Need to add DC offset voltage

[arulpanbu]

Hi all, would be nice to get some help, I am building a function generator circuit using XR2206 chip to generate sine wave of 1HZ Frequency, I have to add DC offset voltage. Currently with my build, I could see the waveform -1 to +1v, I need to shift to 0 to 2V. How do I implement it? Thank you in adavance...

 

[BradtheRad]

I have an XR2206 in my waveform generator. Its raw sine wave output ranges between 1V & 3 V. (The power supply is about 8V.)

Do you want to convert this to AC (positive and negative)? Then put a capacitor in series.

 

[Audioguru]

The XR2206 is normally powered with +12V and 0V so it will already have a DC output offset voltage of +6V which is half its supply voltage. Since yours has zero output offset voltage then it must have a positive and negative supply. Since you want a DC output offset voltage of +1V then make the positive supply 1V higher than the negative supply.

 

[arulpanbu]

The XR2206 is normally powered with +12V and 0V so it will already have a DC output offset voltage of +6V which is half its supply voltage. Since yours has zero output offset voltage then it must have a positive and negative supply. Since you want a DC output offset voltage of +1V then make the positive supply 1V higher than the negative supply.

Thank you for your reply Audio Guru, That's correct, I powered up with 12V and get a Sine wave of 2.12V (+/-1.06)(as my R3 is 43K), but how can I change or include DC Offset voltage so the sine wave form reads 0 to 2.12V, any suggestions will be very valuable...as I got stuck with this circuit, maybe a circuit diagram of how and where to include my DC offset voltage would be very helpful....thank you

- - - Updated - - -

I have an XR2206 in my waveform generator. Its raw sine wave output ranges between 1V & 3 V. (The power supply is about 8V.)

Do you want to convert this to AC (positive and negative)? Then put a capacitor in series.

I need to see my waveform change from 2.12V(+/-1.06V) to 0 to 2.12V...any suggestions please?

 

[BradtheRad]

Both Audioguru and myself stated that the output is in the positive region, and you are saying the output goes into the negative region, even though you power the IC from a positive voltage? A series capacitor can perform that, however you do not say there is any component such as a capacitor.

In any case, if you want to level shift, the easy way is with a resistive divider. Adjust the potentiometer to shift your signal up into the positive region.

The 1M resistor is not necessary. It's there to indicate how the output signal is referenced to ground.

 

[arulpanbu]

Both Audioguru and myself stated that the output is in the positive region, and you are saying the output goes into the negative region, even though you power the IC from a positive voltage? A series capacitor can perform that, however you do not say there is any component such as a capacitor.

In any case, if you want to level shift, the easy way is with a resistive divider. Adjust the potentiometer to shift your signal up into the positive region.

The 1M resistor is not necessary. It's there to indicate how the output signal is referenced to ground.

Thank you Brad for your schematic reply, I will try it, was using fixed resistors, may have to try with a pot...

 

[Audioguru]

I wish you said it correctly in your first post where you said wrongly that the output was -1V to +1V.
Now you say the actual output is (+2.12V - 1.06V=) +1.06V to (+2.12V + 1.06V=) +3.18V.
The level is 2.12 p-p and you want it reduced to 2.0Vp-p and the offset is +2.12V and you want it reduced to +1V.

Add a coupling capacitor to the output and bias its output at +1.0V. Turn down the level to 2.0Vp-p.

 

[arulpanbu]

Thank you will try that Audioguru...