Comments on: USB Isolator.

By: oleg

oleg — Sun, 20 Dec 2009 19:20:03 +0000

Yes this is possible. The host side is powered from the host connector in the standard configuration. The peripheral side can’t be powered from the connector since peripherals don’t provide 5V on the VBus pin but if a peripheral is self-powered, you can use this power (3.3-5V) to power peripheral side of ADuM4160.

By: Ivan

Ivan — Sun, 20 Dec 2009 19:11:12 +0000

Hi Oleg,

I would like to ask you whether both sides of IC ADuM4160 can be powered (i.e. also wired) in the same way. Each part powered by USB bus (+5V). One part is the +5V power supply of PC (USB port) the other one is the +5V power supply from the pheripheral device (USB port). Thanks for the info. Ivan

By: oleg

oleg — Tue, 08 Dec 2009 20:36:30 +0000

The power supply for the peripheral side has to be 7-25V 500ma center-positive barrel connector type. It is further stabilized on the isolator board with 500khz DC-DC type converter; you won’t hear any hum from it, the frequency is too high for the human ear.

To connect it to the computer, you will need standard A to B USB cable, not the extension cable.

By: Henno Täht

Henno Täht — Tue, 08 Dec 2009 19:33:50 +0000

Also, I suppose I will need a small USB cable to connect the computer and the isolator together, right? If so, what kind? I have some regular USB extension cords like this one: http://en.wikipedia.org/wiki/File:Usb_extension_cable.jpg

Will one of those do?

By: Henno Täht

Henno Täht — Tue, 08 Dec 2009 19:23:31 +0000

I’m having the ground loop problem with my USB audio headset. For that reason, I ordered this USB Isolator (prebuilt). As the USB Isolator is traveling towards me, I was wondering what kind of power adapter I should buy for it to get the best audio quality (i.e. eliminate the possibility of USB Isolators power supply generating the 50/60Hz hum). Anyone?

By: Max

Max — Sun, 08 Nov 2009 17:53:15 +0000

Thanks for the info.

By: oleg

oleg — Thu, 15 Oct 2009 00:24:15 +0000

This jumper is mislabeled on the schematic – thank you for catching that! It is labeled correctly on the board though – it’s just spare ground connection on the host side.

External power for the peripheral side can be applied several ways. Straight answer to your question is “connection marked AGND” on the right side of the board next to “SHDN”. It also can be soldered to either of two groung moles of the barrel connector if left unpopulated. My original idea was to solder barrel connector, then run a wire from VIN to VBUS, then supply 5V through the barrel connector – I have so many 5V wall warts that this seems logical.

I shipped your kit two weeks ago, on Oct.1 – you should have received it by now. If you won’t get it this week, let me know, I’ll send you another one.

By: jkeny

jkeny — Thu, 15 Oct 2009 00:13:21 +0000

Sorry, I see that I should be connecting my external regulated 5V DC supply to VBus & AGND

By: jkeny

jkeny — Thu, 15 Oct 2009 00:00:00 +0000

I ordered and one of these & hopefully will receive it shortly. While I’m waiting I have a question – I see on the schematic a jumper, JP6 which seems to connect USB GND to AGND – what’s this for as it negates the purpose of the chip. I don’t, however see this jumper on the pics of the board – maybe not implemented?

I will be supplying an external 5V DC to Vin, where does my Gnd-in connect to?

I’m sure some of these questions would be resolved with the board in front of me but it isn’t so …….

By: TheFallen

TheFallen — Thu, 08 Oct 2009 21:27:08 +0000

Personally I’d make it entirely USB powered. The MAX256 is a switch mode isolation power converter. That’d save for the need for a barrel jack. But otherwise VERY neat.