Differential amplifier, operational amplifier circuit, and electronic device

Abstract

The invention discloses a differential amplifier, an operational amplification circuit and electronic equipment, and belongs to the technical field of amplification circuits. The differential amplifier comprises a differential input module, a load module and an isolation module. The differential input module is configured with a first bias current and comprises a first input end, a second input end, a first amplification node and a second amplification node, the first input end is configured with an input signal, and the second input end is configured with a differential mode signal of the input signal; the load module comprises a first connection node and a second connection node, the first connection node is connected with the first amplification node, and the second connection node serves as the output end of the differential amplifier; the isolation module is connected with the second amplification node and the second connection node, and the control end of the isolation module is connected with the first connection node; wherein the voltage variation of the first connection node is in negative correlation with the conduction degree of the isolation module. The embodiment of the invention can improve the amplification factor of the circuit.

Description

Technical Field

[0001] The present invention relates to the technical field of amplifier circuits, and in particular to a differential amplifier, an operational amplifier circuit, and electronic equipment. Background Art

[0002] At present, due to the Kink effect of transistors in the amplifier circuit, when the source-drain voltage difference (denoted as Vds) of the transistor is too large, the saturation region operating current of the transistor will increase significantly with the increase of Vds. When the transistor works in the saturation region, the equivalent resistance is small, resulting in a lower amplification factor of the amplifier circuit. Summary of the invention

[0003] The invention provides a differential amplifier, an operational amplifier circuit and an electronic device to improve the circuit amplification factor.

[0004] In a first aspect, an embodiment of the present invention provides a differential amplifier, comprising:

[0005] A differential input module, wherein the differential input module is configured with a first bias current, comprises a first input terminal, a second input terminal, a first amplification node and a second amplification node, wherein the first input terminal is configured with an input signal, the second input terminal is configured with a differential signal of the input signal, the first amplification node is used to output an inverted amplified signal of the input signal, and the second amplification node is used to output a non-inverted amplified signal of the input signal;

[0006] A load module, comprising a first connection node and a second connection node, wherein the first connection node is connected to the first amplification node, and the second connection node serves as an output end of the differential amplifier;

[0007] an isolation module, connected to the second amplification node and the second connection node respectively, and a control end of the isolation module is connected to the first connection node;

[0008] The voltage variation of the first connection node is negatively correlated with the conduction degree of the isolation module.

[0009] Optionally, the differential amplifier further includes: a voltage stabilizing module, connected to the first amplifying node and the first connecting node respectively; the voltage stabilizing module is used to stabilize the voltage of the first amplifying node.

[0010] Optionally, the voltage stabilizing module comprises: at least one first transistor in a diode-connected form;

[0011] Preferably, the voltage stabilizing module includes a plurality of the first transistors in a diode-connected form, and the plurality of the first transistors are connected in series between the first amplifying node and the first connecting node.

[0012] Optionally, a first electrode of the first transistor is connected to the first amplification node, and a second electrode of the first transistor is connected to the first connection node;

[0013] The first transistor is a P-type transistor, and the gate of the first transistor is connected to the second electrode of the first transistor; or the first transistor is an N-type transistor, and the gate of the first transistor is connected to the first electrode of the first transistor.

[0014] Optionally, the isolation module includes: a second transistor connected between the second amplification node and the second connection node, and a gate of the second transistor is connected to the first connection node;

[0015] Preferably, the load module comprises: a third transistor and a fourth transistor; a first electrode of the third transistor is connected to the first connection node, a second electrode of the third transistor is configured with a first power supply signal, a gate of the third transistor is respectively connected to the first electrode of the third transistor and the gate of the fourth transistor, a first electrode of the fourth transistor is connected to the second connection node, and a second electrode of the fourth transistor is configured with the first power supply signal;

[0016] The third transistor and the fourth transistor have the same channel type, and the fourth transistor and the second transistor have different channel types;

[0017] Preferably, the third transistor and the fourth transistor are both N-type transistors, and the second transistor is a P-type transistor.

[0018] Optionally, the differential input module includes: a fifth transistor and a sixth transistor; a first electrode of the fifth transistor and a first electrode of the sixth transistor are both configured with the first bias current, a gate of the fifth transistor is connected to the first input terminal, a second electrode of the fifth transistor is connected to the first amplification node, a gate of the sixth transistor is connected to the second input terminal, and a second electrode of the sixth transistor is connected to the second amplification node;

[0019] And / or, the load module includes: a third transistor and a fourth transistor; a first electrode of the third transistor is connected to the first connection node, a second electrode of the third transistor is configured with a first power supply signal, a gate of the third transistor is respectively connected to the first electrode of the third transistor and the gate of the fourth transistor, a first electrode of the fourth transistor is connected to the second connection node, and a second electrode of the fourth transistor is configured with the first power supply signal;

[0020] Preferably, the channel width-to-length ratio of the fifth transistor is the same as that of the sixth transistor.

[0021] Optionally, the differential input module, the load module and the isolation module are all composed of thin film transistors;

[0022] Preferably, the differential amplifier further includes a voltage stabilizing module, and the voltage stabilizing module is composed of a thin film transistor.

[0023] In a second aspect, an embodiment of the present invention further provides an operational amplifier circuit, comprising:

[0024] Differential amplifier;

[0025] An output module, comprising a first control node and a third amplification node; the first control node is connected to the output end of the differential amplifier, and the third amplification node is used to output an inverted amplified signal of a signal at the output end of the differential amplifier;

[0026] A voltage control module comprises a second control node, an input node and an output node; the second control node is configured with a fixed voltage signal, the input node is connected to the third amplification node, the output node is configured with a second bias current, and the output node serves as the output end of the operational amplifier circuit; the voltage control module is controlled by the fixed voltage signal to stably output the voltage of the third amplification node at the output node.

[0027] Optionally, the voltage control module includes: an eighth transistor; a first electrode of the eighth transistor is connected to the output end of the operational amplifier circuit, and a second electrode of the eighth transistor is connected to the third amplification node; and a gate of the eighth transistor is configured with the fixed voltage signal.

[0028] Optionally, the output module comprises: a ninth transistor; a gate of the ninth transistor is connected to the output end of the differential amplifier, a first electrode of the ninth transistor is connected to the third amplification node, and a second electrode of the ninth transistor is configured with a first power supply signal;

[0029] Wherein, the channel type of the ninth transistor is the same as that of the eighth transistor;

[0030] Preferably, the ninth transistor and the eighth transistor are both N-type transistors;

[0031] Preferably, the voltage of the fixed voltage signal is higher than the voltage of the control node.

[0032] Optionally, the differential amplifier is configured with a first bias current;

[0033] The operational amplifier circuit further includes: a bias module, including a first bias output node and a second bias output node; the first bias output node is used to output the first bias current, and the second bias output node is used to output the second bias current.

[0034] Optionally, the bias module includes: a first current source and a second current source, wherein the output end of the first current source is connected to the first bias output node, and the output end of the second current source is connected to the second bias output node;

[0035] Preferably, the first current source comprises: a seventh transistor, a gate of the seventh transistor is configured with a bias voltage, a first electrode of the seventh transistor is configured with a second power supply signal, and a second electrode of the seventh transistor is connected to an output end of the first current source;

[0036] And / or, the second current source includes: a tenth transistor, a gate of the tenth transistor is configured with a bias voltage, a first electrode of the tenth transistor is configured with a second power supply signal, and a second electrode of the tenth transistor is connected to an output end of the second current source.

