a variable voltage varying with the temperature of the DrMOS to apply to the thermal balance terminal; a resistor coupled to the thermal balance terminal to receive a second current according to a voltage at the thermal balance terminal; and a current-to-voltage converter converting a third current related to the second current into a thermal modulation signal to regulate the output current.