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Old 13th April 2015, 03:15 AM   #11
ostripper is offline ostripper  United States
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Quote:
Originally Posted by jwilhelm View Post
There's a 5102A to replace the 5102. TI has loads of different DACs. We better do a bunch of research here. It's looking like the 32bit stuff is their lower end lines.
No , the 1795 is 32. the 5102 just has the I/V , mute ... everything integrated
into the IC. Most likely geared toward mobile devices.
The lower performance is because of the integrated analog.

Yes , we both have a lot to learn .... drool ! - give me mo' datasheets.

OS
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Old 13th April 2015, 03:40 AM   #12
jwilhelm is online now jwilhelm  Canada
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The output buffer isn't a huge issue. I think I'd use a little better op amp though. Here would be the place to use one of your favorite OPAs
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Old 13th April 2015, 03:57 AM   #13
ostripper is offline ostripper  United States
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Originally Posted by jwilhelm View Post
The output buffer isn't a huge issue. I think I'd use a little better op amp though. Here would be the place to use one of your favorite OPAs
But it is a big player.

1792 , 1794-6 use differential current outputs.

1791 , 1793 have voltage diff. outputs. (only 1 op-amp for the LPF).

By placing more (or less) of the analog filtering external , different
degrees of "audiophile" precision can be had.

You can design for "mobile device" all the way up to the "drool" level.

OS
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Old 13th April 2015, 04:08 AM   #14
jwilhelm is online now jwilhelm  Canada
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PCM5102 is looking like the winner to me. Signal is pretty much the same as 1791/3 but it will do 32 bit and doesn't need the extra output buffer. Less pins to connect too.
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Old 13th April 2015, 04:51 AM   #15
ostripper is offline ostripper  United States
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Quote:
Originally Posted by jwilhelm View Post
PCM5102 is looking like the winner to me. Signal is pretty much the same as 1791/3 but it will do 32 bit and doesn't need the extra output buffer. Less pins to connect too.
OK , here is the "nitty gritty" for it ....
PCM5102 Burr-Brown DAC with DIR9001 SPDIF Receiver

-complete with toslink /coax.
- the designer says it is "airy , transparent" ... oh well.
I've also found non-chinese DIY for the 7192/4.


Jeff , above 10K is where the output diff V/I and output LPF refinement
really comes into play. The TI's output is a dirty staircase approximation
of a sine wave (or other waves). The V/I and LPF have the final job
of making this waveform listenable.
The 5102 does this with a 5532 like cheap monolithic setup , and a
virtual negative rail generated within. This is why it is -112db vs >-120
for a 1794.

The "next generation" 5102 is just a move toward the mobile market , not
the performance market. The virtually unusable 32bit interface option is
also a marketing ploy.

Sorry to be this technical , but the datasheets tell it all.

Edit - the 5102 is not THAT bad , it is in the most expensive "pocket dac's" (100 -250$).
Truly a mobile IC !!!

OS
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Last edited by ostripper; 13th April 2015 at 04:55 AM.
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Old 13th April 2015, 05:27 AM   #16
ostripper is offline ostripper  United States
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Default More 5102 "nitty gritty".

Not to denigrate it , we (might) never hear this ... link -
???????????--?????????

Even as it is in Chinese , he brings the output close to 1V for
a -86db thd + noise figure.
Worse than the best case TI documentation.

On the other end of the spectrum (below). Is the ESS9018.
It is like the 1794/5 with it's 3 op-amp V/I -filter.
No on-board charge pump for battery operation.

A 1794/5 circuit would be about in the
middle between the 5102 and ESS9018.

Just a range of options.

OS
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File Type: jpg ess9018.jpg (79.1 KB, 819 views)
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Last edited by ostripper; 13th April 2015 at 05:30 AM.
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Old 13th April 2015, 05:32 AM   #17
apassgear is offline apassgear  Mexico
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Going a step further on the design you may want to consider this SMD LME49600 from TI as a buffer…of course it will take the fun out of designing a discrete buffer section but it could be used as a headphone output.

http://www.ti.com/lit/ds/symlink/lme49600.pdf
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Old 13th April 2015, 05:49 AM   #18
ostripper is offline ostripper  United States
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Originally Posted by apassgear View Post
Going a step further on the design you may want to consider this SMD LME49600 from TI as a buffer…of course it will take the fun out of designing a discrete buffer section but it could be used as a headphone output.

http://www.ti.com/lit/ds/symlink/lme49600.pdf
That is crazy , the LME's block diagram is the EXACT same as my discrete.

I never saw that design before , but came up with it independently ??

Package is cool too , looks like Jeff's relay Mosfets.

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Old 13th April 2015, 06:04 AM   #19
mlloyd1 is offline mlloyd1  United States
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just to throw something into the mix, maxim makes the DS1808 volume control device. it is just pots and control logic, no internal opamps for those that want to have absolute control over the audio circuits.
Cost is not ridiculous either ...
Might be worth a look.DS1808

mlloyd1
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Old 13th April 2015, 06:12 AM   #20
ostripper is offline ostripper  United States
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Originally Posted by mlloyd1 View Post
just to throw something into the mix, maxim makes the DS1808 volume control device. it is just pots and control logic, no internal opamps for those that want to have absolute control over the audio circuits.
Cost is not ridiculous either ...
Might be worth a look.DS1808

mlloyd1
Looks close to the PGA - 10ppm .
Will consider depending on available resources and sourcing.

PGA seems to be far more used (and abused - by alibaba/ebay ).
Edit - HAH ... strange I named it the pitchfork.. It has 3 prongs-pcb'S (DAC /volume/buffers).
OS
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