Input stage circuit of rail-to-rail operational amplifier, rail-to-rail operational amplifier, electrical device and vehicle

Abstract

The invention relates to an input stage circuit of a rail-to-rail operational amplifier, the rail-to-rail operational amplifier, an electrical device and a vehicle. The input stage circuit of the rail-to-rail operational amplifier comprises a differential input module and a current control module, and the current control module is electrically connected with the differential input module and is used for performing tail current control on different types of first input pair transistors and second input pair transistors in the differential input module according to accessed target reference voltage. According to the input stage circuit of the rail-to-rail operational amplifier provided by the embodiment of the invention, only one target reference voltage is introduced into the current control module, and tail current control is carried out on different types of first input geminate transistors and second input geminate transistors in the differential input module at the same time according to the target reference voltage; in addition, corresponding transconductance has only one protruding interval in the whole voltage range, and compared with the scheme of a triple current mirror in the prior art, the number of protrusions is reduced, and power consumption is reduced.

Description

Technical Field

[0001] The present application relates to the technical field of electronic circuits, and in particular to an input stage circuit of an operational amplifier, an operational amplifier, an electrical device and a vehicle. Background Art

[0002] In order to achieve constant transconductance, rail-to-rail op amps use special circuit designs and technologies. One common design method is to use a combination of differential input and current mirror. Specifically, a triple current mirror is currently more commonly used, which is connected to two different reference voltages to control the tail current of the two inputs in the differential input.

[0003] However, this method introduces two reference voltages. When the input voltage of the op amp changes, the corresponding transconductance will have two raised intervals in the entire voltage range, resulting in higher power consumption. Summary of the invention

[0004] The embodiments of the present application provide a rail-to-rail operational amplifier input stage circuit, a rail-to-rail operational amplifier, an electrical device and a vehicle, which can reduce the number of transconductance bumps in the entire voltage range, thereby reducing power consumption, so as to at least partially solve the above-mentioned technical problems.

[0005] In order to achieve the above-mentioned object, according to a first aspect of the present application, there is provided an input stage circuit of a rail-to-rail operational amplifier, comprising a differential input module and a current control module;

[0006] The current control module is electrically connected to the differential input module, and is used to perform tail current control on different types of first input pairs and second input pairs of tubes in the differential input module according to an accessed target reference voltage.

[0007] Optionally, the current control module includes a current source unit, a first on-off control unit and a second on-off control unit;

[0008] The current source unit is electrically connected to the first input pair of tubes through a first on-off control unit and is electrically connected to the second input pair of tubes through a second on-off control unit;

[0009] The first on-off control unit is used to access the input voltage of the operational amplifier and control the on-off of the line between the current source unit and the first input pair of tubes according to the input voltage;

[0010] The second on-off control unit is used to access the target reference voltage and control the on-off of the line between the current source unit and the second input pair tube according to the target reference voltage.

[0011] Optionally, the current control module further includes a first current adjustment unit and a second current adjustment unit;

[0012] The first on-off control unit is electrically connected to the first input pair of tubes through the first current adjustment unit, and the first current adjustment unit is used to transfer the current on the first on-off control unit to the first input pair of tubes;

[0013] The second on-off control unit is electrically connected to the second input pair of tubes through a second current adjustment unit, and the second current adjustment unit is used to transfer the current on the second on-off control unit to the second input pair of tubes.

[0014] Optionally, the first current adjustment unit includes a first current mirror unit, and the second current adjustment unit includes a second current mirror unit;

[0015] The first current mirror unit includes an input tube connected in series with the first on-off control unit and an output tube connected in series with the first input pair tube;

[0016] The second current mirror unit includes an input tube connected in series with the second on-off control unit and an output tube connected in series with the second input pair of tubes.

[0017] Optionally, the first input pair of tubes is an NMOS pair of tubes, and the first current mirror unit includes a first current mirror pair of tubes and a second current mirror pair of tubes;

[0018] The first current mirror pair includes an input tube connected in series with the first on-off control unit and an output tube connected in series with the input tube of the second current mirror pair. The second current mirror pair includes an output tube connected in series with the first input tube.

