What Is a Supersaturated Solution?
Saturation distortion refers to the distortion of the transistor due to the high Q point. When the Q point is too high, although the base dynamic current is an undistorted sine wave, because the transistor enters the saturation region for a certain period of time during which the positive half of the input signal leans into the peak, the collector dynamic current generates top distortion and the collector resistance The resulting voltage waveforms have the same distortion. Because the output voltage is in opposite phase to the voltage change on the collector resistance, the bottom distortion of the output waveform is caused.
Saturation distortion
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- Chinese name
- Saturation distortion
- Foreign name
- Saturation distortion
- Saturation distortion refers to the distortion of the transistor due to the high Q point. When the Q point is too high, although the base dynamic current is an undistorted sine wave, because the transistor enters the saturation region for a certain period of time during which the positive half of the input signal leans into the peak, the collector dynamic current generates top distortion and the collector resistance The resulting voltage waveforms have the same distortion. Because the output voltage is in opposite phase to the voltage change on the collector resistance, the bottom distortion of the output waveform is caused.
- The transistor has three operating regions: a saturation region, a cut-off region, and a linear region (amplified region). For the basic amplifier circuit of the common emitter, the input waveform is exactly opposite to the output waveform, that is, the phase is 180 degrees out of phase. When the positive part of the sine wave is input, the negative part should be output, and when the input peak is large, Beyond the dynamic range of the circuit, distortion can occur. If the positive half cycle of the input signal exceeds the dynamic range, it will enter the saturation region of the transistor, causing saturation distortion. The corresponding output signal is distorted due to the phase difference of 180 degrees.
- In summary, for the NPN single-tube common-radiation amplifier circuit, saturation distortion means that the positive half-wave of the input signal exceeds the amplification capability of the transistor, causing distortion, and the corresponding output waveform is the bottom distortion of the output waveform, that is, the transistor enters the saturation region during output, and the Q setting Too high. The solutions to the saturation distortion are:
- 1 Increasing VCC Because the fundamental reason for the saturation of the triode is the insufficient ability of the collector to collect electrons, increasing VCC can enhance the ability of the collector to collect electrons. In this case, it is possible to eliminate saturation distortion.
- 2 Increase the base resistance RB to reduce the base current, so that the collector current IC = IB. With the collector resistance RC and the collector power source VCC unchanged, the collector voltage obtained by VCE = VCC-IBRC becomes larger. This enhances the collector's ability to collect electrons and eliminates saturation distortion.
- 3 Reduce the collector resistance. With other parameters in the circuit unchanged, reducing the collector resistance RC reduces the voltage drop across RC. U CE = VCC-I B R C is added to the collector junction. The increase in the voltage also increases the collector's ability to collect electrons, thereby eliminating saturation distortion.
- 4 Replace a tube with a smaller . Under the condition that other parameters are unchanged, change a tube with a smaller magnification. From U CE = VCC-I B R C , the voltage drop on the collector resistance is reduced. Small, that is, increasing the potential applied to the collector junction, enhancing the ability of the collector junction to collect electrons, thereby eliminating saturation distortion. [1]