Examples of human-machine interaction are increasing
With proper application of the insulator and safe operation As the era of human-machine interaction begins in earnest, isolation is emerging as a critical issue.

For example, inside an electric vehicle (EV), kilometers of wiring connect switches, sensors, and high-voltage motors. In factories, industrial controllers exchange data, commands, and power with various sensors. In hospitals and nursing facilities, high-voltage medical equipment monitors patients and connects industrial machinery to microcontrollers via USB interfaces. And high-voltage relays operate according to commands from smart controllers.

With the trend of replacing mechanical industrial systems with electric motors, sensors, and actuators, instances of such machine-to-machine and human-to-machine interactions are becoming increasingly common.

Cumbersome mechanical switches are being replaced by sensitive touch controls. As the number of electric motors operating at high voltages rapidly increases, semiconductor switches operating at high voltages are becoming commonplace. All of these devices must communicate and interact with smart controllers and drivers. As industrial, automotive, medical, and offline applications grow, the need for the protection, noise immunity, and reliable operation provided by isolation technology increases.

An isolator is required for reliable operation, and safe operation can be achieved by properly applying the isolator. For example, an isolator can protect people from the risk of electric shock by isolating related circuits from high-voltage or low-voltage processors, such as C2000 microcontrollers that drive powerful industrial motors.

It is establishing itself as a mainstream solution in many industrial applications that tend to transmit data exceeding hundreds of megabits through isolation walls that offer high efficiency and robustness against high-voltage surges. Additionally, in gate driver and industrial sensor applications, both data and power can be transmitted through isolation walls. As the number of channels increases and channel-to-channel isolation becomes required, the demand for miniaturized solutions is also rising.

So, what exactly is insulation? An insulation wall refers to a physical medium that enables the reliable exchange of data and power between two systems while blocking unwanted currents. To achieve an integrated insulation solution, the following points must be considered.

First, one must consider the maximum surge voltage and operating voltage that the isolator can withstand during short periods or normal operation. Additionally, one must consider the maximum rate of change in ground potential difference that the isolator can withstand without causing communication errors. Furthermore, the delay time caused by the isolation walls, the spatial distance and creepage distance between power pins, and the level of electromagnetic interference must also be taken into account.

There are two types of insulation methods.

First is the capacitive method.

By integrating a multilayer silicon oxide-based capacitor internally instead of using an external capacitor, a high level of insulation can be achieved and data can be transmitted via an electric field.

TI's capacitive isolation technology uses two capacitors in series on two dies placed side-by-side within the same module. In this way, an excellent reinforced insulation solution can be provided for high-speed data transmission.

Data rates for isolated walls reach over several hundred megabits per second. Using innovative circuit topologies can further increase data rates, making them more suitable for applications such as industrial Ethernet.

TI's isolator products use customized CMOS technology to provide high-performance reinforced isolation walls.

The following is the inductive method.

A combined pair of inductors can be used to exchange data via magnetic flux while isolating two circuits. The two inductors can be embedded in a laminated PCB or integrated into a single die in a monolithic manner.

The advantage of inductive isolation is that it can transmit over several hundred milliwatts of power through isolation walls. Therefore, an additional power supply is not required on the secondary side. The ability to transmit power with high efficiency and data through isolation walls is critical for many industrial applications because it enables low input current and high maximum operating ambient temperatures.

Digital isolator products integrating TI's power technology use innovative materials and inductor designs to provide maximum power transfer efficiency.

Data and power conditioning are commonly combined with capacitive and inductive isolation. Data conditioning minimizes the risk of transient spikes appearing in the data, thereby protecting signals through isolation and ensuring smooth equipment operation. Power conditioning maximizes power transmission efficiency.

Isolation can also be achieved by physically separating two systems while communicating using optical or electromagnetic waves.

No single isolation solution can meet all requirements. Most industrial solutions require an integrated approach that includes isolated amplifiers, isolated high-speed data links such as RS-485 signals, and isolated gate drivers. As humans and machines increasingly collaborate, high-voltage solutions ensure that systems operate robustly and reliably.

This article is a summary of a piece by Ahmad Bahaï, Chief Technology Officer at Texas Instruments.