With the development of cheap and reliable operational amplifiers the need to design amplifier circuits has disappeared. However it is still necessary to utilise these devices in a range of standard configurations.  When doing this it is important to use the manufacturers' data sheets to identify important parameters so that an appropriate device may be selected from the huge range available.

1. An inverting amplifier is required to amplify the ac signal from a transducer before it is applied to an ADC (Analogue-to-Digital Converter).  The specification is given below:

Signal Source            V_rms = 700 mV @ 0 Hz < frequency < 20 kHz.  R_out = 100 Ω

The maximum acceptable error in the signal voltage must be less than 1%.

ADC                Voltage input range  ± 5 V.    R_in = 8kΩ

Amplifier                741 connected in an inverting configuration.

Analyse the circuit to determine an acceptable design. You should use the design methods and equivalent circuits, in conjunction with the manufacturers' data sheets. The design should include the voltage gain, input resistance and bandwidth of the circuit. The various errors due to bias current etc should also be considered.

1. Modify the above circuit so the voltage gain is 10.

Note:  Make sure you show all the steps of your design including changing values to modify the design.

Using either practical experimentation, or computer simulation, determine the performance of the above circuits (parts a and b). Compare and contrast the results with the theoretical values reconciling any differences.  Credit will be gained for the care, detail and accuracy with which the practical testing, or simulation analysis, is done.