CN105207632B

CN105207632B - A kind of power amplification circuit

Info

Publication number: CN105207632B
Application number: CN201410237806.2A
Authority: CN
Inventors: 李凤朝
Original assignee: Individual
Current assignee: Individual
Priority date: 2014-06-01
Filing date: 2014-06-01
Publication date: 2018-07-20
Anticipated expiration: 2034-06-01
Also published as: CN105207632A

Abstract

The invention discloses a kind of power amplification circuits.The amplifying circuit is made of a series of symmetrical transistors.Ac current signal or ac voltage signal can be divided into two as the current signal of upper lower half, then upper lower half carries out Current amplifier respectively, is finally combined into one complete signal in output stage.In certain occasions（Such as the digital analog converter of R 2R structures, it traditionally needs to amplify output current signal with amplifier）, since the circuit inputs the Static Electro potential difference at both ends（Potential difference in attached drawing between net input and Vref）It can be easily done within 1 millivolt, and the potential difference at input both ends varies less when input AC current signal, therefore amplifier can be replaced, directly carry out Current amplifier, can avoid needing Current Voltage conversion and then the again trouble of voltage amplification using amplifier.The circuit can also carry out power amplification to small-power AC signal direct-coupling.The circuit structure is simple, ingenious in design, and information loss is small in amplification process.The circuit also has stand-by power consumption small simultaneously, and capacity usage ratio is high, the big advantage of thrust output.

Description

A kind of power amplification circuit

Technical field

The present invention is for a kind of electronic circuit, it can be achieved that the power amplification of AC signal.

Background technology

Power amplifier traditionally, Class A efficiency is very low, and Class B power amplification distortion is larger and has intermodulation distortion problem, and first and second Although class power amplifier solves above-mentioned two problems, but general class AB power amplifier input end structure is complicated and information content is lost Larger, class D amplifier distortion is larger.And general class AB power amplifier is all by the way of Differential Input, it is not easy to stablize, So using big loop negative-feedback.The present invention is also a kind of class AB amplifier, need not use big loop negative-feedback, information Amount loss is smaller, can be with direct-coupling.

In the digital analog converter of certain occasions for needing to use amplifier, such as R-2R structures, output is current signal, The current potential of current output terminal and the difference very little of reference potential are asked, within one millivolt, and is required when the curent change of output, Otherwise the potential change very little of current output terminal influences the precision of digital analog converter.Conventionally used amplifier can meet this and want It asks.But need first to carry out current-voltage conversion using amplifier, then power amplification is carried out with triode again.Due to triode It is Current amplifier device, a kind of circuit substitution amplifier, the current signal that the digital analog converter of R-2R structures is exported can be found It takes out, is directly sent to triode and carries out power amplification, be a project for being worth research.The present invention can meet this and want It asks.

Invention content

As shown in Figure of description 1, current source 1 connects the base stage of the positive input and NPN triode Q1 of diode D1； The positive input of diode D1 is connected with the base stage of NPN triode Q1.Current source 3 connect diode D2 reverse input end and The base stage of triode Q3；The reverse input end of diode D2 is connected with the base stage of triode Q3.Current source 2 connects NPN triode The base stage of the collector and NPN triode Q2 of Q1；The collector of NPN triode Q1 is connected with the base stage of NPN triode Q2.Electric current Source 4 connects the base stage of the collector and PNP triode Q4 of PNP triode Q3；The collector and PNP triode of PNP triode Q3 The base stage of Q4 is connected.The emitter of NPN triode Q1 is connected with the emitter of PNP triode Q3, constitutes the reference of input signal Signal.The emitter and PNP of the reverse input end of diode D1 and the positive input of diode D2 and NPN triode Q2 The emitter of triode Q4 is connected, and constitutes input signal.The collector of NPN triode Q2 and the collector of PNP triode Q4 point Not Lian Jie PNP pliotron Q5 and NPN pliotrons Q6 base stage, the emitter of PNP pliotrons Q5 connects positive electricity VCC1, the emitter of NPN pliotrons Q6 is pressed to connect negative voltage-VCC2, PNP pliotron Q5 and NPN pliotron The collector of Q6, which is connected, is output to load Rload.Usual diode D1 uses the triode generation with NPN triode Q1 with model It replaces, and base stage is made to be connected with collector.Diode D2 is used and PNP triode Q3 is replaced with the triode of model, and is made Base stage is connected with collector.Current source 1 and 3 numerical value of current source are close, and current source 2 and 4 numerical value of current source are close, and current source 2 is big In current source 1, current source 4 is more than current source 3.

