Avoid interference and earth loops
Published in issue 430, October 2012
If your USB device ever suffers from noise caused by an earth loop or if you want to protect your PC against external voltages then you need a USB isolator. The circuit described here offers an optimal electrical isolation of both the data lines as well as the supply lines between the PC and the USB device.The project itself is a spin-off from an earlier design for a portable oscilloscope for Android.
• Electrically isolated data and power supply lines
• Configurable data rate of 1.5 Mbit/s or 12 Mbit/s
• Power for the device side can be taken from an extra USB host connection or an external AC power adapter (5 V/min. 0.5 A)
• Transformer isolation = 1500 VAC for 1 min
• ADuM3160 isolation = 565 Vpeak for 50 years
• Maximum output current Iout = 500 mA @ 5 V
Click below to download a PDF copy of this article from Elektor magazine.
Please note. In view of the complexity of international markets, Elektor cannot guarantee the availability of components for this project.