Inverted amplifier circuit design
A reverse amplifier circuit: the output signal is in opposite phase to the input signal and the voltage or current value is proportional.
The diagram below shows a simple inverting amplifier circuit.
To design an inverted amplifier circuit, it is also necessary to first clear the requirements, then analyse them quantitatively and finally build the circuit from the data obtained from the calculations.
Example.
Design Objective.
- The transfer function of the circuit is:
- Determine the starting value of R1, then calculate the value of R2.
The value of R1 will affect the gain error of the signal. Suppose the internal resistance of the signal source is 10Ω and R1 is set to 1000Ω, this will result in an error of 1%.
Therefore determine R1 to be 100k.
- Calculate the gain of the circuit G = 2.
- Calculate the value of R2 as 200k.
- Calculate the bandwidth of the small signal circuit to ensure that it meets the required requirements of the design (5KHz).
- Calculate the bandwidth of the small signal circuit to ensure that the required requirements of the design are met (5KHz).
The calculation leads to a design that meets the required requirements.
Add: NG is the in-phase gain.
- Calculate the minimum slew rate required to minimise distortion due to conversion.
SR=2×π×f×Vp=2×π×5000×6=0.188V/μS
The OP07C has an SR of 0.3V/μS to meet this design requirement.
Simulation results.
DC simulation results.
AC simulation results.
Transient simulation results.
As in the transient simulation results, the output is inverted for the input, which also satisfies the transfer function.
You can also see that the output waveform is a bit distorted, preliminary analysis of the reason: combined with the DC simulation results can be seen in the input is about 6V, the output will show a distorted state.
