Analogue & Digital Data (Cambridge (CIE) IGCSE ICT)

Analogue & Digital Data

What is analogue data?

• Analogue data is continuous data created from non-digital devices

• Analogue data can change gradually and smoothly

• Examples of analogue data include:

  • sound waves produced when you talk

  • data collected by sensors (output)

What is digital data?

• Digital data is data represented in a binary format (1s and 0s)

• Digital data is created and/or stored using digital devices

• Examples of digital data include:

  • software

  • documents/files

Characteristics of analogue & digital data

Analogue to digital conversion (ADC)

• Analogue data must be converted to digital data so that it can be processed by a computer

• The ADC process involves taking samples (measurements) of the analogue signal and converting it to a binary code

• The sample rate and a higher number of binary digits used in the conversion leads to a more accurate representation of the original signal, but, takes up more space on secondary storage

Digital to analogue conversion (DAC)

• Digital data must be converted to analogue data so that it can be used to control devices

• The DAC process involves converting discrete digital values (1s and 0s) back into a continuous analogue signal

• The quality of the analogue signal after conversion is based on the original sample rate and number of bits used in the digital data