A method for stabilizing current, current source circuit and electronic equipment

Abstract

The embodiment of the present invention provides a method for stabilizing current, a current source circuit and an electronic device, which are used to improve the accuracy and stability of the current output by the current source. The method includes: when the power interface is connected to the power supply voltage, generating a first current, a second current and a third current; the first current is the current flowing through the second module; the second current is the current flowing through the first module; the third current is the current flowing through the compensation module; wherein the first current is the sum of the second current and the third current; when the first current changes, adjusting the third current so that the second current is stable.

Description

Technical Field

[0001] The present invention relates to the field of circuits, and in particular to a method for stabilizing current, a current source circuit and electronic equipment. Background Art

[0002] A single-chip microcomputer system includes power management module, clock module, ADC / DAC and other modules. Each module requires a current source circuit to provide bias current to put the circuit into working state. Therefore, the accuracy of the bias current affects the working performance of each module. However, due to problems with integrated circuit technology and design, or due to unstable power supply voltage, the current provided by the current source may deviate. For the circuits of each module, such deviations may affect circuit performance, increase circuit power consumption, and even cause abnormal operation of the single-chip microcomputer. Therefore, how to provide a stable current is a problem that needs to be solved. Summary of the invention

[0003] The embodiments of the present invention provide a method for stabilizing current, a current source circuit and an electronic device, which can improve the stability of the current generated by the current source.

[0004] In a first aspect, an embodiment of the present invention provides a method for stabilizing current, which is applied to a current source circuit, wherein the current source circuit includes a power interface, a compensation module, a first path, and a second path, wherein the compensation module is connected between the power interface and a first node, wherein the first node is a node between a first module and a second module on the first path, and both the first path and the second path are connected between the power interface and a ground point, wherein the method includes:

[0005] When the power interface is connected to the power supply voltage, a first current, a second current and a third current are generated; the first current is the current flowing through the second module; the second current is the current flowing through the first module; the third current is the current flowing through the compensation module; wherein the first current is the sum of the second current and the third current;

[0006] When the first current changes, the third current is adjusted so that the second current remains stable.

[0007] Optionally, before the step of adjusting the third current when the first current changes so that the second current remains stable, the method further includes:

[0008] generating an output current, wherein the output current is a current on the second path; and the output current is positively correlated with the second current;

[0009] When the first current changes, adjusting the third current so that the second current remains stable includes:

[0010] When the first current changes, the third current is adjusted so that the output current remains stable.

[0011] Optionally, when the first current changes, adjusting the third current so that the second current remains stable includes:

[0012] When the first current increases by M, the third current is adjusted to increase by M so that the second current remains stable; or,

[0013] When the first current decreases by M, the third current is adjusted to decrease by M, so that the second current remains stable.

[0014] Optionally, the compensation module includes a first transistor, a source and a gate of the first transistor are connected to the power interface, a drain of the first transistor is connected to the first node, and the third current is a current flowing through the compensation module, including:

[0015] The third current is a current flowing through the first transistor.

[0016] Optionally, the first module includes a second transistor, a source of the second transistor is connected to the power interface, a gate and a drain of the second transistor are connected to the first node, the second path includes a third module, the third module includes a fourth transistor, a source of the fourth transistor is connected to the power interface, and the fourth transistor and the second transistor have a common gate;

[0017] The output current is positively correlated with the second current, including: the output current satisfies:

[0018]

[0019] Wherein, W3 and L3 are the width and length of the second transistor, W4 and L4 are the width and length of the fourth transistor, I3 is the second current, and I out2 is the output current; when the width and length of the second transistor and the fourth transistor are determined, the output current is positively correlated with the second current.

[0020] Optionally, the second module includes a third transistor and a second resistor, the drain of the third transistor is connected to the first node, the gate of the third transistor is connected to the power interface, the source of the third transistor is connected to the second resistor, and the other end of the second resistor is connected to the ground point; the power supply voltage also includes a sixth transistor and a seventh transistor, the drain of the sixth transistor is connected to the power interface, the sixth transistor and the third transistor have a common gate, the source of the sixth transistor is connected to the emitter of the seventh transistor, and the base and collector of the seventh transistor are connected to the ground point;

[0021] The first current is a current flowing through the third transistor in the second module, satisfying:

[0022]

[0023] Among them, the V be is the voltage between the base and emitter of the seventh transistor, the V gs1 is the voltage between the gate and source of the sixth transistor, the V th2 is the turn-on voltage of the third transistor, R2 is the resistance of the second resistor, I2 is the first current; V be and the V th2 is a fixed value, the V gs1 will change with the change of the power supply voltage, and the I2 will change with the V gs1 changes have occurred.

