For a DAC, a DNL error of -1LSB implies that the output did not increase for an increasing input code. A DNL error of greater than - 1LSB implies that the device is non-monotonic. For an ADC a DNL error of greater than -1LSB implies that at least one code is missing, meaning that there is no analog voltage which will generate a particular code. Most manufacturers will include a “NO MISSING CODES” specification. A modern SAR A/D converter uses an array of capacitors and a comparator to determine the value of each bit in the conversion result. Variations of the individual capacitors will produce periodic fluctuations in the DNL data. These variations can be seen in DNL vs Code plots of a datasheet.