Nonlinear current generating circuit, chip and electronic device

Abstract

The application provides a nonlinear current generating circuit, a chip and an electronic device. The nonlinear current generating circuit comprises: a direct current module configured to output an initial direct current; an impedance enhancement module; and a transconductance linear module comprising a first transistor, wherein the impedance enhancement module is connected with the first transistor, the impedance enhancement module is configured to equivalently increase the output resistance of the first transistor, and the transconductance linear module is configured to nonlinearly transform the initial direct current under the power supply of a power supply voltage and output a nonlinear current. The nonlinear current generating circuit provided by the application comprises the impedance enhancement module, the impedance enhancement module can equivalently increase the output resistance of the first transistor in the transconductance linear module, so that the influence of the fluctuation of the power supply voltage on the nonlinear current is reduced, and then the nonlinear power supply circuit is suitable for a wider power supply voltage scene, is less affected by the parameters of the transistor device itself, and has a larger adjustment range.

Description

Technical Field

[0001] This application relates to the field of circuit technology, and in particular to a nonlinear current generating circuit, chip, and electronic device. Background Technology

[0002] The core circuit of a bandgap reference circuit is generally implemented using a bipolar junction transistor (BJT). The voltage between the base and emitter of the BJT is called VT. BE V BE It has highly predictable and relatively stable temperature characteristics, and the V of the two BJTs BE The difference ΔV BE With V BE When added together, because the two have opposite and almost linear temperature characteristics, the result is a reference voltage with a temperature coefficient of almost zero. This reference voltage is represented by V. BG This indicates that the temperature characteristics of semiconductor materials will cause V... BE The temperature characteristics of [the material] have an inherent nonlinear error, also known as curvature error, therefore the reference voltage V [is affected]. BG The temperature coefficient has a certain lower limit.

[0003] Existing technologies utilize high-order curvature-compensated bandgap reference circuits, introducing nonlinear voltages to compensate for V. BE The curvature error is addressed by using a nonlinear current generation circuit to generate a nonlinear current. This nonlinear current flows through a resistor, producing a nonlinear voltage, which is then superimposed on V. BG Above, thus eliminating V BE The curvature error.

[0004] However, the nonlinear current generated by the nonlinear current generation circuit in the existing technology is easily affected by the power supply voltage. Since the curvature error is an extremely small voltage, the fluctuation of the power supply voltage will have a significant impact on the curvature compensation effect, thereby affecting the stable operation of the bandgap reference circuit. Summary of the Invention

[0005] This application provides a nonlinear current generating circuit, chip, and electronic device, the main purpose of which is to reduce the impact of power supply voltage fluctuations on curvature compensation.

[0006] In a first aspect, embodiments of this application provide a nonlinear current generating circuit, including:

[0007] DC module, used to output initial DC current;

[0008] Impedance enhancement module;

[0009] The transconducting linear module includes a first transistor, which is the output stage transistor of the transconducting linear module. The impedance enhancement module is connected to the first transistor and is used to effectively increase the output resistance of the first transistor. The transconducting linear module is used to perform nonlinear transformation on the initial DC current under the power supply voltage and output a nonlinear current.

[0010] Furthermore, the transconductance linear module includes a second transistor connected to the control terminal of the first transistor, and the impedance enhancement module includes a first impedance enhancement circuit and a second impedance enhancement circuit, wherein:

[0011] The first impedance enhancement circuit is connected to the first transistor and is used to effectively increase the output resistance of the first transistor.

[0012] The second impedance enhancement circuit is connected to the second transistor and is used to effectively increase the output resistance of the second transistor.

[0013] Furthermore, the first impedance enhancement circuit includes a third transistor and a first bias voltage unit, wherein:

[0014] The first terminal of the third transistor is used to connect to the target circuit, the control terminal of the third transistor is connected to the first bias voltage unit, and the second terminal of the third transistor is connected to the first terminal of the first transistor.

[0015] The first bias voltage unit is used to provide a bias voltage for the third transistor.

[0016] Furthermore, the first bias voltage unit includes a first current generating device, one end of which is connected to the power supply voltage, and the other end of which is connected to the control terminal of the third transistor.

[0017] Furthermore, the first bias voltage unit also includes a first unidirectional conducting device, one end of which is connected to the other end of the first current generating device, and the other end of which is grounded.

[0018] Furthermore, the second impedance enhancement circuit includes a fourth transistor and a second bias voltage unit, wherein:

[0019] The first terminal of the fourth transistor is connected to the power supply voltage, the control terminal of the fourth transistor is connected to the second bias voltage unit, and the second terminal of the fourth transistor is connected to the first terminal of the second transistor.

[0020] The second bias voltage unit is used to provide a bias voltage for the fourth transistor.

[0021] Furthermore, the second bias voltage unit includes a second current generating device, one end of which is connected to the power supply voltage, and the other end of which is connected to the control terminal of the fourth transistor.

[0022] Furthermore, the second bias voltage unit also includes a second unidirectional conducting device, one end of which is connected to the other end of the second current generating device, and the other end of which is grounded.

