# Why Digital?

The future is digital, a “marketing” subject for many of us. It adds value to devices, but is it truly better?

Analog electronic circuits work with analog (continuous) voltages and analog (continuous) currents. In those circuits, information exists in electrical voltages and currents. So even the slightest change in voltage or current means the data held in the signal modifies.

The circuit’s temperature and, as a result, the generated noise will play a significant role in the behavior of currents and voltages. Temperature differences define the parameters of many electronic components in analog circuitry. So, the characteristics of the circuit will change with the ambient temperature. So will the voltages and currents which carry the information.

The development of an analog circuit is all about how to keep changes in characteristics within specifications. Imagine you create an analog filter. Will the cut-off frequency be stable? The answer is NO because the cut-off frequency will vary slightly with temperature. The developer’s challenge is making the circuit as stable as possible for these temperature changes.

In an analog system, information is in the value of voltages and currents.

Voltage and current are susceptible to change because the electronic components are temperature-dependent.

If the voltages and currents change by temperature, your information content will also alter with temperature!

For example, a digital filter will use the discrete values (samples) and process them with a mathematical algorithm running on a Digital Signal Processor (DSP). Whatever temperature change the processor will undergo. The algorithm will continue to run, delivering the same characteristics, and the filter characteristics will not change. Algorithms or computer programs are independent of temperature!

Moreover, if you work with digital voltages, the voltage and currents can vary slightly as in analog circuits, but a “0” will stay a “0,” and a “1” will stay a “1”. This independence of temperature and noise makes digital electronics so much better in modern electronics. It is clear that the future is digital, and the use of analog circuitry will only happen at the edge of the circuit (analog to digital and digital to analog circuitry).

However, digital has a drawback. Using a DSP will introduce some delay. Executing an algorithm means handling it step by step. Each step will consume a specific time, so the signal at the output will be delayed compared to the input.

It gives us an answer to why it took so long to use these fantastic digital circuits. The number of electronic components we can integrate on a silicon chip today is much more significant than 40 years ago. Smaller components on a chip can be much faster (charges of lesser electrons can change state more rapidly). Moreover, the smaller parts will use lesser power. It has become essential for mobile devices such as DAB(+) receivers.

Assume a portable mobile DAB(+) receiver with a short battery autonomy. Nobody would buy it. We do not want to change the batteries every few days!

DAB(+) would not be possible without our giant leap in faster electronics (High Integrated Density). Developing DAB(+) devices with standard components would never work because of the temperature instability of the high-complexity electronic circuits needed for DAB(+). We can say that DAB(+) is genuinely a product of electronic evolution.

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