*Question E8A02:
Which of the following is a type of analog-to-digital conversion?*  

*Correct Answer is  A: Successive approximation*  

### AI Response: (may contain errors)  

Successive approximation is a type of analog-to-digital conversion. Here's why:

1. **Correct Answer: Successive Approximation**
   - **Explanation**: Successive approximation is a method used in analog-to-digital converters (ADCs) to convert a continuous analog signal into a digital signal. It works by approximating the input voltage in steps, refining the approximation with each step until the digital output closely matches the analog input. This method is efficient and widely used in ADCs due to its balance between speed and accuracy.

2. **Incorrect Choices**:
   - **Harmonic Regeneration**: This is not related to analog-to-digital conversion. Harmonic regeneration typically refers to the process of restoring or enhancing harmonics in a signal, often used in audio processing or signal conditioning.
   - **Level Shifting**: This involves changing the DC level of a signal without altering its shape. It is used in interfacing circuits with different voltage levels but is not a method of analog-to-digital conversion.
   - **Phase Reversal**: This refers to changing the phase of a signal by 180 degrees. It is used in signal processing but does not relate to converting an analog signal to a digital one.

In summary, successive approximation is the correct choice because it directly pertains to the process of converting an analog signal into a digital format, which is the essence of analog-to-digital conversion. The other options describe processes that do not involve this type of conversion.