Post Go back to editing

Negative output voltage in Dig Pot AD5243 or AD5242

Hi,

Could you please clarify the following statement that I found in the datasheet of the above mentiuoned devices: "The digital potentiometer easily generates a voltage divider at wiper to B and wiper to A, proportional to the input voltage at A to B. Unlike the polarity of VDD to GND, which must be positive, voltage across A to B, W to A, and W to B can be at either polarity."?

If I would like to produce a negative output, must I have a negative power rail and therefore select the AD5242? 

Or can I use unipolar power supply with AD5243 and put the negative rail into the A or B pins?