[0037] Optionally, the operational amplifier circuit further includes: a storage module connected between the output end of the differential amplifier and the output end of the operational amplifier circuit;

[0038] Preferably, the storage module comprises: a capacitor connected between the output end of the differential amplifier and the output end of the operational amplifier circuit.

[0039] Optionally, the differential amplifier comprises:

[0040] A differential input module, wherein the differential input module is configured with a first bias current, and comprises a first input terminal, a second input terminal, a first amplification node, and a second amplification node; the first input terminal is configured with an input signal, and the second input terminal is configured with a differential signal of the input signal; the first amplification node is used to output an inverted amplified signal of the input signal, and the second amplification node is used to output a non-inverted amplified signal of the input signal;

[0041] A load module, the load module comprising a first connection node and a second connection node, the first connection node is connected to the first amplification node, the second connection node is connected to the second amplification node; the second connection node serves as an output end of the differential amplifier;

[0042] Preferably, the voltage of the fixed voltage signal is different from the voltage of the output terminal of the differential amplifier.

[0043] Optionally, the differential amplifier is the differential amplifier provided in the first aspect of the present invention.

[0044] Optionally, the second amplification node provides the fixed voltage signal, and the second control node is connected to the second amplification node;

[0045] Alternatively, the differential amplifier includes the voltage stabilizing module provided by the first aspect of the present invention, the first amplifying node provides the fixed voltage signal, and the second control node is connected to the first amplifying node;

[0046] Alternatively, the differential amplifier comprises a voltage stabilizing module as provided in the first aspect of the present invention, the voltage stabilizing module comprises at least two first transistors connected in series in a diode-connected form, a connection node between any two adjacent first transistors provides the fixed voltage signal, and the second control node is connected to the connection node;

[0047] Alternatively, the second control node is connected to a fixed voltage signal line, the fixed voltage signal line is used to transmit the fixed voltage signal, and the voltage of the fixed voltage signal is different from the voltage of the output end of the differential amplifier.

[0048] Optionally, the differential amplifier, the output module and the voltage control module are all composed of thin film transistors;

[0049] Preferably, the operational amplifier circuit further includes a bias module, and the bias module is composed of a thin film transistor.

[0050] In a third aspect, an embodiment of the present invention further provides an electronic device, comprising: an amplifier circuit; the amplifier circuit comprises the differential amplifier provided by any embodiment of the present invention, or the amplifier circuit comprises the operational amplifier circuit provided by any embodiment of the present invention.

[0051] Optionally, the electronic device is: a radio frequency identification device, a music player or a display device;

[0052] Preferably, the electronic device is a flexible electronic device.

[0053] Optionally, the electronic device is a display device; the display device comprises: a driving chip, a plurality of data lines and a plurality of the amplifying circuits, and the driving chip transmits a data signal to each of the data lines through each of the amplifying circuits.

[0054] In the differential amplifier provided by the embodiment of the present invention, a differential input module, a load module and an isolation module are provided. The differential input module and the load module constitute a basic amplification circuit structure, and the first bias current is equivalent to a stable bias signal provided to the differential input module; the isolation module can be used to control the degree of isolation between the second amplification node and the second connection node, and by setting the voltage change of the first connection node to be negatively correlated with the conduction degree of the isolation module, the second connection node has a larger voltage change range following the voltage difference between the first input terminal and the second input terminal, thereby improving the amplification factor of the differential structure amplifier circuit, that is, improving the amplification factor of the differential amplifier.

[0055] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0057] Figure 1 is a structural schematic diagram of a differential amplifier provided by an embodiment of the present invention;

[0058] Figure 2 is a schematic structural diagram of another differential amplifier provided by an embodiment of the present invention;

[0059] Figure 3 is a structural schematic diagram of another differential amplifier provided by an embodiment of the present invention;

[0060] Figure 4 is a structural schematic diagram of another differential amplifier provided by an embodiment of the present invention;

[0061] Figure 5 is a structural schematic diagram of another differential amplifier provided by an embodiment of the present invention;

[0062] Figure 6 is a schematic structural diagram of an operational amplifier circuit provided by an embodiment of the present invention;

[0063] Figure 7 is a schematic structural diagram of another operational amplifier circuit provided by an embodiment of the present invention;

[0064] Figure 8 is a structural schematic diagram of another operational amplifier circuit provided by an embodiment of the present invention;

[0065] Fig. 9 is a structural schematic diagram of another operational amplifier circuit provided by an embodiment of the present invention;

[0066] Fig.10 is a structural schematic diagram of another operational amplifier circuit provided by an embodiment of the present invention;

[0067] Fig.11 is a structural schematic diagram of another operational amplifier circuit provided by an embodiment of the present invention;

[0068] Fig.12is a structural schematic diagram of another operational amplifier circuit provided by an embodiment of the present invention;

[0069] Fig.13 is a structural schematic diagram of another operational amplifier circuit provided by an embodiment of the present invention;

[0070] Fig.14 is a structural schematic diagram of another operational amplifier circuit provided by an embodiment of the present invention;

[0071] Fig.15 is a structural schematic diagram of another operational amplifier circuit provided by an embodiment of the present invention;

[0072] Fig.16 is a structural schematic diagram of another operational amplifier circuit provided by an embodiment of the present invention;

[0073] Fig.17 is a structural schematic diagram of another operational amplifier circuit provided by an embodiment of the present invention;

[0074] Fig.18 is a key node voltage characteristic curve diagram of an operational amplifier circuit provided by an embodiment of the present invention;

[0075] Fig.19 is a graph showing a key node voltage characteristic curve of another operational amplifier circuit provided by an embodiment of the present invention;

[0076] Fig. 20 is a key node voltage characteristic curve diagram of another operational amplifier circuit provided by an embodiment of the present invention;

[0077] Fig.21 is a comparison diagram of key node voltage characteristic curves of the operational amplifier circuit provided by the embodiment of the present invention and the comparative example;

[0078] Fig. 22 It is a structural schematic diagram of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0079] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0080] 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 are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions.

[0081] An embodiment of the present invention provides a differential amplifier. Figure 1 is a schematic diagram of the structure of a differential amplifier provided by an embodiment of the present invention. Figure 1 , the differential amplifier includes: a differential input module 210, a load module 220 and an isolation module 240. The differential input module 210 is configured with a first bias current I1. The differential input module 210 includes a first input terminal IN1, a second input terminal IN2, a first amplification node N1 and a second amplification node N2. The first input terminal IN1 is configured with an input signal, and the second input terminal IN2 is configured with a differential signal of the input signal. The first amplification node N1 is used to output an inverted amplified signal of the input signal, and the second amplification node N2 is used to output a non-inverted amplified signal of the input signal. The load module 220 includes a first connection node N3 and a second connection node N4. The first connection node N3 is connected to the first amplification node N1, and the second connection node N4 serves as the output terminal OUT of the differential amplifier. The isolation module 240 is connected to the second amplification node N2 and the second connection node N4 respectively. In other words, the isolation module 240 is connected between the second amplification node N2 and the second connection node N4; and the control end of the isolation module 240 is connected to the first connection node N3. The isolation module 240 controls the conduction degree of the isolation module 240 according to the voltage of the first connection node N3 , and the voltage variation of the first connection node N3 is negatively correlated with the conduction degree of the isolation module 240 .

