| Specification |
Definition |
Key Applications / Use Cases |
| Resolution (N bits) |
Number of output bits the ADC produces; defines the smallest voltage step it can theoretically resolve. |
Precision measurements, sensor interfaces, metrology, control systems |
| Sampling Rate (fs) |
Number of samples per second the ADC can take. Expressed in samples per second (SPS or Hz). |
Audio, RF, imaging, fast control loops, high-speed data acquisition |
| Input Voltage Range |
Acceptable min and max input voltages the ADC can convert without clipping. |
Signal chain design, amplifier selection, matching sensor ranges |
| SNR (Signal-to-Noise Ratio) |
Ratio of signal power to noise power (excluding distortion), usually in dB. |
Audio, medical imaging, RF Communication, sensor fidelity |
| THD (Total Harmonic Distortion) |
Ratio of total harmonic power to fundamental signal power, expressed in dB. |
Audio, communication systems, instrumentation requiring signal purity |
| SINAD (Signal-to-Noise and Distortion) |
Ratio of signal power to combined noise + harmonic distortion power. Typically combination of SNR and THD. Used to calculate ENOB. |
General-purpose dynamic performance, especially for sinewave inputs |
| ENOB (Effective Number of Bits) |
The number of bits of actual resolution an ADC achieves, based on SINAD. |
System accuracy analysis, error budgets, DSP headroom |
| INL (Integral Nonlinearity) |
Maximum deviation of the ADC’s transfer function from an ideal straight line, after offset/gain error correction. |
Precision instrumentation, DC measurement accuracy |
| DNL (Differential Nonlinearity) |
Difference between an actual code width and ideal 1 LSB step. If >1 LSB, ADC can be non-monotonic. |
Control systems, DAC feedback, waveform generation, code stability |
| Offset Error |
Deviation of the ADC output from zero when input is 0 V. |
Low-level signal measurement, calibration circuits |
| Gain Error |
Error in the slope of the ADC transfer function after offset correction. |
Analog signal conditioning, voltage scaling accuracy |
| Aperture Jitter (Time Uncertainty) |
Variability in the exact time a sample is taken. Critical in high-speed ADCs. |
RF sampling, digitizing high-frequency analog signals, clock synchronization |
| Latency / Pipeline Delay |
Time delay between sampling and output availability, especially in pipelined ADCs. |
Closed-loop control, real-time systems, time-sensitive signal processing |
| Input Capacitance |
Equivalent input capacitance seen by the signal source. |
Matching driver circuitry, sample-and-hold design, bandwidth optimization |
| Input Impedance |
The resistance between the input pin and ground (or reference). |
Buffer/driver design, matching to high-impedance sources |
