Selecting an operational amplifier (op amp) to drive an analog-to-digital converter (ADC) is not a trivial task. Usually dictated by the end equipment, the choice of ADC is based on trade-offs of several parameters. Even within the same sector or market segment, ADC requirements can differ. For example, in test and measurement you will find a mix between successive approximation register (SAR) and delta-sigma ADCs. SAR ADCs tend to be popular in parametric measurement units, memory testers and battery cell formation testers.

Delta-sigma ADCs are typically used for vibration analysis, data acquisition and scientific instrumentation. Some applications can be common to both, depending on the overall system requirements. Highly accurate weigh scales benefit more from delta-sigma ADCs given their higher resolution, whereas consumer and low-end models rely on the SAR topology to minimize power consumption.

Likewise, datacom optical modules tend to use SAR ADCs whereas telecom optical modules often rely on delta-sigma ADCs even though both applications are part of the same sector, namely data centers.

Paying careful attention to the DC and AC specifications of the op amp (or analog front end) can help avoid ADC performance degradation and minimize errors.