No.
In any case, clock is not powered directly from Vbus, there is LD (5v->3.3v).
USB requirements to the clock are not very strong, it is not the audio clock.
You will get even worst results. So, no - PC side should be powered from PC. Isolated side, should be powered from the connected device, or also from the PC side through isolated DC-DC.
In case of 3166/4166 and the secondary is powered from the connected device, there is no clock.
Alex.
Hello,
Here's the circuit I'm planning to build.
It will be placed between my streamer and my DAC.
If you have any comments, they're welcome.
Here's the circuit I'm planning to build.
It will be placed between my streamer and my DAC.
If you have any comments, they're welcome.
Hello Altor,
You say you're using TI's ISOUSB211 chip.
Do you have any reasons to prefer this chip over the ADuMx16x chips? (For audio applications).
I have a simple criterion. I'll be the one soldering these chips onto the PCB. I can solder correctly up to a spacing of 0.95 mm.
Below that, my soldering is unreliable.
You say you're using TI's ISOUSB211 chip.
Do you have any reasons to prefer this chip over the ADuMx16x chips? (For audio applications).
I have a simple criterion. I'll be the one soldering these chips onto the PCB. I can solder correctly up to a spacing of 0.95 mm.
Below that, my soldering is unreliable.
If you reserve space for the crystal and 2 capacitors also on pins 5-6, you will be able to try both 65 and 66 chips.
TI seems more reliable to me, although a little more expensive.
I've tried it with several DACs (not mine, since my DACs already have isolation on the I2S bus between the USB part and the DAC part), and I use it all the time with the Cosmos ADC to prevent ground loops during measurements.
With AD sometimes you had to unplug and plug the device back in to get it to work.
Also my customers prefer TI.
AD and TI have the same pitch - 0.65mm.
Use mini-wave soldering tip (BCM2, in case of T12) and don't skimp on flux 🙂
I did it many times 🙂
You can also order PCBA at JLCPB, they have 3165/66 at stock.
Alex.
Thanks for the great idea of implementing the two crystals to test versions 65 and 66.
The ADuMs are in SOIC-20 package, with a 1.27mm pitch according to the datasheet. This is the reason for my choice.
The ADuMs are in SOIC-20 package, with a 1.27mm pitch according to the datasheet. This is the reason for my choice.
Yes, the 3165/6 is in an SSOP package and the 4165/6 is in an SOIC package.
But you were right to insist, as I only just discovered it.
I instinctively went for the 41 without looking at the 31 in detail.
I also just discovered that the 31 is significantly cheaper than the 41. Without your intervention, I might have been tempted to go for the 31.
The difference in isolation is explained by the difference in package size.
So I'll stick with the 41, but I'll keep your idea of the dual layout so I can test the 4165 vs. the 4166.
But you were right to insist, as I only just discovered it.
I instinctively went for the 41 without looking at the 31 in detail.
I also just discovered that the 31 is significantly cheaper than the 41. Without your intervention, I might have been tempted to go for the 31.
The difference in isolation is explained by the difference in package size.
So I'll stick with the 41, but I'll keep your idea of the dual layout so I can test the 4165 vs. the 4166.
I just sent two PCBs for manufacturing, one for the 4166 chip and the other for the 4165 chip.
I will keep you updated on the comparison between a cable without an isolator, a cable with a 4166 isolator, and a cable with a 4165 isolator.
To be continued.
Alain
I will keep you updated on the comparison between a cable without an isolator, a cable with a 4166 isolator, and a cable with a 4165 isolator.
To be continued.
Alain
Hi Alren,
I'm mainly interested in your opinion about the difference between 65/66.
Alex.
P.S. The difference between "with isolator" and without " - I know". I actually made it specifically for the Cosmos ADC, since it has no isolation and when connecting it and the DUT to the PC at the same time, sometimes there are ground loops (mostly because JTAG/XTAG connection).
And this is very clearly visible with a spectrum analyzer.
(My own measuring ADC, Olivine-2 has, like all my DACs, an I2S isolation inside, Cosmos ADC not, but it allows to measure smaller distortions).
