Typical test methods for characterizing the single event upset performance of an analog to digital converter (ADC) have involved holding the input at static values. As a result, output error signatures are seen for only a few input voltage and output codes. A test method using an input beat frequency and output code error detection allows an ADC to be characterized with a dynamic input at a high frequency. With this method, the impact of an ion strike can be seen over the full code range of the output. The error signatures from this testing can provide clues to which area of the ADC is sensitive to an ion strike.