[0082] The differential amplifier is an amplifier circuit using differential input. The differential input module 210 may include a bias node, and the bias node is connected to the first bias current I1. The power supply terminal of the load module 220 may be configured (or said) with a first power supply signal. The differential input module 210 and the load module 220 may be composed of transistors, for example, both are thin film transistors (TFT). The differential input module 210 may include two transistors respectively connected between the bias node and the first amplification node N1, and between the bias node and the second amplification node N2, respectively used to control the current output by the first amplification node N1 and the second amplification node N2 according to the signal connected to the first input terminal IN1 and the second input terminal IN2. The load module 220 may include two transistors respectively connected between the power supply terminal of the load module 220 and the first connection node N3, and between the power supply terminal of the load module 220 and the second connection node N4, which are equivalent to the load resistance between the power supply terminal of the load module 220 and the first connection node N3, and between the power supply terminal of the load module 220 and the second connection node N4.

[0083] Exemplarily, the working principle of the differential amplifier is as follows: as the voltage difference between the first input terminal IN1 and the second input terminal IN2 increases, the current output by the first amplification node N1 and the second amplification node N2 changes in opposite directions, for example, one increases and the other decreases, and the current change gradually increases; in this process, in conjunction with the action of the load module 220, the voltage of the first connection node N3 and the second connection node N4 changes in opposite directions, and the voltage change gradually increases. The voltage of the second connection node N4 of the load module 220 is used as the output voltage of the output terminal OUT of the differential amplifier.

[0084] Further, by setting the isolation module 240, the second amplification node N2 and the second connection node N4 can be separated. The degree of conduction of the isolation module 240 determines the degree of isolation between the second amplification node N2 and the second connection node N4; the higher the degree of conduction of the isolation module 240, the closer the voltage of the second connection node N4 is to the voltage of the second amplification node N2; the lower the degree of conduction of the isolation module 240, the less the voltage of the second connection node N4 is affected by the second amplification node N2, and the voltage of the second connection node N4 can be determined to a greater extent based on the current received by the second connection node N4 and the load connected to it, so that the voltage of the second connection node N4 is basically not pulled by the voltage of the second amplification node N2. Therefore, by setting the voltage change of the first connection node N3 to be negatively correlated with the degree of conduction of the isolation module 240, when the voltage change of the first connection node N3 increases during the operation of the differential amplifier, the degree of conduction of the isolation module 240 decreases, so that the voltage of the second amplification node N2 can be more stable, and the second connection node N4 can obtain a larger voltage change range. Compared with the case where the isolation module 240 is not provided, by providing the isolation module 240, when the voltage difference between the first input terminal IN1 and the second input terminal IN2 increases by the same amount, the second connection node N4 has a larger voltage change, thereby improving the amplification factor of the differential amplifier.

[0085] The specific working process of the isolation module 240 can be seen in the following example: the power supply end of the load module 220 is connected to the first power supply signal, a section of the component providing the first bias current I1 is connected to the bias node of the differential input module 210, and the other end is connected to the second power supply signal, and the voltage of the first power supply signal is different from that of the second power supply signal, for example, the first power supply signal has a low voltage, and the second power supply signal has a high voltage. On this basis, the change trend of the degree of conduction of the isolation module 240 is consistent with the change trend of the degree of conduction between the bias node and the second amplification node N2. When the bias node and the second amplification node N2 tend to be disconnected so that the current output by the second amplification node N2 gradually decreases, the voltage of the second amplification node N2 decreases, the current output by the first amplification node N1 gradually increases, and the voltage of the first connection node N3 gradually increases; at this time, the isolation module 240 gradually tends to be disconnected, so that the voltage of the second connection node N4 is lower than the voltage of the second amplification node N2, and the voltage difference gradually increases. Then, when the voltage change at the second input terminal IN2 is consistent, compared with the case where the isolation module 240 is not set, after setting the isolation module 240, the second connection node N4 can obtain a lower voltage and a larger voltage change, which is equivalent to improving the amplification factor of the differential amplifier.

[0086] In the differential amplifier provided in the embodiment of the present invention, a differential input module 210, a load module 220 and an isolation module 240 are provided. The differential input module 210 and the load module 220 constitute a basic amplification circuit structure, and the first bias current I1 is equivalent to a stable bias signal provided to the differential input module 210; the isolation module 240 can be used to control the degree of isolation between the second amplification node N2 and the second connection node N4, and by setting the voltage variation of the first connection node N3 to be negatively correlated with the conduction degree of the isolation module 240, the second connection node N4 has a larger voltage variation range following the voltage difference between the first input terminal IN1 and the second input terminal IN2, thereby improving the amplification factor of the differential structure amplifier circuit, that is, improving the amplification factor of the differential amplifier.

[0087] Figure 2 is a schematic diagram of the structure of another differential amplifier provided by an embodiment of the present invention. Figure 2 On the basis of the above embodiments, optionally, the differential amplifier further includes a voltage stabilizing module 230, which is connected to the first amplifying node N1 and the first connecting node N3, respectively, or in other words, the voltage stabilizing module 230 is connected between the first amplifying node N1 and the first connecting node N3. The voltage stabilizing module 230 is used to stabilize the voltage of the first amplifying node N1.

[0088] In this embodiment, by setting the voltage stabilizing module 230 to stabilize the voltage of the first amplifying node N1, the working state of the transistor between the bias node and the first amplifying node N1 can be stabilized, thereby avoiding unnecessary current fluctuations of the first amplifying node N1 due to a large voltage difference during operation, thereby ensuring the stability of the current output by the first amplifying node N1 and the second amplifying node N2, ensuring the stability of the working state of the differential amplifier, and ensuring the reliability of its amplification function.

[0089] The specific structure of each module in the differential amplifier is exemplarily described below, but it is not intended to limit the present invention.

[0090] Figure 3 is a schematic diagram of the structure of another differential amplifier provided by an embodiment of the present invention. Figure 3 In one embodiment, optionally, the differential input module 210 includes: a fifth transistor T5 and a sixth transistor T6; the first electrode of the fifth transistor T5 and the first electrode of the sixth transistor T6 are both configured with a first bias current I1, for example, both are connected to the bias node N5, the gate of the fifth transistor T5 is connected to the first input terminal IN1, the second electrode of the fifth transistor T5 is connected to the first amplification node N1, the gate of the sixth transistor T6 is connected to the second input terminal IN2, and the second electrode of the sixth transistor T6 is connected to the second amplification node N2. Exemplarily, the channel type of the fifth transistor T5 and the sixth transistor T6 is the same, Figure 2As an example, the fifth transistor T5 and the sixth transistor T6 are both P-type transistors. The fifth transistor T5 and the sixth transistor T6 have the same channel width-to-length ratio to ensure the normal operation of the differential input module 210.

