The filter capacitor on the BIAS pin can be increased to increase rise and fall time of DC reference voltage in order to reduce the pop. MAX9789/MAX9790 feature an internally generated, power-supply independent, common-mode bias voltage of 1.8V referenced to GND. BIAS provides both click-and-pop suppression and sets the DC bias level for the amplifiers. The bias voltage must be established for the internal circuit to operate, and a bypass capacitor to the ground needs to be connected to the pin to reduce noise.