AK4497 won't be Flagship anymore

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I can appreciate why Jens wants this for instrumentation, but we're so far past the "DAC chip is the limiting factor", that I'm far more interested in whether the 4493 is a marked improvement on the 4490 *as installed*, and/or ease of use.

Haven't seen the 4493 chip proliferate the internets so I'm sitting tight. :)
 
ES9038Pro is a bear not so much because of the OP current but the
combination of high OP current and extremely low OP impedance.

Spot on. Its a current mode DAC that's tending more towards a voltage source than a current source by virtue of having such a low OP impedance. Meaning in practice your I/V stage does have the challenge of getting low enough input impedance. Not to mention that decent PSRR wasn't one of the design criteria...
 
Spot on. Its a current mode DAC that's tending more towards a voltage source than a current source by virtue of having such a low OP impedance. Meaning in practice your I/V stage does have the challenge of getting low enough input impedance. Not to mention that decent PSRR wasn't one of the design criteria...

It will be interesting to see what approach AKM have taken.

If it's a straight unity weight resistor architecture like Sabre, to acheive 140dB DR, there -has- to be many R's in parallel.

Hopefully they have gone the current source route aka PCM1794.

T
 
I used to think the PCM1794 had "hot" outputs. ESS then redefined what that means.

I guess if you can't lower the noise floor you have to output heroic levels to reach these insane numbers.

I am glad that AKM is releasing a product like this though. I really don't like the fact that you can't source ESS parts except through old-school style distributors and you need to sign an NDA to get what is a poor excuse for a datasheet.

I do wonder why they need a 128 pin package for a 4 channel DAC with I2C/SPI control...
 
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There is a integrated voltage reference in the diagram, so it is likely FETs' drain output type. IIRC, AKM had patented some circuits for that architecture some years ago.

edit
Well, it was IREF in the diagram not VREF, but I think it have VREF behind IREF like PCM179x .
 
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