[0091] The load module 220 includes: a third transistor T3 and a fourth transistor T4; the first electrode of the third transistor T3 is connected to the first connection node N3, the second electrode of the third transistor T3 is configured with the first power signal VSS, the gate of the third transistor T3 is respectively connected to the first electrode of the third transistor T3 and the gate of the fourth transistor T4, the first electrode of the fourth transistor T4 is connected to the second connection node N4, and the second electrode of the fourth transistor T4 is configured with the first power signal VSS. In this way, a current mirror circuit structure is formed by the third transistor T3 and the fourth transistor T4. Exemplarily, the second electrode of the third transistor T3 and the second electrode of the fourth transistor T4 are both connected to the first power supply terminal of the differential amplifier, and the first power supply terminal is connected to the first power supply signal VSS. The third transistor T3 and the fourth transistor T4 have the same channel type, Figure 2 As an example, the third transistor T3 and the fourth transistor T4 are both N-type transistors.

[0092] In this embodiment, the amplification structure in the differential amplifier is composed of a current mirror circuit and a differential amplifier, wherein the transconductance of the fifth transistor T5 and the sixth transistor T6, and the output resistance of the sixth transistor T6 and the fourth transistor T4 determine the amplification factor of the differential amplifier. When the above transistors are all TFTs, the amplification factor of the differential amplifier is low due to the small transconductance and output resistance of the TFT. The embodiment of the present invention increases the amplification factor of the differential amplifier by adding a voltage stabilizing module 230 and an isolation module 240 to the differential amplifier, which is equivalent to increasing the equivalent output resistance of the differential amplifier on the basis of improving the stability of the differential amplifier. The following is an exemplary description of the possible structures of the voltage stabilizing module 230 and the isolation module 240.

[0093] Continue to see Figure 3 In one implementation, optionally, the voltage stabilizing module 230 includes: at least one first transistor T1 in a diode-connected form connected between the first amplifying node N1 and the first connecting node N3. Figure 3 The example in FIG. 2 shows that the voltage stabilizing module 230 includes a first transistor T1, but this is not intended to limit the present invention. In other embodiments, see Figure 4 When the voltage stabilizing module 230 includes a plurality of (two are shown in the figure as an example) first transistors T1 in diode connection form, the plurality of first transistors T1 are connected in series between the first amplifying node N1 and the first connecting node N3.

[0094] In this embodiment, by introducing at least one first transistor T1 in the form of a diode connection on the basis of the current mirror circuit, it is possible to avoid introducing a resistor with a large resistance value in the differential amplifier. The first transistor T1 in the form of a diode connection can well stabilize the DC operating point of each transistor in the differential amplifier.

[0095] Among them, based on the different channel types of the first transistor T1, its specific connection method in the circuit is slightly different, which is described in detail below.

[0096] For ease of explanation, an electrode of the first transistor T1 connected to (for example, directly connected or indirectly connected through another first transistor T1) the first amplification node N1 is referred to as the first electrode of the first transistor T1, and an electrode of the first transistor T1 connected to (for example, directly connected or indirectly connected through another first transistor T1) the first connection node N3 is referred to as the second electrode of the first transistor T1. Figure 3 and Figure 4 , when the first transistor T1 is a P-type transistor, the gate of the first transistor T1 is connected to the second electrode of the first transistor T1. Figure 5 When the first transistor T1 is an N-type transistor, the gate of the first transistor T1 is connected to the first electrode of the first transistor T1.

[0097] Continue to see Figure 3-5 On the basis of the above embodiments, optionally, the isolation module 240 includes: a second transistor T2; the gate of the second transistor T2 is connected to the first connection node N3, the first electrode of the second transistor T2 is connected to the second amplification node N2, and the second electrode of the second transistor T2 is connected to the second connection node N4. In this embodiment, the isolation module 240 is configured to be composed of one transistor, so that the structure of the isolation module 240 is simple and easy to implement.

[0098] Understandably, see Figure 3-5 The differential amplifier is composed of six transistors. The differential amplifier has good symmetry and can effectively avoid zero offset of the differential amplifier, so that when there is no voltage difference between the first input terminal IN1 and the second input terminal IN2, the voltage of the output terminal OUT of the differential amplifier is as close to 0V as possible.

[0099] It should be noted that when multiple first transistors T1 are provided, the operating range of the input signal of the differential amplifier will be limited to a certain extent. Therefore, the number of first transistors T1 can be selected by comprehensively considering the voltage regulation requirement of the first amplification node N1 and the operating range of the input signal of the differential amplifier. In addition, considering the symmetry of the differential amplifier, only one first transistor T1 can be provided.

[0100] On the basis of the above-mentioned embodiments, optionally, the channel type of the fourth transistor T4 is different from that of the second transistor T2. Exemplarily, the third transistor T3 and the fourth transistor T4 are both N-type transistors, and the second transistor T2 is a P-type transistor. It can be understood that the second connection node N4 serves as the output terminal OUT of the differential amplifier. From the structure of the output part of the differential amplifier, by setting the second transistor T2 and the fourth transistor T4 with different channel types, it is equivalent to designing an inverter for the output terminal of the differential amplifier, which can effectively improve the output resistance of the differential amplifier, thereby improving the amplification factor of the differential amplifier.

[0101] On the basis of the above-mentioned embodiments, the differential amplifier can be optionally composed of thin film transistors. The flexible electronic technology using TFT technology has the characteristics of low cost, large substrate area and flexibility, which is conducive to the application of differential amplifiers in occasions with high requirements on cost and product space occupation. Specifically, the differential input module 210, the load module 220 and the isolation module 240 can all be composed of thin film transistors. Further, when the differential amplifier includes a voltage regulator module 230, the voltage regulator module 230 is also composed of thin film transistors. That is, the first transistor T1 to the sixth transistor T6 can all be thin film transistors.

[0102] An embodiment of the present invention further provides an operational amplifier circuit. Figure 6 is a schematic diagram of the structure of an operational amplifier circuit provided by an embodiment of the present invention. Figure 6 The operational amplifier circuit includes: a differential amplifier 200, an output module 310 and a voltage control module 320.

[0103] The differential amplifier 200 may include a differential amplifier of any structure. The differential amplifier 200 is configured with a first bias current I1, an input signal VIN1, and a differential signal VIN2 of the input signal. Specifically, the first input terminal of the differential amplifier 200 is connected to the input signal VIN1, the second input terminal is connected to the differential signal VIN2 of the input signal, the bias node is connected to the first bias current I1, and the output terminal outputs the first amplified signal VOUT1. The output module 310 includes a first control node N8 and a third amplification node N7; the first control node N8 is connected to the output terminal of the differential amplifier 200; the third amplification node N7 is used to output the inverted amplified signal of the signal at the output terminal of the differential amplifier 200, that is, to output the inverted amplified signal of the first amplified signal VOUT1. The voltage control module 320 includes a second control node N9, an input node N10 and an output node N11; the second control node N9 is configured with a fixed voltage signal VDC, the input node N10 is connected to the third amplification node N7, the output node N11 is configured with a second bias current I2, and the output node N11 serves as the output end OUT2 of the operational amplifier circuit; the voltage control module 320 is used to stabilize the voltage of the third amplification node N7, specifically, the voltage of the third amplification node N7 is stably output at the output node N11 under the control of the fixed voltage signal VDC.

