Self-adaptive full-wave rectification circuit and earth leakage protection device

Abstract

The invention relates to the technical field of analog integrated circuits, and particularly discloses a self-adaptive full-wave rectification circuit and a leakage protection device, and the circuit comprises a waveform preprocessing unit, a phase detection unit, a positive-phase waveform transmission unit, a negative-phase waveform transmission unit, and a phase conversion unit. The waveform preprocessing unit is used for carrying out amplitude amplification processing after overlapping a common-mode level on an alternating-current input voltage waveform, wherein the alternating-current input voltage waveform at least comprises a small-signal alternating-current voltage waveform; the phase detection unit is used for performing positive phase detection and negative phase detection on the preprocessed voltage waveform; the normal-phase waveform transmission unit is used for transmitting a normal-phase waveform through a normal-phase transmission channel; the negative-phase waveform transmission unit is used for transmitting a negative-phase waveform through a negative-phase transmission channel; and the phase conversion unit is used for performing phase conversion on the negative phase waveform and then outputting the negative phase waveform and the positive phase waveform. The self-adaptive full-wave rectification circuit provided by the invention can automatically and accurately carry out full-wave rectification on the waveform of the small-signal AC voltage.

Description

Technical Field

[0001] The present invention relates to the technical field of analog integrated circuits, and in particular to an adaptive full-wave rectifier circuit and a leakage protection device. Background Art

[0002] An AC voltage waveform refers to a voltage signal whose magnitude and direction change periodically over time. A full-wave rectifier is a circuit that rectifies an AC voltage waveform. In a full-wave rectifier circuit, the current flows through a rectifier device (such as a crystal diode) in half a cycle, and in the other half a cycle, the current flows through a second rectifier device, and the connection of the two rectifier devices enables the current flowing through them to flow through the load in the same direction.

[0003] The full-wave rectifier circuit is usually composed of two rectifiers, one for the positive direction and the other for the reverse direction. The most typical full-wave rectifier circuit on the market is a rectifier bridge composed of four diodes, which can also be built with MOS tubes and is generally used for power supply rectification. Figure 1 As shown, when the voltage waveform Vac is a positive phase voltage, the diodes D2 and D4 in the rectifier circuit are turned on, and the waveform on the load at the rectifier output end is a voltage positive phase waveform; when the voltage waveform Vac is a negative phase voltage, the diodes D1 and D3 in the rectifier circuit are turned on, and the waveform on the load at the rectifier output end is an inverse waveform of the negative phase voltage, that is, the negative phase waveform of Vac is converted into a positive phase waveform of the same size, so the circuit can convert the AC voltage waveform Vac into a voltage waveform in the same direction, achieving the effect of full-wave rectification. Although the full-wave rectifier circuit has a simple structure, it has two defects: the first is that the diodes D1~D4 in the circuit have a forward conduction threshold voltage Vbe. When Vac is less than Vbe, the rectifier diodes D1~D4 will not be turned on and cannot achieve the effect of full-wave rectification; the second is that the circuit cannot couple the small signal AC voltage waveform to a suitable common mode level for amplitude amplification. Therefore, the full-wave rectifier circuit is only suitable for full-wave rectification of AC voltage waveforms with larger amplitudes, but cannot perform full-wave rectification on the waveform of small signal AC voltage Vac.

[0004] Therefore, how to provide a circuit that can automatically and accurately perform full-wave rectification on the waveform of a small signal AC voltage has become a technical problem that needs to be urgently solved by those skilled in the art. Summary of the invention

[0005] The present invention provides an adaptive full-wave rectifier circuit and a leakage protection device, which solve the problem in the related art that full-wave rectification of the waveform of a small signal AC voltage cannot be achieved.

[0006] As a first aspect of the present invention, an adaptive full-wave rectifier circuit is provided, which includes: a waveform preprocessing unit, a phase detection unit, a positive-phase waveform transmission unit, a negative-phase waveform transmission unit, and a phase conversion unit. The phase detection unit, the positive-phase waveform transmission unit, and the negative-phase waveform transmission unit are all electrically connected to the waveform preprocessing unit, and the positive-phase waveform transmission unit and the negative-phase waveform transmission unit are also both electrically connected to the phase conversion unit;

[0007] The waveform preprocessing unit is used to perform amplitude amplification processing on the AC input voltage waveform after superimposing a common-mode level to obtain a preprocessed voltage waveform, where the AC input voltage waveform at least includes a small-signal AC voltage waveform;

[0008] The phase detection unit is used to perform positive-phase detection and negative-phase detection on the preprocessed voltage waveform to obtain a positive-phase waveform and a negative-phase waveform;

[0009] The positive-phase waveform transmission unit is used to transmit the positive-phase waveform through a positive-phase transmission channel;

[0010] The negative-phase waveform transmission unit is used to transmit the negative-phase waveform through a negative-phase transmission channel;

[0011] The phase conversion unit is used to perform phase conversion on the negative-phase waveform and output it together with the positive-phase waveform to obtain a full-wave rectified output voltage waveform;

[0012] Wherein, the phase detection unit includes: a voltage comparison sub-unit and a buffer sub-unit. The input end of the voltage comparison sub-unit is connected to the output end of the waveform preprocessing unit, the output end of the voltage comparison sub-unit is connected to the input end of the buffer sub-unit, and the output end of the buffer sub-unit is the output end of the phase detection unit;

[0013] The voltage comparison sub-unit is used to compare the preprocessed voltage waveform with a preset common-mode level to achieve positive-phase detection and negative-phase detection of a preset processed voltage waveform;

[0014] The buffer sub-unit is used to perform enhancement processing on the results after positive-phase detection and the results after negative-phase detection to obtain a positive-phase waveform and a negative-phase waveform.

