This article has compiled the basic knowledge points of the model, and the foundation is not good enough to collect.
1. At room temperature, the threshold voltage of the silicon diode is about 0.5V, and the forward voltage drop at a large current after conduction is about 0.7V; the threshold voltage of the germanium diode is about 0.1V, which is larger after conduction. The forward voltage drop at current is approximately 0.2V.
2. The forward resistance of the diode is small; the reverse resistance is large.
3. The most important characteristic of a diode is unidirectional conductivity. When the PN junction is applied with a forward voltage, the diffusion current is greater than the drift current, and the depletion layer is narrowed.
4. The most important electrical characteristic of the diode is unidirectional conductivity. When the Zener diode is in use, the Zener diode is connected in parallel with the load. A resistor must be added between the Zener diode and the input power supply.
5. Electronic technology is divided into two parts: analog electronic technology and digital electronic technology. The electronic circuit and its technology, which work under smooth and continuously changing voltage or current signals, are called analog electronic technology.
6. When the PN junction is reverse biased, the internal electric field of the PN junction is enhanced. The PN has a unidirectional conductivity characteristic.
7. After the silicon diode is turned on, the tube voltage drop is constant and does not change with current, typically 0.7 volts; its threshold voltage Vth is about 0.5 volts.
8. When the diode is forward biased, its forward conduction current is formed by the diffusion motion of the majority carriers.
9. A plurality of P-type semiconductors are holes, and a plurality of N-type semiconductors are free electrons, and carriers of an intrinsic semiconductor are electron-hole pairs.
10. Impurity semiconductors may be two types of hole (P) semiconductors and electron (N) semiconductors due to different properties of doped impurities.
11. The most important characteristic of a diode is unidirectional conductivity. Its two main parameters are the maximum rectified current reflecting the forward characteristic and the reverse breakdown voltage reflecting the reverse characteristic.
12. At room temperature, the turn-on voltage of the silicon diode is about 0.5 V, and the forward voltage drop at a large current after conduction is about 0.7V.
13. Frequency response refers to the steady-state response of the output continuously changing with frequency when a sinusoidal signal is input.
15. Most carriers in an N-type semiconductor are electrons, and minority carriers are holes.
16. According to the conduction angle of a triode in a cycle, the power amplifier circuit can be divided into three basic types: Class A, Class B, and Class A and Class B.
17. In the RC-coupled multi-stage amplifier circuit, the coupling and bypass capacitors affect the amplification of the low-frequency signal, and the junction capacitance is affected by the amplification of the high-frequency signal.
18. In the basic common-emitter amplifying circuit composed of the NPN transistor, if the other parameters of the circuit are unchanged, the β of the triode increases, the IBQ increases, the ICQ increases, and the UCEQ decreases.
19. The three working areas of the triode are cut-off, saturated, and amplified. An integrated operational amplifier is an amplifying circuit that uses a direct coupling method.
20. The triode in an amplifying circuit measures its pin voltage Va = 1.2V, Vb = 0.5V, Vc = 3.6V in the working state. The triode is a silicon tube (material), and the NPN type triode The collector of the tube is C in a, b, c.
21. It is known that the logarithmic gains of the first and second stages in a two-stage amplifying circuit are 60 dB and 20 dB, respectively, and the total logarithmic gain of the amplifying circuit is 80 dB, and the total voltage amplification factor is 10000.
22. The external conditions for the amplification of the triode are: the positive junction of the emitter junction and the reverse bias of the collector junction. The triode in an amplifier circuit measures the pin voltage Va = -1V, Vb = -3.2V, Vc = -3.9V, which is a silicon tube (silicon, germanium), NPN type, and the collector pin is a.
23. The three different coupling modes of the amplifying circuits are: RC coupling, direct coupling and transformer coupling, where direct coupling can amplify slowly changing signals.
24. In the multi-stage amplifier circuit, the input resistance of the latter stage is the load of the previous stage, and the output resistance of the front stage can be regarded as the internal resistance of the signal source of the latter stage. The total passband of the multistage amplifier circuit is narrower than the passband of each of the stages.
25. The output voltage of an amplifier circuit when the load is open is 4V. After the 12kΩ load resistor is connected, the output voltage drops to 3V, which indicates that the output resistance of the amplifier circuit is 4kΩ.
26. In order to ensure that the triode works in the amplification region, it is required that: 1 the emitter junction is forward biased, and the collector junction is reverse biased. 2 For NPN type transistors, VBC<0 should be made.
27. The coupling mode between amplifiers mainly includes three types: RC coupling, direct coupling and transformer coupling.
28. In the three different configurations of the amplifying circuit composed of triodes, the common-emitter and common-base configurations have voltage amplification, the common-emitter configuration has current amplification, and the common-emitter and common-set configurations have phase-in effects; The configuration has strong load capacity, and the current collected by the common configuration to the signal source is small, and the frequency response of the common base configuration is good.