[0024] Optionally, when the first current changes, adjusting the third current so that the output current is stable includes:

[0025] When the first current undergoes a first change, adjusting the third current to a first value, and the corresponding output current to a second value;

[0026] When the first current undergoes a second change, the third current is adjusted to a third value, and the corresponding output current is a fourth value;

[0027] A coefficient n is determined based on the second value and the fourth value, and the coefficient n satisfies:

[0028]

[0029] When the coefficient η is less than the threshold, the output current I is determined out2 Stable; wherein said I out2_A is the second value, the I out2_B is the fourth value, the VCC Ais the value of the power supply voltage corresponding to the first change of the first current, the VCC B is the value of the power supply voltage corresponding to the second change of the first current.

[0030] In a second aspect, an embodiment of the present invention provides a current source circuit, including:

[0031] Power interface, used to connect to the power supply;

[0032] A compensation module, one end of which is connected to the power interface, and the other end of which is connected to the first node;

[0033] a first path, wherein the first path is a path between the power interface and a ground point; and the first node is a node between a first module and a second module on the first path;

[0034] A second path, the second path is another path between the power interface and the grounding point, and the second path includes a third module;

[0035] When the power interface is connected to the power supply voltage, a first current, a second current and a third current are generated; the first current is the current flowing through the second module; the second current is the current flowing through the first module; the third current is the current flowing through the compensation module; wherein the first current is the sum of the second current and the third current;

[0036] When the first current changes, the third current is adjusted so that the second current remains stable.

[0037] Optionally, the compensation module includes a first transistor; the source and gate of the first transistor are connected to the power interface, and the drain of the first transistor is connected to the first node; the current source circuit also includes a first resistor; one end of the first resistor is connected to the power interface, and the other end is connected to the gate of the first transistor.

[0038] Optionally, the first module includes a second transistor; a source of the second transistor is connected to the power interface, and a gate and a drain of the second transistor are connected to the first node.

[0039] Optionally, the second module includes a third transistor and a second resistor; the drain of the third transistor is connected to the first node, the gate of the third transistor is connected to the power interface, the source of the third transistor is connected to the second resistor, and the other end of the second resistor is connected to the ground point.

[0040] Optionally, the third module includes a fourth transistor and a fifth transistor; the source of the fourth transistor is connected to the power interface, and the fourth transistor and the second transistor have a common gate; the drain of the fourth transistor is connected to the gate and drain of the fifth transistor, and the source of the fifth transistor is connected to the ground point.

[0041] Optionally, the current source circuit further includes: a sixth transistor and a seventh transistor;

[0042] The drain of the sixth transistor is connected to the power interface, and the sixth transistor and the third transistor have a common gate; the source of the sixth transistor is connected to the emitter of the seventh transistor; and the base and collector of the seventh transistor are connected to the ground point.

[0043] In a third aspect, an embodiment of the present invention provides an electronic device, including:

[0044] Circuit boards; and,

[0045] The current source circuit integrated on the circuit board, the current source circuit is the current source circuit as described in the above second aspect or any one of the second aspects.

[0046] A method for stabilizing current provided in an embodiment of the present invention adds a compensation module in a current source circuit so that the current generated by the current source circuit does not change with the increase or decrease of the power supply voltage, thereby ensuring the accuracy and stability of the circuit output current and ensuring the stability of the circuit's working state and power consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 It is a current source circuit in the prior art;

[0048] Figure 2 A schematic diagram of the structure of a current source circuit provided by an embodiment of the present invention;

[0049] Figure 3 A schematic diagram of the structure of another current source circuit provided by an embodiment of the present invention;

[0050] Figure 4 A schematic diagram of the structure of another current source circuit provided by an embodiment of the present invention;

[0051] Figure 5 A schematic diagram of the structure of another current source circuit provided by an embodiment of the present invention;

[0052] Figure 6 A schematic diagram of the structure of another current source circuit provided by an embodiment of the present invention;

[0053] Figure 7A schematic diagram of the structure of another current source circuit provided by an embodiment of the present invention;

[0054] Figure 8 A schematic diagram of the structure of another current source circuit provided by an embodiment of the present invention;

[0055] Fig. 9 A schematic flow chart of a method for stabilizing current provided by an embodiment of the present invention;

[0056] Fig.10 A schematic diagram of an output current curve of a current source circuit provided by an embodiment of the present invention;

[0057] Fig.11 A schematic diagram of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0058] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the technical solution of the present invention, rather than all of the embodiments. Based on the embodiments recorded in the present invention document, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the technical solution of the present invention.