[0015] Further, the waveform preprocessing unit includes a first-stage superimposed amplification sub-unit and a second-stage superimposed amplification sub-unit. The input end of the first-stage superimposed amplification sub-unit is the input end of the waveform preprocessing unit, the output end of the first-stage superimposed amplification sub-unit is connected to the input end of the second-stage superimposed amplification sub-unit, and the output end of the second-stage superimposed amplification sub-unit is the output end of the waveform preprocessing unit;

[0016] The first - stage superposition and amplification subunit is used to superpose the AC input voltage waveform to a preset common - mode level for the first time and perform amplification processing according to a first preset amplification ratio to obtain an intermediate - processed waveform;

[0017] The second - stage superposition and amplification subunit is used to superpose the intermediate - processed waveform to the preset common - mode level for the second time and amplify the amplitude of the intermediate - processed waveform according to a second preset amplification ratio to obtain a pre - processed voltage waveform.

[0018] Further, the first - stage superposition and amplification subunit includes: a first capacitor, a first resistor, a second resistor, and a first amplifier. One end of the first capacitor is the input end of the first - stage superposition and amplification subunit, the other end of the first capacitor is connected to one end of the first resistor, the other end of the first resistor is connected to the inverting input end of the first amplifier, the non - inverting input end of the first amplifier is used to input the preset common - mode level, the output end of the first amplifier is the output end of the first - stage superposition and amplification subunit, one end of the second resistor is connected to the inverting input end of the first amplifier, and the other end of the second resistor is connected to the output end of the first amplifier;

[0019] The second - stage superposition and amplification subunit includes: a second capacitor, a third resistor, a fourth resistor, and a second amplifier. One end of the second capacitor is connected to the output end of the first - stage superposition and amplification subunit, the other end of the second capacitor is connected to the signal ground, one end of the third resistor is connected to one end of the second capacitor, the other end of the third resistor is connected to the inverting input end of the second amplifier, the non - inverting input end of the second amplifier is used to input the preset common - mode level, the output end of the second amplifier is the output end of the second - stage superposition and amplification subunit, one end of the fourth resistor is connected to the inverting input end of the second amplifier, and the other end of the fourth resistor is connected to the output end of the second amplifier;

[0020] The first preset amplification ratio is the resistance ratio of the second resistor to the first resistor, and the second preset amplification ratio is the resistance ratio of the fourth resistor to the third resistor.

[0021] Further, the voltage comparison subunit includes a voltage comparator. The non - inverting input end of the voltage comparator is the input end of the phase - detection unit, the inverting input end of the voltage comparator is used to input the preset common - mode level, and the output end of the voltage comparator is the output end of the voltage comparison subunit;

[0022] The buffer subunit includes a first inverter and a second inverter. The input end of the first inverter is the input end of the buffer subunit, the output end of the first inverter is connected to the input end of the second inverter, and the output end of the second inverter is the output end of the buffer subunit.

[0023] Further, the positive-phase waveform transmission unit includes: a first transmission gate unit and a second transmission gate unit. The input end of the first transmission gate unit is used to connect to a preset common-mode level. The control ends of the first transmission gate unit and the second transmission gate unit are connected and used as the input end of the positive-phase waveform transmission unit to connect to the output end of the phase detection unit. The output ends of the first transmission gate unit and the second transmission gate unit are connected and used as the output end of the positive-phase waveform transmission unit;

[0024] The negative-phase waveform transmission unit includes: a third transmission gate unit and a fourth transmission gate unit. The input end of the third transmission gate unit is connected to the input end of the second transmission gate unit and then connected to the output end of the waveform preprocessing unit. The control ends of the third transmission gate unit and the fourth transmission gate unit are connected and used as the input end of the negative-phase waveform transmission unit to connect to the output end of the phase detection unit. The output ends of the third transmission gate unit and the fourth transmission gate unit are connected and used as the output end of the negative-phase waveform transmission unit.

[0025] Further, the first transmission gate unit, the second transmission gate unit, the third transmission gate unit, and the fourth transmission gate unit all include: a first PMOS transistor and a first NMOS transistor connected. The gate terminals of the first PMOS transistor and the first NMOS transistor are both formed as the control end of the transmission gate unit. The source terminals of the first PMOS transistor and the first NMOS transistor are connected and formed as the input end of the transmission gate unit. The drain terminals of the first PMOS transistor and the first NMOS transistor are connected and formed as the output end of the transmission gate unit.

[0026] Further, the phase conversion unit includes: a third amplifier, a fourth amplifier, an equal-ratio current mirror structure, a fifth resistor, and a sixth resistor. The non-inverting input end of the third amplifier is connected to the output end of the positive-phase waveform transmission unit. The inverting input end of the third amplifier is connected to one end of the fifth resistor. The output end of the third amplifier is connected to the control end of the equal-ratio current mirror structure. The first end of the equal-ratio current mirror structure is connected to the power supply. The second end of the equal-ratio current mirror structure is respectively connected to one end of the fifth resistor and one end of the sixth resistor. The non-inverting input end of the fourth amplifier is connected to the output end of the negative-phase waveform transmission unit. The inverting input end of the fourth amplifier is connected to the other end of the fifth resistor. The other end of the sixth resistor is connected to the signal ground. One end of the sixth resistor is the output end of the phase conversion unit;

[0027] When the positive-phase waveform transmission unit outputs a positive-phase waveform at its output end or the negative-phase waveform transmission unit outputs a negative-phase waveform at its output end, the current direction of the fifth resistor is from one end of the fifth resistor to the other end of the fifth resistor, and the current direction and magnitude in the equal-ratio current mirror structure are the same as those of the fifth resistor, so that the voltage waveform formed by the sixth resistor is a positive-phase waveform.

[0028] Further, it further includes: a common-mode level acquisition unit, and the common-mode level acquisition unit is used to obtain a common-mode level after voltage division and filtering according to the power supply.

[0029] As another aspect of the present invention, a leakage protection device is provided, which includes the adaptive full-wave rectification circuit described above.