[0023] Furthermore, the first unidirectional conducting device includes a diode and / or a field-effect transistor.

[0024] Furthermore, the nonlinear current generating circuit further includes:

[0025] A current mirror module is used to amplify the nonlinear current proportionally.

[0026] Secondly, embodiments of this application provide a chip including a nonlinear current generating circuit as provided in the first aspect.

[0027] Thirdly, embodiments of this application provide an electronic device, including a nonlinear current generating circuit as provided in the first aspect, or including a chip as provided in the second aspect.

[0028] This application discloses a nonlinear current generation circuit, chip, and electronic device. The nonlinear current generation circuit includes a DC module, an impedance enhancement module, and a transconductance linear module including a first transistor. When the nonlinear current generation circuit is operating, the DC module first outputs an initial DC current. Under the power supply voltage, the transconductance linear module performs a nonlinear transformation on the initial DC current, thereby outputting a nonlinear current. Compared with existing nonlinear current generation circuits, the nonlinear current generation circuit proposed in this application adds an impedance enhancement module. This impedance enhancement module can effectively increase the output resistance of the first transistor in the transconductance linear module, thereby reducing the impact of power supply voltage fluctuations on the nonlinear current. Therefore, this nonlinear power supply circuit is suitable for a wider range of power supply voltage scenarios and is less affected by the parameters of the transistor itself, allowing for a larger adjustment range. Attached Figure Description

[0029] Figure 1 A circuit diagram of a nonlinear current generation circuit provided in the prior art;

[0030] Figure 2 This is a schematic diagram illustrating an application scenario of a nonlinear current generation circuit provided in an embodiment of this application.

[0031] Figure 3 This is a schematic diagram of a nonlinear current generating circuit provided in an embodiment of this application;

[0032] Figure 4 This is a schematic diagram of the impedance enhancement module provided in the embodiments of this application;

[0033] Figure 5 A circuit diagram of a nonlinear current generating circuit provided in an embodiment of this application;

[0034] Figure 6 This is a schematic diagram of the structure of a first bias voltage unit provided in an embodiment of this application;

[0035] Figure 7 A circuit diagram of a nonlinear current generating circuit provided in an embodiment of this application;

[0036] Figure 8 This is a schematic diagram of the structure of a second bias voltage unit provided in an embodiment of this application;

[0037] Figure 9 A circuit diagram of a current limiting unit provided in one embodiment of this application;

[0038] Figure 10 A circuit diagram of a current limiting unit provided in another embodiment of this application;

[0039] Figure 11 A circuit diagram of a current limiting unit provided for another embodiment of this application;

[0040] Figure 12 A circuit diagram of a current limiting unit provided in another embodiment of this application;

[0041] Figure 13 A circuit diagram of a current limiting unit is also provided in another embodiment of this application;

[0042] Figure 14 A circuit diagram of a nonlinear current generating circuit provided in another embodiment of this application;

[0043] Figure 15 A circuit diagram of a nonlinear current generating circuit provided for another embodiment of this application;

[0044] Figure 16 A circuit diagram of a nonlinear current generating circuit provided in another embodiment of this application;

[0045] Figure 17 A circuit diagram of a nonlinear current generating circuit is provided in another embodiment of this application;

[0046] Figure 18 This is a schematic diagram of a nonlinear current generating circuit provided in an embodiment of this application.

[0047] Figure label:

[0048] 100, Nonlinear current generating circuit; 200, Target circuit;

[0049] 110, DC module; 120, impedance enhancement module;

[0050] 130, Transconductance linear module; 121, First impedance enhancement circuit;

[0051] 122, Second impedance enhancement circuit; 123, First bias voltage unit;

[0052] 124, Second bias voltage unit; 125, First current generating device;

[0053] 126, Second current generating device; 127, First unidirectional conducting device;

[0054] 128, Second unidirectional conduction device; 140, Current mirror module.

[0055] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0056] The embodiments of this application are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0057] To enable those skilled in the art to better understand the solutions of this application, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0058] In the embodiments of this application, "at least one" refers to one or more; "multiple" refers to two or more. In the description of this application, terms such as "first," "second," and "third" are used only for descriptive purposes and should not be construed as indicating or implying relative importance or order. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0059] References such as “one embodiment” or “some embodiments” as described in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the terms “comprising,” “including,” “having,” and variations thereof, as used in this specification, mean “including, but not limited to,” unless otherwise specifically emphasized.

[0060] It should be noted that in the embodiments of this application, "connection" can be understood as electrical connection. The connection between two electrical components can be a direct or indirect connection between the two electrical components. For example, the connection between A and B can be a direct connection between A and B, or an indirect connection between A and B through one or more other electrical components.

