Single-supply applications

btty038

Single-supply applications [Copy link]

In the actual use of op amps, in order to maintain the frequency characteristics of the op amps, we generally use dual power supplies. But sometimes in actual use, we only have a single power supply and can also achieve normal operation of the op amp.

First, we use the op amp follower circuit to achieve a VCC/2 voltage divider:

Voltage divider circuit

Of course, if the requirements are not very high, we can directly use resistor divider to obtain +VCC/2, but due to the characteristics of resistor divider, its dynamic response speed will be very slow, so please use it with caution.

After obtaining +VCC/2, we can use a single power supply to achieve signal amplification, as shown below:

Single-supply applications

In this circuit, R66=R67//R68, and the output gain of the signal G=-R67/R68.

The specific application is as follows: the op amp is powered by a single +5V_AD, the voltage of the AD chip is 3.3V (obtained by the reference voltage chip REF3033), the 3.3V is divided by resistors and followed by the op amp to obtain 1.65V, which is given to the op amp's in-phase input terminal

Single power supply differential input and amplification application

Appendix: Key points for the application of operational amplifiers

Fred_1977

Ordinary consumer electronic products are basically powered by a single power supply.

btty038

Fred_1977 posted on 2021-12-23 13:42 Ordinary consumer electronic products basically use op amps powered by a single power supply.

I haven't used dual power supplies.