[0019] Optionally, the second input pair of tubes is a PMOS pair of tubes, and the second current mirror unit includes a third current mirror pair of tubes;

[0020] The third current mirror pair of tubes includes an input tube connected in series with the second on-off control unit and an output tube connected in series with the second input pair of tubes.

[0021] Optionally, the first replication ratio of the first current mirror unit and the second replication ratio of the second current mirror unit are determined based on coefficient factors of the NMOS tube and the PMOS tube;

[0022] The first replica ratio and the second replica ratio are used together to control the input stage circuit so that a first transconductance when only the first input pair of tubes is working and a second transconductance when only the second input pair of tubes is working are equal.

[0023] Optionally, the first on-off control unit includes a first control tube, the second on-off control unit includes a second control tube, and the current source unit includes a current source tube;

[0024] The current source tube is connected in series with the first control tube and the input tube of the first current mirror unit in the first branch, and is connected in series with the second control tube and the input tube of the second current mirror unit in the second branch.

[0025] According to a second aspect of the present application, a rail-to-rail operational amplifier is provided, comprising an input stage circuit of the rail-to-rail operational amplifier in any of the above embodiments and an amplifier circuit electrically connected to a differential input module in the input stage circuit of the rail-to-rail operational amplifier.

[0026] According to a third aspect of the present application, an electrical device is provided, comprising the rail-to-rail operational amplifier in any one of the above embodiments.

[0027] According to a fourth aspect of the present application, a vehicle is provided, comprising the electrical device in any one of the above embodiments.

[0028] The current control module of the input stage circuit of the rail-to-rail operational amplifier in the embodiment of the present application only introduces one target reference voltage, and performs tail current control on different types of first input pairs and second input pairs in the differential input module according to the target reference voltage. When the input voltage of the operational amplifier changes, the corresponding transconductance will have only one raised interval in the entire voltage range. Compared with the triple current mirror solution in the prior art, the number of raised areas is reduced, thereby reducing power consumption.

[0029] Other features and advantages of the present application will be described in detail in the subsequent detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present application, 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 application, and those skilled in the art can obtain other drawings based on these drawings without creative work.

[0031] In order to more completely understand the present application and its beneficial effects, the following description will be given in conjunction with the accompanying drawings, wherein the same figure numbers represent the same parts in the following description.

[0032] Figure 1 is a schematic structural diagram of an input stage circuit of a rail-to-rail operational amplifier provided in an exemplary embodiment of the present application;

[0033] Figure 2 It is a structural schematic diagram of an input stage circuit of a rail-to-rail operational amplifier including a current source unit, a first on-off control unit and a second on-off control unit provided in an exemplary embodiment of the present application;

[0034] Figure 3 is a structural schematic diagram of an input stage circuit of a rail-to-rail operational amplifier including a first current adjustment unit and a second current adjustment unit provided in an exemplary embodiment of the present application;

[0035] Figure 4is a schematic diagram of a specific circuit implementation of an input stage circuit of a rail-to-rail operational amplifier provided in an exemplary embodiment of the present application;

[0036] Figure 5 is a schematic diagram of a transconductance simulation experiment of an input stage circuit of a rail-to-rail operational amplifier provided in an exemplary embodiment of the present application;

[0037] Figure 6 Schematic diagram of the structure of a rail-to-rail operational amplifier provided in an exemplary embodiment of the present application.

[0038] Description of reference numerals:

[0039] +IN, non-inverting input terminal; -IN, inverting input terminal; NM1-NM5, NMOS tubes; PM1-PM8, PMOS tubes; Vref, target reference voltage; Vb1, bias voltage; I, current. DETAILED DESCRIPTION

[0040] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0041] According to the first aspect of the present application, Figure 1 As shown, a rail-to-rail operational amplifier input stage circuit is provided, including a differential input module and a current control module.

[0042] Among them, in the rail-to-rail operational amplifier, "rail-to-rail" means that the input and output signals of the amplifier can cover the entire power supply voltage range, from the negative power supply voltage to the positive power supply voltage. This means that the amplifier can provide the maximum input and output range when close to the negative power supply and the positive power supply voltage, so that the signal can be fully amplified and processed.

