Isolation is a means of preventing any DC and unwanted AC interaction between two parts of a system, while still enabling data and power transfer between those two parts. For example, a motor control circuit with a high voltage side which has a motor running from 690V and a low voltage side which powers the 5V microcontroller. It is desirable to have good communication between these two sides, without any noise transferring from the high voltage side to the low voltage side. An isolation device would be the right device to place between the high voltage and the low voltage sides to enable good communication between them. There are multiple reasons to isolate. One is to help protect from, and safely withstand, high voltage surges that could damage equipment or harm humans. An example of this is a PLC system in which the field side operates at 24V and the control side at 5V. In this case, any field side noise or surges could affect the control side. With isolation, the control side components are protected. A second example would be a system in which there are large ground potential differences, such as when RS-485 interfaces are used which run over thousands of meters. Due to the long distance, the ground potential at the control room and the factory floor may not be the same, causing ground loop currents. Isolation helps tolerate the large ground potential differences and breaks any disruptive ground loops in circuits that have high energy or are separated by great distances. A final example is the ability to reliably communicate with high side components in high-voltage motor/inverter drive systems, switches, and metrology applications. On the right side of this slide is an example of a four channel isolator. Isolators come in different channel configurations. In this case, INA and INB represents the two inputs on the primary side and INC and IND represent the two inputs on the secondary side, making this a two forward, two reverse architecture in a 16-pin SOIC wide body package. As can be seen in the image, there are two supply pins, VCC1 on the primary side and VCC2 on the secondary side, implying that two power supplies are needed for this isolator.