[0104] In the operational amplifier circuit provided by the embodiment of the present invention, the differential amplifier 200 serves as the first-stage amplifier circuit in the operational amplifier circuit, and the output module 310 cooperates with the voltage control module 320 to form the output-stage amplifier circuit in the operational amplifier circuit. The output module 310 can further amplify the first amplified signal VOUT1 output by the differential amplifier 200 and then output it, and adopts two-stage amplification to effectively improve the amplification factor of the operational amplifier circuit. The voltage control module 320 can suppress the variation range of the voltage of the third amplification node N7 by stabilizing the voltage of the third amplification node N7, and realize the suppression of the Kink effect of the internal transistor of the output module 310, thereby improving the linear relationship between the input and output signals of the circuit, reducing signal transmission distortion, and avoiding the influence of the Kink effect on the amplification factor of the output module 310.

[0105] Figure 7 is a schematic diagram of the structure of another operational amplifier circuit provided by an embodiment of the present invention. Figure 7In one implementation, optionally, the output module 310 includes: a ninth transistor T9; the gate of the ninth transistor T9 is connected to the output terminal of the differential amplifier 200, the first electrode of the ninth transistor T9 is connected to the third amplification node N7, and the second electrode of the ninth transistor T9 is configured with a first power supply signal VSS; illustratively, the operational amplifier circuit includes a first power supply terminal, which is connected to the first power supply signal VSS. In this embodiment, the output module 310 is configured to include a transistor, so that the structure of the output module 310 is simple and easy to implement. Based on the above embodiments, optionally, the ninth transistor T9 is a thin film transistor to reduce the cost of the operational amplifier circuit.

[0106] Through research, it is found that due to the Kink effect of the thin film transistor, the input-output relationship of the amplification region of the ninth transistor T9 has a nonlinear problem, which will cause signal distortion. To solve the signal distortion problem, the embodiment of the present invention adds a voltage control module 320 in the output stage amplifier circuit to improve the linearity of the input-output relationship and reduce signal transmission distortion.

[0107] Specifically, see Figure 7 , the voltage control module 320 may include: an eighth transistor T8; the first electrode of the eighth transistor T8 is connected to the output node N11, and then connected to the output terminal OUT2 of the operational amplifier circuit; the second electrode of the eighth transistor T8 is connected to the input node N10, that is, connected to the third amplification node N7; the gate of the eighth transistor T8 is connected to the second control node N9, and then configured with a fixed voltage signal VDC. The eighth transistor T8 is controlled by the fixed voltage signal VDC to stably output the voltage of the third amplification node N7 at the output node N11. Exemplarily, the channel type of the ninth transistor T9 is the same as that of the eighth transistor T8. Figure 7 As shown, the ninth transistor T9 and the eighth transistor T8 may both be N-type transistors.

[0108] Among them, the fixed voltage signal VDC has a stable voltage. When the difference between the fixed voltage signal VDC and the voltage of the third amplifying node N7 (equivalent to the gate-source voltage difference of the eighth transistor T8) controls the eighth transistor T8 to be turned on, since the voltage of the fixed voltage signal VDC is stable and the gate-source voltage difference of the eighth transistor T8 does not change much, the voltage variation range of the third amplifying node N7 can be effectively limited, and the current fluctuation of the third amplifying node N7 caused by the Kink effect of the ninth transistor T9 can be suppressed, thereby improving the amplification factor and linearity of the output stage amplifier circuit.

[0109] Exemplarily, the voltage of the fixed voltage signal VDC is different from the voltage at the output end of the differential amplifier 200, so as to avoid the gate voltages of the eighth transistor T8 and the ninth transistor T9 being consistent so that the gate-source voltage difference of the eighth transistor T8 is small and cannot be fully turned on. The voltage of the fixed voltage signal VDC is different from the voltage at the output end of the differential amplifier 200, which can be specifically: the voltage of the fixed voltage signal VDC is not within the normal output voltage range of the output end of the differential amplifier 200. For example, when the ninth transistor T9 and the eighth transistor T8 are both N-type transistors, the voltage of the fixed voltage signal VDC can be higher than the voltage at the output end of the differential amplifier 200, for example, higher than the maximum voltage that the differential amplifier 200 can output when receiving a voltage within the normal operating voltage range, so as to ensure that the eighth transistor T8 is fully turned on. The specific voltage value of the fixed voltage signal VDC can be determined based on the operating voltage range of the eighth transistor T8, combined with the simulation analysis of the circuit.

[0110] Figure 8 is a schematic diagram of the structure of another operational amplifier circuit provided by an embodiment of the present invention, see Figure 8 In one embodiment, optionally, the differential amplifier 200 includes: a differential input module 210 and a load module 220. The differential input module 210 is configured with a first bias current I1, for example, the bias node N5 is connected to the first bias current I1. The differential input module 210 includes a first input terminal IN1, a second input terminal IN2, a first amplification node N1 and a second amplification node N2. The first input terminal IN1 is configured with an input signal, and the second input terminal IN2 is configured with a differential signal of the input signal. The first amplification node N1 is used to output an inverted amplified signal of the input signal, and the second amplification node N2 is used to output a non-inverted amplified signal of the input signal. The load module 220 includes a first connection node N3 and a second connection node N4. The first connection node N3 is connected to the first amplification node N1, and the second connection node N4 is used as an output terminal OUT of the differential amplifier to output a first amplified signal VOUT1. In this embodiment, the fixed voltage signal VDC can be provided by a separately set fixed voltage signal line; the voltage of the fixed voltage signal VDC can be set to be different from the voltage of the output terminal of the differential amplifier 200. It is understandable that the differential input module 210 and the load module 220 may have the structure given in any of the above embodiments, which will not be described in detail here.

[0111] In another embodiment, the differential amplifier 200 may include the structure of the differential amplifier provided in any of the above embodiments. For example, the differential amplifier 200 may include a differential input module 210 , a load module 220 , and an isolation module 240 , and may further include a voltage stabilization module 230 .

[0112] Based on the above embodiments, optionally, there are multiple ways to supply the fixed voltage signal VDC, several of which are exemplified below, but are not intended to limit the present invention.

[0113] In one embodiment, optionally, a fixed voltage signal VDC may be additionally introduced to ensure that the potential of the second control node N9 is stable and will not be affected by the circuit working state, thereby ensuring the linearity of the operational amplifier circuit. This embodiment is applicable to a differential amplifier 200 with any structure.

[0114] See also Figure 9-11 In another embodiment, optionally, when the differential amplifier 200 has a differential input module 210, a load module 220 and an isolation module 240 (and may further have a voltage stabilizing module 230), the second amplification node N2 may provide a fixed voltage signal, and the second control node N9 may be directly connected to the second amplification node N2. Since the isolation module 240 (or the voltage stabilizing module 230 cooperates with the isolation module 240) in the differential amplifier 200, the voltage of the second amplification node N2 may be stabilized, so that the voltage of the second amplification node N2 itself is relatively stable and can be multiplexed into a fixed voltage signal VDC. In this way, the internal node voltage of the differential amplifier 200 may be multiplexed into a fixed voltage signal VDC without providing an additional switch control signal, and the operational amplifier circuit structure may be simplified. Moreover, based on the existence of the isolation module 240, there is a voltage difference between the second amplification node N2 and the output end of the differential amplifier 200, so that there is a voltage difference between the second control node N9 and the first control node N8, which can ensure that the eighth transistor T8 is fully turned on when needed, avoiding the problem of insufficient conduction of the eighth transistor T8 caused by short-circuiting the gates of the eighth transistor T8 and the ninth transistor T9.

