What are the advantages of amplified signals in op amps compared to amplified signals in discrete co

Integrated op amps have many advantages over discrete component amplification circuits, and their outstanding advantages are:

1) In integrated circuits, active devices (transistors, field effect transistors) are manufactured.

etc.) is smaller than the area occupied by manufacturing large resistors, and the process will not increase trouble, therefore, a large number of active components are used in integrated circuits to obtain large resistance, and the amplification factor of the amplification circuit is improved; It is composed of a current source to obtain a stable bias current. Therefore, the magnification of the integrated op amp is generally much larger than that of the discrete components.

2) Because all the components in the integrated circuit are on the same silicon wafer, very close to each other, and manufactured under the same process conditions, therefore, although the absolute accuracy of each component parameter is poor, their relative accuracy is good, so the symmetry performance is good, and it is especially suitable for making circuits with high symmetry requirements, such as differential circuits, mirror current sources, etc.

3) In the integrated arithmetic amplification circuit, the connection method of composite tube is used to improve the performance of single tube.

Integrated op amp is an integrated circuit with high magnification. Inside it is a multi-stage amplifier that is directly coupled, and the whole circuit can be divided into three parts: input stage, intermediate stage, and output stage. The input stage uses differential amplification circuitry.

to eliminate zero drift.

and suppression of interference; The intermediate stage generally uses a common emitter circuit to obtain a sufficiently high voltage gain; The output stage generally adopts a complementary symmetrical power amplifier circuit to output a sufficiently large voltage and current, with small output resistance and strong load capacity.

Operational amplifiers.

There are three basic circuits: common emitter amplification circuit, voltage divider bias common emitter amplification circuit, and emitter output.

A common emitter amplification circuit is a common emitter amplification circuit. C1 is the input capacitor, C2 is the output capacitor, and the transistor.

VT is the device that plays the role of amplification, and RB is the base pole of Jingyin.

Bias resistance, RC is the collector load resistor, the end is the input, and the end is the output. The 3rd end is a common point, usually grounded, also known as the "ground" end. The direct flow path during static time is shown on the right in Figure 1.

The characteristics of the circuit are that the voltage amplification factor is from more than ten to more than 100, the phase of the output voltage and the input voltage are opposite, and the performance is not bright and stable enough, which can be used in general occasions.

Summary. The two working areas of the operational amplifier are: 1. Linear working area.

The op amp is working in the amplified state. 2 non-linear workspaces. The output constant voltage power supply, the op amp works in a saturated state.

In general, the linear workspace is used for differential amplification of signals, and the nonlinear workspace is used for signal comparison. Operational amplifiers are circuit units with very high amplification. In the actual circuit, it is usually combined with the feedback network to form a certain functional module.

It is an amplifier with a special coupling circuit and feedback.

What are the two working areas of the integrated op amp? Write about their characteristics separately.

The two working areas of the operational amplifier are: 1. Linear working area. The op amp is working in the amplified state.

2 non-linear workspaces. The output constant voltage power supply, the op amp works in a saturated state. In general, the linear workspace is used for differential amplification of signals, and the nonlinear workspace is used for signal comparison.

Operational amplifiers are circuit units with very high amplification. In the actual circuit, it is usually combined with the feedback network to form a certain functional module. It is an amplifier with a special coupling circuit and feedback.

Design a three-person voting combination logic circuit! The inputs are a, b, and c, and the output resolution result is y. When two or more people agree, the resolution is passed, otherwise it is not passed. Requirements:1The process should be detailed.

Is this the problem complete?

Can you be more careful about this picture?

The function of the three-person voting machine is that when A, B, and C vote on a proposal, two or more people agree, and the proposal passes, otherwise the proposal does not pass. This voting machine logic diagram involves the NAND gate of a digital circuit. With the door (English:

and gate) is also known as "and circuit", "product" of logic, and "and" circuit of logic. It is the basic logic gate circuit that performs the AND operation. There are multiple inputs, one output.

The output is high when all inputs are high (logic 1) at the same time, otherwise the output is low (logic 0). NAND gate (English: not gate), also known as non-circuit, inverter, inverter, logic negation circuit, referred to as NAND gate, is the basic unit of logic circuit.

Good. Can you be more careful about this picture?

Experimental Phenomenon and Result Analysis of Three-person Voting Instrument Product Experimental Phenomenon: When the circuit board is soldered, the +5V power supply is turned on, and the buttons S1, S2, S3, S1, S3 or S1, S2, S3 or S1, S2, S3 are respectively pressed, and when only one of the three buttons of S1, S2 and S3 is pressed, it is observed that the LED cannot be lit at this time. Analysis of results:

From the above experimental phenomena, it can be seen that the logic function of this circuit is correct.

The op amp input signal is connected to the "non-inverting input" of the amp, and when the signal increases in the forward direction, the output of the op amp also increases in the forward direction.

When the op amp is used as a proportional amplifier, if the input signal is input from the inverting terminal, when the signal increases in the positive direction, the output of the op amp changes in the negative direction (voltage decreases), and if the input signal is input from the inverting terminal, the output changes in the same direction as the input signal.

The input signal is brought in from the inverting input of the integrated op amp, and the output signal is inverted to the input signal.

At the inverting input, the voltage at the inverting terminal is almost zero, so the collector voltage of the differential pair tube varies by only one tube. In the case of in-phase input, the voltage at the inverting terminal is equal to the voltage at the inverting terminal, so the common-mode voltage and the input voltage are equal. That is to say, in addition to the part of the two tubes that change in different directions at the same time, there is also a quantity that changes in the same direction, which is the common-mode output voltage.

It and the voltage of one of the tubes are added in phase. Therefore, it is easy to cause the tube to tend to saturate (or cut-off), but fortunately, the amplification of the common mode voltage is only tens of thousands of ten-thousandths of the differential mode amplification.

The op amp operates in the linear region, introduces deep negative feedback, and the phase difference between the input signal and the output signal is 180 degrees.

The input resistance is large, the output resistance is small、、、 the common-mode rejection capability is strong, and the magnification can be adjusted.

First, the meaning is different:

Power amplification is the amplification of current.

A small signal amplifier is an amplified voltage signal.

Second, the role is different:

The main requirements of the power amplifier in terms of performance are safety, high efficiency and the output of the required signal power without distortion within the allowable range.

In terms of performance, small signal amplifiers mainly focus on input resistance, output resistance, gain, frequency response, and nonlinear distortion.

3. Different purposes:

The main purpose of power amplifier is to amplify current to achieve power increase, and some amplifiers also have a certain voltage amplification ability (but it is never the main function), and its output impedance is very small, which is suitable for heavy loads (speakers, motors, etc.).

The voltage amplification ability of the small signal amplification circuit is very strong, but the current amplification ability is weak, the output power is small, and the output impedance is medium, which makes it difficult to drive relatively heavy loads (small resistance).