WO2023061387A1

WO2023061387A1 - Class-a amplification apparatus

Info

Publication number: WO2023061387A1
Application number: PCT/CN2022/124759
Authority: WO
Inventors: 郭桥石; 刘建德; 李永东
Original assignee: 郭桥石
Priority date: 2021-10-13
Filing date: 2022-10-12
Publication date: 2023-04-20
Also published as: CN116940895A; AU2022362476A1

Abstract

The present invention relates to a class-A amplification apparatus, in particular to a class-A amplification apparatus which is connected in series in a circuit by using an energy source, is used for eliminating a cut-off of a fully controlled device, and has a high energy efficiency to satisfy a high-dynamic class-A output. The apparatus comprises devices for amplification, wherein the devices comprise a first device and a second device, the first device and the second device forming a push-pull amplification circuit; and the apparatus further comprises a diode and an energy source, wherein first electrodes of the devices and second electrodes of the devices are connected to the energy source in series, and the diode is connected to the energy source in parallel. The present invention has a rational design, and has the advantages of being convenient to implement, high energy efficiency, and the large dynamic range of a class-A output.

Description

Class A amplifier

technical field

The invention relates to a Class A amplification device, in particular to a Class A amplification device which uses an energy source in series to eliminate the cut-off problem of a full-control device, and has high energy efficiency and high dynamic Class A output.

Background technique

In traditional amplifying devices, when devices (including fully controlled devices such as triodes, field effect transistors, and IGBTs) appear cut-off phenomena (such as audio push-pull power amplifiers, pulse amplification, etc.), various related problems (such as switch distortion , crossover distortion, lower operating frequency, etc.), while the traditional Class A amplifiers have the problems of extremely large quiescent current and extremely low energy efficiency; Class A and B amplifiers also have the problems of large static power consumption and low efficiency, and can only meet small Class A power output has the disadvantage of a small dynamic range of Class A output; the second page of the preface of the sixth edition of the Chinese version of the book "Audio Power Amplifier Design Manual" by the famous British power amplifier designer Douglas Self also discusses the current technology Various disadvantages, and revealed that the "XD class (intermodulation displacement) amplifier" invented by himself cannot completely eliminate the crossover distortion and switching distortion problems caused by the device cut-off.

Contents of the invention

The purpose of the present invention is to solve the problem of the technical background, to provide a Class A amplification device which is easy to implement and can satisfy high dynamic Class A output under the condition of relatively low quiescent current (to achieve high energy efficiency).

Realize that the object of the present invention is achieved by the following technical solutions:

A Class A amplification device, which includes a device for amplification, the device includes a first device and a second device, the first device and the second device form a push-pull amplifier circuit, and also includes a diode, an energy A source; the first electrode of the device, the second electrode of the device are connected in series with the energy source, and the diode is connected in parallel with the energy source.

Working principle: The energy source is connected in series in the bias input circuit of the device. The energy source maintains the output current during the working process. As long as the energy source provides a small quiescent current, the first device and the second device can be alternated (full power) In the state of high current output, both the first device and the second device are maintained in the conduction state, realizing the full power Class A output of the amplifying device, and eliminating the distortion (switching distortion, crossover distortion, etc.) caused by the cut-off of the device.

The invention has the advantages of reasonable design, convenient implementation, high energy efficiency and large dynamic range of Class A output.

Description of drawings

Fig. 1 is a principle diagram of the first embodiment of the class A amplification device of the present invention.

Fig. 2 is a principle diagram of Embodiment 2 of the Class A amplifier of the present invention.

Fig. 3 is a principle diagram of the third embodiment of the class A amplifier of the present invention.

Fig. 4 is a principle diagram of Embodiment 4 of the Class A amplification device of the present invention.

Detailed ways

Embodiment one of the present invention:

As shown in Figure 1, a Class A amplifier includes devices Q1 and Q2 for amplification. Device Q1 and device Q2 form a push-pull amplifier circuit. It also includes diodes (D1, D2), energy source E1 (battery BT connected in series current limiting element R); the first electrode P1-1 of the device Q1, the second electrode P1-2 of the device Q1, the energy source E1, the second electrode P2-2 of the device Q2, and the first electrode P2-1 of the device Q2 A bias input circuit is formed in series; the third electrode P1-3 of the device Q1, the second electrode P1-2 of the device Q1, the energy source E1, the second electrode P2-2 of the device Q2, and the third electrode P2-3 of the device Q2 A series circuit is formed in series in sequence, the second electrode (P1-2, P2-2) is used to output the amplified signal, the first electrode P1-1 of the device Q1, and the first electrode P2-1 of the device Q2 are used to input the pre-amplified signal signal; the diode D1 and the diode D2 are connected in series, and the common node N1 of the diode D1 and the diode D2 is used to connect with the load RL, that is, the second electrode (P1-2, P2-2) is amplified through the output of the diode (D1, D2) signal, the series circuit composed of diode D1 and diode D2 is connected in parallel with energy source E1.

