Which device changes the voltage of received signals into numeric values?

Which device changes the voltage of received signals into numeric values?

• A. Analog to Digital Converter
• B. Digital to Analog Converter
• C. Digital Memory
• D. Scan Converter

Answer: (A)

Converting an analog signal to digital numbers is performed by an Analog to Digital Converter. The ultrasound transducer output is a continuous voltage that changes over time; the ADC samples this voltage at regular intervals and assigns each sample a finite numeric value through quantization. This process turns the wave into a stream of digital data that the ultrasound system can process, store, and display. The sampling rate should be high enough to capture the signal details (Nyquist criterion) and the resolution depends on the converter’s bit depth. Other devices do different jobs: a digital-to-analog converter would turn those numbers back into a voltage; digital memory stores data but doesn’t convert the incoming signal to numbers; and a scan converter maps image data for display rather than performing the voltage-to-digital conversion.

Converting an analog signal to digital numbers is performed by an Analog to Digital Converter. The ultrasound transducer output is a continuous voltage that changes over time; the ADC samples this voltage at regular intervals and assigns each sample a finite numeric value through quantization. This process turns the wave into a stream of digital data that the ultrasound system can process, store, and display. The sampling rate should be high enough to capture the signal details (Nyquist criterion) and the resolution depends on the converter’s bit depth. Other devices do different jobs: a digital-to-analog converter would turn those numbers back into a voltage; digital memory stores data but doesn’t convert the incoming signal to numbers; and a scan converter maps image data for display rather than performing the voltage-to-digital conversion.