[0061] To analyze the reasons why power supply voltage fluctuations affect nonlinear current, such as Figure 1 As shown in the diagram, VDD represents the power supply voltage, GND represents ground, I1 and I2 both represent current sources used to provide DC current to the transconducting linear circuit; Q1, Q2, Q3 and Q4 all represent transistors. These four transistors form the transconducting linear circuit, used to perform nonlinear transformation on the input DC current, outputting a nonlinear current I. out In this circuit, base bias circuit 1 provides a bias voltage to the base of Q1, and base bias circuit 2 provides a bias voltage to the base of Q2; due to the nonlinear current I... out Due to the influence of the preceding transconducting linear circuit, its size may not meet the requirements of the target circuit. Therefore, a current mirror circuit is added, which affects I. out The amplified nonlinear current I is proportionally amplified. out1 with I out It has a specific ratio B, which can be set according to the requirements of the target circuit.

[0062] Through the processing of this nonlinear current generating circuit, I out I out1It is a nonlinear function of the current sources I1 and I2, based on the following principle: Neglecting the base current of the BJT, we have the following Kirchhoff's Law (KVL) equation:

[0063] V BE1 +V BE2 =V BE3 +V BE4 (1)

[0064] According to BJT's V BE The relationship with the collector current can be rewritten as follows:

[0065] ln(I1 / I S1 )+ln(I1 / I S2 )=ln(I2 / I S3 )+ln(I out / I S4 (2)

[0066] I S1 ~I S4 Let I be the saturation current of Q1 to Q4 respectively. S3 *I S4 / I S1 *I S2 =A, obtained from the above formula:

[0067]

[0068] It can be seen that I out It is a nonlinear function of I1 and I2, while the amplified nonlinear current I out1 as follows:

[0069]

[0070] Amplified nonlinear current I out1 It will be used for curvature compensation.

[0071] The nonlinear current generated by the existing nonlinear current generation circuit described above is easily affected by the power supply voltage. If the change in power supply voltage is represented by ΔVDD, then I out I out1 This will produce a large change ΔI out ΔI out1 The curvature error is an extremely small voltage, typically on the order of several millivolts, therefore I out I out1 The change in ΔI with respect to ΔVDD out ΔI out1 This will have a significant impact on the curvature compensation effect.

[0072] This makes existing nonlinear current generation circuits unsuitable for scenarios with a wide power supply voltage range, as variations in the power supply voltage directly affect the temperature characteristics of the reference voltage. Of course, VDD can also be provided by an internal voltage regulator module, limiting VDD to a very small range and making ΔVDD smaller, but this will increase the cost and complexity of the circuit.

[0073] Figure 1 The diagram schematically shows the equivalent small-signal impedances of some components, which are the output resistance r of Q3. o3 The output resistance r of Q4 o4 The input resistance r of Q4 pi The small-signal resistance r between n6 and VDD m .

[0074] Studies have shown that VDD primarily affects I by influencing the voltages at nodes n5 and n6. out I out1 The size, approximately, ΔVDD and ΔI out ΔI out1 Follow the following relationship:

[0075]

[0076]

[0077] From the above ΔVDD and ΔI out ΔI out1 The relationship shows that increasing r of Q3 and Q4 o3 r o4 It can reduce ΔI out / ΔVDD、ΔI out1 / ΔVDD. However, r o3 r o4 The base width and collector current of a BJT device are related, and the adjustment range is limited.

[0078] To address the aforementioned problems, this application provides a nonlinear current generating circuit 100 to solve the issue that power supply voltage fluctuations have a significant impact on nonlinear currents in the prior art. For example... Figure 2 As shown, the output terminal of the nonlinear current generating circuit 100 is connected to the input terminal of the target circuit 200. When the nonlinear current generating circuit 100 is working, the DC module 110 first outputs an initial DC current. Under the power supply voltage, the transconductance linear module 130 performs a nonlinear transformation on the initial DC current, thereby outputting a nonlinear current. An impedance enhancement module 120 is added, which can effectively increase the output resistance of the first transistor in the transconductance linear module 130, thereby reducing the impact of power supply voltage fluctuations on the nonlinear current.

[0079] In this embodiment, the target circuit 200 can be any circuit requiring nonlinear current, including analog circuits, digital circuits, etc., and can be determined according to actual conditions. This embodiment does not impose specific limitations on it. For example, the target circuit 200 can be a bandgap reference circuit.

[0080] Note that all transistors involved in the embodiments of this application include a control terminal, a first terminal, and a second terminal. When the transistor is a bipolar junction transistor (BJT), taking an NPN transistor as an example, the control terminal of the NPN transistor is the base, the first terminal of the NPN transistor is the collector, and the second terminal of the NPN transistor is the emitter. When the transistor is a MOS transistor, taking an NMOS transistor as an example, the control terminal of the transistor is the gate of the MOS transistor, the first terminal of the transistor is the drain of the MOS transistor, and the second terminal of the transistor is the source of the MOS transistor.

[0081] For PNP transistors or PMOS transistors, adaptive transformations are made based on the above connection relationships.

