SHANGHAI, Oct. 9, 2023 /PRNewswire/ -- Some may see isolation as a too-often-heard topic, but it actually plays an important role in protecting circuit and personal safety.
Here's a simple example. The battery voltage in an electric vehicle (EV) can reach 400V, or even 800V, but the driver can calmly and safely operate all devices, instruments and knobs inside it. Behind this calmness and safety, various forms of isolation play a crucial role – they build a safe and reliable connection between high and low voltage systems.
Considering such a profound effect, the selection of isolation type particularly matters. Thanks to the advances of semiconductor technology, digital isolators have become rising stars.
It's not difficult to understand digital isolators. They are similar to optocouplers, except that the photovoltaic conversion and modulation is changed to other technologies. However, it's noted that optical attenuation will not occur in digital isolators. Unlike optocouplers, digital isolators provide many benefits, including good switching characteristic, low vulnerability to aging, high reliability, high voltage withstand ability, high speed, and energy transferability. All these are underpinned by semiconductor technology.
However, perfection never exists in the realm of technology. Digital isolators boast visible advantages, but there are always trade-offs. For example, common mode interference may occur in capacitive isolators, which needs to be suppressed. There are several methods to significantly enhance the immunity to common-mode interference. Taking the Chinese isolator manufacturer NOVOSENSE as an example, it has developed the Adaptive OOK® proprietary modulation technology on the basis of OOK, which improves the capability of digital isolators to resist common-mode interference.
The so-called Adaptive OOK® technology uses the common mode detection circuit inside the IC to detect the state of common mode signals, and then depending on the signals detected, dynamically and adaptively modulates the internal key circuit characteristics or gains. When the common mode noise is large, it can better suppress the noise, so as to provide higher robustness and enhanced immunity to common mode interference.
Another benefit of adaptive modulation is that high common-mode interference resistance does not need to be guaranteed at full operation state. Only when the instantaneous interference is relatively high, the circuit needs to perform more functions to suppress interference. In most cases where there is no harsh conditions and a low requirement for common-mode interference resistance, Adaptive OOK® technology can strike a good balance between system properties and power consumption to optimize the overall performance.
We've seen the rise and dominance of electromagnetic relays and optocouplers, but now it's the dawn of digital isolators. They are becoming increasingly vital in guaranteeing the security of our systems and safeguarding users. If you're still using an optocouplers in system, it might be time to rethink and dive deeper into the world of digital isolator technology.
