ADC Static Characterization Using Nonlinear Ramp Signal

Static characteristics of an analog-to-digital converter (ADC) can be directly determined from the histogram-based quasi-static approach by measuring the ADC output when excited by an ideal ramp/triangular signal of sufficiently low frequency. This approach requires only a fraction of time compared to the conventional dc voltage test, is straightforward, is easy to implement, and, in principle, is an accepted method as per the revised IEEE 1057. However, the only drawback is that ramp signal sources are not ideal. Thus, the nonlinearity present in the ramp signal gets superimposed on the measured ADC characteristics, which renders them, as such, unusable. In recent years, some solutions have been proposed to alleviate this problem by devising means to eliminate the contribution of signal source nonlinearity. Alternatively, a straightforward step would be to get rid of the ramp signal nonlinearity before it is applied to the ADC. Driven by this logic, this paper describes a simple method about using a nonlinear ramp signal, but yet causing little influence on the measured ADC static characteristics. Such a thing is possible because even in a nonideal ramp, there exist regions or segments that are nearly linear. Therefore, the task, essentially, is to identify these near-linear regions in a given source and employ them to test the ADC, with a suitable amplitude to match the ADC full-scale voltage range. Implementation of this method reveals that a significant reduction in the influence of source nonlinearity can be achieved. Simulation and experimental results on 8- and 10-bit ADCs are presented to demonstrate its applicability.

[1]  Turker Kuyel Linearity testing issues of analog to digital converters , 1999, International Test Conference 1999. Proceedings (IEEE Cat. No.99CH37034).

[2]  A. Cruz Serra A new measurement method for the static test of ADCs , 2000 .

[3]  Pasquale Daponte,et al.  Performance analysis of an ADC histogram test using small triangular waves , 2002, IEEE Trans. Instrum. Meas..

[4]  Solomon Max,et al.  Ramp testing of ADC transition levels using finite resolution ramps , 2001, Proceedings International Test Conference 2001 (Cat. No.01CH37260).

[5]  Francisco André Corrêa Alegria,et al.  Overdrive in the ramp histogram test of ADCs , 2005, IEEE Transactions on Instrumentation and Measurement.

[6]  Ieee Std,et al.  IEEE Standard for Terminology and Test Methods for Analog-to-Digital Converters , 2011 .

[7]  Pasquale Daponte,et al.  An ADC histogram test based on small-amplitude waves , 2002 .

[8]  L. Satish,et al.  A time efficient method for determination of static non-linearities of high-speed high-resolution ADCs , 2005 .

[9]  Linus Michaeli,et al.  Triangular testing signal for identification of unified error model parameters , 2007 .

[10]  F.C. Alegria Proposal for high accuracy linearity test of triangular waveform generators , 2007, AFRICON 2007.

[11]  Degang Chen,et al.  Accurate testing of analog-to-digital converters using low linearity signals with stimulus error identification and removal , 2005, IEEE Transactions on Instrumentation and Measurement.

[12]  Solomon Max Fast accurate and complete ADC testing , 1989, Proceedings. 'Meeting the Tests of Time'., International Test Conference.