1 Introduction

The ADC128S102QML-SP may exhibit code errors called sparkle codes at the output of the device. A sparkle code is an erroneous output that occurs very infrequently under very specific input conditions. A code error is defined as an error in the output code of an analog to digital converter (ADC) that exceeds a defined error threshold. The acceptable range of an ADCs output is commonly defined to include performance parameters including, but not limited to, offset, gain, and noise. If the output exceeds the expected amplitude of the ADC’s acceptable error threshold, this is considered an error code. A sparkle code is a single erroneous output code either above or below the threshold that can be easily identified in the presence of noise, in the case of the ADC128S102-SP, by a minimum delta of 0xFF from the expected output code. Another way to explain this definition is that the observed error amplitude occurs with a probability exceeding the expected probability of the error amplitude given the ADC’s assumed Gaussian distributed noise. That is, sparkle codes are clearly visible and easily recognizable in data sample sets and data sample plots as shown in Figure 1-1.

An important characteristic that defines sparkle code is that it will only occur when the expected converter output code is at very specific values. The erroneous sparkle code measured will occur at predicted values, available in Table 3-1. For example, if the expected output code is in the range of 0x0FF – 0x100 than a sparkle could occur where the output value is 0x1FF. A sparkle code can only occur under certain output value conditions and has a predictable sparkle code value. The physical mechanism causing the sparkle code will be described in the Root Cause Analysis section.

Figure 1-1 Example of Sparkle Code Outside of Expected Output Range