[0030] The adaptive full-wave rectification circuit provided by the present invention, for the preprocessing of the AC input voltage waveform, can not only automatically convert the AC input voltage waveform into a voltage waveform with an amplified amplitude on the common-mode level, but also simultaneously convert the negative-phase voltage waveform into a positive-phase voltage waveform of the same magnitude, so that the adaptive full-wave rectification circuit of the present invention can be applicable to small-signal AC input voltage waveforms and also to large-signal AC input voltage waveforms, and the adaptive full-wave rectification circuit provided by the present invention can very accurately perform full-wave rectification and amplification output on small-signal AC voltage waveforms, and when performing full-wave rectification and amplification output on large-signal AC voltage waveforms, in addition to achieving accurate amplification output, compared with the existing rectifier bridge method, a smoother rectification output result can be obtained due to the absence of diode voltage drop. Description of the Drawings

[0031] The drawings are used to provide a further understanding of the present invention, and constitute a part of the specification, and are used to explain the present invention together with the following specific embodiments, but do not constitute a limitation to the present invention.

[0032] Figure 1 It is the schematic diagram of the full-wave rectification circuit in the prior art.

[0033] Figure 2 The structural block diagram of the adaptive full-wave rectification circuit provided by the present invention.

[0034] Figure 3 It is the schematic diagram of the circuit of an embodiment of the adaptive full-wave rectification circuit provided by the present invention.

[0035] Figure 4 It is the circuit schematic diagram of the transmission gate unit provided by the present invention.

[0036] Figure 5 It is the schematic diagram of the circuit of another embodiment of the adaptive full-wave rectification circuit provided by the present invention.

[0037] Figure 6 This is the circuit waveform diagram of the adaptive full-wave rectifier circuit provided by the present invention. Specific embodiments

[0038] It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments may be combined with each other. The present invention will be described in detail below with reference to the drawings and in conjunction with the embodiments.

[0039] In order to enable those skilled in the art to better understand the solution of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0040] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and do not have to be used to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances, so as to implement the embodiments of the present invention described here. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units does not have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0041] In this embodiment, an adaptive full-wave rectifier circuit is provided. Figure 2 It is the structural block diagram of the adaptive full-wave rectifier circuit provided according to the embodiment of the present invention. As Figure 2 shown, it includes: a waveform preprocessing unit 100, a phase detection unit 200, a positive-phase waveform transmission unit 300, a negative-phase waveform transmission unit 400, and a phase conversion unit 500. The phase detection unit 200, the positive-phase waveform transmission unit 300, and the negative-phase waveform transmission unit 400 are all electrically connected to the waveform preprocessing unit 100, and the positive-phase waveform transmission unit 300 and the negative-phase waveform transmission unit 400 are also both electrically connected to the phase conversion unit 500;

[0042] The waveform preprocessing unit 100 is used to perform amplitude amplification processing on the AC input voltage waveform after superimposing a common-mode level to obtain a preprocessed voltage waveform, where the AC input voltage waveform at least includes a small-signal AC voltage waveform;

[0043] The phase detection unit 200 is configured to perform positive phase detection and negative phase detection on the preprocessed voltage waveform to obtain a positive phase waveform and a negative phase waveform;

[0044] The positive phase waveform transmission unit 300 is configured to transmit the positive phase waveform through a positive phase transmission channel;

[0045] The negative phase waveform transmission unit 400 is configured to transmit the negative phase waveform through a negative phase transmission channel;

[0046] The phase conversion unit 500 is configured to perform phase conversion on the negative phase waveform and output it together with the positive phase waveform to obtain a full-wave rectified output voltage waveform.

[0047] In an embodiment of the present invention, the waveform preprocessing unit 100 superimposes the AC input voltage waveform onto a common-mode level and performs amplitude amplification processing to obtain a preprocessed voltage waveform. For this preprocessed voltage waveform, the phase detection unit 200 performs positive phase detection to obtain a positive phase waveform and performs negative phase detection to obtain a negative phase waveform. The positive phase waveform transmission unit 300 can form a positive phase transmission channel to transmit the positive phase waveform, the negative phase waveform transmission unit 400 can form a negative phase transmission channel to transmit the negative phase waveform, and the phase conversion unit 500 can perform phase conversion on the negative phase waveform output by the negative phase waveform transmission unit 400 to become a positive phase waveform and output it together with the positive phase waveform output by the positive phase waveform transmission unit to obtain a full-wave rectified output voltage waveform.

[0048] It should be noted that the AC input voltage waveform in the embodiment of the present invention can specifically be a small-signal AC voltage waveform or a large-signal AC voltage waveform. It should be understood that the difference in the processing of the small-signal AC voltage waveform and the large-signal AC voltage waveform lies in the difference in the amplification ratio during amplitude amplification processing.

[0049] It should be understood that a small-signal AC voltage waveform generally refers to an AC voltage waveform whose amplitude does not cause a significant deviation in the operating point of a device or circuit, where the amplitude is usually in the millivolt (mV) or microvolt (μV) range, which is much smaller than the DC bias voltage (such as V in a transistor). be ).

[0050] Therefore, the adaptive full-wave rectifier circuit provided by the present invention, for the preprocessing of the AC input voltage waveform, can not only automatically convert the AC input voltage waveform into a voltage waveform with an amplified amplitude on the common-mode level, but also simultaneously convert the negative-phase voltage waveform into a positive-phase voltage waveform of the same magnitude. As a result, the adaptive full-wave rectifier circuit of the present invention can be applied to small-signal AC input voltage waveforms and large-signal AC input voltage waveforms. Moreover, the adaptive full-wave rectifier circuit provided by the present invention can very accurately perform full-wave rectification and amplification output on small-signal AC voltage waveforms. When performing full-wave rectification and amplification output on large-signal AC voltage waveforms, in addition to achieving accurate amplification output, compared with the existing rectifier bridge method, a smoother rectification output result can be obtained due to the absence of diode voltage drops.