[0059] In the prior art, the bias current provided by the current source is easily affected by factors such as unstable power supply voltage and may produce deviations. Such deviations may affect the performance of the circuit, increase the power consumption of the circuit, and even cause abnormal conditions when the components in the circuit are working.

[0060] In view of this, an embodiment of the present invention provides a method for stabilizing current, which can ensure that the current generated by the current source circuit does not change with the increase or decrease of the power supply voltage, thereby ensuring the accuracy and stability of the circuit output current and ensuring the stability of the circuit's working state and power consumption.

[0061] The technical solution provided by the embodiments of the present invention is introduced below in conjunction with the accompanying drawings.

[0062] Figure 1 1 is a schematic diagram of a current source circuit in the prior art, including a start-up circuit 101 and a current source circuit 102 .

[0063] The startup circuit includes: a first PMOS transistor 103, a second PMOS transistor 104 and a first resistor 105; the power supply circuit 102 includes: a third PMOS transistor 106, a first NMOS transistor 107, a fourth PMOS transistor 108, a second NMOS transistor 109 and a second resistor 110. The third PMOS transistor 106 and the fourth PMOS transistor 108 are in a mirror relationship, and the first NMOS transistor 107 and the second NMOS transistor 109 are in a mirror relationship. When the current source circuit is connected to the power supply voltage (Volt Current Condenser, VCC), the calculation formula of the current flowing through the second branch is as follows:

[0064]

[0065] Wherein, W1 is the width of the third PMOS transistor 106, L1 is the length of the third PMOS transistor 106, W2 is the width of the fourth PMOS transistor 107, and L2 is the length of the fourth PMOS transistor 107. From formula (1), we can get I out1 .

[0066] Although the current source circuit 102 can reduce the influence of the power supply voltage on the output current of the current source, the circuit has an obvious disadvantage, that is, there will be a degeneracy point in the circuit. Due to the existence of the degeneracy point, when the current source circuit 102 is connected to the power supply voltage, the current in the circuit may be zero and remain in this abnormal state. Therefore, in order to avoid the generation of a degeneracy point in the current source circuit 102, it is necessary to additionally add a startup circuit 101 to the circuit so that the circuit can operate in a normal state when the power supply voltage is connected. However, although adding a startup circuit to the current source circuit can eliminate the degeneracy point, it will also cause the current source circuit to generate additional power consumption.

[0067] The current source circuit provided in the embodiment of the present invention eliminates the influence of the change of the power supply voltage on the output current by adopting a compensation method, thereby ensuring the stability of the output current. Moreover, the current source circuit in the embodiment of the present invention does not require an additional startup circuit, so no additional power consumption is generated.

[0068] Figure 2 A schematic diagram of the structure of a current source circuit provided by an embodiment of the present invention.

[0069] like Figure 2As shown, the current source circuit includes: a power interface 201, a compensation module 202, a first path 203 and a second path 204, wherein the first path 203 includes a first module 203a and a second module 203b, and the second path 204 includes a third module 204a. The power interface 201 is used to connect to VCC to provide voltage for the current source circuit in the embodiment of the present invention; one end of the compensation module 202 is connected to the power interface 201, and the other end is connected to the first node B, which is used to eliminate the influence of the change of the power supply voltage on the output current and ensure the stability of the output current; the first path 203 is a path between the power interface 201 and the ground point (GND), and the first node B is a node between the first module 203a and the second module 203b on the first path 203; the second path 204 is another path between the power interface 201 and the ground point (GND).

[0070] When the power supply interface 201 in the figure is connected to the power supply voltage, a corresponding current will be generated in the circuit, wherein the first current flowing through the second module 203b is the sum of the second current flowing through the first module 203a and the third current flowing through the compensation module 202. When the power supply voltage changes, the first current flowing through the second module 203b will also change accordingly. At this time, the compensation module 202 can adjust the third current so that the difference between the first current and the third current remains unchanged, so that the second current flowing through the first module 203a will not change with the change of the power supply voltage. In addition, the output current flowing through the second path 204 is positively correlated with the second current flowing through the first module. Therefore, when the second current flowing through the first module 203a does not change with the change of the power supply voltage, the output current of the circuit will not change with the change of the power supply voltage. The current source circuit provided in the embodiment of the present invention can output a stable current without adding an additional startup circuit. Compared with Figure 1 The current source circuit in the embodiment has a simpler structure, a smaller chip area, and a more stable output current.

