ADUM4160 Analog Devices USB Isolator, issues with RTL SDR dongle...

[rwgast_lowlevellogicdesin]

So I wanted to lower the noise floor of my SDR dongle, I decided to use an ADUM4160 chip instead of the usual technique used, which is passing the USB data lines through but isolating the power supply.

Anyways I threw together an ADUM isolator on a piece of prefboard along with a 5v Linear LDO to power the isolated side of the USB. I got the ADUM4160 working just fine, I pluged some cypress devboards in no problem, next I tried an FTDI USB to serial converter, worked just fine, I also got a memmory stick and a bluetooth module working. When I plug in the RTL SDR windows is able to see it, but the Zadig driver install nor SDR sharp can see the dongle.

I was wondering if anyone else has gotten a realtek dongle working with a USB isolater, and maybe specifically one based on an ADUM4160?

[daveshah]

Not sure if this is the problem, but those isolators only support up to full speed (12Mbps) but the RTLSDR device is a high speed device (480Mbps).

[Scrts]

Not sure if this is the problem, but those isolators only support up to full speed (12Mbps) but the RTLSDR device is a high speed device (480Mbps).

Yes, this will be a problem.
OP: cut the USB cable, let the USB D+/D- go through also leave the GND connected, but cut the +5V wire and use your low-noise power supply to power the dongle.