Tutorial 6 (Intro to Op-Amp)
1. For the following circuit where Vi = 3mV, Ri = 10kΩ and Rf = 400kΩ calculate
(a) The amplification factor A, of the circuit
(b) The output voltage Vo
(c) You are designing a circuit where you require an amplification factor of -20.
Calculate values for Ri and Rf to achieve this.
2. For the following circuit where Va = 0.5V, Vb = 0.8V, Vc = 1.2V, Ra = 10kΩ, Rb =
20kΩ, Rc = 30kΩ and Rf = 50kΩ calculate the output voltage Vo.
3. For the following circuit where Vi = 2V, Ri = 75kΩ and Rf = 10MΩ
(a) Calculate the amplification factor and output voltage Vo.
(b) Sketch a sample input and output sine wave of where the maximum amplitude of this
input waveform is Vi.
(c) Looking at the value of the amplification factor, state if you think this value is a
reasonable amplification factor and give reasons to support your statement.
4. Name and explain what the function of the circuit below is. Research and find three
examples of a situation where this circuit may be used.