Working principle: For ease of understanding, Figure 1 includes input unit B (other circuits can also be used). Input unit B is used to implement constant voltage bias on devices Q1 and Q2. Devices Q1 and Q2 work in the amplification area (quiescent current can be Choose between a few milliamps to tens of milliamperes), eliminate the distortion caused by the cut-off of diode D1 and diode D2, and be used for linear amplification (such as audio amplification); before the node N1 outputs the signal, the diode D1 (diode D2) is turned on , and then the device Q1 (device Q2, either) amplifies the current to the node N1; when the input signal is of high amplitude, when either the diode D1 or the diode D2 is cut off, the current generated by the energy source E1 (the energy source E1 The output voltage of the bias input circuit is boosted) so that the device Q1 and the device Q2 maintain the conduction state, and eliminate various problems caused by the cut-off of the device Q1 and the device Q2.

Embodiment two of the present invention:

As shown in Figure 2, a Class A amplifier differs from Embodiment 1 in that Q1 and Q2 are used as driving stages to amplify, the third electrodes (P1-3, P2-3) are connected in series with resistors (R1, R2), and the third The electrodes (P1-3, P2-3) output amplified signals; this embodiment may further include a circuit C, which includes a device Q3 (triode), a device Q4 (triode), a diode D3, a diode D4, and a second bias circuit E2 (the output electromotive force can be selected between 0.3 volts and 2 volts); the common node of the third electrode of the device Q1 and the resistor R1 (the first resistor) is connected to the first electrode of the device Q3 through the diode D3, and the third electrode of the device Q2 The common node of the electrode and resistor R2 (the second resistor) is connected to the first electrode of the device Q4 through the diode D4; the second electrode of the device Q1 is connected to the third electrode of the device Q3 through the diode D1, and the second electrode of the second device Q2 The third electrode of the device Q4 is connected to the third electrode of the device Q4 through the diode D2; the third electrode of the device Q3 and the third electrode of the device Q4 have a common node N1 for connecting to the load RL; the first electrode of the device Q3, the first electrode of the device Q4 and the first electrode of the device Q4 The two bias circuits E2 are connected, and the current provided by the second bias circuit E2 overcomes the devices Q3 and Q4 to cut off. In practical applications, a resistor can be connected in series at both ends of the node N1.

Embodiment three of the present invention:

As shown in Figure 3, a Class A amplifier differs from Embodiment 1 in that Q1 and Q2 are used as driving stages, and the resistor RA (selected according to requirements) connected in series with diode D1 (which can also be composed of multiple diodes in series) is used for Increase the potential difference between the nodes N1-1 and N1-2 to facilitate DC coupling to the subsequent stage. The second electrodes (P1-2, P2-2) are used to output the amplified signal. The diode D1 is connected in parallel with the energy source E1. The anode of the energy source E1 (through the resistor RA) is connected to the cathode of the diode D1, and the cathode of the energy source E1 is connected to the anode of the diode D1; when the diode D1 is cut off, the current generated by the energy source E1 makes the devices Q1 and Q2 maintain The conduction state eliminates various problems caused by the cut-off of the device Q1 and the device Q2 in the amplifying device.

This embodiment may further include a circuit C, which includes a diode D3, a diode D4, a device Q3, a device Q4, and a second bias circuit E2 (the output electromotive force is greater than 3 times the turn-on voltage of the device Q3); the second electrode of the device Q1 is passed through the first A diode D1 (the current limiting element RA is selected as required) is connected to the second electrode of the device Q2, the second electrode of the device Q1 is connected to the first electrode of the device Q3 through the diode D3, and the second electrode of the device Q2 is connected through the fourth The diode D4 is connected to the first electrode of the device Q4; the first electrode of the third device Q3 and the first electrode of the device Q4 are connected to the second bias circuit E2, and the current provided by the second bias circuit E2 overcomes the devices Q3, The device Q4 is turned off, and the common node of the second electrode of the device Q3 and the second electrode of the device Q4 is used to output the amplified signal.

