While the nominal vertical resolution of a high-speed waveform digitizer (specified in bits) is often promoted, its true performance is provided by its measured Dynamic Parameters and in particular by its Effective Number of Bits (ENOB). This paper describes measurement of the Dynamic Parameters and presents measurements for a leading-edge 12-bit Digitizer.

We discuss different measurement methods for characterizing the performance of signal waveform capture A/D digitizer instruments, and how ENOB is the most important overall indicator of digitizer performance. You will gain an understanding of ENOB and dynamic parameters such as Signal-to-Noise Ratio (SNR), Total Harmonic Distortion (THD), Signal-to-Noise-and-Distortion Ratio (SINAD), and Spurious Free Dynamic Range (SFDR) in relation to targeted operating signal frequency range. Input bandwidth can assist developers in selecting the appropriate best performing digitizer instrument for the desired application under test.