[0051] As a specific implementation manner, as Figure 3 shown, the waveform preprocessing unit 100 includes a first-stage superposition amplification subunit 110 and a second-stage superposition amplification subunit 120. The input end of the first-stage superposition amplification subunit 110 is the input end Vac of the waveform preprocessing unit. The output end of the first-stage superposition amplification subunit 110 is connected to the input end of the second-stage superposition amplification subunit 120. The output end of the second-stage superposition amplification subunit 120 is the output end of the waveform preprocessing unit 100.

[0052] The first-stage superposition amplification subunit 110 is used to first superpose the AC input voltage waveform to a preset common-mode level and perform amplification processing according to a first preset amplification ratio to obtain an intermediate processed waveform.

[0053] The second-stage superposition amplification subunit 120 is used to secondarily superpose the intermediate processed waveform to the preset common-mode level and perform amplification processing on the amplitude of the intermediate processed waveform according to a second preset amplification ratio to obtain a preprocessed voltage waveform.

[0054] Specifically, the first-stage superposition amplification subunit 110 includes: a first capacitor C1, a first resistor R1, a second resistor R2, and a first amplifier AMP1. One end of the first capacitor C1 is the input end of the first-stage superposition amplification subunit 110. The other end of the first capacitor C1 is connected to one end of the first resistor R1. The other end of the first resistor R1 is connected to the inverting input end of the first amplifier AMP1. The non-inverting input end of the first amplifier AMP1 is used to input the preset common-mode level. The output end of the first amplifier AMP1 is the output end of the first-stage superposition amplification subunit 110. One end of the second resistor R2 is connected to the inverting input end of the first amplifier AMP1. The other end of the second resistor R2 is connected to the output end of the first amplifier AMP1.

[0055] The second-stage superposition amplification subunit 120 includes: a second capacitor C2, a third resistor R3, a fourth resistor R4, and a second amplifier AMP2. One end of the second capacitor C2 is connected to the output end of the first-stage superposition amplification subunit 110, and the other end of the second capacitor C2 is connected to the signal ground. One end of the third resistor R3 is connected to one end of the second capacitor C2, and the other end of the third resistor R3 is connected to the inverting input end of the second amplifier AMP2. The non-inverting input end of the second amplifier AMP2 is used to input a preset common-mode level. The output end of the second amplifier AMP2 is the output end of the second-stage superposition amplification subunit 120. One end of the fourth resistor R4 is connected to the inverting input end of the second amplifier AMP2, and the other end of the fourth resistor R4 is connected to the output end of the second amplifier AMP2;

[0056] The first preset amplification ratio m is the resistance ratio of the second resistor R2 to the first resistor R1, and the second preset amplification ratio n is the resistance ratio of the fourth resistor R4 to the third resistor R3.

[0057] In the embodiment of the present invention, the inverting input end of the first amplifier AMP1 in the waveform preprocessing unit 100 is coupled to the common connection end of the first resistor R1 and the second resistor R2, and its non-inverting input end is connected to the common-mode voltage Vcm; one end of the first capacitor C1 can be specifically connected to the small-signal AC voltage waveform input end, and the other end is connected to one end of the first resistor R1; one end of the second capacitor C2 is connected to the output end of the first amplifier AMP1, and the other end is connected to the ground wire; one end of the third resistor R3 is connected to the output end of the first amplifier AMP1, and the other end is connected to the inverting input end of the second amplifier AMP2; one end of the fourth resistor R4 is coupled to the common connection end of the inverting input end of the second amplifier AMP2 and the third resistor R3, and the other end is connected to the output end of the second amplifier AMP2; the non-inverting input end of the second amplifier AMP2 is connected to the common-mode voltage Vcm.

[0058] In the embodiment of the present invention, the first amplifier AMP1, the first resistor R1, and the second resistor R2 constitute a first-stage inverting proportional operation circuit, and its voltage amplification factor is ; the second amplifier AMP2, the third resistor R3, and the fourth resistor R4 constitute a second-stage inverting proportional operation circuit, and its voltage amplification factor is ; therefore, the amplification factor of the AC voltage signal output by the waveform preprocessing unit is .

[0059] It should be noted that the second capacitor C2 is connected to the output end of the first-stage inverting proportional operation circuit, and its purpose is to eliminate the internal self-excitation oscillation of the op-amp system.

[0060] As a specific implementation manner of the phase detection unit, as Figure 3 shown, the phase detection unit 200 includes: a voltage comparison sub-unit 210 and a buffer sub-unit 220. The input end of the voltage comparison sub-unit 210 is connected to the output end of the waveform preprocessing unit 100. The output end of the voltage comparison sub-unit 210 is connected to the input end of the buffer sub-unit 220. The output end of the buffer sub-unit 220 is the output end of the phase detection unit 200;

[0061] The voltage comparison sub-unit 210 is configured to compare the preprocessed voltage waveform with a preset common-mode level to implement positive-phase detection and negative-phase detection of the preset processed voltage waveform;

[0062] The buffer sub-unit 220 is configured to perform enhancement processing on the results after positive-phase detection and the results after negative-phase detection to obtain a positive-phase waveform and a negative-phase waveform.

[0063] Specifically, as Figure 3 shown, the voltage comparison sub-unit 210 includes a voltage comparator COMP. The non-inverting input end of the voltage comparator COMP is the input end of the phase detection unit 200. The inverting input end of the voltage comparator COMP is used to input a preset common-mode level. The output end of the voltage comparator COMP is the output end of the voltage comparison sub-unit 210;

[0064] The buffer sub-unit 220 includes a first inverter INV1 and a second inverter INV2. The input end of the first inverter INV1 is the input end of the buffer sub-unit 220. The output end of the first inverter INV1 is connected to the input end of the second inverter INV2. The output end of the second inverter INV2 is the output end of the buffer sub-unit 220.