[0082] This application provides a schematic diagram of the structure of a nonlinear current generating circuit 100, as shown in the embodiment. Figure 3 As shown, the nonlinear current generating module includes a DC module 110, an impedance enhancement module 120, and a transconductance linear module 130. The output terminal of the DC module 110 is connected to the first input terminal of the transconductance linear module 130; the output terminal of the impedance enhancement module 120 is connected to the second input terminal of the transconductance linear module 130, and the second input terminal is also connected to the first transistor in the transconductance linear module 130; the third input terminal of the transconductance linear module 130 is used to connect to the power supply voltage; and the output terminal of the transconductance linear module 130 outputs a nonlinear current.

[0083] It should be noted that the power supply voltage can be set inside the nonlinear current generating circuit 100 or obtained by connecting an external power supply. The specific voltage can be determined according to the actual situation, and this application embodiment does not make specific limitations on this.

[0084] During the operation of the nonlinear current generating circuit 100, the DC module 110 first outputs an initial DC current. This DC module 110 can be any circuit capable of outputting DC current; its specific structure can be determined based on actual conditions, and this embodiment does not impose any specific limitations. After receiving the initial DC current, the transconductance linear module 130, under the power supply voltage, performs a nonlinear transformation on the initial DC current, outputting a nonlinear current. The transconductance linear module 130 is commonly used in the nonlinear current generating circuit 100. It consists of a closed loop formed by forward-biased emitter junctions or diodes. The number of forward-biased junctions in the clockwise direction is equal to the number in the counterclockwise direction, and there must be an even number of forward-biased emitter junctions in the transconductance linear closed loop. The transconductance linear module 130 can be any circuit with nonlinear transformation capabilities; its specific structure can be determined based on actual conditions, and this embodiment does not impose any specific limitations.

[0085] It should be noted that, in this embodiment, the first transistor refers to the transistor located in the output stage of the transconductance linear module 130, that is, after the transconductance linear module 130 performs a nonlinear transformation on the initial DC current, the branch containing the first transistor outputs a nonlinear current. For example, in Figure 1 In the circuit shown, the first transistor is Q4. Improving the output resistance of the first transistor is equivalent to r o4 Magnified several times.

[0086] In this embodiment, the nonlinear current generating circuit 100 further includes an impedance enhancement module 120. The main function of the impedance enhancement module 120 is to effectively increase the output resistance of the first transistor. For example, the output resistance of the first transistor can be amplified by several times. As shown in formula (5), when the output resistance of the first transistor is amplified by several times, it is equivalent to r o4 Magnifying the formula by several times increases the denominator in formula (5), thus making ΔI... out When the ratio of / ΔVDD decreases, the influence of the nonlinear current changing with the power supply voltage is reduced, thus making the nonlinear power supply circuit suitable for a wider range of power supply voltage scenarios.

[0087] It should be noted that the first transistor can be a bipolar transistor or a MOSFET, and the specific type can be determined according to the actual situation. This application does not make any specific limitation on this.

[0088] It should also be noted that the impedance enhancement circuit can be any circuit that can increase the output resistance of the first transistor, and the specific circuit can be selected according to the actual situation. This application does not impose any specific limitations on this.

[0089] This application proposes a nonlinear current generation circuit 100, which includes a DC module 110, an impedance enhancement module 120, and a transconductance linear module 130 including a first transistor. When the nonlinear current generation circuit 100 is operating, the DC module 110 first outputs an initial DC current. Under the influence of the voltage provided by the power supply, the transconductance linear module 130 performs a nonlinear transformation on the initial DC current, thereby outputting a nonlinear current. Compared with existing nonlinear current generation circuits, the nonlinear current generation circuit 100 proposed in this application adds an impedance enhancement module 120. This impedance enhancement module 120 can effectively increase the output resistance of the first transistor in the transconductance linear module 130, thereby reducing the impact of power supply voltage fluctuations on the nonlinear current. This makes the nonlinear power supply circuit suitable for a wider range of power supply voltage scenarios and less affected by the parameters of the transistor itself, allowing for a larger adjustment range.

[0090] In some embodiments, such as Figure 4 As shown, the transconductance linear module 130 includes a second transistor connected to the control terminal of the first transistor, and the impedance enhancement module 120 includes a first impedance enhancement circuit 121 and a second impedance enhancement circuit 122, wherein:

[0091] The first impedance enhancement circuit 121 is connected to the first transistor and is used to effectively increase the output resistance of the first transistor.

[0092] The second impedance enhancement circuit 122 is connected to the second transistor and is used to effectively increase the output resistance of the second transistor.

[0093] In this embodiment, the transcontinental module 130 further includes a second transistor, the second terminal of which is connected to the control terminal of the first transistor, thereby allowing the position of the second transistor within the transcontinental module 130 to be determined. For example, in... Figure 1 In the transconducting linear circuit shown, the second transistor refers to Q3.

[0094] Accordingly, the impedance enhancement module 120 includes a first impedance enhancement circuit 121 and a second impedance enhancement circuit 122. The first impedance enhancement circuit 121 is connected to the first transistor, and its function is to effectively increase the output resistance of the first transistor, equivalent to r o4 Magnifying the formula by several times increases the denominator in formula (5), thus making ΔI... out A smaller ratio of / ΔVDD reduces the influence of nonlinear current variations with power supply voltage. The second impedance enhancement circuit 122 is connected to the second transistor. The function of the second impedance enhancement circuit 122 is to effectively increase the output resistance of the second transistor, equivalent to ro3 Magnifying the formula by several times increases the denominator in formula (5), thus making ΔI... out A smaller ratio of / ΔVDD can further reduce the influence of nonlinear current variations with power supply voltage.