[0043] Traditional amplifier designs may experience distortion or truncation when the input and output signals are close to the power supply voltage. This is because the output range of the amplifier is limited by the power supply voltage, resulting in the signal not being fully amplified. Rail-to-rail operational amplifiers use special circuit design and technology to allow the input and output signals to be close to the power supply voltage, thereby providing a larger dynamic range and more accurate signal amplification.

[0044] exist Figure 1 In the embodiment, the current control module is electrically connected to the differential input module and is used to perform tail current control on different types of first input pairs and second input pairs of tubes in the differential input module according to an accessed target reference voltage Vref.

[0045] Among them, the transconductance of the operational amplifier refers to the gain relationship between the input voltage and the output current. It represents the response of the operational amplifier to changes in input voltage, that is, how the output current changes with changes in input voltage. It is one of the core characteristics of the operational amplifier and determines the amplifier's amplification capability and linearity. Constant transconductance can improve the linearity of the operational amplifier. Linearity refers to whether the relationship between input and output is linear. When the transconductance is constant, the proportional relationship between the change in input voltage and the change in output current remains unchanged, thereby achieving more accurate signal amplification and processing. This is very important for applications that require high precision and low distortion. Constant transconductance can improve the stability of the operational amplifier. When the transconductance is constant, a small change in input voltage will result in a corresponding change in output current, thereby maintaining the stability of the amplifier. This is very important for resisting the influence of noise, temperature changes and other environmental factors to ensure the stability and reliability of the output signal. Constant transconductance can improve the driving capability of the operational amplifier. Driving capability refers to the output current capability that the amplifier can provide. When the transconductance is constant, the amplifier can better drive the load and provide a larger output current change. This is very important for applications that need to drive low impedance loads or require large output currents, such as power management and motor drives.

[0046] The core of the constant transconductance of the rail-to-rail op amp is to match the tail currents of the first input pair and the second input pair of different types in the differential input module. In the process of tail current matching, the common practice is to compare and judge the input voltage of the op amp by introducing a reference voltage, so as to control the input current of the first input pair and the second input pair in the differential input module in real time according to the comparison result, thereby achieving the purpose of tail current matching.

[0047] Among them, in the prior art, when realizing tail current matching, two reference voltages are usually introduced, one of which is used to realize the current control of the first input pair of tubes in the differential input module, and the other reference voltage is used to realize the current control of the second input pair of tubes in the differential input module. However, due to the introduction of two reference voltages, the corresponding transconductance will have two raised intervals in the entire voltage range. Compared with the prior art, this embodiment only introduces one target reference voltage, and the target reference voltage is used to simultaneously realize the current control of the first input pair of tubes and the second input pair of tubes in the differential input module.

[0048] To summarize, the current control module of the input stage circuit of the rail-to-rail operational amplifier in the embodiment of the present application only introduces a target reference voltage, and performs tail current control on different types of first input pairs and second input pairs in the differential input module according to the target reference voltage. When the input voltage of the operational amplifier changes, the corresponding transconductance will have only one raised interval in the entire voltage range. Compared with the triple current mirror solution in the prior art, the number of raised areas is reduced, thereby reducing power consumption.

[0049] like Figure 2 As shown, optionally, the current control module includes a current source unit, a first on-off control unit and a second on-off control unit.

[0050] exist Figure 2 In the embodiment, the current source unit is electrically connected to the first input pair of tubes through the first on-off control unit and is electrically connected to the second input pair of tubes through the second on-off control unit.

[0051] The first on-off control unit is used to access the input voltage of the operational amplifier and control the on-off of the line between the current source unit and the first input pair of tubes according to the input voltage.

[0052] The second on-off control unit is used to access the target reference voltage and control the on-off of the line between the current source unit and the second input pair tube according to the target reference voltage.