[0115] In yet another embodiment, optionally, see Figure 12-13 In the case where the differential amplifier 200 has a differential input module 210, a load module 220, an isolation module 240 and a voltage regulator module 230, the second amplification node N1 can provide a fixed voltage signal, and the second control node N9 can be directly connected to the first amplification node N1. Since the voltage regulator module 230 can stabilize the voltage of the first amplification node N1, the voltage of the first amplification node N1 of the differential input module 210 itself is relatively stable and can be multiplexed into a fixed voltage signal VDC. This setting is also equivalent to using the internal node voltage of the differential amplifier 200 to multiplex into a fixed voltage signal VDC, which can simplify the operational amplifier circuit structure.

[0116] In yet another embodiment, optionally, see Fig.14In the case where the voltage stabilizing module 230 includes at least two first transistors T1 connected in series in a diode connection form, the connection node between any two adjacent first transistors T1 can provide a fixed voltage signal, and the second control node N9 can also be connected to the connection node between any two adjacent first transistors T1. Since any first transistor T1 connected in a diode connection form has the function of stabilizing the voltage, the connection node between any two adjacent first transistors T1 also has a relatively stable voltage and can be reused as a fixed voltage signal VDC.

[0117] In another embodiment, optionally, when the differential amplifier 200 has Figure 9-14 When any structure shown in , a separate fixed voltage signal line can also be set to provide a fixed voltage signal VDC. The second control node N9 can be connected to the fixed voltage signal line; the voltage of the fixed voltage signal VDC is different from the voltage of the output terminal of the differential amplifier. Exemplarily, when the differential amplifier 200 has an isolation module 240, the voltage value of the fixed voltage signal VDC can be equal to the voltage of the second amplification node N2 (or within the voltage variation range of the second amplification node N2); when the differential amplifier 200 has a voltage stabilization module 230 and an isolation module 240, the voltage value of the fixed voltage signal VDC can be equal to the voltage of the second amplification node N2 (or within the voltage variation range of the second amplification node N2), or equal to the voltage of the first amplification node N1 (or within the voltage variation range of the first amplification node N1), or between the voltage of the connection node between any two adjacent first transistors T1 and the voltage of the first amplification node N1.

[0118] Fig.14 is a schematic diagram of the structure of another operational amplifier circuit provided by an embodiment of the present invention. Fig.14 On the basis of the above embodiments, optionally, the operational amplifier circuit further includes: a bias module 100, the bias module 100 includes a first bias output node N12 and a second bias output node N13; the first bias output node N12 is used to output a first bias current I1, and the second bias output node N13 is used to output a second bias current I2. The input end of the bias module 100 is, for example, configured with a second power supply signal VDD. Exemplarily, the operational amplifier circuit includes a second power supply end, which is connected to the second power supply signal VDD. In this embodiment, the bias module 100 can provide corresponding bias currents to the differential amplifier 200 and the output stage amplifier circuit respectively.

[0119] Specifically, see Fig.16The bias module 100 includes: a first current source IS1 and a second current source IS2. The output end of the first current source IS1 is connected to the first bias output node N12 for providing the first bias current I1. The output end of the second current source IS2 is connected to the second bias output node N13 for providing the second bias current I2.

[0120] Among them, see Fig.17 The first current source IS1 may include: a seventh transistor T7, a gate of the seventh transistor T7 is configured with a bias voltage BIAS, a first electrode of the seventh transistor T7 is configured with a second power signal VDD, and a second electrode of the seventh transistor T7 is connected to the output end of the first current source IS1. In this embodiment, by setting the first current source IS1 to include one transistor, the structure of the first current source IS1 is simple and easy to implement.

[0121] The second current source IS2 includes: a tenth transistor T10, a gate of the tenth transistor T10 is configured with a bias voltage BIAS, a first electrode of the tenth transistor T10 is configured with a second power supply signal VDD, and a second electrode of the tenth transistor T10 is connected to an output end of the second current source IS2. In this embodiment, by setting the second current source IS2 to include one transistor, the structure of the second current source IS2 is simple and easy to implement.

[0122] It is understandable that the operational amplifier circuit may include a bias terminal connected to a bias voltage BIAS; during operation of the operational amplifier circuit, the bias terminal provides a DC bias voltage BIAS, so that the bias current output by the first current source IS1 and the second current source IS2 is stable.

[0123] Based on the above embodiments, optionally, the differential amplifier 200, the output module 310 and the voltage control module 320 are all composed of thin film transistors to reduce circuit cost. Further, the operational amplifier circuit also includes a bias module 100, which can also be composed of thin film transistors to reduce circuit cost.

[0124] Based on the above embodiments, optionally, see Fig.17 The operational amplifier circuit also includes: a storage module 330, connected between the output end of the differential amplifier 200 and the output end OUT2 of the operational amplifier circuit, for stabilizing the output signal of the circuit. The output module 310, the voltage control module 320 and the storage module 330 can together constitute an output stage amplifier circuit. Specifically, the storage module 330 includes: a capacitor C, connected between the output end of the differential amplifier 200 and the output end OUT2 of the operational amplifier circuit.

[0125] In summary, in the operational amplifier circuit provided by the embodiment of the present invention, the differential amplifier 200 serves as the first-stage amplifier circuit; the output module 310, the voltage control module 320 and the storage module 330 constitute the output-stage amplifier circuit; and the bias module 100 provides bias current to the two-stage amplifier circuits respectively. Among them, the arrangement of the voltage stabilizing module 230, the isolation module 240 and the voltage control module 320 is equivalent to adding an equivalent output resistance to both the differential amplifier and the output-stage amplifier circuit, which can provide a higher operational amplifier gain and reduce signal transmission distortion. Specifically, the bias module 100, the differential input module 210, the load module 220, the voltage stabilizing module 230, the isolation module 240, the output module 310 and the voltage control module 320 can all be composed of thin film transistors to reduce circuit costs.

[0126] Specifically, see Fig.17 In the operational amplifier circuit, the gate of the seventh transistor T7 and the gate of the tenth transistor T10 are both configured with a bias voltage BIAS to form two current sources; the fifth transistor T5 and the sixth transistor T6 constitute a differential input module 210; each of the first transistors T1 and the third transistor T3 forms at least two equivalent diodes connected in series; the second transistor T2 and the fourth transistor T4 constitute an inverter structure to increase the amplification factor of the differential amplifier 200; the ninth transistor T9 is used as an output tube to amplify the output signal of the differential amplifier 200 again and output it to the output terminal OUT2 of the operational amplifier circuit; the eighth transistor T8 plays a role in stabilizing the voltage of the third amplification node N7, reducing the influence of the Kink effect of the ninth transistor T9, and improving the linearity of the input-output relationship.

