Regarding the knowledge of fully integrated isolators, the editor of UE Electronic will give you a brief introduction.
       All isolated DC/DC power converters include input filters, output filters, transformers, primary switches, secondary rectifiers and a controller.The controller can be referenced to either primary or secondary ground.An isolated half-bridge power converter with a controller referenced to primary ground.There are a total of 4 crossing points on the isolation boundary: the power transformer, the feedback signal, and the 2 synchronous rectifier MOSFET control signals.Because the feedback signal is a relatively slow analog signal, an optocoupler is often used to isolate the feedback signal.Most optocouplers are too slow for use in synchronous MOSFET gate electronics to drive isolation.Suitable fast optocouplers are now available, but this results in a significant increase in cost.
       All these newly developed fully integrated isolators are very practical.They promise better reliability than traditional transformer-based gate drive isolators while also being smaller in size when sending gate drive information across the isolation boundary.As with any isolation scheme, power converter applications can be quite difficult.Another issue that must be treated with caution is dV/dt sensitivity.We need to quickly transition potential from one ground to another and know whether the isolator differential output maintains state during and after the transient.
　　Electromagnetic sensitivity is another concern. The isolator must remain in a suitable state when encountering external magnetic fields. Many new devices are limited to operating temperatures below 85°C, which may be too low in some power converter applications. Most of these new technologies require an independent 5V bias on the primary and secondary sides of the device. Compared with traditional isolation transformers, this may require additional supporting components. The inputs of these new devices are typically configured for TTL thresholds up to 5V. Some new controllers (such as NS's LM5035C) provide 0~5V control output to be directly compatible with this new isolator.