DAC with 2 output voltage design(Normal Vs inverted)

[ansonyeap]

Hi All,

Currently I need to work on DAC which can produce 2 output voltage at the same time i.e Normal output voltage and another one is inverted output voltage of the 1st one.

My design for the DAC is a R2R type with normal output voltage from 0(CODE0) ~ 5V(CODEFULL). I need to produce another inverted output voltage from 5V(CODE0) ~ 0V(CODEFULL).

Can anyone suggestion idea on how to be able to do this?

is there any buffer topology can able to do this?

thank you in advance.

 

[Warpspeed]

A standard differential amplifier will do this.
Connect the inverting input to the output of your DAC, and the non inverting input to your +5v ref.

When your DAC output is +5v, both inputs to the differential amplifier will be at +5, and the output of the differential amplifier will be 0v.

When your DAC output is at 0v, the non inverting input will be at +5v, and the differential amplifier output will also be at +5v.

The op amp output will need to swing fully rail to rail, and the input common mode range must go all the way up to +5v.

Easiest way would be to use a split supply of greater than +/- 5v if that is available.