[Tianjin University of Technology] Differential amplifier circuit tester Zhao Yuanrui

Design and build a triode differential circuit characteristic tester to measure the characteristics of differential amplifier circuits.

The system structure is shown in the figure below

Task requirements: 1. Build a triode differential amplification circuit and debug it to work properly. Use 9013 as the triode. as the picture shows:

2. Design a differential signal source to test the performance of the amplifier produced, and generate the differential signal Uid used for testing. Uid should meet the following requirements: (1) Common mode signal voltage range: 0~1V, 10mv step. (2) Differential mode signal voltage range: amplitude: 0~100mv, 10mv step; frequency: 100~1MHz, 100Hz step. (3) Uid common mode signal voltage and differential mode signal amplitude can be set, and differential mode signal frequency can be set. (4) The tester displays Uid parameter indicators, and the error with the Uid parameter measured by the oscilloscope does not exceed 5mv.

3. Measure the magnification and display the record. 4. Input resistance measurement 5. Measure the amplitude-frequency characteristics of the differential amplifier circuit and display it on the LCD screen to calculate the upper limit cutoff frequency.

Note: (1) The power supply can be powered by a DC regulated power supply. (2) Reserve test interfaces at the differential input and differential output signal lines shown in Figure 1 to facilitate signal observation. (3) During the test, use a dual-channel oscilloscope to observe the differential signal. Through the subtraction operation in the math function of the oscilloscope, you can observe the differential to single-ended signal. (4) First test the triode differential amplifier circuit. You can use a dual-channel signal generator to generate a differential input signal and observe the differential output signal. (5) When testing the differential signal source, also use a dual-channel oscilloscope to observe the output signal of the differential signal source, and observe the differential to single-ended signal through the subtraction operation in the math function of the oscilloscope. If the output signal is not a differential signal, subsequent testing will not be performed. If the differential signal source is not completed, subsequent testing will not be performed. (6) Except for the power line, only the two input differential line pairs are connected between the differential signal source and the transistor differential amplification circuit. No other additional connecting lines are allowed. Except for the power line, only the two output differential line pairs are connected between the transistor differential amplification circuit and the measurement display circuit, and other connecting lines are not allowed to be added.

The specific implementation plan can be found in the attached paper. Of course, the required functions have not been fully realized.