Hi,
We have a custom board design that uses ISOUSB111 with a self-powered USB device to provide ground loop isolation between the USB host and the device. The device is not earthed; it is powered from a galvanically isolated DC power supply, that has only two prongs with no earth connection. We did not see any guidance in the ISOUSB111 datasheet on how to connect the USB shell. Anecdotally, the noise levels measured within the device go down with a capacitive connection between the USB shell the device's internal signal ground. Can anyone confirm if there is official guidance on how to connect the ISOUSB111 shield for self powered USB devices that use ISOUSB111 to isolate a USB data connection?
Thanks