[0053] Among them, Figure 2 In the embodiment, the first on-off control unit is a positive differential input voltage connected through the in-phase input terminal +IN. However, due to the virtual short between the in-phase input terminal and the inverting input terminal of the op amp, the positive differential input voltage connected to the in-phase input terminal +IN and the negative differential input voltage connected to the inverting input terminal -IN can be basically understood to be equal. Therefore, in other embodiments, the first on-off control unit can also be connected to a negative differential input voltage. The average value of the positive differential input voltage and the negative differential input voltage can also be understood as the input common mode voltage. Since the positive differential input voltage and the negative differential input voltage can be basically understood to be equal, it can be obtained that the input common mode voltage, the positive differential input voltage and the negative differential input voltage are basically equal.

[0054] Among them, since the first on-off control unit is connected to the positive differential input voltage (or the input common mode voltage), and the second on-off control unit is connected to the target reference voltage Vref. Therefore, when the input common mode voltage is close to the positive power rail, the first on-off control unit is turned on and the second on-off control unit is turned off. This allows the current to be fully distributed to the first input pair of tubes in the differential input module, the first input pair of tubes in the differential input module enters the saturation region, and the second input pair of tubes in the differential input module is in the off state. At this time, the transconductance of the input stage circuit of the entire rail-to-rail op amp is equal to the transconductance of the first input pair of tubes in the differential input module. Similarly, when the input common mode voltage is close to the negative power rail, the first on-off control unit is turned off and the second on-off control unit is turned on. This allows the current to be fully distributed to the second input pair of tubes in the differential input module, the second input pair of tubes in the differential input module enters the saturation region, and the first input pair of tubes in the differential input module is in the off state. At this time, the transconductance of the input stage circuit of the entire rail-to-rail op amp is equal to the transconductance of the second input pair of tubes in the differential input module.

[0055] Based on the above analysis, in order to achieve constant transconductance of the input stage circuit of the rail-to-rail op amp when the input voltage changes, it is only necessary to control the transconductance of the first input pair of tubes in the differential input module corresponding to different input voltages and the transconductance of the second input pair of tubes in the differential input module to be the same. It should be noted that in this process, when the current of the first input pair of tubes and the second input pair of tubes in the differential input module is controlled, it is necessary to consider the respective current multiples and the process-related coefficient factor differences between the first input pair of tubes and the second input pair of tubes due to the device type, so as to achieve tail current matching and then achieve constant transconductance.

[0056] like Figure 3 As shown, optionally, the current control module further includes a first current adjustment unit and a second current adjustment unit.

[0057] exist Figure 3 In the embodiment, the first on-off control unit is electrically connected to the first input pair of tubes through the first current adjustment unit, and the first current adjustment unit is used to transfer the current on the first on-off control unit to the first input pair of tubes.

[0058] exist Figure 3 In the embodiment, the second on-off control unit is electrically connected to the second input pair of tubes through the second current adjustment unit, and the second current adjustment unit is used to transfer the current on the second on-off control unit to the second input pair of tubes.

[0059] Among them, the above embodiments have mentioned that when current control is performed based on the introduced target reference voltage Vref, the transconductance of the input stage circuit of the rail-to-rail op amp is initially simplified to the transconductance of the first input pair of tubes in the differential input module or the transconductance of the second input pair of tubes in the differential input module. On this basis, in order to complete the tail current matching that can achieve constant transconductance, only the current multiples of the first input pair of tubes and the second input pair of tubes in the differential input module and the difference in their respective coefficient factors need to be considered, so as to achieve tail current matching based on the control variable.

[0060] It can be seen that the first input pair and the second input pair in the differential input module require different current multiples due to the difference in coefficient factors. Therefore, in this embodiment, it is necessary to respectively set corresponding first current adjustment units and second current adjustment units, so as to achieve the differentiation of current multiples of the first input pair and the second input pair in the differential input module during current control.

[0061] The first current adjustment unit and the second current adjustment unit may adopt any device or component with current adjustment capability in the prior art, for example, a buffer may be adopted for driving and amplifying.

[0062] Optionally, the first current adjustment unit includes a first current mirror unit, and the second current adjustment unit includes a second current mirror unit.

[0063] Among them, the current mirror realizes current adjustment by copying the current from the input tube to the output tube, and the copy ratio of the current mirror determines the current multiple it adjusts.