[0065] It should be understood that the non-inverting input end of the voltage comparator COMP in the phase detection unit is connected to the output end of the second amplifier AMP2, and its inverting input end is connected to the common-mode voltage Vcm; the input end of the first inverter INV1 is connected to the output end of the voltage comparator COMP, and its output end is connected to the input end of the second inverter INV2. The first inverter INV1 and the second inverter INV2 together form a digital buffer, and the purpose is to enhance the driving ability of the output signal.

[0066] In the embodiment of the present invention, as Figure 3As shown, the positive-phase waveform transmission unit 300 includes: a first transmission gate unit TG1 and a second transmission gate unit TG2. The input end of the first transmission gate unit TG1 is used to connect to a preset common-mode level. After the control ends of the first transmission gate unit TG2 and the second transmission gate unit TG2 are connected, they serve as the input end of the positive-phase waveform transmission unit 300 and are connected to the output end of the phase detection unit 200. After the output ends of the first transmission gate unit TG1 and the second transmission gate unit TG2 are connected, they serve as the output end of the positive-phase waveform transmission unit 300;

[0067] The negative-phase waveform transmission unit 400 includes: a third transmission gate unit TG3 and a fourth transmission gate unit TG4. The input end of the third transmission gate unit TG3 is connected to the input end of the second transmission gate unit TG2 and then connected to the output end of the waveform preprocessing unit 100. After the control ends of the third transmission gate unit TG3 and the fourth transmission gate unit TG4 are connected, they serve as the input end of the negative-phase waveform transmission unit 400 and are connected to the output end of the phase detection unit 200. After the output ends of the third transmission gate unit TG3 and the fourth transmission gate unit TG4 are connected, they serve as the output end of the negative-phase waveform transmission unit 400.

[0068] Further specifically, as Figure 4 shown, the first transmission gate unit TG1, the second transmission gate unit TG2, the third transmission gate unit TG3, and the fourth transmission gate unit TG4 all include: a first PMOS transistor and a first NMOS transistor connected. The gate ends of the first PMOS transistor and the first NMOS transistor both form the control end of the transmission gate unit. After the source ends of the first PMOS transistor and the first NMOS transistor are connected, they form the input end of the transmission gate unit. After the drain ends of the first PMOS transistor and the first NMOS transistor are connected, they form the output end of the transmission gate unit.

[0069] It should be understood that, as Figure 3 shown, the input end of the first transmission gate unit TG1 in the positive-phase waveform transmission unit 300 is connected to the common-mode voltage Vcm, and its output end is connected to the non-inverting input end of the third amplifier AMP3; the input end of the second transmission gate unit TG2 is connected to the output end of the second amplifier AMP2, and its output end is connected to the non-inverting input end of the third amplifier AMP3; the input end of the third transmission gate unit TG3 in the negative-phase waveform transmission unit 400 is connected to the output end of the second amplifier AMP2, and its output end is connected to the non-inverting input end of the fourth amplifier AMP4; the input end of the fourth transmission gate unit TG4 is connected to the common-mode voltage Vcm, and its output end is connected to the non-inverting input end of the fourth amplifier AMP4.

[0070] Among them, the specific structure of the transmission gate unit in the embodiment of the present invention is as follows Figure 4 shown. Inside the first transmission gate unit TG1 to the fourth transmission gate unit TG4, they can all be composed of connecting the source and drain ends of NMOS transistors and PMOS transistors respectively.

[0071] In the embodiment of the present invention, as Figure 3 shown, the phase conversion unit 500 includes: a third amplifier AMP3, a fourth amplifier AMP4, an equal-ratio current mirror structure, a fifth resistor R5, and a sixth resistor R6. The non-inverting input terminal of the third amplifier AMP3 is connected to the output terminal of the positive-phase waveform transmission unit 300. The inverting input terminal of the third amplifier AMP3 is connected to one end of the fifth resistor R5. The output terminal of the third amplifier AMP3 is connected to the control terminal of the equal-ratio current mirror structure. The first end of the equal-ratio current mirror structure is connected to the power supply Vcc. The second end of the equal-ratio current mirror structure is respectively connected to one end of the fifth resistor R5 and one end of the sixth resistor R6. The non-inverting input terminal of the fourth amplifier AMP4 is connected to the output terminal of the negative-phase waveform transmission unit 400. The inverting input terminal of the fourth amplifier AMP4 is connected to the other end of the fifth resistor R5. The other end of the sixth resistor R6 is connected to the signal ground. One end of the sixth resistor R6 is the output terminal of the phase conversion unit 500;

[0072] When the positive-phase waveform transmission unit 300 outputs a positive-phase waveform or the negative-phase waveform transmission unit 400 outputs a negative-phase waveform, the current direction of the fifth resistor R5 is from one end of the fifth resistor R5 to the other end of the fifth resistor R5. The current direction and magnitude in the equal-ratio current mirror structure are the same as those of the fifth resistor R5, so that the voltage waveform formed by the sixth resistor R6 is a positive-phase waveform.

[0073] It should be noted that the equal-ratio current mirror structure in the embodiment of the present invention can specifically be composed of two P-type MOS transistors. It should be understood that two PNP transistors can also be used to implement it. Specifically, the embodiment of the present invention does not make any limitations and can be selected according to needs.

[0074] In an embodiment of the present invention, a proportional current mirror structure composed of two P-type MOS transistors (i.e., the first transistor PM1 and the second transistor PM2) is taken as an example for illustration. The control end of the first transistor PM1 in the phase conversion unit 500 is connected to the output end of the third amplifier AMP3, the power supply end of the first transistor PM1 is connected to the power supply Vcc, and the output end of the first transistor PM1 is connected to the upper end of the fifth resistor R5; the control end of the second transistor PM2 is connected to the output end of the third amplifier AMP3, the power supply end of the second transistor PM2 is connected to the power supply Vcc, and the output end of the second transistor PM2 is connected to the upper end of the sixth resistor R6, and the lower end of the sixth resistor R6 is connected to the signal ground.

