i/v conversion

Hello all,

Despite the ad1955 is not a modern converter, I believe the chip will still do his work.

I had still a few ic's on the shelf, so I decided to make a diy dac with the ad1955.

I have reading the datasheet a few times, the only thing what confuse me is this statement,

" Passive I/V conversion should not be used, since the dac performance will be seriously degraded." 

I like to know what this means, is an I/V output transformer not possible?

In my opinion opamps degraded the sound to, feedback and a bad power supply.

Is here somebody who can give an explanation about this topic?

Thanks a lot.

  • 0
    •  Analog Employees 
    on Jun 16, 2018 2:04 AM

    Hello practys.

    Here is a quick and simple explanation.

    The drive capabilities of the DAC output is low. So it cannot sink or source much current. Plus it is sitting at a common mode voltage if I remember right. (It has been a while). So it will not be able to drive a transformer directly, you must translate the current into a voltage and then drive the transformer. Perhaps you can find a discrete component design that does this with out Op-Amps?

    Dave T