[0064] The first current mirror unit includes an input tube connected in series with the first on-off control unit and an output tube connected in series with the first input pair of tubes.

[0065] Among them, since the input tube in the first current mirror unit is connected in series with the first on-off control unit, the input tube in the first current mirror unit can obtain the current flowing through the first on-off control unit. Based on the working principle of the current mirror, the input tube in the first current mirror unit can transfer the obtained current to the output tube in the first current mirror unit according to the set replication ratio. And since the output tube in the first current mirror unit is connected in series with the first input pair of tubes in the differential input module, the output tube in the first current mirror unit can provide the current transferred by the input tube in the first current mirror unit to the first input pair of tubes in the differential input module. Based on the above process, the purpose of transferring the current flowing through the first on-off control unit to the first input pair of tubes in the differential input module at the set current multiple is achieved.

[0066] The second current mirror unit includes an input tube connected in series with the second on-off control unit and an output tube connected in series with the second input pair of tubes.

[0067] Among them, similarly, since the input tube in the second current mirror unit is connected in series with the second on-off control unit, the input tube in the second current mirror unit can obtain the current flowing through the second on-off control unit. Based on the working principle of the current mirror, the input tube in the second current mirror unit can transfer the obtained current to the output tube in the second current mirror unit according to the set replication ratio. And since the output tube in the second current mirror unit is connected in series with the second input pair of tubes in the differential input module, the output tube in the second current mirror unit can provide the current transferred by the input tube in the second current mirror unit to the second input pair of tubes in the differential input module. Based on the above process, the purpose of transferring the current flowing through the second on-off control unit to the second input pair of tubes in the differential input module at the set current multiple is achieved.

[0068] It should be noted that the first current mirror unit and the second current mirror unit involved in this embodiment are used to realize the transmission of current at different current multiples. However, each current mirror pair can realize the transmission of corresponding current multiples. Therefore, in this embodiment, the number of current mirror pairs contained in the first current mirror unit and the second current mirror unit is not limited.

[0069] For example, the first current mirror unit may include a current mirror pair, so that the current transfer function corresponding to the embodiment is realized based on the current mirror pair, and the input tube and output tube in the first current mirror unit refer to the input tube and output tube of the current mirror pair respectively; of course, in other embodiments, the first current mirror unit may also include multiple current mirror pairs connected end to end, so that the current transfer function corresponding to the embodiment is realized based on multiple transfers of the multiple current mirror pairs, and the input tube in the first current mirror unit refers to the input tube of the first current mirror pair among the multiple current mirror pairs connected end to end, and the output tube in the first current mirror unit refers to the output tube of the last current mirror pair among the multiple current mirror pairs connected end to end. The second current mirror unit is similar, and will not be described here.

[0070] like Figure 4As shown, optionally, the first on-off control unit includes a first control tube (including a PMOS tube PM7), the second on-off control unit includes a second control tube (including a PMOS tube PM8), the current source unit includes a current source tube (including an NMOS tube NM3, and the NMOS tube NM3 realizes current source control by the connected bias voltage Vb1); the first input pair of tubes is an NMOS pair of tubes (including an NMOS tube NM1 and an NMOS tube NM2), the first current mirror unit includes a first current mirror pair of tubes (including a PMOS tube PM3 and a PMOS tube PM4) and a second current mirror pair of tubes (including an NMOS tube NM4 and an NMOS tube NM5); the second input pair of tubes is a PMOS pair of tubes (including a PMOS tube PM1 and a PMOS tube PM2), and the second current mirror unit includes a third current mirror pair of tubes (including a PMOS tube PM5 and a PMOS tube PM6).

[0071] exist Figure 4 In the embodiment, the NMOS transistor NM3 is connected in series with the PMOS transistors PM7 and PM3 in the first branch, and is connected in series with the PMOS transistors PM8 and PM5 in the second branch.

[0072] exist Figure 4 In the embodiment, the PMOS transistor PM3 as the input transistor in the first current mirror pair is connected in series with the PMOS transistor PM7, the output transistor in the first current mirror pair is connected in series with the NMOS transistor NM4 as the input transistor of the second current mirror pair, and the NMOS transistor NM5 as the output transistor of the second current mirror pair is respectively connected to the NMOS transistor NM1 and the NMOS transistor NM2 in the NMOS pair.