[0075] In an embodiment of the present invention, the inverting input end of the third amplifier AMP3 in the phase conversion unit 500 is connected to the upper end of the fifth resistor R5; the inverting input end of the fourth amplifier AMP4 is connected to its own output end and is simultaneously coupled to the lower end of the fifth resistor R5.

[0076] It should be noted that when the AC voltage waveform is a positive-phase waveform, the voltage value of the voltage waveform is greater than the Vcm voltage value at this time, and the phase detection unit 200 will control the second transmission gate unit TG2 and the fourth transmission gate unit TG4 to conduct. The voltage difference across the fifth resistor R5 is the positive-phase waveform voltage minus the Vcm voltage; when the AC voltage waveform is a negative-phase waveform, the voltage value of the voltage waveform is less than the Vcm voltage value at this time, and the phase detection unit 200 will control the first transmission gate unit TG1 and the third transmission gate unit TG3 to conduct. The voltage difference across the fifth resistor R5 is the Vcm voltage minus the negative-phase waveform voltage. In both cases, the current flowing through the fifth resistor R5 is in the same direction from top to bottom. At the same time, the fifth resistor R5 and the first transistor PM1 are in a series relationship. Therefore, the current direction of the first transistor PM1 is from the power supply Vcc through the drain-source of the first transistor PM1 and then to the fifth resistor R5. At the same time, because the second transistor PM2 and the first transistor PM1 are in a proportional mirror current source relationship, that is, the current magnitude and direction of the second transistor PM2 and the first transistor PM1 are exactly the same. Therefore, the current flowing out of the second transistor PM2 forms the final voltage waveform Vout through the sixth resistor R6, which is a positive-phase waveform.

[0077] In an embodiment of the present invention, the resistance values of the fifth resistor R5 and the sixth resistor R6 in the phase conversion unit 500 are in a proportional relationship, and the proportionality coefficient is k.

[0078] Based on this, the fifth resistor R5 in the phase conversion unit converts the input positive and negative phase voltage waveforms into corresponding current waveforms, and the sixth resistor R6 converts the current waveforms into voltage waveforms. At the same time, the phase conversion unit further amplifies the amplitudes of the input positive and negative phase voltage waveforms to .

[0079] Therefore, the final amplification multiple of the amplitude of the AC input voltage waveform is , so the required amplification multiple of the rectified waveform can be set by adjusting the values of m, n, and k.

[0080] It should be noted that in order to obtain the common-mode level, as Figure 5 shown, the embodiment of the present invention further includes: a common-mode level acquisition unit 600, and the common-mode level acquisition unit 600 is used to obtain the common-mode level after voltage division and filtering according to the power supply.

[0081] Specifically, the common-mode level acquisition unit 600 includes a seventh resistor R7, an eighth resistor R8, and a third capacitor C3. The seventh resistor R7, the eighth resistor R8, and the third capacitor C3 perform voltage division and filtering on the power supply Vcc. Since R7 = R8 = R, the voltage of the center tap line between R7 and R8 is , and this tap line is connected to the common-mode voltage Vcm terminal, that is: .

[0082] In summary, for the adaptive full-wave rectifier circuit provided by the embodiment of the present invention, even if the AC input voltage waveform is a small-signal AC voltage, only by connecting the output terminal of the small-signal AC voltage to the signal input port of the first capacitor C1, the AC voltage waveform Vac will be automatically filtered and amplified and then input into the phase detection unit for logical judgment. Then, the corresponding positive and negative phase waveform transmission unit channels are opened, the positive phase waveform is input to the input terminal of the high-side amplifier, and the negative phase waveform is input to the input terminal of the low-side amplifier. Finally, the negative phase waveform is converted into a positive phase waveform of the same size through the phase conversion unit to achieve the effect of full-wave rectification, and the final voltage amplification multiple of the waveform is Gv = m * n * k. Therefore, the adaptive full-wave rectifier circuit provided by the present invention can not only very accurately perform full-wave rectification and amplification output on the small-signal AC voltage waveform, but also has the characteristics of stable performance, simple structure, and strong operability.

[0083] Next, a detailed description will be given in conjunction with Figure 5 the specific application schematic diagram of the adaptive full-wave rectifier circuit shown.

[0084] The adaptive full-wave rectifier circuit of the embodiment of the present invention is applied in a small-signal AC voltage full-wave rectifier device, and its purpose is to perform full-wave rectification and amplification output on the AC voltage signal Vac.

[0085] In this embodiment, the voltage of Vcc is divided and filtered by resistors R7, R8 and capacitor C3. Since R7 = R8 = R, the voltage of the center tap line between R7 and R8 is , and this tap line is connected to the common-mode voltage Vcm terminal, that is: .

[0086] In this embodiment, since the amplitude of the AC voltage Vac signal is small, it is necessary to amplify the waveform amplitude, then judge the positive and negative phases of the waveform, and finally perform phase conversion. Its waveform diagram is as Figure 6 shown, where Vac is the waveform of the input AC voltage signal, Vac1 is the waveform of the amplified voltage signal, and Vout is the waveform of the voltage signal after full-wave rectification.

[0087] First, connect the output terminal of the small-signal AC voltage Vac to the signal input port of the first capacitor C1, couple and input Vac to the input terminal of the amplifier. The waveform preprocessing unit in the adaptive full-wave rectification circuit will automatically convert the small-signal AC voltage Vac into a voltage waveform Vac1 with an amplified amplitude on the common-mode level, and its phase remains unchanged. The amplification factor of the amplified voltage waveform Vac1 is .

[0088] The amplified AC voltage waveform Vac1 is input to the phase detection unit for logical comparison and judgment, and then corresponding channel control signals are sent out; when Vac1 is greater than Vcm, it is determined as a positive-phase waveform, and the phase detection unit will control the second transmission gate unit TG2 and the fourth transmission gate unit TG4 to conduct; when Vac1 is less than Vcm, it is determined as a negative-phase waveform, and the phase detection unit will control the first transmission gate unit TG1 and the third transmission gate unit TG3 to conduct.