29. The three basic configurations of the triode amplifying circuit are common set, common ground, and common shot.
30. The coupling connection between the stages of the multi-stage amplifier is generally direct coupling, RC coupling, and transformer coupling.
31. In a single-stage common-emitter amplifier circuit, if the input is a sinusoidal waveform, and the oscilloscope is used to observe the waveforms of VO and VI, the phase difference between VO and VI is 180°; when it is a common collector circuit, then VO and VI are The phase difference is zero.
32. The amplifier has two different types of distortion, namely saturation distortion and cutoff distortion.
33. When the transistor is working in the saturation region, the emitter junction is positively biased, and the collector junction is positively biased; when working in the amplification region, the collector junction is reverse biased and the emitter junction is forward biased.
34. In the three kinds of amplification circuit configurations of common-emitter, common-collection and common-base, it is desirable that the voltage amplification factor is large, the output voltage is inverted with the input voltage, and the common-emitter configuration can be selected; the input resistance is large, the output voltage and the input voltage are desired. In phase, a common set configuration is available. 35. Compared with the bipolar transistor, the field effect transistor has large input resistance and good thermal stability.
36. The upper limit frequency fL of the passband of the amplifying circuit is affected by the DC blocking capacitor and the interelectrode capacitor.
37. When the triode is operating in the amplification region, its emitter junction remains forward biased and the collector junction remains reverse biased.
38. The FET has three configurations: common source, common gate, and common leakage.
39. The total passband in the multistage amplifier circuit is narrower than the passband of each of the stages.
40. The FET is structurally divided into two types of junction FET and MOSFET, which belong to voltage control type devices.
41. The FET is a voltage controlled current type device, and the bipolar semiconductor transistor can be considered as a current controlled current type device.
42. The field effect transistor is a voltage controlled current device that relies only on majority carriers to conduct electricity.
43. According to the output characteristics of the field effect transistor, the working condition can be divided into four regions: a variable resistance region, a constant current region, a breakdown region and a cutoff region.
44. When the gate-source voltage is equal to zero, the enhancement FET has no conductive channel, and the junction FET has the smallest channel resistance.
45, FET is a voltage control device, BJT is a current control device.
46. ​​In Class A, Class B and Class A and Class B power amplifier circuits, the least efficient circuit is Class A.
. 47. A loudspeaker circuit with an output power of 10W. If a Class B push-pull amplifier is used, 2 power tubes with a rated power consumption of at least 2W should be selected.
48. In Class A, Class B and Class A power amplifier circuits, the circuit with the lowest efficiency is Class A. In order to eliminate crossover distortion, Class A and Class B circuits are often used.
49. The main advantage of Class B power amplifiers is their high efficiency, but crossover distortion occurs. The method of overcoming crossover distortion is to use Class A and Class B.
50. The class B complementary symmetrical power amplifier circuit produces a unique distortion phenomenon called crossover distortion.
51. Dual power supply complementary symmetrical power amplifier circuit (OCL) has VCC=8v, RL=8Ω, and the maximum output power of the circuit is 4W. In this case, the maximum power consumption should be greater than 0.8W power tube.
52. The function of the long tail resistance Re or the constant current tube in the differential amplifier circuit is to introduce a common mode negative feedback.
53. Knowing that a certain differential amplifier circuit Ad=100 and KCMR=60 dB, its AC=0.1. An integrated circuit operational amplifier generally consists of a differential input stage, an intermediate stage, an output stage, and a bias circuit.
54. The differential amplifying circuit can amplify the direct current and the alternating current signal, and has the amplification capability for the differential mode signal, and has the ability to suppress the common mode signal.
55. The differential amplifier circuit can suppress zero drift and common mode input signals.
56, the circuit shown in Figure 1, T1, T2 and T3 characteristics are exactly the same, then I2 ≈ 0.4mA, I3 ≈ 0.2mA, then R3 ≈ 10kΩ.
57. The integrated operational amplifier usually consists of four parts: input stage, intermediate stage, output stage and offset stage.
58. Positive feedback means that the feedback signal enhances the net input signal; negative feedback means that the feedback signal attenuates the net input signal.
59. Current parallel negative feedback can stabilize the output current of the circuit and reduce the input resistance.
60. Negative feedback improves the performance of the amplifier circuit by improving the stability of the gain, reducing the nonlinear distortion, suppressing the noise in the feedback loop, expanding the frequency band, changing the input resistance and the output resistance.
61. In order to meet the following requirements separately, what kind of feedback should be introduced: 1 reduce the current demanded by the circuit to the signal source: series negative feedback. 2 When the ambient temperature changes or replaces the triode with different values, the static working point of the amplifying circuit is required to be stable: DC negative feedback. 3 stable output current: current negative feedback.
