*Question E8A04:
What is “dither” with respect to analog-to-digital converters?*  

*Correct Answer is  B: A small amount of noise added to the input signal to reduce quantization noise*  

### AI Response: (may contain errors)  

Dither is a technique used in analog-to-digital converters (ADCs) to improve the quality of the digital representation of an analog signal. 

### Correct Answer Explanation:
- **Correct Answer: B**: A small amount of noise added to the input signal to reduce quantization noise.
  - **Why it's correct**: Dither is intentionally introduced noise that helps to randomize the quantization error. By adding this small noise, the ADC can more effectively represent the analog signal, reducing the effects of quantization noise and improving the overall fidelity of the digital output.

### Incorrect Answer Explanations:
- **Choice A**: An abnormal condition where the converter cannot settle on a value to represent the signal.
  - **Why it's incorrect**: This describes a malfunction or instability in the ADC, not the purposeful technique of dither. Dither is a controlled addition of noise, not an abnormal condition.

- **Choice C**: An error caused by irregular quantization step size.
  - **Why it's incorrect**: Irregular quantization step sizes can lead to distortion, but dither specifically addresses the issue of quantization noise by adding noise to the input signal. Dither does not relate to the step size itself.

- **Choice D**: A method of decimation by randomly skipping samples.
  - **Why it's incorrect**: Decimation involves reducing the sample rate of a signal, typically by averaging or selecting specific samples. Dither does not involve skipping samples; it is about enhancing the signal representation by adding noise.

### Summary:
Dither is a valuable technique in ADCs that helps to minimize quantization noise, leading to a more accurate digital representation of the analog signal. Understanding this concept is crucial for the Extra Class exam, as it highlights the importance of signal processing techniques in communication systems.