Non-exam preparation materials
1.21
Chapter 15 Basic Amplification Circuit
The last stage or the last stage of the multi-stage amplifier circuit is generally a power amplifier stage, which is used to amplify the power of the low-frequency signal sent by the pre-voltage amplifier stage to drive the load. Requirements: 1. Can output as much power as possible without distortion. 2. Due to the large power, it is necessary to improve the efficiency (the ratio of the AC signal power obtained by the load to the DC power supplied by the power supply)
complementary symmetrical amplifier circuit: OTL, OCL.
Chapter 16 Integrated Operational Amplifier
The integrated circuit (see 1.18 Expanding Knowledge) simultaneously manufactures the various components of the entire circuit and the connections between them on a semiconductor chip to form a whole. Small size, light weight, low power consumption, stable work.
Digital integrated circuits and analog integrated circuits (integrated operational amplifiers, integrated power amplifiers, integrated stabilized power supplies, analog-to-digital converters)
integrated operational amplifier circuits can often be divided into input stage (differential amplification), intermediate stage (common emitter), Output stage (emitter follower) and bias circuit (provide stable and appropriate bias current).
Expand knowledge
1. Self-excited oscillation: refers to the steady and continuous oscillation that is generated by itself without external excitation signal. If no input signal is added to the input end of the amplifier, there is still a certain amplitude and frequency output signal at the output end, which is not conducive to the amplifying circuit and will make the amplifying circuit unstable or burn out.
2. The principle of invariance is the theory of controlling and eliminating disturbances on the control system in automatic control theory. The actual control system will be affected by external disturbances. If this disturbance can be measured, it is possible to use it to produce a control effect to eliminate its influence on the output. Phase compensation control refers to the automatic control of the DC output voltage by controlling the phase of the trigger pulse based on the principle of invariance.
3. An analog-to-digital converter, or A/D converter, or ADC for short, usually refers to an electronic component that converts an analog signal into a digital signal. The usual analog-to-digital converter converts an input voltage signal into an output digital signal. Because the digital signal only represents a relative size. Therefore, any analog-to-digital converter needs a reference analog quantity as the conversion standard, and the most common reference standard is the largest convertible signal size. The output digital quantity represents the magnitude of the input signal relative to the reference signal.
4. Constant current source: When the transistor works in the amplifying area and IB is constant, its IC hardly changes with UCE, showing constant current characteristics. The dynamic resistance of constant current components is very high, but the DC voltage drop across it is not large. .