Chapter 4 - Signal Capture

Abstract

This chapter focuses on the importance of how to use similar concepts and equations in order to capture the device under test (DUT) signal output. A mixed signal device usually generates analog information in either an analog or a digital form, which is, in turn, captured by the ATE systems' signal capture devices. The signal capture instruments store a numerical photocopy of the analog information from the DUT in the test systems' capture memory. If the stimulus waveform is in the digital form, the signal capture receives the data from the digital pin receivers. At the same time, the level and timing parameters are the same as for a digital test. The chapter also describes the contents of the signal capture memory that represents a digitized analog signal and not the digital logic states. The digital signal processor (DSP) usually analyzes the signal data in order to extract the analog signal information that includes peak, signal-to-noise, and harmonic distortion. In most ATE systems, the signal capture can be started and stopped either with the help of the program or the micro-code in the pattern.