[0089] The third amplifier AMP3 in the phase conversion unit and the first transistor PM1 together form a voltage follower, following the voltage at the non-inverting input terminal of the third amplifier AMP3 to the upper end of the fifth resistor R5; the inverting input terminal of the fourth amplifier AMP4 is connected to its own output terminal, also forming a voltage follower, following the voltage at the non-inverting input terminal of the fourth amplifier AMP4 to the lower end of the fifth resistor R5.

[0090] Therefore, when the AC voltage waveform is a positive-phase waveform, the phase detection unit will control the second transmission gate unit TG2 and the fourth transmission gate unit TG4 to conduct. At this time, the voltage difference across the fifth resistor R5 is the positive-phase waveform voltage minus the Vcm voltage, and the current flowing through the fifth resistor R5 is from top to bottom; when the AC voltage waveform is a negative-phase waveform, the phase detection unit will control the first transmission gate unit TG1 and the third transmission gate unit TG3 to conduct. At this time, the voltage difference across the fifth resistor R5 is the Vcm voltage minus the negative-phase waveform voltage. Therefore, the current in the fifth resistor R5 is still in the same direction from top to bottom.

[0091] Since the fifth resistor R5 is in series with the first transistor PM1, the magnitude and direction of the current in the first transistor PM1 are the same as those in the fifth resistor R5. At the same time, since the second transistor PM2 and the first transistor PM1 are in an equal-proportion mirror current source relationship, that is, the magnitude and direction of the current in the second transistor PM2 are exactly the same as those in the first transistor PM1. Therefore, the current flowing out of the second transistor PM2 forms the final voltage waveform Vout through the sixth resistor R6, which is all positive-phase waveforms. Thus, this circuit perfectly realizes the function of full-wave rectifying and amplifying the small-signal voltage waveform Vac for output.

[0092] In summary, for the adaptive full-wave rectifying circuit provided by the present invention, first, the input small-signal AC voltage Vac waveform is filtered and amplified to obtain an AC voltage waveform Vac1 with a larger voltage amplitude and the same phase. Then Vac1 is input into the phase detection unit for comparison and judgment processing, and then the corresponding positive and negative phase waveform output unit channels are opened. The positive-phase waveform is input into the input terminal of the high-side amplifier AMP3, and the negative-phase waveform is input into the input terminal of the low-side amplifier AMP4. Finally, the negative-phase waveform is converted into the positive-phase waveform Vout through the phase conversion unit, achieving the effect of full-wave rectification. And the final voltage amplification factor of this waveform is , so the adaptive full-wave rectifying circuit provided by the present invention can not only very accurately perform full-wave rectifying and amplifying output on the weak voltage waveform, but also has the characteristics of stable performance, simple structure, and strong operability.

[0093] As another embodiment of the present invention, a leakage protection device is provided, which includes the adaptive full-wave rectifying circuit described above.

[0094] It should be understood that in the leakage protection device, since the leakage signal of the leakage protector collected is an AC small signal, it can be subjected to full-wave rectifying processing through the adaptive full-wave rectifying circuit.

[0095] The leakage protection device provided by the present invention, due to the adaptive full-wave rectifier circuit described above, can achieve full-wave rectification and amplification output of the leakage signal, so as to obtain an accurate leakage signal, and further enable the leakage protection device to accurately implement the leakage protection function.

[0096] It can be understood that the above embodiments are merely exemplary embodiments adopted to illustrate the principle of the present invention, but the present invention is not limited thereto. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also regarded as the protection scope of the present invention.

Claims

1. An adaptive full-wave rectifier circuit, characterized in that: include: A waveform preprocessing unit, a phase detection unit, a positive phase waveform transmission unit, a negative phase waveform transmission unit and a phase conversion unit, wherein the phase detection unit, the positive phase waveform transmission unit and the negative phase waveform transmission unit are all electrically connected to the waveform preprocessing unit, and the positive phase waveform transmission unit and the negative phase waveform transmission unit are also electrically connected to the phase conversion unit; The waveform preprocessing unit is used to perform amplitude amplification processing on the AC input voltage waveform after superimposing the common mode level to obtain a preprocessed voltage waveform, wherein the AC input voltage waveform at least includes a small signal AC voltage waveform; The phase detection unit is used to perform positive phase detection and negative phase detection on the preprocessed voltage waveform to obtain a positive phase waveform and a negative phase waveform; The positive phase waveform transmission unit is used to transmit the positive phase waveform through the positive phase transmission channel; The negative phase waveform transmission unit is used to transmit the negative phase waveform through the negative phase transmission channel; The phase conversion unit is used to perform phase conversion on the negative phase waveform and output it together with the positive phase waveform to obtain a full-wave rectified output voltage waveform; Wherein, the phase detection unit comprises: a voltage comparison subunit and a buffer subunit, the input end of the voltage comparison subunit is connected to the output end of the waveform preprocessing unit, the output end of the voltage comparison subunit is connected to the input end of the buffer subunit, and the output end of the buffer subunit is the output end of the phase detection unit; The voltage comparison subunit is used to compare the pre-processed voltage waveform with a preset common mode level to achieve positive phase detection and negative phase detection of the preset processed voltage waveform; The buffer subunit is used to enhance the result after the positive phase detection and the result after the negative phase detection to obtain a positive phase waveform and a negative phase waveform.