[0073] Among them, current transfer is achieved between the PMOS tube PM7 serving as the first on-off control unit and the NMOS pair of tubes through the first current mirror pair of tubes and the second current mirror pair of tubes. This is for the location of the NMOS pair of tubes so that the current provided to the NMOS pair of tubes is only related to the current on the PMOS tube PM7, thereby ensuring the accuracy of current transfer.

[0074] exist Figure 4 In the embodiment, the PMOS transistor PM5 and the PMOS transistor PM8 as the input transistors in the third current mirror pair are connected in series, and the PMOS transistor PM6 as the output transistor in the third current mirror pair are connected in series with the PMOS transistor PM1 and the PMOS transistor PM2 in the PMOS pair respectively.

[0075] Among them, the replication ratio of the first current mirror pair formed by the PMOS tube PM3 and the PMOS tube PM4 can be set to 1:1, and the replication ratio of the second current mirror pair formed by the NMOS tube NM4 and the NMOS tube NM5 can be set to 1:n, so that the first replication ratio of the first current mirror unit is 1:n. Similarly, the replication ratio of the first current mirror pair formed by the PMOS tube PM3 and the PMOS tube PM4 can be set to 1:m, so that the second replication ratio of the second current mirror unit is 1:m. When presetting the first replication ratio and the second replication ratio, they need to be determined according to the coefficient factors of the NMOS tube and the PMOS tube, so as to ensure that the first transconductance of the input stage circuit when only the first input pair works and the second transconductance when only the second input pair works are equal.

[0076] In order to make the above embodiments clearer, the above embodiments are now described in combination. Figure 4 As shown, the N input pair consists of NMOS tubes NM1 and NMOS tubes NM2, the P input pair consists of PMOS tubes PM1 and PMOS tubes PM2, and the current control module consists of PMOS tubes PM3, PMOS tubes PM4, PMOS tubes PM5, PMOS tubes PM6, PMOS tubes PM7, PMOS tubes PM8, NMOS tubes NM3, NMOS tubes NM4 and NMOS tubes NM5. +IN and -IN are respectively the in-phase input terminal and the inverting input terminal of the rail-to-rail operational amplifier, Vref is the target reference voltage preset by the previous stage, and Vb1 is the bias voltage preset by the previous stage.

[0077] First, bias voltage Vb1 is input to the gate of NMOS tube NM3 to generate bias current I. The drain of NMOS tube NM3 is connected to the drain of PMOS tube PM7 and the drain of PMOS tube PM8 respectively. The gate input of PMOS tube PM7 is a positive differential input voltage, and the gate input of PMOS tube PM8 is a preset target reference voltage Vref. Assume that the replication ratio of the current mirror composed of PMOS tube PM3 and PMOS tube PM4 is 1:1, the replication ratio of the current mirror composed of PMOS tube PM5 and PMOS tube PM6 is 1:m, and the replication ratio of the current mirror composed of NMOS tube NM4 and NMOS tube NM5 is 1:n. The size of the P input pair is (w / l) p , N inputs the size of the tube (w / l) n , then:

[0078] When the input common-mode voltage is close to the positive power rail, the current I passes through the PMOS tube PM3 in its entirety, and only the tail current generated by the replication of the N input pair tube passes through. The NMOS tubes NM1 and NM2 in the N input pair tube enter the saturation region, and the PMOS tubes PM1 and PM2 in the P input pair tube are both turned off. At this time, the transconductance of the input stage circuit of the rail-to-rail op amp is equal to the transconductance of the N input pair tube. At this time, g m The expression is as follows:

[0079]

[0080] Among them, I n Refers to the current supplied to the N input pair tube.

