Sine wave with DAC, getting + and - voltage?

[Fred.Amoson]

I'm using a PIC microcontroller with an MCP4922 DAC to make a sine wave. Right now I can make a sine wave that goes between 0 and 5V just fine. However, I don't know how to get it to go between -5 and 5 volts, or -2.5 and 2.5 volts. I've never really dealt with negative voltage supplies before. Does anyone have any suggestions on where to start?

Should I just leave the code as is and add some sort of amplifier that will drive it into both the positive and negative voltages? I will be needing an amp anyway, since this is a motor driver, and the current output of the MCP4922 is low. Any recommendations on an amp?

Thanks!

 

[Nigel Goodwin]

Just use an opamp to DC shift the output, and give whatever gain is required.

If you're not concerned about ultra-low frequencies?, a simple coupling capacitor, with a load resistor to 0V, will also shift it to centre around 0V.