Compare single/dual power supply OPAMP?

[bicave]

Which is better?
for my idea, I preffer use Single OPAMP because it's easy to design power supply. But if we want to amplify small signal ~ 0 to 10mV we need shift it to DC voltage to fit with bias condition. Do you have any idea?

 

[hemant03]

For smaller voltages, instrumentation amplifiers work well. Try INA138 and see if suits well.

Thanks,
- Hemant

 

[adinogcas]

Dual power supply is easy to work with cause you dont need to create "virtual ground" (mid point of Vcc). However, as you said single power supply is easy to design. But to have OPAMP works with single power supply you have to create mid point voltage so the AC (or small voltage you said) will not be cut off.

Say you have AC voltage about 1Vpp, if you dont bias, you will only have the positive part of that AC cause 0- (-1)V will be cut off. Therefore, if you shift DC voltage to 2.5V (Vcc=5V e.g), you will capture all the AC voltage. And than you can amplify that voltage within that range.

For Dual power supply OPAMP, you do not need to worry about that "virtual ground" cause you already have 0V in between.