[0095] It should be noted that the first impedance enhancement circuit 121 and the second impedance enhancement circuit 122 can be any circuit that effectively increases the output resistance, and the specific design can be determined according to the actual situation. This application embodiment does not impose any specific limitations on this. The structure of the first impedance enhancement circuit 121 can be the same as or different from that of the second impedance enhancement circuit 122.

[0096] In some embodiments, such as Figure 5 As shown, the first impedance enhancement circuit 121 includes a third transistor and a first bias voltage unit 123, wherein:

[0097] The first terminal of the third transistor is used to connect to the target circuit 200, the control terminal of the third transistor is connected to the first bias voltage unit 123, and the second terminal of the third transistor is connected to the first terminal of the first transistor.

[0098] The first bias voltage unit 123 is used to provide a bias voltage for the third transistor.

[0099] In this embodiment, the first impedance enhancement circuit 121 includes a third transistor and a first bias voltage unit 123. The first terminal of the third transistor is connected to the target circuit 200, the control terminal of the third transistor is connected to the first bias voltage unit 123, and the second terminal of the third transistor is connected to the first terminal of the first transistor. The function of the first bias voltage unit 123 is to provide a base bias voltage for the third transistor.

[0100] like Figure 5 As shown, in this embodiment, the DC module 110 includes two current sources, denoted by I1 and I2 respectively; the transconductance linear module 130 includes four N-type transistors, denoted by Q1 to Q4 respectively, wherein the first transistor refers to Q4 and the second transistor refers to Q3; the third transistor in the first impedance enhancement circuit 121 is illustrated using an N-type transistor as an example, denoted by Q5, and the first impedance enhancement circuit 121 is used to equivalently amplify the output resistance of the first transistor; the output nonlinear current is denoted by I... out express.

[0101] During the operation of the first impedance enhancement circuit 121, the first bias voltage unit 123 provides a base bias voltage to the third transistor, thereby making the third transistor in a conducting state and achieving the effect of effectively increasing the output resistance of the first transistor.

[0102] The first impedance enhancement circuit 121 can effectively increase the output resistance r of the first transistor. o4 This reduces the impact of power supply voltage fluctuations on I. out The first impedance enhancement circuit 121 is embedded between the collector of the first transistor and the target circuit 200. By introducing the first impedance enhancement circuit 121, the fluctuation of the power supply voltage will be reduced to ΔI. out The relationship becomes:

[0103]

[0104] From equation (7) above, it can be seen that r o4 This is equivalent to increasing G1 by a factor, where G1 is the intrinsic gain of the third transistor. If G1 >> 1, then I out The impact of power supply voltage fluctuations will be greatly reduced, thus the nonlinear current output by the nonlinear current generation circuit 100 in this embodiment is suitable for a wider range of power supply voltage scenarios.

[0105] As one implementation method, such as Figure 6 As shown, the first bias voltage unit 123 includes a first current generating device 125. One end of the first current generating device 125 is connected to the power supply voltage, and the other end of the first current generating device 125 is connected to the control terminal of the third transistor.

[0106] In this embodiment, the first bias voltage unit 123 includes a first current generating device 125. The two ends of the first current generating device 125 are connected to the power supply voltage and the control terminal of the third transistor, respectively. The first current generating device 125 can be any device that can provide a stable current; this embodiment does not specifically limit its capabilities. For example, the first current generating device 125 can be a current source.

[0107] As one implementation method, such as Figure 6 As shown, the first bias voltage unit 123 further includes a first unidirectional conducting device 127, one end of the first unidirectional conducting device 127 is connected to the other end of the first current generating device 125, and the other end of the first unidirectional conducting device 127 is grounded.

[0108] In this embodiment, the first bias voltage unit 123 further includes a first unidirectional conducting device 127. The first current generating device 125 is grounded through the first unidirectional conducting device 127. The first single-phase conduction can be any device capable of achieving single-phase conduction, and this embodiment does not specifically limit it. For example, in this embodiment, the first unidirectional conducting device 127 can be a plurality of diodes connected end to end.

[0109] In some embodiments, such as Figure 7As shown, the second impedance enhancement circuit 122 includes a fourth transistor and a second bias voltage unit 124, wherein:

[0110] The first terminal of the fourth transistor is connected to the power supply voltage, the control terminal of the fourth transistor is connected to the second bias voltage unit 124, and the second terminal of the fourth transistor is connected to the first terminal of the second transistor.

[0111] The second bias voltage unit 124 is used to provide a bias voltage for the fourth transistor.

