IADCs

IADCs, or integrated analog-to-digital converters, are ADCs on a single integrated circuit that include essential analog front-end functions such as amplifiers, references, and often a multiplexer or sample-and-hold. This integration reduces external components, minimizes parasitics, and improves sensor-interface reliability.

Common IADC architectures include SAR, delta-sigma, pipeline, and flash. SAR and pipeline devices balance speed and linearity, delta-sigma emphasizes high resolution at lower frequencies via oversampling and noise shaping, while flash offers ultra-fast conversion for specialized high-speed needs.

Performance is described by resolution, sampling rate, SNR, ENOB, and INL/DNL. Other metrics include gain and offset errors, power consumption, and temperature stability. Some devices include on-chip calibration and reference sources.

Integration often provides a programmable gain amplifier, input multiplexer, and on-chip anti-alias filtering. Digital outputs typically use SPI or I2C, with some devices offering parallel interfaces. Selectable input ranges and sampling schemes are common.

Applications include data acquisition, instrumentation, medical devices, automotive sensors, industrial controls, and consumer electronics. On-chip integration simplifies boards, reduces noise, and enables compact, low-power solutions.

Design considerations include noise, linearity, distortion, thermal drift, input bandwidth, and the speed–resolution–power trade-off. Packaging and process technology also influence performance and cost.

See also: Analog-to-Digital Converter, Mixed-signal integrated circuit, Data acquisition system.