2. The adaptive full-wave rectifier circuit according to claim 1, characterized in that: The waveform preprocessing unit comprises a first-stage superposition and amplification subunit and a second-stage superposition and amplification subunit, the input end of the first-stage superposition and amplification subunit is the input end of the waveform preprocessing unit, the output end of the first-stage superposition and amplification subunit is connected to the input end of the second-stage superposition and amplification subunit, and the output end of the second-stage superposition and amplification subunit is the output end of the waveform preprocessing unit; The first-stage superposition and amplification subunit is used to superimpose the AC input voltage waveform to a preset common mode level for the first time and perform amplification processing according to a first preset amplification ratio to obtain an intermediate processing waveform; The second-stage superposition and amplification subunit is used to superimpose the intermediate processing waveform to a preset common mode level for a second time and amplify the amplitude of the intermediate processing waveform according to a second preset amplification ratio to obtain a preprocessed voltage waveform.

3. The adaptive full-wave rectifier circuit according to claim 2, characterized in that: The first-stage superposition amplification subunit includes: a first capacitor, a first resistor, a second resistor and a first amplifier, one end of the first capacitor is the input end of the first-stage superposition amplification subunit, the other end of the first capacitor is connected to one end of the first resistor, the other end of the first resistor is connected to the inverting input end of the first amplifier, the in-phase input end of the first amplifier is used to input a preset common mode level, the output end of the first amplifier is the output end of the first-stage superposition amplification subunit, one end of the second resistor is connected to the inverting input end of the first amplifier, and the other end of the second resistor is connected to the output end of the first amplifier; The second-stage superposition amplification subunit includes: a second capacitor, a third resistor, a fourth resistor and a second amplifier, one end of the second capacitor is connected to the output end of the first-stage superposition amplification subunit, the other end of the second capacitor is connected to the signal ground, one end of the third resistor is connected to one end of the second capacitor, the other end of the third resistor is connected to the inverting input end of the second amplifier, the in-phase input end of the second amplifier is used to input a preset common mode level, the output end of the second amplifier is the output end of the second-stage superposition amplification subunit, one end of the fourth resistor is connected to the inverting input end of the second amplifier, and the other end of the fourth resistor is connected to the output end of the second amplifier; The first preset amplification ratio is a resistance ratio of the second resistor to the first resistor, and the second preset amplification ratio is a resistance ratio of the fourth resistor to the third resistor.

4. The adaptive full-wave rectifier circuit according to claim 1, characterized in that: The voltage comparison subunit comprises a voltage comparator, a non-phase input terminal of the voltage comparator is an input terminal of the phase detection unit, an inverting input terminal of the voltage comparator is used to input a preset common mode level, and an output terminal of the voltage comparator is an output terminal of the voltage comparison subunit; The buffer subunit includes a first inverter and a second inverter, the input end of the first inverter is the input end of the buffer subunit, the output end of the first inverter is connected to the input end of the second inverter, and the output end of the second inverter is the output end of the buffer subunit.

5. The adaptive full-wave rectifier circuit according to claim 1, characterized in that: The positive phase waveform transmission unit comprises: a first transmission gate unit and a second transmission gate unit, the input end of the first transmission gate unit is used to connect a preset common mode level, the control end of the first transmission gate unit is connected with the control end of the second transmission gate unit and then serves as the input end of the positive phase waveform transmission unit to connect the output end of the phase detection unit, and the output end of the first transmission gate unit is connected with the output end of the second transmission gate unit and then serves as the output end of the positive phase waveform transmission unit; The negative phase waveform transmission unit includes: a third transmission gate unit and a fourth transmission gate unit, the input end of the third transmission gate unit is connected to the input end of the second transmission gate unit and then connected to the output end of the waveform preprocessing unit, the control end of the third transmission gate unit is connected to the control end of the fourth transmission gate unit and then serves as the input end of the negative phase waveform transmission unit connected to the output end of the phase detection unit, and the output end of the third transmission gate unit is connected to the output end of the fourth transmission gate unit and then serves as the output end of the negative phase waveform transmission unit.

6. The adaptive full-wave rectifier circuit according to claim 5, characterized in that: The first transmission gate unit, the second transmission gate unit, the third transmission gate unit and the fourth transmission gate unit all include: a first PMOS transistor and a first NMOS transistor are connected, the gate end of the first PMOS transistor and the gate end of the first NMOS transistor are both formed as the control end of the transmission gate unit, the source end of the first PMOS transistor is connected to the source end of the first NMOS transistor to form the input end of the transmission gate unit, and the drain end of the first PMOS transistor is connected to the drain end of the first NMOS transistor to form the output end of the transmission gate unit.

7. The adaptive full-wave rectifier circuit according to claim 1, characterized in that: The phase conversion unit includes: a third amplifier, a fourth amplifier, a proportional current mirror structure, a fifth resistor and a sixth resistor, the in-phase input terminal of the third amplifier is connected to the output terminal of the positive phase waveform transmission unit, the inverting input terminal of the third amplifier is connected to one end of the fifth resistor, the output terminal of the third amplifier is connected to the control terminal of the proportional current mirror structure, the first end of the proportional current mirror structure is connected to the power supply, the second end of the proportional current mirror structure is respectively connected to one end of the fifth resistor and one end of the sixth resistor, the in-phase input terminal of the fourth amplifier is connected to the output terminal of the negative phase waveform transmission unit, the inverting input terminal of the fourth amplifier is connected to the other end of the fifth resistor, the other end of the sixth resistor is connected to the signal ground, and one end of the sixth resistor is the output terminal of the phase conversion unit; When the output end of the positive phase waveform transmission unit outputs a positive phase waveform or the output end of the negative phase waveform transmission unit outputs a negative phase waveform, the current direction of the fifth resistor is from one end of the fifth resistor to the other end of the fifth resistor, and the current direction and current magnitude in the proportional current mirror structure are the same as those of the fifth resistor, so that the voltage waveform formed by the sixth resistor is a positive phase waveform.

8. The adaptive full-wave rectifier circuit according to claim 1, characterized in that: Also includes: A common mode level acquisition unit is used to obtain a common mode level after voltage division and filtering according to a power supply.

9. A leakage protection device, characterized in that: The adaptive full-wave rectifier circuit comprises the adaptive full-wave rectifier circuit as described in any one of claims 1 to 9.

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