[0127] by Fig.17 As an example, combined with the circuit structure in Fig.18The voltage curve of the key node in the operational amplifier circuit is recorded as VOUT. The specific working principle of the operational amplifier circuit can be: when the first input terminal IN1 is grounded and the actual input voltage (recorded as Vin+) is provided at the second input terminal IN2, as the actual input voltage Vin+ increases, the current of the sixth transistor T6 will decrease, and the current of the fifth transistor T5 will increase, thereby increasing the voltage of the first connection node N3, and then increasing the opening degree of the fourth transistor T4; at the same time, the second transistor T2 and the sixth transistor T6 tend to be closed, so that the voltage VN2 of the second amplification node N2 and the voltage VN4 of the second connection node N4 both decrease, wherein, due to the blocking effect of the second transistor T2 tending to be closed, the voltage VN2 of the second amplification node N2 decreases relatively slowly; at the output terminal OUT2 of the operational amplifier circuit, due to the existence of the eighth transistor T8, the voltage VN7 of the third amplification node N7 will not be pulled too high, and is maintained at a voltage slightly lower than the voltage of the second amplification node N2, thereby suppressing the Kink effect of the ninth transistor T9, and improving the linear relationship between the input and output of the operational amplifier circuit.

[0128] Fig.19 This is a key node voltage characteristic curve diagram of another operational amplifier circuit provided by an embodiment of the present invention. Fig.19 For the general Fig.17 In the circuit shown, when the gate of the eighth transistor T8 is changed to be connected to the first amplification node N1, the first input terminal IN1 is grounded, and the voltage characteristic curve diagram when the actual input voltage Vin+ is provided at the second input terminal IN2.

[0129] Fig.19 The relationship between the voltage VN1 of the first amplifying node N1, the voltage VN4 of the second connecting node N4, the output voltage VOUT of the operational amplifier circuit and the voltage VN7 of the third amplifying node N7 and the actual input voltage Vin+ is respectively given in FIG. Fig.19 It can be seen that when the gate of the eighth transistor T8 is connected to the first amplifying node N1, since the voltage VN1 of the first amplifying node N1 is relatively stable and not much different from the actual input voltage Vin+, it can limit the voltage VN7 of the third amplifying node N7 from being too high and suppress the Kink effect of the ninth transistor T9.

[0130] Fig. 20 This is a key node voltage characteristic curve diagram of another operational amplifier circuit provided by an embodiment of the present invention. Fig. 20 For the general Fig.17 A voltage characteristic curve diagram when the first transistor T1 in the circuit shown is changed to an N-type transistor, the first input terminal IN1 is grounded, and the actual input voltage Vin+ is provided at the second input terminal IN2; Fig. 20The relationship between the voltage VN2 of the second amplifying node N2, the voltage VN4 of the second connecting node N4, the output voltage VOUT of the operational amplifier circuit and the voltage VN7 of the third amplifying node N7 and the actual input voltage Vin+ is respectively given in FIG. Fig. 20 It can be seen that when the first transistor T1 is an N-type transistor, the same Fig.18 The basically consistent effect can ensure the amplification factor and linearity of the operational amplifier circuit.

[0131] In order to verify the effect of the operational amplifier circuit provided by the embodiment of the present invention, the inventors conducted a simulation comparison of the working characteristics of the operational amplifier circuit provided by the embodiment of the present invention and the comparative example; wherein, the embodiment of the present invention selects Fig.17 The operational amplifier circuit shown in the comparative example Fig.17 The first transistor T1, the second transistor T2 and the eighth transistor T8 are deleted, which is equivalent to the first amplifying node N1 being directly connected to the first connection node N3, the second amplifying node N2 being directly connected to the second connection node N4, and the third amplifying node N7 being directly connected to the output terminal OUT2 of the operational amplifier circuit. Fig.21 It can be seen that in the operational amplifier circuit provided by this embodiment, the voltage VN4 of the second connection node N4, that is, the output voltage of the differential amplifier 200 has a higher amplification factor. When the output voltage VOUT in the comparative example is close to a high level, it rises too slowly with the increase of the actual input voltage Vin+. This is because the Kink effect begins to appear, and the current of the ninth transistor T9 is difficult to suppress, so the input and output present a nonlinear relationship, resulting in distortion of signal transmission. When the output voltage VOUT of the embodiment of the present invention is close to a high level, it rises rapidly with the increase of the actual input voltage Vin+, which can effectively solve the above-mentioned distortion problem.

[0132] An embodiment of the present invention further provides an electronic device, comprising: an amplifier circuit; the amplifier circuit may be a differential amplifier provided by any embodiment of the present invention, or an operational amplifier circuit provided by any embodiment of the present invention, and has corresponding beneficial effects.

[0133] Exemplarily, the electronic device may be: a radio frequency identification device, a music player or a display device, or any other electronic device that requires a built-in operational amplifier function. The amplifier circuit may be used in the electronic device to form an integrator, a differentiator, a multiplier, an adder, an amplifier, a voltage follower, and other devices. Exemplarily, the electronic device may be a flexible electronic device, and each transistor in the amplifier circuit may be a thin film transistor to realize the application of flexible electronics.

[0134] In a specific implementation, illustratively, the electronic device may be a display device. Fig. 22, the display device may include: a driving chip 20, a plurality of data lines LD and a plurality of amplifier circuits 10, and the plurality of data lines LD and the plurality of amplifier circuits 10 may be connected one by one. Specifically, the amplifier circuit may be an operational amplifier circuit, the first input terminal and / or the second input terminal of the differential input module in the amplifier circuit 10 may be connected to the driving chip 20, and the output terminal of the amplifier circuit 10 is connected to the corresponding data line LD. The driving chip 20 transmits a data signal to each data line LD through each amplifier circuit 10. For example, the plurality of data lines LD are arranged in the display panel 30, and are used to provide data signals to sub-pixels (not shown in the figure) in the display panel to realize the display function of the display panel.

[0135] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the present invention can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution of the present invention can be achieved, and this document does not limit this.

[0136] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A differential amplifier, characterized in that: include: A differential input module, wherein the differential input module is configured with a first bias current, comprises a first input terminal, a second input terminal, a first amplification node and a second amplification node, wherein the first input terminal is configured with an input signal, the second input terminal is configured with a differential signal of the input signal, the first amplification node is used to output an inverted amplified signal of the input signal, and the second amplification node is used to output a non-inverted amplified signal of the input signal; A load module, comprising a first connection node and a second connection node, wherein the first connection node is connected to the first amplification node, and the second connection node serves as an output end of the differential amplifier; an isolation module, connected to the second amplification node and the second connection node respectively, and a control end of the isolation module is connected to the first connection node; The voltage variation of the first connection node is negatively correlated with the conduction degree of the isolation module.

2. The differential amplifier according to claim 1, wherein: Also includes: A voltage stabilizing module is connected to the first amplifying node and the first connecting node respectively; the voltage stabilizing module is used to stabilize the voltage of the first amplifying node.

3. The differential amplifier according to claim 2, characterized in that: The voltage stabilizing module comprises: at least one first transistor in a diode-connected form; Preferably, the voltage stabilizing module includes a plurality of the first transistors in a diode-connected form, and the plurality of the first transistors are connected in series between the first amplifying node and the first connecting node.

4. The differential amplifier according to claim 3, characterized in that: A first electrode of the first transistor is connected to the first amplification node, and a second electrode of the first transistor is connected to the first connection node; The first transistor is a P-type transistor, and the gate of the first transistor is connected to the second electrode of the first transistor; or the first transistor is an N-type transistor, and the gate of the first transistor is connected to the first electrode of the first transistor.

