Output Impedance of pcm1792a or pcm1794a

Hemant Nile

Other Parts Discussed in Thread: PCM1792A

Hi,

I am trying to design I/V stage for pcm1792a dac and trying different combination of opamps in pspice.

I need output impedance to simulate dac in pspice as input to i/v stage.

My design is inspired from A High-Fidelity Headphone Amplifier for Current Output Audio DACs Reference Design and to find value of Vbias ,this output impedance value is essential.

thank you,

Hemant

over 9 years ago

0 Justin Bohr over 9 years ago

TI__Mastermind 27850 points

Hi Hemant,

I am looking into this and will get back to you soon.

Justin

0 Justin Bohr over 9 years ago in reply to Justin Bohr

TI__Mastermind 27850 points

Hi Hemant,

In the data sheet an equation for the output is provided: Vout = 7.8 mA * Rf (Rf being the feedback resistor in the recommended I/V stage in the data sheet). So there is effectively no output resistance, just a current output, and to create a voltage you must use an I/V stage. The designer of this part is no longer with the company so it is difficult to find answers to some of the architectural questions.

Justin

0 Hemant Nile over 9 years ago in reply to Justin Bohr

Prodigy 40 points

Hi Justin.

Thank you for your efforts. Can you suggest any other way to measure it?

Hemant

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Output Impedance of pcm1792a or pcm1794a