Patent ID: 8416956

Claim:
A digital audio driver having a pulse-width modulation (PWM) input and controlling a stage of high- and low-side MOSFETs series connected at a node, the driver comprising: an input interface circuit having a protection circuit to provide protection against an over-current condition at least one of the high- and low-side MOSFETs; and high and low side circuits for driving the high- and low-side MOSFETs, each high and low side circuit including a current sensing circuit which requires no external shunt resistor to detect the over-current condition at either positive or negative load current direction, wherein at least one of the current sensing circuits uses a drain to source resistance (R DS(ON) ) of the at least one of the high- and low-side MOSFETs as a current sensing resistor and once the R DS(ON) exceeds a pre-determined threshold, feeds an over current output signal to the protection circuit to shutdown one of the high- and low-side MOSFETs independently from shutdown of the other of the high- and low-side MOSFETs.