High Speed (UAC2) USB Galvanic Isolator

Photo of the first prototype, production device may differ.


Model I


Model II

High Speed USB Isolator - "Ground Loop Breaker"

For measurement and audio.


Based on new TI' ISOUSB211 chip, this device provides full isolation between PC and external equipment. This is to prevent noise coming from the PC and eliminate ground loops.

Model I - with external power option

There are two possible use cases:

  1. Using DC/DC power from USB, to provide 5v to the external device.
    This can be used with any USB devices, self powered or PC powered, just place an isolator between the PC and the device. Noise from DC / DC is certainly present, but usually this noise is less than the noise from the PC. The power limitation of the DC/DC converter must also be taken into account.

  2. Using an external 5 V DC power supply to power the secondary part of the isolator, as well as an external device. This provides complete isolation, but may be overkill for many devices.
    However, this option can provide much higher current to the external device and less noise if a linear power supply is used.

This time there is no case, just assembled PCB.

Model II - without external power option

Device in plastic case. Pay attention - input is mini-USB connector, not USB-B.


Hint: since all Altor Audio USB audio devices are already isolated (on the I2S bus) and do not require this USB isolation, this isolator is mainly intended for use with equipment from other companies.

For example, E1DA's Cosmos ADC is a very good device, but due to the non-isolated design, there are sometimes increased noise levels and noise peaks. If you measure a non-isolated DAC or something else that has its own connection to a PC (or mains safety ground), you will get the classic "ground loop". We encountered this problem even with an isolated DAC, after connecting a non-isolated JTAG interface to the DAC microcontroller.