Analog Still Matters — Here’s When to Use It

BY Editor

These days, discussions of analog and digital technology tend to be framed in terms of “either –or,” often with the intent of proving that digital is preferable. Analog is often viewed as old-fashioned or irrelevant in today’s digitally focused world.

However, nothing could be further from the truth. The fact is, analog technology still matters and is an important part of much of the tech we use every day. While many analog signals are converted to digital (for example, many of the sensors used on fitness trackers are analog, which then convert those signals into digital data for interpretation), there are still times when analog is preferable.

Analog vs. Digital Overview

To begin the discussion of when it’s better to use an analog signal as opposed to digital, it’s useful to explore the differences between the two signals.

Both analog and digital signals transmit information by collecting information and transforming it into electrical signals. However, analog technologies translate the information into electric pulses of varying amplitude; it is one continuous signal representing a continuous measurement. Digital technology, on the other hand, translates the data into binary format (zero or one) that represents the signal within a specific moment in time, with each bit representing two distinct amplitudes. In simpler terms, analog technology records the data exactly as it is, while digital technology transforms the recording into a limited set of numbers.

The effect, then, is that digital technologies can lose some of the nuance of the data, since the data recording is constrained by the limitations of the binary system. That being said, analog technologies also have some limitations; for example, the data can be deteriorated by “noise” during transmission. This is why, for example, your fitness tracker might measure your steps differently when you walk on soft carpet than when you stroll down a concrete sidewalk. However, analog data collection can happen in real time, and it’s generally less expensive than digital technology.

When it comes to quality of the signal, especially when making copies of the data, analog has a clear advantage. Because digital technology translates and reassembles data into a binary form, it’s more likely to lose quality in the process, even if it does detect and isolate noise in the data and removes them. Analog allows for less manipulation of the signal, but that is part of the appeal in many of the most common uses.

When Analog Has the Advantage

So what are the applications in which analog technology has the advantage?

Sensors. When a device needs to convert real-world information from a non-electrical format into one that can be used by a computer or embedded system, analog is the best choice. Fitness trackers, HVAC systems, household appliances, and other consumer products are some of the common uses of these sensors.

In many cases, because the signals collected by these sensors are of such low amplitude, they require some analog signal conditioning, or preparation for the signal for the next step of processing for signal improvement.

Control systems.  Digital control systems are becoming more common, but analog systems tend to be easier to use. As analog-to-digital converters become faster and more accurate, this could change, but for now the simplicity of analog control systems is a significant advantage.

Music. It’s not hard to find a music lover who rails against the use of digital signals in recording. While some stereo systems have decent digital-to-analog conversion capabilities, purists often prefer to listen to their music exactly as it was recorded, without the filters and manipulation that digital recordings allow. Preserving audio fidelity is one of the most common applications of analog technology, even as digital tools are developed that can faithfully recreate the original sound.

Controlling the Signal. Digital technology has some limitations when it comes to capturing all data. If you capture a signal at an amplitude that is higher than your analog-to-digital converter can handle, then you will need to condition the signal so that it can be read by your ADC. This is only possible with an analog signal.

Undoubtedly, digital does have some advantages, and there are some applications in which it is the better choice. That doesn’t mean that analog is no longer useful, though, or outdated. In fact, it’s unlikely that analog will ever be completely replaced by digital.