What Defines Performance in High-Speed Digitizers

The white paper “What Defines Performance in High-Speed Digitizers” by Andrew Dawson from Vitrek LLC explores the critical performance parameters engineers should consider when selecting high-speed digitizers for various applications. It highlights the differences between digitizers and Digital Storage Oscilloscopes (DSOs), emphasizing that digitizers are optimized for high-fidelity signal acquisition and rapid detection of small signal changes. The paper discusses key specifications such as channel count, vertical resolution, and maximum sampling rate, and explains why these alone are insufficient for evaluating performance. It introduces the concept of Effective Number of Bits (ENOB) as a true measure of vertical performance, accounting for signal distortion and noise.

Additionally, the paper underscores the importance of frequency response in digitizers, illustrating how the frequency response curve impacts signal attenuation and overall performance. It explains that while higher bandwidth can improve signal acquisition, it often degrades ENOB due to increased high-frequency noise. Therefore, engineers must balance bandwidth and ENOB to optimize digitizer performance. The paper concludes that understanding both ENOB and frequency response is crucial for selecting the right digitizer for specific applications, ensuring accurate and reliable signal acquisition.