62. Voltage series negative feedback can stabilize the output voltage of the circuit and make the input resistance large.
63. A negative feedback amplification circuit has an open-loop amplification factor A=100000, a feedback coefficient F=0.01, and a closed-loop amplification factor of 100.
64. The condition that the negative feedback amplifying circuit generates self-oscillation is.
65. The four basic types of negative feedback amplifier circuits are voltage series, voltage parallel, current series, and current parallel.
66. In order to stabilize the output signal of the circuit, the circuit should adopt negative feedback. In order to generate a sine wave signal, the circuit should use positive feedback.
67. The ideal condition for an ideal integrated operational amplifier is
68, idealized operating conditions of the ideal operational amplifier
69. The current source circuit is characterized by small DC equivalent resistance and large AC equivalent resistance.
70. The current source is characterized by a constant output current, a small DC equivalent resistance, and a large AC equivalent resistance.
71. The ideal integrated operational amplifiers operating in the linear region have two important conclusions: virtual and short.
72, ideal operational amplifier,
73. The integrated operational amplifier operates in an open loop or positive feedback state when the voltage comparator is constructed.
74. If the useful signal frequency is higher than 1000Hz, a high-pass filter can be used; if a useful signal below 500 Hz is desired, a low-pass filter can be selected.
75. When selecting a signal with a frequency higher than 1000Hz, a high-pass filter can be selected; when suppressing 50 Hz AC interference, a band-stop filter can be selected; if it is desired to suppress signals below 500 Hz, a high-pass filter can be selected.
76. The useful signal frequency is higher than 1000Hz. High-pass filter can be selected. It is desirable to suppress 50Hz AC power interference. The band-stop filter can be used. If you want to pass only the useful signal from 500Hz to 1kHz, you can use a band-pass filter.
77. According to the working signal frequency range, the filter can be divided into: low pass filter, high pass filter, band pass filter and band stop filter.
78. The integrated operational amplifier draws two important conclusions under linear conditions and ideal operating conditions. They are: virtual and virtual short.
79. The general-purpose integrated computing amplifier input stage mostly adopts differential amplifying circuit, and the output stage mostly adopts a common collecting circuit.
81. When the sine wave oscillation circuit generates oscillation, the amplitude balance condition is: the phase balance condition is
82. The principle of the signal generator is when the circuit is negatively feedback, such as a self-excited circuit. In positive feedback, such as a Venturi oscillation circuit.
83. The quartz crystal oscillator is a special form of the LC oscillating circuit, so the oscillation frequency has high stability.
84. The condition that the sine wave oscillation circuit generates oscillation by using positive feedback is that the phase balance condition is that n is an integer, and the amplitude condition is to make the circuit start.
85. The sine wave oscillation circuit must be composed of four parts: the amplification circuit, the feedback network, the frequency selection network, and the stabilization link.
86. When the RC sine wave oscillation circuit reaches a stable equilibrium state, there are:
87. The equilibrium condition of the sinusoidal self-oscillation circuit oscillation is that n is an integer.
88. The condition for starting the sine wave oscillation circuit is that n is an integer.
89. The useful signal frequency is higher than 1000Hz, and a high-pass filter can be selected. The amplification circuit voltage amplification factor in the Wien bridge oscillator can meet the start-up condition.
90. In order to stabilize the output signal of the circuit, the circuit should adopt AC negative feedback. In order to generate a sine wave signal, the circuit should use positive feedback.
91. The DC power supply is an energy conversion circuit that converts AC voltage of the grid voltage into DC power.
92, three-terminal integrated voltage regulator 7805 output voltage +5V, 7915 output voltage -15V.
93. The DC power supply generally consists of the following four parts: they are: power transformer, filter circuit, voltage regulator circuit and rectifier circuit. The voltage regulator integrated circuit W7810 output voltage +10 V.
94. The circuit for converting alternating current into pulsating direct current is called a rectifying circuit; the average value of the direct current voltage output by the half-wave rectifying circuit is equal to 0.45 times the effective value of the input alternating current voltage (ie, the voltage of the secondary side of the transformer); and the direct current output of the full-wave rectifying circuit The average value of the voltage is equal to 0.9 times the effective value of the input AC voltage (ie, the transformer secondary voltage).
95, the three-terminal integrated voltage regulator 7915 has an output voltage of -15 volts.
96. The amplification target in the series regulator circuit is the output sampling voltage.
97. The reason why the switching type DC power supply is more efficient than the linear DC power supply is that the state of the adjusting tube is different.
98. The small power regulated power supply is generally composed of four parts: a power transformer, a rectifier circuit, a filter, and a voltage regulator circuit.
99. Amplitude distortion and phase distortion are collectively referred to as frequency distortion.
100. The series feedback regulator circuit consists of four parts: adjustment tube, comparative amplification, reference voltage and sampling.
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