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Which one to buy: UpTone USB REGEN or Intona USB Isolator?


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Sorry, that is incorrect. No DAC provides VBUS power to an upstream connected device. Both sides of the Intona's single board are powered via the VBUS from the computer.

 

In the below photo you can see the Coilcraft transformer sitting at the bottom, across the moat. This is how they transfer VBUS power across without loosing the galvanic isolation. It is also why their VBUS power (when connected to a standard 500mA limited computer USB host port) is limited to 300mA.

(Sadly, they also place the one clock--which is used for both FPGAs--on the upstream "dirty" side. And then the Silicon Labs digital isolators use add jitter. Hopefully they do some sort of further rechecking in the downstream FPGA, but it must still be based on the clock coming from the upstream side through the isolators.)

 

Don't get me wrong, the Intona is effective as a galvanic isolator (I've had one for over a year). But it sure sounds a lot better with a REGEN (powered by an LPS-1 so as not to defeat the isolation) after it. :)

 

[ATTACH=CONFIG]33735[/ATTACH]

 

 

http://intona.eu/en/answer/popular

 

Intona Answer Database (FAQ)

 

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Answer #1236

 

Is there any customization possible, for example using a better oscillator?

 

What would you expect by using a "better" oscillator?

We measured 12.5ps of RMS jitter on the USB packet clock. A more or less jittery oscillator would not make any difference on this, because of the very low tuned lp-filter in the transceiver's PLL.

We use four clocks in our design, all shifted slightly in phase and affected from natural spread spectrum of the isolator chips and other sources. This really helps to bring EMI down and to spread current peaks – e.g. to lower the packet noise.

If we would tune everything inside to least jitter, this would rise packet noise and also EMI radiation.

One need to distinguish between

 

  • sample clock in an ADC or DAC: low jitter is the most important, because only the right sample at the right time is the right sample
  • transmission clock of a serial system: BER (bit error rate) or eye mask to be specified
  • clock passing integrated logic: setup and hold times to be met

We decided to go for low noise, so spreading clocks and accepting inter-logic-skew was the way to go. Further, clever design of return currents and also a good and low impedance decoupling network of the power supplies are by far more important to meet your needs than looking for the oscillator.

Intona Answer Database (FAQ)

 

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Answer #1240

 

Is it possible to power the USB Isolator with a linear power supply instead of the PC USB +5V bus?

 

This would be possible if you use an external adapter cable which does split the supply.

But please note:

Internal voltages are generated by linear regulators. The isolated side is supplied by our own proprietary and very careful designed DC/DC converter followed by linear regulators.

The isolated USB output voltage is generated by the Analog Devices ADP125 linear regulator.

Because of the isolation barrier, this is really always the same low noise independent from host/computer cable type.

 

 

7054_fft_output[1].png

 

Answer #1130

 

Assuming a 1A+ USB supply on the primary side, what is the maximum continuous current that the isolated side can draw?

 

Maximum continuous current that can be drawn from the 7054-based isolators is 500mA. The output voltage will drop if more than 500mA is drawn and shuts down in hiccup-mode at 800mA.

Sustained short circuit-proof: the unit was tested on short circuit for 1 hour and no damage occurred.

 

7054_i_vs_u.png

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