Yes, VCML is going to the 1st 1632, VCMR - to the second, through separate buffers. They are not connected.
Alex.
Alex.
Based on my experience with the noise from previous builds, I decided to add an isolator and move the MCLK to the DAC side.
The si8661 I already purchased seems to fit well with the USB-I2S bridge (i2s, mclk sel, mclk/2 for MCU).
Feel free to recommend an isolator for i2c that would work well with this!
I'm also considering using a CPLD on the DAC side behind the isolator to align the i2s edges.
It would be easier to integrate since I'll need other glue logic as well.
I also need to use a high-performance clock buffer to achieve the purpose of the CCHD clock.
I have several xc2c64a-7vqg44 and epm240t100c3n.
The si8661 I already purchased seems to fit well with the USB-I2S bridge (i2s, mclk sel, mclk/2 for MCU).
Feel free to recommend an isolator for i2c that would work well with this!
I'm also considering using a CPLD on the DAC side behind the isolator to align the i2s edges.
It would be easier to integrate since I'll need other glue logic as well.
I also need to use a high-performance clock buffer to achieve the purpose of the CCHD clock.
I have several xc2c64a-7vqg44 and epm240t100c3n.
I also use 8661/62, works fine.
Not necessary, just MCLK is important, but why to use CPLD for this?! Use 74LVC logic.
I think about 74LVC125 or similar, for what you need trigger here? To make re-clock?
It is not necessary for AK449x.
It's fine if you use the CPLD for other purposes too, but using a CPLD instead of a simple buffer like the 74LCV125 would be a big overkill.
Moreover, the buffer is not needed there at all, you can connect the signal from 8661 to the DAC.
Of course, through series resistors of 30-50 ohms, which are required in any case, also before/after the buffer too, to dump ringing.
Alex.
OK, in this case CPLD maybe useful (I said: "It's fine if you use the CPLD for other purposes too").
P.S. However, I use or simple logic (75LVC157 for USB-SPDIF I2S switching), or DIX9211 as SPDIF receiver and also I2S switch (and other functions), "to put all of this together".
Alex.
P.S. However, I use or simple logic (75LVC157 for USB-SPDIF I2S switching), or DIX9211 as SPDIF receiver and also I2S switch (and other functions), "to put all of this together".
Alex.
MAX14850. Smaller than ISO1640 and has 2+2 additional channels as well.
Very good chip!
No however smaller - SO8 vs 16SSOP, and more expensive, but if 2+2 additional line required - very useful.
Alex.
Maybe I saw the wrong numbers.
16QSOP at MAX's datasheet is 21-0055
It's pdf can be found at https://www.analog.com/en/resources/packaging-quality-symbols-footprints/package-index.html
Also SO8 drawing from TI ISO1640 datasheet.
Both sises are app. the same - 6x5mm.
Alex.
16QSOP at MAX's datasheet is 21-0055
It's pdf can be found at https://www.analog.com/en/resources/packaging-quality-symbols-footprints/package-index.html
Also SO8 drawing from TI ISO1640 datasheet.
Both sises are app. the same - 6x5mm.
Alex.
Attachments
Hopefully you are aware we don't always all agree with each other on some things.
For your first dac design of this scope you are getting one set of mostly agreeable opinions. That's okay, but there can be more information and opinion to be exposed to over time.
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https://www.ti.com/tool/SN6501-MULXFMR-EVM
And I'm interested in this push-pull transformer driving.
Transformers come in a variety of turns ratios to form any voltage required and provide insulation.
I think that the isolation between the digital domain and the power domain makes the analog domain
behave like the body of a car suspended by suspension.
And I'm interested in this push-pull transformer driving.
Transformers come in a variety of turns ratios to form any voltage required and provide insulation.
I think that the isolation between the digital domain and the power domain makes the analog domain
behave like the body of a car suspended by suspension.
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IMHO, there are few points:
1) U2 - if you input voltage is 5v, better to use LP5907
2) R19 R20 - one common resistor is enough.
3) U4 - I usually use simple transistor, let say 2N7002 + 2 resistors, but this is not important.
4) If the oscillators are located <5-7 cm from the DAC chip, U5 is not needed.
Alex.
Even better choice for U22 is TPS7A2033 and for U5 LMK1C1104 is cheaper.