In a described example, a circuit includes a sensor, a controller and an amplifier. The sensor has a sensor input and a sensor output. The sensor input is adapted to be coupled to a chassis of a switch-mode power supply (SMPS). The controller has an input, a timing output and a level output. The input of the control circuit is coupled to the sensor output. The amplifier has a timing control input, a level control input and an amplifier output. The level control input is coupled to the level output of the controller. The timing control input is coupled to the timing output, and the amplifier output is coupled to the sensor input. The amplifier is configured to provide compensation pulses at the amplifier output having magnitude and timing to reduce common-mode noise on the chassis.