5. The differential amplifier according to claim 1, wherein: The isolation module includes: a second transistor connected between the second amplification node and the second connection node, and a gate of the second transistor is connected to the first connection node; Preferably, the load module comprises: a third transistor and a fourth transistor; a first electrode of the third transistor is connected to the first connection node, a second electrode of the third transistor is configured with a first power supply signal, a gate of the third transistor is respectively connected to the first electrode of the third transistor and the gate of the fourth transistor, a first electrode of the fourth transistor is connected to the second connection node, and a second electrode of the fourth transistor is configured with the first power supply signal; The third transistor and the fourth transistor have the same channel type, and the fourth transistor and the second transistor have different channel types; Preferably, the third transistor and the fourth transistor are both N-type transistors, and the second transistor is a P-type transistor.

6. The differential amplifier according to claim 1, wherein: The differential input module comprises: a fifth transistor and a sixth transistor; a first electrode of the fifth transistor and a first electrode of the sixth transistor are both configured with the first bias current, a gate of the fifth transistor is connected to the first input terminal, a second electrode of the fifth transistor is connected to the first amplification node, a gate of the sixth transistor is connected to the second input terminal, and a second electrode of the sixth transistor is connected to the second amplification node; And / or, the load module includes: a third transistor and a fourth transistor; a first electrode of the third transistor is connected to the first connection node, a second electrode of the third transistor is configured with a first power supply signal, a gate of the third transistor is respectively connected to the first electrode of the third transistor and the gate of the fourth transistor, a first electrode of the fourth transistor is connected to the second connection node, and a second electrode of the fourth transistor is configured with the first power supply signal; Preferably, the channel width-to-length ratio of the fifth transistor is the same as that of the sixth transistor.

7. The differential amplifier according to any one of claims 1 to 6, characterized in that: The differential input module, the load module and the isolation module are all composed of thin film transistors; Preferably, the differential amplifier further includes a voltage stabilizing module, and the voltage stabilizing module is composed of a thin film transistor.

8. An operational amplifier circuit, characterized in that: include: Differential amplifier; An output module, comprising a first control node and a third amplification node; the first control node is connected to the output end of the differential amplifier, and the third amplification node is used to output an inverted amplified signal of a signal at the output end of the differential amplifier; A voltage control module comprises a second control node, an input node and an output node; the second control node is configured with a fixed voltage signal, the input node is connected to the third amplification node, the output node is configured with a second bias current, and the output node serves as the output end of the operational amplifier circuit; the voltage control module is controlled by the fixed voltage signal to stably output the voltage of the third amplification node at the output node.

9. The operational amplifier circuit according to claim 8, characterized in that: The voltage control module includes: an eighth transistor; a first electrode of the eighth transistor is connected to the output end of the operational amplifier circuit, and a second electrode of the eighth transistor is connected to the third amplification node; and a gate of the eighth transistor is configured with the fixed voltage signal.

10. The operational amplifier circuit according to claim 9, characterized in that: The output module comprises: a ninth transistor; a gate of the ninth transistor is connected to the output end of the differential amplifier, a first electrode of the ninth transistor is connected to the third amplification node, and a second electrode of the ninth transistor is configured with a first power supply signal; Wherein, the channel type of the ninth transistor is the same as that of the eighth transistor; Preferably, the ninth transistor and the eighth transistor are both N-type transistors; Preferably, the voltage of the fixed voltage signal is higher than the voltage of the control node.

11. The operational amplifier circuit according to claim 8, characterized in that: The differential amplifier is configured with a first bias current; The operational amplifier circuit further includes: a bias module, including a first bias output node and a second bias output node; The first bias output node is used to output the first bias current, and the second bias output node is used to output the second bias current.

12. The operational amplifier circuit according to claim 11, characterized in that: The bias module includes: a first current source and a second current source, wherein the output end of the first current source is connected to the first bias output node, and the output end of the second current source is connected to the second bias output node; Preferably, the first current source comprises: a seventh transistor, a gate of the seventh transistor is configured with a bias voltage, a first electrode of the seventh transistor is configured with a second power supply signal, and a second electrode of the seventh transistor is connected to an output end of the first current source; And / or, the second current source includes: a tenth transistor, a gate of the tenth transistor is configured with a bias voltage, a first electrode of the tenth transistor is configured with a second power supply signal, and a second electrode of the tenth transistor is connected to an output end of the second current source.

13. The operational amplifier circuit according to claim 8, characterized in that: Also includes: A storage module connected between the output end of the differential amplifier and the output end of the operational amplifier circuit; Preferably, the storage module comprises: a capacitor connected between the output end of the differential amplifier and the output end of the operational amplifier circuit.

14. The operational amplifier circuit according to any one of claims 8 to 13, characterized in that: The differential amplifier comprises: A differential input module, wherein the differential input module is configured with a first bias current, and comprises a first input terminal, a second input terminal, a first amplification node, and a second amplification node; the first input terminal is configured with an input signal, and the second input terminal is configured with a differential signal of the input signal; the first amplification node is used to output an inverted amplified signal of the input signal, and the second amplification node is used to output a non-inverted amplified signal of the input signal; A load module, the load module comprising a first connection node and a second connection node, the first connection node is connected to the first amplification node, the second connection node is connected to the second amplification node; the second connection node serves as an output end of the differential amplifier; Preferably, the voltage of the fixed voltage signal is different from the voltage of the output terminal of the differential amplifier.

15. The operational amplifier circuit according to claim 8, characterized in that: The differential amplifier is the differential amplifier according to any one of claims 1 to 7.

16. The operational amplifier circuit according to claim 15, characterized in that: The second amplification node provides the fixed voltage signal, and the second control node is connected to the second amplification node; Alternatively, the differential amplifier includes the voltage stabilizing module as claimed in claim 2, the first amplification node provides the fixed voltage signal, and the second control node is connected to the first amplification node; Alternatively, the differential amplifier comprises the voltage stabilizing module as claimed in claim 2, the voltage stabilizing module comprises at least two first transistors connected in series in a diode-connected form, a connection node between any two adjacent first transistors provides the fixed voltage signal, and the second control node is connected to the connection node; Alternatively, the second control node is connected to a fixed voltage signal line, the fixed voltage signal line is used to transmit the fixed voltage signal, and the voltage of the fixed voltage signal is different from the voltage of the output end of the differential amplifier.

17. The operational amplifier circuit according to any one of claims 8 to 13, characterized in that: The differential amplifier, the output module and the voltage control module are all composed of thin film transistors; Preferably, the operational amplifier circuit further includes a bias module, and the bias module is composed of a thin film transistor.

18. An electronic device, characterized in that: include: Amplifier circuit; the amplifier circuit includes the differential amplifier according to any one of claims 1-7, or the amplifier circuit includes the operational amplifier circuit according to any one of claims 8-17.

19. The electronic device according to claim 18, characterized in that: The electronic device is: a radio frequency identification device, a music player or a display device; Preferably, the electronic device is a flexible electronic device.

20. The electronic device according to claim 18, characterized in that The electronic device is a display device; the display device comprises: a driving chip, a plurality of data lines and a plurality of the amplifying circuits, and the driving chip transmits data signals to each of the data lines through each of the amplifying circuits.

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