The ADS121x1 family of analog-to-digital converters represents a unique form of device for industrial use. To accomplish the performance level of no missing codes to 24 bits and effective resolution to 23 bits (ADS1210/11) requires some special handling. Each of the members of the ADS121x family of A/D converters is a digital subsystem with an analog front-end. This paper is intended to help understand the operation and therefore make the inclusion of these unique devices easier for the system designer.