[0081] When the input common-mode voltage is close to the negative power rail, the current I passes through the PMOS tube PM5 in its entirety, and only the tail current generated by the replication of the P input pair tube passes through. The PMOS tubes PM1 and PM2 in the P input pair tube enter the saturation region, and the NMOS tubes NM1 and NM2 in the N input pair tube are both turned off. At this time, the transconductance of the input stage circuit of the rail-to-rail op amp is equal to the transconductance of the P input pair tube. At this time, g m The expression is as follows:

[0082]

[0083] Among them, I p Refers to the current supplied to the P input pair tube.

[0084] Therefore, according to the coefficient factor k of the PMOS tube and NMOS tube of the selected process, the replication ratio of the two groups of current mirrors of PMOS tube PM5, PMOS tube PM6, NMOS tube NM4, and NMOS tube NM5 and the size of the two groups of input pairs of tubes of PMOS tube PM1, PMOS tube PM2, NMOS tube NM1, and NMOS tube NM2 are designed, so that the transconductance g of the input stage circuit of the rail-to-rail operational amplifier when only the N input pairs are working is mn The transconductance g when only P input pair is working mp Equally, we have:

[0085]

[0086] When +IN=-IN≈Vref, current flows through both PMOS tube PM3 and PMOS tube PM5. Let the tail current through the N input pair be I n1 , the input transconductance is gmn1 , the tail current of the tube through P input is I p1 , the input transconductance is g mp1 , then the current distribution can be expressed as:

[0087]

[0088] That is:

[0089] n.I p1 +m·I n1 =m·n·I

[0090] At this time m The expression is as follows:

[0091]

[0092] like Figure 5 As shown, it can be seen that this design uses a relatively simple structure. Through the design of the N-input pair tubes and the P-input pair tubes and the current control module, the input stage circuit of the operational amplifier can achieve rail-to-rail input. At the same time, the input transconductance of the operational amplifier is basically maintained constant within the entire rail-to-rail common-mode input voltage range, and the input transconductance curve has only one protrusion interval within the entire common-mode input voltage range.

[0093] According to the second aspect of the present application, Figure 6 As shown, a rail-to-rail operational amplifier is provided, comprising the input stage circuit of the rail-to-rail operational amplifier in any of the above embodiments and an amplifier circuit electrically connected to the differential input module in the input stage circuit of the rail-to-rail operational amplifier.

[0094] The current control module of the rail-to-rail operational amplifier of the embodiment of the present application introduces only one target reference voltage, and performs tail current control on different types of first input pairs and second input pairs in the differential input module according to the target reference voltage. When the input voltage of the operational amplifier changes, the corresponding transconductance will have only one raised interval in the entire voltage range. Compared with the triple current mirror solution in the prior art, the number of raised areas is reduced, and the power consumption is reduced.

[0095] According to a third aspect of the present application, an electrical device is provided, comprising the rail-to-rail operational amplifier in any one of the above embodiments.

[0096] The current control module provided in the electrical device of the embodiment of the present application only introduces one target reference voltage, and performs tail current control on different types of first input pairs and second input pairs in the differential input module according to the target reference voltage. When the input voltage of the operational amplifier changes, the corresponding transconductance will have only one raised interval in the entire voltage range. Compared with the triple current mirror solution in the prior art, the number of raised intervals is reduced, thereby reducing power consumption.

[0097] According to a fourth aspect of the present application, a vehicle is provided, comprising the electrical device in any one of the above embodiments.

[0098] The current control module set in the vehicle of the embodiment of the present application only introduces a target reference voltage, and performs tail current control on different types of first input pairs and second input pairs in the differential input module at the same time according to the target reference voltage. When the input voltage of the operational amplifier changes, the corresponding transconductance will have only one raised interval in the entire voltage range. Compared with the triple current mirror solution in the prior art, the number of raised areas is reduced and the power consumption is reduced.

[0099] The vehicle may be a pure fuel vehicle, or a pure electric vehicle, a plug-in hybrid vehicle, an extended-range hybrid vehicle or other new energy vehicle, and this application does not make any specific limitations on this.

[0100] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0101] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0102] The embodiments, implementation methods and related technical features of the present application can be combined and replaced with each other without conflict.