Embodiment 4 of the present invention

A Class A amplifier shown in Figure 4 is a schematic diagram of a bridge circuit, and its working principle is the same as above, so it will not be repeated here.

The above embodiment can also include circuit B to form a loop-free negative feedback amplifying device, which can give full play to the technical advantages of the present invention. Circuit B includes a first coupling element C1 (preferably a capacitor), a second coupling element C2 (preferably a capacitor), and an energy output Type photoelectric unit E3 (the output electromotive force is greater than 3 times the turn-on voltage of the device Q1), the first coupling element C1 is connected to the first electrode of the first device Q1, and the second coupling element C2 is connected to the first electrode of the second device Q2; The output terminals of the unit E3 are respectively connected to the first electrode of the first device Q1 and the first electrode of the second device Q2, and the discharge unit RV (preferably, a resistor) connected in parallel to the photoelectric unit E3 is used for discharge.

In the above embodiment, when the influence of the diodes (D1, D2) on the distortion is not considered, the equipotential connection is also possible, that is, the input unit B does not need to be biased, and the first electrode of the device Q1 is connected to the first electrode of the device Q2. The first electrode can be connected to the ground through a resistor, and this scheme is more suitable as a digital power amplifier (that is, pulse signal amplification, or digital audio power amplifier); when the first electrode of the device Q1 and the first electrode of the device Q2 are not equipotentially connected, pass The current of the device Q1 (Q2) is equal to the current of the diode D1 (D2) plus the energy source E1; the first electrode of the device Q1, the second electrode of the device Q1, the diode (D1, D2, which can be D1 alone), and the current of the device Q2 The bias input circuit composed of the second electrode and the first electrode of the device Q2 connected in series, before realizing the output signal of N1 (or N1-1, N1-2), the diodes (D1, D2) are first turned on, which is used to eliminate the diodes (D1, D2) Distortion caused by the cut-off, Note: It is recommended that the quiescent current design of the diodes (D1, D2) be selected in the range of 2 times to 5 times the output current value of the energy source E1.

The above embodiments D1, D2, D3, D4 are respectively defined as the first diode, the second diode, the third diode, and the fourth diode; Q1, Q1, Q3, and Q4 are respectively defined as the first device , the second device, the third device, and the fourth device.

Above embodiment has following characteristics:

1. When the diodes (D1, D2) are cut off, the quiescent current passed by the devices (Q1, Q2) depends on the current provided by the energy source E1, which is almost independent of whether the diodes (D1, D2) are on or not and the device (Q1 , Q2) influence of exaggeration (or current magnification), good consistency in mass production;

2. The energy source connected in series with the output circuit of the device (the common electrode of the input circuit and the output circuit) has the advantages of stable output current and almost zero interference;

3. The energy source is connected in series in the bias input circuit. The energy source maintains the output current during the working process to achieve a balanced bias on the device (Q1, Q2), and the current does not pass through the load, eliminating the distortion caused by the cut-off of the device (switching distortion, crossover distortion, etc.), compared with the traditional Class A amplifier, the static power consumption is extremely low (close to the energy efficiency of the Class B power amplifier), the dynamic range is larger, and the full power Class A output of the amplifier can be realized. The present invention It has strong adaptability to load impedance. For loads such as speakers and earphones with different impedances, it can meet Class A driving loads with different impedances without adjusting the operating point of the device.

The energy source E1 of the present invention is an energy source whose output electromotive force is in the interval of zero point 3 volts to 3 volts, and the energy source can be a battery (the battery can be connected to the charging circuit of a pair of batteries; for the convenience of battery replacement, the detachable structure design of the battery can also be adopted ), when using a battery with the characteristics of a voltage source, the battery can be connected in series with the current limiting element R, and the energy source can also use E1 (E2, E3) as shown in Figures 2, 3, and 4 as a photoelectric unit, which is also defined as a photoelectric cell ( used for audio power amplifier), which can include photoelectric conversion elements (preferably composed of multiple photodiodes connected in parallel, or in series, or mixed), and further include electro-optical conversion elements (preferably using multiple light-emitting diodes), using photoelectric conversion elements and The second electrodes of the devices (Q1, Q2) are connected in series. In the present invention, the electro-optical conversion element of the photoelectric unit E1 (E2, E3) and the photoelectric conversion element are packaged into a module, which is convenient to use; the driving current of the photoelectric conversion element is adjusted to adjust the energy source. Output current.