[0112] In this embodiment, the second impedance enhancement circuit 122 includes a fourth transistor and a second bias voltage unit 124. The first terminal of the fourth transistor is connected to the power supply voltage, the control terminal of the fourth transistor is connected to the second bias voltage unit 124, and the second terminal of the fourth transistor is connected to the first terminal of the second transistor. The function of the second bias voltage unit 124 is to provide a base bias voltage for the fourth transistor.

[0113] like Figure 7 As shown, in this embodiment, the DC module 110 includes two current sources, denoted by I1 and I2 respectively; the transconductance linear module 130 includes four NPN transistors, denoted by Q1 to Q4 respectively, wherein the first transistor is Q4 and the second transistor is Q3; the third transistor in the first impedance enhancement circuit 121 is denoted by Q5, taking an N-type transistor as an example, and the first impedance enhancement circuit 121 is used to equivalently amplify the output resistance of the first transistor; the fourth transistor in the second impedance enhancement circuit 122 is denoted by Q6, taking an NPN transistor as an example, and the second impedance enhancement circuit 122 is used to equivalently amplify the output resistance of the fourth transistor; the output nonlinear current is denoted by I... out express.

[0114] During the operation of the first impedance enhancement circuit 121, the first bias voltage unit 123 provides a base bias voltage to the third transistor, thereby making the third transistor in a conducting state and achieving the effect of effectively increasing the output resistance of the first transistor.

[0115] During the operation of the second impedance enhancement circuit 122, the second bias voltage unit 124 provides a base bias voltage to the fourth transistor, thereby making the fourth transistor in the conducting state and achieving the effect of effectively increasing the output resistance of the second transistor.

[0116] The first impedance enhancement circuit 121 can effectively increase the output resistance r of the first transistor. o4 This reduces the impact of power supply voltage fluctuations on I. outDue to the influence of the first impedance enhancement circuit 121, it is embedded between the collector of the first transistor and the target circuit 200. Through this second impedance enhancement circuit 122, the output resistance r of the second transistor can be effectively increased. o3 This reduces the impact of power supply voltage fluctuations on I. out The second impedance enhancement circuit 122 is embedded between the collector of the second transistor and the power supply voltage. By introducing the first impedance enhancement circuit 121 and the second impedance enhancement circuit 122, the fluctuation of the power supply voltage will be affected by ΔI. out The relationship becomes:

[0117]

[0118] From equation (8) above, it can be seen that r o3 This is equivalent to increasing G2 by a factor, where G2 is the intrinsic gain of the fourth transistor Q6. If G2 >> 1, then I out The impact of power supply voltage fluctuations will be further reduced, thus the nonlinear current generation circuit 100 output by the nonlinear current generation circuit 100 in this embodiment is suitable for scenarios with a wider power supply voltage.

[0119] As one implementation method, such as Figure 8 As shown, the second bias voltage unit 124 includes a second current generating device 126. One end of the second current generating device 126 is connected to the power supply voltage, and the other end of the second current generating device 126 is connected to the control terminal of the fourth transistor.

[0120] In this embodiment, the second bias voltage unit 124 includes a second current generating device 126. The two ends of the second current generating device 126 are respectively connected to the power supply voltage and the control terminal of the fourth transistor. The second current generating device 126 can be any device that can provide a stable current; this embodiment does not specifically limit its capabilities. For example, the second current generating device 126 can be a current source.

[0121] In one embodiment, the second bias voltage unit 124 further includes a second unidirectional conducting device 128, one end of which is connected to the other end of the second current generating device 126, and the other end of which is grounded.

[0122] In this embodiment, the second bias voltage unit 124 further includes a second unidirectional conducting device 128. The second current generating device 126 is grounded through the second unidirectional conducting device 128. The second single-phase conduction can be any device capable of achieving single-phase conduction, and this embodiment does not specifically limit it. For example, in this embodiment, the second unidirectional conducting device 128 can be a plurality of diodes connected end to end.

[0123] As an example, in this embodiment, the first unidirectional conducting device 127 includes a diode and / or a field-effect transistor. In this embodiment, the first unidirectional conducting device 127 can be either a diode or a field-effect transistor, and the specific choice can be determined according to the actual situation. This embodiment does not impose a specific limitation on this.

[0124] It should be noted that the second unidirectional conducting device 128 is a diode, or it can be a field-effect transistor. The specific type can be determined according to the actual situation. This application does not make specific limitations on this.

[0125] The first unidirectional conducting device 127 and the second unidirectional conducting device 128 can be any one of the following: a number of diodes connected in sequence, a number of transistors connected in sequence, and a number of MOSFETs connected in sequence.

[0126] The following explanation uses the first unidirectional conducting device 127 as an example.

[0127] For example, such as Figure 9 As shown, the first unidirectional conducting device 127 can be a plurality of diodes connected end-to-end in sequence, and one end of the first current generating device 125 is grounded through these diodes connected end-to-end. The number of diodes can be determined according to actual conditions, and this embodiment does not impose a specific limitation on this. Figure 9 The first unidirectional conducting device 127, which includes three diodes, will be used as an example for illustration.

