Which statement describes the signal immediately after the encoder in the ADC chain?

Which statement describes the signal immediately after the encoder in the ADC chain?

• A. A Digital output signal
• B. B Discrete-time, discrete amplitude signal
• C. C Analog signal
• D. D Continuous-time signal

Answer: (A)

The signal immediately after the encoder is a digital output signal. The encoder’s job is to take each quantized value from the previous stage and convert it into a binary code that represents that value. Since sampling has already occurred, these codes arrive at discrete time instants, and because quantization reduces the analog value to a finite set of levels, the amplitude is represented in discrete steps. So the encoder outputs a stream of binary words at the sampling rate, which is exactly what makes it a digital output signal. This distinguishes it from the analog, continuous-time description that would apply before encoding.