This tutorial introduced a lot of terms, so here's a recap in case you need to refresh your memory on one:

## 1LSB:

One Least-Significant Bit:  The smallest change of input voltage that will make an ADC's ouput change from one code to another, or the smallest voltage an ADC can measure repeatably.

Analog-to-Digital Converter:  A circuit whose output consists of digital patterns called codes.  Each code corresponds to a specific input voltage.

## Aperture:

The time when a sample-and-hold circuit is connected to the input.

## ASR:

Aperture Slew Rate: The fastest a signal can change and still be measured accurately by an ADC.

## Calibration:

Comparing a measurement to a better one, or measuring a known signal, to find a circuit's error.

## Code:

A pattern of ones and zeros.  In this case, a code is the output produced by an ADC.

## Compensation:

Subtracting a known error from a measurement without actually correcting the circuit to remove the error.

## Correction:

Modifying a circuit to remove a repeatable error.

## Correlation:

A relationship between the error and the signal being measured.

## Distortion:

Error that changes depending on the size of the input signal.

## Dynamic signals:

Signals that change at least 1LSB during an ADC's sampling interval.

## Error:

The difference between the actual input voltage and the voltage represented by the ADC's output code.

## Gaussian distribution:

A common kind of random signal with convenient statistical properties.

## Input-referred error:

The signal you'd have to add to a perfect ADC's input to make it produce the same output as a real ADC.

## NFCR:

Noise-Free Code Resolution: The amount of useful information you can get from an ADC in a given set of operating conditions.

## Noise:

For the purposes of this tutorial, noise is random error that can't be corrected or compensated.

## Offset:

A DC voltage added to another signal.

## Repeatability:

The ability to reproduce a condition on demand.. the main difference between ideal circuits/signals and real ones.

## RMS:

Root-mean-square:  A way to measure AC signals that lets us compare them to DC measurements.

## S&H:

Sample and Hold: The input circuit for most ADCs.  It captures the input quickly, then holds that voltage stable while the ADC generates an output code.

## Sample rate:

The number of different codes an ADC can produce in one second.

## Sampling interval:

The time it takes an ADC to generate a code.

## SAR:

Successive Approximation Register: an ADC architecture that compares the input to its last guess several times, reducing the error with each new guess.

## Sigma-Delta:

An ADC architecture that uses positive and negative pulses of known charge to make a capacitor's voltage equal the input voltage.

## Slew rate:

The amount a signal's voltage changes over time.

## Standard deviation:

The band of values around a signal's average that contains 68% of the readings.

## Static signals:

Signals that stay at a fixed voltage, or change less than 1LSB during an ADC's sampling interval.

This guide was first published on May 23, 2019. It was last updated on May 23, 2019.