[0128] For example, such as Figure 10 As shown, the first unidirectional conducting device 127 can be several PNP transistors, and their connection method can be referred to Figure 10 The number of transistors can be determined according to actual conditions, and this application does not impose a specific limitation on this. Figure 10 The first unidirectional conducting device 127, which includes two PNP transistors, will be used as an example for explanation.

[0129] For example, such as Figure 11 As shown, the first unidirectional conducting device 127 can be several NPN transistors, and their connection method can be referred to Figure 11 The number of transistors can be determined according to actual conditions, and this application does not impose a specific limitation on this. Figure 11 The first unidirectional conducting device 127, which includes two NPN transistors, will be used as an example for explanation.

[0130] For example, such as Figure 12 As shown, the first unidirectional conducting device 127 can be a plurality of PMOS transistors, and their connection method can be referred to Figure 12The number of PMOS transistors can be determined according to actual conditions, and this application does not impose a specific limitation on this. Figure 12 The first unidirectional conducting device 127, which includes two PMOS transistors, will be used as an example for explanation.

[0131] For example, such as Figure 13 As shown, the first unidirectional conducting device 127 can be several NMOS transistors, and their connection method can be referred to Figure 13 The number of NMOS transistors can be determined according to actual conditions, and this application embodiment does not impose a specific limitation on this. Figure 13 The first unidirectional conducting device 127, which includes two NMOS transistors, will be used as an example for explanation.

[0132] This application embodiment includes both a first impedance enhancement circuit 121 and a second impedance enhancement circuit 122, such as Figure 14 As shown, the first impedance enhancement circuit 121 includes three diodes connected in sequence as a current-limiting power supply, and the second impedance enhancement circuit 122 includes two diodes connected in sequence as a current-limiting unit 123. The first impedance enhancement circuit 121 is embedded between the collector of Q4 and the power supply voltage, and the second impedance enhancement circuit 122 is embedded between the collector of Q3 and ground. By introducing the first impedance enhancement circuit 121 and the second impedance enhancement circuit 122, the difference between ΔVDD and ΔI will be reduced. out The relationship becomes:

[0133]

[0134] From the above formula, we can see that r o3 r o4 Each of these factors is equivalent to increasing G1 and G2 by a factor of 1. If G1 and G2 >> 1, then I... out The impact of VDD fluctuations will be greatly reduced, and the improved nonlinear current generation circuit 100 is suitable for scenarios with a wider range of power supply voltages.

[0135] This application provides various implementation schemes for the impedance enhancement module 120, which can adopt corresponding solutions for different application scenarios. out When minimizing the impact of VDD, one can adopt... Figure 14 The proposed scheme simultaneously increases r by an equivalent amount. o3 and r o4 When I out When the degree of influence from VDD is not strictly required, it can be adopted. Figure 5 The proposed solution only applies to r. o3 or r o4 Perform an equivalent increase.

[0136] It should be noted that, in the embodiments of this application, the first transistor, the second transistor, the third transistor, and the fourth transistor can be any one of P-type transistors, N-type transistors, PMOS transistors, and NMOS transistors.

[0137] As an example, Figure 14 Q1 to Q6 are all P-type transistors, and their connection relationship is as follows: Figure 14 As shown, the transconductance linear module 130 can be a ring circuit composed of four P-type transistors. In this case, the first and second transistors are both P-type transistors; the third and fourth transistors are also P-type transistors.

[0138] As yet another example Figure 15 Q1 to Q6 are all N-type transistors, and their connection relationship is as follows: Figure 15 As shown, the transconductance linear module 130 can be a ring circuit composed of four N-type transistors. In this case, the first transistor and the second transistor are both N-type transistors; the third transistor and the fourth transistor are also N-type transistors.

[0139] As another example Figure 16 Q1 to Q6 are all PMOS transistors, and their connection relationship is as follows: Figure 16 As shown, the transconducting linear module 130 can be a ring circuit composed of four PMOS transistors. In this case, the first and second transistors are both PMOS transistors; the third and fourth transistors are also PMOS transistors.

[0140] As another example Figure 17 Q1 to Q6 are all NMOS transistors, and their connection relationship is as follows: Figure 17 As shown, the transconducting linear module 130 can be a ring circuit composed of four NMOS transistors. In this case, the first and second transistors are both NMOS transistors; the third and fourth transistors are also NMOS transistors.

[0141] In some embodiments, such as Figure 18 As shown, the nonlinear current generating circuit 100 further includes:

[0142] The current mirror module 140 is used to amplify the nonlinear current proportionally.

[0143] In this embodiment of the application, due to the nonlinear current I outDue to the influence of the preceding transconducting linear circuit, its size may not meet the requirements of the target circuit 200, therefore a current mirror module 140 is added. The nonlinear current generating circuit 100 also includes a current mirror module 140, whose input terminal is connected to the output terminal of the transconducting linear module 130. The current mirror module 140 receives the nonlinear current output by the transconducting linear module 130 and amplifies this nonlinear current proportionally to obtain an amplified nonlinear current. In this embodiment, I is used. out1 This represents the amplified nonlinear current, with an amplification ratio of B, such that the amplified nonlinear current I... out1 with I out It has a specific ratio B, which can be set according to the requirements of the target circuit 200.