As shown in Figure of description 1, lower half is divided into two in input signal, is sent to NPN triode Q1 and PNP tri- respectively Pole pipe Q3 carries out recommending amplification, and the collector and PNP triode Q3 collectors of NPN triode Q1 are sent to tri- poles NPN respectively again Pipe Q2 and PNP triode Q4 are amplified, and then NPN triode Q2 is negative anti-with the electric current of the PNP triode Q4 emitters being connected It is fed to the port that diode D1 is connected with D2, collectively forms input signal.This profound and negative feedbck can make entire circuit static Stabilization of operating point.Analog result shows the Static Electro potential difference between input signal and reference signal within 1 millivolt.Due to warp Crossed two-stage triode amplification, amplification factor up to tens thousand of times, one very little of input signal voltage change can so that On the emitter of NPN triode Q2 and PNP triode Q4（It is connected with input signal）There are one prodigious curent change, this So that the input impedance of entire circuit is very low, it is a kind of current follower.In a static condition, NPN triode Q2 and PNP tri- Electric current on the collector of pole pipe Q4 is very close.This circuit is particularly suited for use in certain occasions needed using amplifier, than Such as the digital analog converter of R-2R structures, the upper lower half current signal being divided into two, the collection of NPN triode Q2 can be directly detected The collector of electrode and PNP triode Q4 distinguish the above lower half and are sent into power amplification circuit, are finally combined into one complete letter Number, it is sent to load Rload.

As shown in Figure of description 2, four current sources of circuit shown in attached drawing 1, same work(can be reached by changing resistance into Energy.Current source 1 changes resistance R2 into, and current source 2 changes resistance R3 into, and current source 3 changes resistance R4 into, and current source 4 changes resistance R5 into.Electricity R2 is hindered, resistance R3 is connected with positive supply VCC3, and resistance R4, resistance R5 is connected with negative supply-VCC4.

As shown in Figure of description 3, the diode and triode of circuit shown in attached drawing 1, changing metal-oxide-semiconductor into can reach same Function, circuit theory is as circuit shown in attached drawing 1.The grid of the connection NMOS tube of current source 1 Q1 and drain electrode and NMOS tube The grid of Q2；The grid of NMOS tube Q1 and drain electrode are connected with the grid of NMOS tube Q2.Current source 2 connects the drain electrode of NMOS tube Q2 With the grid of NMOS tube Q3；The drain electrode of NMOS tube Q2 is connected with the grid of NMOS tube Q3.Current source 3 connects the grid of PMOS tube Q4 And the grid of drain electrode and PMOS tube Q5；The grid of PMOS tube Q4 and drain electrode are connected with the grid of PMOS tube Q5.Current source 4 connects Connect the grid of the drain electrode and PMOS tube Q6 of PMOS tube Q5；The drain electrode of PMOS tube Q5 is connected with the grid of PMOS tube Q6.NMOS tube Q1 Source electrode and the source electrode of PMOS tube Q4 and the source electrode of NMOS tube Q3 be connected with the source electrode of PMOS tube Q6, collectively form input letter Number.The source electrode of NMOS tube Q2 is connected with the source electrode of PMOS tube Q5, constitutes the reference signal of input signal.The drain electrode of NMOS tube Q3 and The drain electrode of PMOS tube Q6 is separately connected the base stage of PNP pliotron Q7 and NPN pliotrons Q8, PNP pliotrons Q7 Emitter connection positive voltage VCC1, NPN pliotron Q8 emitter connection negative voltage-VCC2, PNP pliotron Q7 It is connected with the collector of NPN pliotrons Q8 and is output to load Rload.

