A Technique For Reducing Differential Non-linearity Errors In Flash A/D Converters

A modification of the conventional flash converter improves final test yield to 0.5LSB differential nonlinearity (DNL) more than four times. In the past, flash converter performance improved primarily due to IC processing innovations. Speed and resolution both increased and power consumption and die area decreased as device geometries shrank. Now device mismatch often limits the DNL of the standard-design architecture and is a fundamental limit on making high-resolution converters.