[0071] Figure 3 A schematic diagram of the structure of another current source circuit provided by an embodiment of the present invention, optionally, the compensation module 202 (the portion surrounded by the dotted line in the figure) in the circuit may include a first transistor 301, the source and gate of the first transistor 301 are connected to the power interface 201, and the drain is connected to the first node B, wherein the first transistor 301 may be a PMOS transistor or a PNP transistor. When the first transistor 301 is a PNP transistor, the emitter and the base are connected to the power interface, and the collector is connected to the first node B.

[0072] It should be noted that Figure 3The compensation module 202 shown in the figure (the portion surrounded by the dotted line in the figure) is only an example of the structure of the compensation module. The compensation module can also be a circuit structure composed of other components as long as it can achieve the purpose of eliminating the influence of the change of the power supply voltage on the output current.

[0073] Figure 4 A schematic diagram of the structure of another current source circuit provided in an embodiment of the present invention. Optionally, the circuit may further include a first resistor 401 , one end of the first resistor 401 is connected to the power interface 201 , and the other end is connected to the gate of the first transistor 301 .

[0074] The embodiment of the present invention does not impose any limitation on the resistance value, model or quantity of the first resistor 401 .

[0075] like Figure 5 As shown, the first module 203a in the current source circuit may include a second transistor 501, wherein the second transistor 501 may be a PMOS transistor or a PNP transistor, which is not limited in the present invention. When the second transistor 501 is a PMOS transistor, its source is connected to the power interface 201, and its gate and drain are connected to the first node B. When the second transistor 501 is a PNP transistor, its transmitter is connected to the power interface 201, and its collector and base are connected to the first node B.

[0076] like Figure 6 As shown, optionally, the second module 203b may include a third transistor 601 and a second resistor 602. Wherein, the third transistor 601 may be an NMOS transistor or an NPN transistor, and the present invention does not impose any limitation on the model of the third transistor 601. When the third transistor 601 is an NMOS transistor, its drain is connected to the first node B, the gate is connected to the power interface 201, the source is connected to the second resistor 602, and the other end of the second resistor is connected to the ground point. Similarly, the embodiment of the present invention does not impose any limitation on the resistance value, model or quantity of the second resistor 602.

[0077] like Figure 7As shown, optionally, the third module 204a may include a fourth transistor 701 and a fifth transistor 702. The fourth transistor 701 may be a PMOS transistor or a PNP transistor; the fifth transistor 702 may be an NMOS transistor or an NPN transistor. When the fourth transistor 701 is a PMOS transistor and the fifth transistor 702 is an NMOS transistor, the source of the fourth transistor 701 is connected to the power interface, the fourth transistor 701 and the second transistor 501 have a common gate, and the drain of the fourth transistor 701 and the fifth transistor 702 have a common drain, the gate and drain of the fifth transistor 702 are connected, and the source is connected to the ground point.

[0078] like Figure 8 A current source circuit is shown, wherein the circuit may further include a sixth transistor 801 and a seventh transistor 802. The sixth transistor 801 may be an NMOS transistor, or may be replaced by an NPN transistor; the seventh transistor may be a PNP bipolar transistor, or may be replaced by a diode. When the sixth transistor 801 is an NMOS transistor, its drain is connected to the power interface 201, the sixth transistor 801 and the third transistor 601 have a common gate, the source of the sixth transistor 801 is connected to the emitter of the seventh transistor 802; the base and collector of the seventh transistor 802 are connected to the ground point.

[0079] The following is based on Figure 8 A method for stabilizing current provided by an embodiment of the present invention is specifically described.

[0080] See also Fig. 9 , is a flow chart of a method for stabilizing current provided by an embodiment of the present invention, which specifically includes the following steps:

[0081] Step 901: When the power interface is connected to the power supply voltage, a first current, a second current and a third current are generated, wherein the first current is the current flowing through the second module, the second current is the current flowing through the first module, the third current is the current flowing through the compensation module, and the first current is the sum of the second current and the third current.

