Conversion Topology
Mixed-signal integrated circuits convert continuous physical voltage waveforms into discrete binary numbers for digital processing systems. An analog to digital converter establishes the bridge between physical sensor signals and microprocessor logic. Architecture selection dictates whether a system optimizes for sample rate or effective resolution.
Successive approximation register circuits achieve moderate speed with high accuracy, whereas delta-sigma architectures oversample to isolate low-frequency sensor signals.
Quantization Boundary
Resolution specifications establish the theoretical minimum voltage step that an analog to digital converter can distinguish. Differential nonlinearity describes the deviation between actual step widths and the ideal least significant bit voltage. When differential nonlinearity exceeds one least significant bit, missing codes occur and output codes skip specific binary values entirely.
Cumulative errors across the full code range create integral nonlinearity, which bends the transfer function away from an ideal straight line. Temperature variations cause reference drift that alters the full-scale slope, while operational amplifier input offsets shift the zero-scale point across the operating range.
Reference Sensitivity
Voltage reference stability governs the long-term repeatability of digitized measurement data. Noise on the reference input maps directly into output code jitter, degrading the signal-to-noise ratio. Proper printed circuit board layout keeps analog input traces isolated from digital switching bus paths.
Ground plane splits prevent return currents from introducing unwanted offset voltages.
Sampling Artifact
Nyquist limits require input signal frequencies to remain below half the sampling frequency. An analog to digital converter samples high-frequency noise down into the passband if anti-aliasing filters fail to attenuate out-of-band signals. Input settling time limits how fast multiplexed channels can switch without cross-channel contamination.