[0144] exist Figure 15 With the circuit configuration shown, adding a current mirror module 140, analysis reveals that the impedance gains G1 and G2 mentioned earlier are VA5 / VT and VA6 / VT, respectively. VA5 and VA6 are the Erlich voltages of Q5 and Q6 (typically in the 50V range), VT is the thermal voltage (approximately 26mV at room temperature), and G1 and G2 are typically in the 2000 range. That is to say, I... out1 The impact of VDD fluctuations is reduced by a factor of 2000. Therefore, even if VDD fluctuates within a wide range, I... out1 It can remain basically unchanged.

[0145] This application provides a chip that includes the aforementioned nonlinear current generating circuit 100. The chip (Integrated Circuit, IC) can be, but is not limited to, a System on Chip (SOC) chip or a System in Package (SIP) chip.

[0146] This application provides an electronic device, which includes a device body and a nonlinear current generating circuit 100 or chip as described above, disposed within the device body. The electronic device may be, but is not limited to, a weight scale, body fat scale, nutrition scale, infrared electronic thermometer, pulse oximeter, body composition analyzer, power bank, wireless charger, fast charger, car charger, adapter, display, USB (Universal Serial Bus) docking station, stylus, true wireless earphones, car center console screen, automobile, smart wearable device, mobile terminal, and smart home device. Smart wearable devices include, but are not limited to, smartwatches, smart bracelets, and neck massagers. Mobile terminals include, but are not limited to, smartphones, laptops, tablets, and POS (Point of Sales Terminal) machines. Smart home devices include, but are not limited to, smart sockets, smart rice cookers, smart robot vacuums, and smart lights.

[0147] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is used as an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above.

[0148] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A nonlinear current generating circuit, characterized in that, include: DC module, used to output initial DC current; Impedance enhancement module; The transconducting linear module includes a first transistor, which is the output stage transistor of the transconducting linear module. The impedance enhancement module is connected to the first transistor and is used to effectively increase the output resistance of the first transistor. The transconducting linear module is used to perform nonlinear transformation on the initial DC current under the power supply voltage and output a nonlinear current.

2. The nonlinear current generating circuit according to claim 1, characterized in that, The transconducting linear module includes a second transistor connected to the control terminal of the first transistor, and the impedance enhancement module includes a first impedance enhancement circuit and a second impedance enhancement circuit, wherein: The first impedance enhancement circuit is connected to the first transistor and is used to effectively increase the output resistance of the first transistor. The second impedance enhancement circuit is connected to the second transistor and is used to effectively increase the output resistance of the second transistor.

3. The nonlinear current generating circuit according to claim 2, characterized in that, The first impedance enhancement circuit includes a third transistor and a first bias voltage unit, wherein: The first terminal of the third transistor is used to connect to the target circuit, the control terminal of the third transistor is connected to the first bias voltage unit, and the second terminal of the third transistor is connected to the first terminal of the first transistor. The first bias voltage unit is used to provide a bias voltage for the third transistor.

4. The nonlinear current generating circuit according to claim 3, characterized in that, The first bias voltage unit includes a first current generating device, one end of which is connected to the power supply voltage, and the other end of which is connected to the control terminal of the third transistor.

5. The nonlinear current generating circuit according to claim 4, characterized in that, The first bias voltage unit further includes a first unidirectional conducting device, one end of which is connected to the other end of the first current generating device, and the other end of which is grounded.

6. The nonlinear current generating circuit according to claim 2, characterized in that, The second impedance enhancement circuit includes a fourth transistor and a second bias voltage unit, wherein: The first terminal of the fourth transistor is connected to the power supply voltage, the control terminal of the fourth transistor is connected to the second bias voltage unit, and the second terminal of the fourth transistor is connected to the first terminal of the second transistor. The second bias voltage unit is used to provide a bias voltage for the fourth transistor.

7. The nonlinear current generating circuit according to claim 6, characterized in that, The second bias voltage unit includes a second current generating device, one end of which is connected to the power supply voltage, and the other end of which is connected to the control terminal of the fourth transistor.

8. The nonlinear current generating circuit according to claim 7, characterized in that, The second bias voltage unit further includes a second unidirectional conducting device, one end of which is connected to the other end of the second current generating device, and the other end of which is grounded.

9. The nonlinear current generating circuit according to claim 5, characterized in that, The first unidirectional conducting device includes a diode and / or a field-effect transistor.

10. The nonlinear current generating circuit according to any one of claims 1 to 9, characterized in that, The nonlinear current generating circuit further includes: A current mirror module is used to amplify the nonlinear current proportionally.

11. A chip, characterized in that, Includes the nonlinear current generating circuit as described in any one of claims 1 to 10.

12. An electronic device, characterized in that, Includes the nonlinear current generating circuit as described in any one of claims 1 to 10, or the chip as described in claim 11.

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