Patent ID: 7889011

Claim:
An apparatus for testing an amplifier having a first output and a second output, the apparatus comprising: an upper power supply rail; a lower power supply rail; a first driver that is coupled to the upper power supply rail, wherein the first driver includes an output; a first filter that is coupled between the output of the first driver and a first output of the amplifier, wherein the first filter is operable to produce a demodulated output signal from a higher frequency modulated signal at the output of the first driver; a first voltage level detector that is coupled to the output of the first driver; a second driver that is coupled to the upper power supply rail, wherein the second output driver includes an output; a second filter that is coupled between the output of the second driver and the second output of the amplifier; a second voltage level detector that is coupled to the output of the second driver; a pulldown switch that is coupled between the output of the first driver and the lower power supply rail; and a control circuit operable to detect at least one fault based on a voltage level measured at one or more of the outputs from the first and second drivers by the first and second voltage level detectors.