The forty-sixth summary of analog circuit design is the door!

1. The voltage of the same phase amplification circuit applied to the two input terminals is nearly equal
2. The important feature of the inverting amplifier circuit is the concept of "virtual ground".
3, PN junction has a very good mathematical model: the switch model à diode was born à another PN junction, the triode was born
4. In the high-frequency circuit, the influence of the PN junction capacitance must be considered (the forward bias is the diffusion capacitor, and the reverse bias is the barrier capacitance)
5. Point contact diodes are suitable for rectification, and surface contact diodes are suitable for high frequency circuits.
6, the silicon tube forward pressure drop is 0.7V, the manifold is 0.2V
7, Zener diode (voltage regulator) works in reverse breakdown state
8. Schottky diode (SBD) is suitable for high frequency switching circuits. The forward voltage drop and reverse voltage drop are very low (0.2V), but the reverse breakdown voltage is low and the leakage current is also large.

9, photodiode (converts the optical signal into an electrical signal) 10, the main parameters of the diode: the maximum rectified current, the maximum reverse voltage, leakage current 11, the triode has an emitter (the highest concentration < need to emit electrons (holes), Of course the concentration is high >), collector, base (lowest concentration). The arrow is written on the top of the emitter. <The launching thing of course requires an arrow! >12. The emitter is positively biased, and the collector reverse bias is the precondition for the BJT to work in the amplified state. Three connection methods: common base, common emitter (maximum, because current, voltage, power can be amplified), common collector. Three methods of discriminating: common emitter, base input, collector output; common collector, base input, emitter output; common base, emitter input, collector output. 13. Main parameters of triode: current amplification factor β, reverse current between poles, (maximum allowable current of collector, maximum allowable dissipated power of collector, reverse breakdown voltage = 3 important limit parameters determine BJT working in safe area) 14, triode mathematical model: single tube current amplification 15, emitter bias circuit: used to eliminate the effect of temperature on the static operating point (double power supply is better) 16, three BJT amplifier circuit comparison: common-shot amplifier circuit, current The voltage can be amplified. Common collector amplifying circuit: only amplifies the current, follows the voltage, the input R is large, and the output R is small, and is used as an input stage and an output stage. Common base amplifier circuit: only amplifies the voltage, follows the current, and has good high-frequency characteristics. 17. Decoupling capacitor: The output signal capacitor is grounded, and the high-frequency clutter of the signal is filtered out. Bypass capacitor: The input signal capacitor is grounded to filter out the high frequency clutter of the signal. The AC signal is short-circuited for these two capacitors. 18, BJT is a current-controlled current-type device (bipolar), the FET is a medium-voltage-controlled current device (unipolar), and the mainstream is from the emitter to the collector. The IC, the bias current is the Ib from the emitter to the base. Relative to the main circuit, the circuit that supplies current to the base is the so-called bias circuit. 20. Three aluminum electrodes of FET: gate g, source s, drain d. Corresponding to the base b of the triode, the emitter e, and the collector c. <The source needs to emit something, so it corresponds to the emitter e. The English name of the gate is gate, the same as the gate, and the role of the base is similar.> The P-type substrate is generally connected to the gate g. 21. Enhanced FET It must rely on the gate-source voltage Vgs to function (turn-on voltage Vt). The depletion-mode FET does not require the gate-source voltage. Under positive Vds, a large drain current flows to the source (if negative Vgs is applied). , then there may be pinch-off, the voltage at this time becomes the pinch-off voltage Vp*** important characteristic ***: can work under positive and negative gate-source voltage) 22, N-channel MOS tube needs positive Vds (equivalent The transistor is applied to the collector Vcc) and the positive Vt (corresponding to the transistor's base and emitter Vbe), while the P-channel MOS transistor requires a negative Vds and a negative Vt23. The main parameters of the MOSFET are: turn-on voltage Vt, clip Break voltage Vp. Limit parameters: maximum drain current Idm, maximum dissipation power Pdm24, MOSFET three kinds of amplification circuits: common source amplifier circuit (common emitter), common drain amplifier circuit (common collector), common gate amplifier circuit (total Base) 25, differential amplifier circuit: differential mode signal: the difference between the two input signals. Common mode signal: The sum of the two input signals divided by two. Thus: using the definition of differential mode and common mode to represent the two input signals can obtain an important mathematical model: any one input signal = common mode signal ± differential mode signal / 226, differential amplifier circuit only amplifies the differential mode signal, suppressing common mode signal. With this feature, the influence of changes in external factors such as temperature on circuit performance can be well suppressed. Specific performance indicators: common mode rejection ratio Kcmr27, the temperature drift of the integrated op amp is the main source of drift 28, the parameters of the integrated op amp: the maximum output current, the maximum output voltage 29, VCC is the supply voltage of the circuit, VDD is the chip Operating Voltage
30, the interference of the amplifier circuit: 1, the power supply away from the amplifier circuit 2, the input stage shield 3, DC power supply voltage fluctuations (using regulated power supply, input and output plus filter capacitor)

31. Four configurations of negative feedback amplifier circuit: voltage series negative feedback (stable output voltage), voltage parallel negative feedback, current series negative feedback (stable output current), current parallel negative feedback 32, voltage and current feedback determination method: Output short circuit method, set RL=0, if the feedback signal does not exist, it is voltage feedback, otherwise, it is current feedback.

33. Determination method of series and parallel feedback: the summation of feedback signal and input signal, if it is voltage form, it is series feedback, if it is current form, it is parallel feedback

34, the class of power amplifier circuit: Class A (all), Class A (50% or more), Class B (50%) (according to the input signal flowing through the device over the entire cycle percentage greater than 0) 35, RC oscillator circuit is suitable for Low frequency, LC oscillating circuit is suitable for high frequency circuit 36, voltage comparator, time delay comparator, integrated voltage comparator, square wave generating circuit, sawtooth wave generating circuit 37, DC regulated power supply: power transformer à rectifier circuit à filter circuit à voltage regulator circuit

38. Filter circuit: It can play a good filtering role by utilizing the energy storage function of the reactance component. Inductors (series, high power) and capacitors (parallel, low power) can all function as flat waves.

39, switching power supply and linear power supply: linear power supply, low efficiency, strong heat, but the output is very stable. Switching power supply, high efficiency, general heat, but large output ripple, need flat wave

40, switching regulator power supply has two kinds of buck and boost, there are freewheeling diodes in the buck, LC filter circuit. There are inductors, Zener diodes and capacitors in the boost.