In a case of using structure shown in attached file, both outputs of a differential amplifier (OUTP and OUTN) will always be below from some common-mode voltage, independent on the input digital code (D0,D1,...).
No. The common mode path of a fully differential amplifier will enforce (Voutp+Voutpn)/2 = Vcm.
The amplifier polarities are drawn wrong, by the way.
Yes, otherwise the feedback resistors don't work.You mean that INP should be connected to OUTN, and INN to OUTP ?
I'm referring to usual fully differential amplifiers, that include a common mode feedback path. It's discussed in analog IC design text books, e.g. Gray/Hurst/Lewis/Meyer, Analysis and Design of Analog Integrated Circuits, Chapter 12. I don't know the features of your differential amplifier.Could you please explain this in more detail?
Is it possible with only one type current sources (nmos type, in the example in my first post) and fully differential OA usage to get a fully differential DAC, which outputs (OA outputs) vary over common-mode in both directions.
It depends on the input common range of amplifier and current source voltage range.
The most negative amplifier output voltage can't swing below the input common mode range and current source output voltage range. Depending on the intended output voltage range it may work.is it possible with the scheme attached in the first post as well
The most negative amplifier output voltage can't swing below the input common mode range and current source output voltage range. Depending on the intended output voltage range it may work.
So, how to have a fully differential outputs? I mean, that both OA outputs (OUTP and OUTN) could vary from 0.1*VDD to 0.9*VDD, whereas input common voltage is 0.5*VDD.
Thanks in advance.
when you steer the current the output would swing based on CurrentSteered*Resistance.
Can someone please show practical implementation of fully differential current-steering DAC. It is not clear is it possible with the circuit shown in #14 to have an OA outputs (OUTP and OUTN) which could vary from 0.1*VDD to 0.9*VDD (input common voltage is 0.5*VDD).
Help me Please.
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?