1. TESTING ANALOG-TO-DIGITAL CONVERTERS
- Author
-
Mark Baker
- Subjects
Total harmonic distortion ,Effective number of bits ,Offset (computer science) ,Differential nonlinearity ,Histogram ,Electronic engineering ,Linearity ,Test method ,Integral linearity ,Mathematics - Abstract
The methodology of analog-to-digital (ADC) testing is different from that of digital-to-analog converter (DAC) testing. Understanding a general, all purpose ADC can help us understand all testing requirements. In a 3-bit ADC transfer diagram, there are eight output codes. This chapter illustrates the various procedures of offset measurement. The linearity test overview is explained with the help of various parameters like differential linearity and integral linearity. When the digital output codes have gaps, they are said to have a “missing code.” A histogram can also be used to test DC linearity. It has been noticed that there is a direct correlation between the numbers of events in a histogram and the amount of differential nonlinearity (DNL) error seen for that bit. Different kinds of waveforms are used for the histogram test method. The “segmented ramp” technique is also used along with the histogram test method. In testing, understanding the conversion time is also important. Harmonic distortion tests are used to test the impact of errors. Effective number of bits (ENOBS) presents a way of calculating the ratio of the signal energy to the noise energy.
- Published
- 2003