A device includes a voltage converter and an analog to digital converter (ADC). The voltage converter includes an input to receive a first voltage and an output to output a second voltage based on a switching signal having a first discrete converter frequency and a second discrete converter frequency. The ADC is coupled to and proximate to the voltage converter. The ADC includes a digital filter configured to substantially attenuate a first filter frequency and a second filter frequency. The voltage converter further includes a frequency control device configured to set the first discrete converter frequency and the second discrete converter frequency so that the first discrete converter frequency is approximately equal to the first filter frequency and the second discrete converter frequency is approximately equal to the second filter frequency.