[0103] The above are only preferred embodiments of the present application and do not constitute any form of limitation to the present application. In the embodiments of the present application, the description of each embodiment has its own focus. For the parts not described in detail in a certain embodiment, please refer to the relevant contents of other embodiments. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present application without departing from the content of the technical solution of the present application are still within the scope of the technical solution of the present application.

Claims

1. A rail-to-rail operational amplifier input stage circuit, characterized in that: It includes a differential input module and a current control module; The current control module is electrically connected to the differential input module, and is used to perform tail current control on different types of first input pairs and second input pairs of tubes in the differential input module according to an input target reference voltage.

2. The input stage circuit of the rail-to-rail operational amplifier according to claim 1, characterized in that: The current control module includes a current source unit, a first on-off control unit and a second on-off control unit; The current source unit is electrically connected to the first input pair of tubes through the first on-off control unit and is electrically connected to the second input pair of tubes through the second on-off control unit; The first on-off control unit is used to access the input voltage of the operational amplifier, and control the on-off of the line between the current source unit and the first input pair of tubes according to the input voltage; The second on-off control unit is used to access the target reference voltage and control the on-off of the line between the current source unit and the second input pair tube according to the target reference voltage.

3. The input stage circuit of the rail-to-rail operational amplifier according to claim 2, characterized in that: The current control module further includes a first current adjustment unit and a second current adjustment unit; The first on-off control unit is electrically connected to the first input pair of tubes through the first current adjustment unit, and the first current adjustment unit is used to transfer the current on the first on-off control unit to the first input pair of tubes; The second on-off control unit is electrically connected to the second input pair of tubes through the second current adjustment unit, and the second current adjustment unit is used to transfer the current on the second on-off control unit to the second input pair of tubes.

4. The input stage circuit of the rail-to-rail operational amplifier according to claim 3, characterized in that: The first current adjustment unit includes a first current mirror unit, and the second current adjustment unit includes a second current mirror unit; The first current mirror unit includes an input tube connected in series with the first on-off control unit and an output tube connected in series with the first input pair of tubes; The second current mirror unit includes an input tube connected in series with the second on-off control unit and an output tube connected in series with the second input pair of tubes.

5. The input stage circuit of the rail-to-rail operational amplifier according to claim 4, characterized in that: The first input pair of transistors is an NMOS pair of transistors, and the first current mirror unit includes a first current mirror pair of transistors and a second current mirror pair of transistors; The first current mirror pair includes an input tube connected in series with the first on-off control unit and an output tube connected in series with the input tube of the second current mirror pair, and the second current mirror pair also includes an output tube connected in series with the first input pair.

6. The input stage circuit of the rail-to-rail operational amplifier according to claim 4, characterized in that: The second input pair of transistors is a PMOS pair of transistors, and the second current mirror unit includes a third current mirror pair of transistors; The third current mirror pair of tubes includes an input tube connected in series with the second on-off control unit and an output tube connected in series with the second input pair of tubes.

7. The input stage circuit of the rail-to-rail operational amplifier according to any one of claims 4 to 6, characterized in that: The first replication ratio of the first current mirror unit and the second replication ratio of the second current mirror unit are determined based on coefficient factors of the NMOS tube and the PMOS tube; The first replication ratio and the second replication ratio are used together to control the first transconductance of the input stage circuit when only the first input pair of tubes is working and the second transconductance when only the second input pair of tubes is working to be equal.

8. The input stage circuit of the rail-to-rail operational amplifier according to any one of claims 4 to 6, characterized in that: The first on-off control unit includes a first control tube, the second on-off control unit includes a second control tube, and the current source unit includes a current source tube; The current source tube is connected in series with the first control tube and the input tube of the first current mirror unit in the first branch, and is connected in series with the second control tube and the input tube of the second current mirror unit in the second branch.

9. A rail-to-rail operational amplifier, characterized in that: The invention comprises the input stage circuit of the rail-to-rail operational amplifier according to any one of claims 1 to 8 and an amplifier circuit electrically connected to the differential input module in the input stage circuit of the rail-to-rail operational amplifier.

10. An electrical device, characterized in that: Including the rail-to-rail operational amplifier as described in claim 9.

11. A vehicle, characterized in that: An electrical device comprising the electrical device of claim 10.

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