As shown in Figure of description 4, four current sources of circuit shown in attached drawing 3, same work(can be reached by changing resistance into Can, current source 1 changes resistance R2 into, and current source 2 changes resistance R3 into, and current source 3 changes resistance R4 into, and current source 4 changes resistance R5 into, electricity R2 is hindered, resistance R3 is connected with positive supply VCC3, and resistance R4, resistance R5 is connected with negative supply-VCC4.

Claims

1. a kind of power amplifier, which is characterized in that circuit is configured to：Current source 1 connect diode D1 positive input and The base stage of NPN triode Q1；The positive input of diode D1 is connected with the base stage of NPN triode Q1, and current source 3 connects two poles The reverse input end of the base stage of the reverse input end and triode Q3 of pipe D2, diode D2 is connected with the base stage of triode Q3, electricity Stream source 2 connects the base stage of the collector and NPN triode Q2 of NPN triode Q1, tri- pole of collector and NPN of NPN triode Q1 The base stage of pipe Q2 is connected, and current source 4 connects the base stage of the collector and PNP triode Q4 of PNP triode Q3, PNP triode Q3 Collector be connected with the base stage of PNP triode Q4, the emitter of NPN triode Q1 is connected with the emitter of PNP triode Q3, Constitute the reference signal of input signal, tri- pole of the reverse input end of diode D1 and the positive input of diode D2 and NPN The emitter of pipe Q2 is connected with the emitter of PNP triode Q4, constitutes input signal, the collector and PNP tri- of NPN triode Q2 The collector of pole pipe Q4 is separately connected the base stage of PNP pliotron Q5 and NPN pliotrons Q6, PNP pliotrons Q5 Emitter connection positive voltage VCC1, NPN pliotron Q6 emitter connection negative voltage-VCC2, PNP pliotron Q5 It is connected with the collector of NPN pliotrons Q6 and is output to load Rload.

2. power amplifier as described in claim 1, which is characterized in that current source 1 changes resistance R2 into, and current source 2 changes electricity into R3 is hindered, current source 3 changes resistance R4 into, and current source 4 changes resistance R5, resistance R2 into, and resistance R3 is connected with positive supply VCC3, resistance R4, resistance R5 are connected with negative supply-VCC4.

3. power amplifier as described in claim 1, which is characterized in that current source 1 connects grid and the drain electrode of NMOS tube Q1, And the grid of NMOS tube Q2, the grid of NMOS tube Q1 and drain electrode are connected with the grid of NMOS tube Q2, current source 2 connects NMOS The drain electrode of the grid of the drain electrode and NMOS tube Q3 of pipe Q2, NMOS tube Q2 is connected with the grid of NMOS tube Q3, and current source 3 connects PMOS The grid of the grid of pipe Q4 and drain electrode and PMOS tube Q5, the grid phase of the grid of PMOS tube Q4 and drain electrode and PMOS tube Q5 Even, current source 4 connects the grid of the drain electrode and PMOS tube Q6 of PMOS tube Q5, the drain electrode of PMOS tube Q5 and the grid phase of PMOS tube Q6 Even, the source electrode of NMOS tube Q1 and the source electrode of the source electrode of PMOS tube Q4 and NMOS tube Q3 are connected with the source electrode of PMOS tube Q6, constitute The source electrode of input signal, NMOS tube Q2 is connected with the source electrode of PMOS tube Q5, constitutes the reference signal of input signal, NMOS tube Q3's Drain electrode and the drain electrode of PMOS tube Q6 are separately connected the base stage of PNP pliotron Q7 and NPN pliotrons Q8, PNP power three Emitter connection negative voltage-VCC2, the PNP power three of emitter connection positive voltage VCC1, the NPN pliotron Q8 of pole pipe Q7 Pole pipe Q7 is connected with the collector of NPN pliotrons Q8 is output to load Rload.

4. power amplifier as claimed in claim 3, which is characterized in that current source 1 changes resistance R2 into, and current source 2 changes electricity into R3 is hindered, current source 3 changes resistance R4 into, and current source 4 changes resistance R5, resistance R2 into, and resistance R3 is connected with positive supply VCC3, resistance R4, resistance R5 are connected with negative supply-VCC4.