The device (Q1, Q2, one being N-type and the other being P-type) used for amplification in the present invention is a fully controlled device, which can be a field effect transistor, or a triode, or an IGBT, or an electron tube, or a Darlington device The second electrode is the common electrode of the input circuit and the output circuit of the device; the specific types of Q1 and Q2 in the above embodiments can be flexibly changed and selected according to the needs, the first electrode is the base or the grid, and the second electrode is the device source, or cathode, or emitter, and the third electrode is a collector, or a drain, or an anode; the first electrode and the second electrode can be connected in series with resistors according to actual needs; the diode is preferably a Schottky diode, a switching diode , fast recovery diodes, high-frequency diodes, etc., whose switching speed is higher than that of the device and the turn-on voltage is smaller than that of the device.

The present invention is especially suitable for linear (analog) amplification (such as high-fidelity audio amplification, realizing high-dynamic class A amplification, that is, HA class amplification), high-performance D (digital, HD, and a speaker at the load end of node N1 can be connected to a filter unit; The first electrode of the device Q1 and the first electrode of the device Q2 are equipotentially connected) type amplification; it can also be used for other high-frequency switch (pulse) amplification; the energy source that claims the same purpose as the present invention also falls under the patent protection of the present invention scope.

Claims

A Class A amplification device, which includes a device for amplification, the device includes a first device and a second device, the first device and the second device form a push-pull amplifier circuit, and it is characterized in that: it also includes A diode and an energy source; the first electrode of the device and the second electrode of the device are connected in series with the energy source, and the diode is connected in parallel with the energy source.
The class A amplification device according to claim 1, characterized in that: the first electrode of the first device, the second electrode of the first device, the energy source, the second electrode of the second device , the first electrode of the second device is connected in series to form a bias input circuit, the third electrode of the first device, the second electrode of the first device, the energy source, the second electrode of the second device The electrode and the third electrode of the second device form a series circuit.
The Class A amplifier device according to claim 2, characterized in that: said diode is connected in series with a resistor.
The Class A amplifier device according to claim 2, characterized in that: the first electrode is used for inputting the signal before amplification, and the second electrode or the third electrode is used for outputting the signal after amplification.
The class A amplifier device according to claim 2, characterized in that: the first electrode of the first device is equipotentially or non-equipotentially connected to the first electrode of the second device.
The class A amplifier according to claim 2, wherein the anode of the energy source is connected to the cathode of the diode, and the cathode of the energy source is connected to the anode of the diode.
The Class A amplification device according to claim 2, wherein the diode comprises a first diode and a second diode, and the first diode and the second diode are connected in series, A common node of the first diode and the second diode is used for connecting with a load.
The Class A amplifier device according to claim 7, characterized in that: the series circuit composed of the first diode and the second diode is connected in parallel with the energy source.
The Class A amplifier device according to claim 2, wherein the energy source is a battery.
The Class A amplifier device according to claim 9, characterized in that: said battery is connected in series with a current limiting element.
The Class A amplifier according to claim 2, characterized in that: said diodes include a first diode and a second diode, and also include a third device, a fourth device, a third diode, a fourth A diode, a first resistor, a second resistor, and a second bias circuit; the common node of the third electrode of the first device and the first resistor passes through the third diode and the third device connected to the first electrode of the second device, the common node of the third electrode of the second device and the second resistor is connected to the first electrode of the fourth device through the fourth diode; The second electrode is connected to the third electrode of the third device through the first diode, and the second electrode of the second device is connected to the third electrode of the fourth device through the second diode. connection; the third electrode of the third device and the third electrode of the fourth device have a common node for connecting with the load; the first electrode of the third device, the first electrode of the fourth device and the connected to the second bias circuit.
The Class A amplifier according to claim 2, characterized in that: said diode is a first diode, and also includes a third diode, a fourth diode, a third device, a fourth device, a second A bias circuit; the second electrode of the first device is connected to the second electrode of the second device through the first diode, and the second electrode of the first device is connected through the third diode Connected to the first electrode of the third device, the second electrode of the second device is connected to the first electrode of the fourth device through the fourth diode; the first electrode of the third device , the first electrode of the fourth device is connected to the second bias circuit, and the common node of the second electrode of the third device and the second electrode of the fourth device is used to output an amplified signal.