Unipolar to Bipolar converter help

Thread Starter


Joined Mar 19, 2013
Hey there,

I am just starting to learn about PLC at my new job.

The supervisor has given me a task to design and build a circuit that would be able to produce the following voltages for a AI PLC.

0V to +10V
-10V to +10V
-5V to +5V
0V to +5V
+1V to +5V

I was only given a 24VDC power supply, a voltage regulator (24V to 10V) and a variable resistor.

The first task was to be able to make the unipolar supply 10V into a bipolar using op-amps.

I did my research and found out that a differential amplifier circuit using op-amps would be the prefect unipolar to bipolar converter.

However, I am confused regarding which op-amp would be the best of this kind of circuit esp since I only have a single supply but still need a rail to rail voltage.

Thank you....


Joined Mar 14, 2008
A differential amp can't convert voltage to a polarity that is different from the supply voltage(s). It can't convert a unipoplar supply to a bipolar supply. For that you need a switching power supply. For low currents you may be able to use a switched-capacitor design. For more than a 100mA or so you will need a switching supply using magnetics.