[0082] like Figure 8 As shown, the substrates of all NMOS transistors are grounded, and the substrates of PMMOS transistors are connected to the power supply voltage. When the power supply interface is connected to the power supply voltage, a current is generated in the first resistor 401. As the power supply voltage increases, a current is also generated in the first path 203. The current flowing through the second module 203b is the first current. The specific calculation formula is shown in formula (2):

[0083]

[0084] Wherein, Vbe is the base and emitter voltage of the seventh transistor 802, Vgs1 is the gate and source voltage of the sixth transistor 801, and Vth2 is the turn-on voltage of the third transistor 602. R2 is the resistance value of the second resistor 602. Vbe is the forward bias voltage of the PN junction. In the traditional silicon-based process, Vbe will be determined after the process and size of the seventh transistor 802 are determined. For example, the value can be 0.7V.

[0085] The calculation formula of the turn-on voltage Vth2 of the third transistor 602 is shown in formula (3).

[0086]

[0087] Among them, Vth0 is the turn-on voltage of the long-channel MOS tube at zero bias. When the transistor process is determined, the value of Vth0 will be determined. γ is the body effect coefficient, φ s is the work function. The body effect coefficient γ and the work function φ s The calculations are shown in Equations 4 and 5.

[0088]

[0089] Among them, q is the electron charge, ξsi is the dielectric constant of silicon material, kB is the Boltzmann constant, Nsubstrate is the doping concentration of the tube substrate, Coxe is the gate oxide capacitance, T is the temperature, ni is the carrier concentration, and NDEP is the channel doping concentration. It can be seen from the formula that when the transistor process and temperature are determined, the body effect coefficient γ and the work function φ s is a constant value. The turn-on voltage Vth2 of the M2 tube is only related to Vbs2. When designing the circuit, the voltage at point C is equal to that at point D by adjusting the resistance value of R2, so that Vbs2 is equal to Vbe, and the value of Vbs2 is also kept at a constant value. In this way, the turn-on voltage Vth2 of the third transistor 602 is also a constant value. At the same time, it also means that the first current I2 is only related to Vgs1. Vgs1 will change with the change of the power supply voltage VCC, so the first current I2 will also change with the change of the power supply voltage VCC.

[0090] when Figure 8 When the first transistor 301 is not present in the circuit shown, the current on the first path 203 is the first current I2, that is, the first current I2 is equal to the second current I3. Because the second transistor 501 and the fourth transistor 701 are in a mirror relationship, the output current I out2 The calculation formula is shown in formula (6):

[0091]

[0092] Wherein, W3 and L3 are the width and length of the second transistor 501, and W4 and L4 are the width and length of the fourth transistor 701. When the sizes of the second transistor 501 and the fourth transistor 701 are determined, the output current I out2 is positively correlated with the second current I3, and because the first current I2 is equal to the second current I3. Therefore, the output current I out2 will also change with the change of the first current I2, that is to say, the output current I out2 It will still change with the change of power supply voltage.

[0093] Step 902: When the first current changes, adjust the third current so that the second current remains stable.

[0094] In the embodiment of the present invention, a compensation module 202 is added. When the power supply voltage rises, the relationship between the second current I3 flowing through the first module 203a and the third current I4 flowing through the compensation module 202 is as shown in formula (7):

[0095] I3=I2-I4 (7)

[0096] It can be seen from the formula that the compensation module reduces the current flowing through the second transistor 501. From formula (2) and the above analysis, it can be seen that the first current I2 increases as the power supply voltage VCC increases (or decreases as the power supply voltage VCC decreases).

[0097] Because when the power supply voltage VCC rises, the |Vgs6| of the first transistor 301 will increase as the power supply voltage increases (or decrease as the power supply voltage VCC decreases), so that the third current I4 flowing through the first transistor 301 will also increase as the power supply voltage VCC increases (or decrease as the power supply voltage VCC decreases). Therefore, the third current I4 will offset the change of the first current I2 with the power supply voltage VCC to a certain extent, making the second current I3 relatively stable. This avoids the output current I out2 Varies with supply voltage.

[0098] Optionally, when the power supply voltage changes and causes the first current I2 to change, the size of the first transistor 301 can be adjusted to change the third current I4 flowing through the first transistor 301, thereby adjusting the size of the second current I3, and thereby adjusting the output current I out2 The size is adjusted so that the output current I out2 Stay steady.

[0099] Specifically, when the first current I2 increases by M, the first transistor 301 can be adjusted to increase the third current I4 by M, so that the second current I3 remains stable, and thus the output current I out2 Stay stable;

[0100] Alternatively, when the first current I2 decreases by M, the first transistor 301 may be adjusted to reduce the third current I4 by M, so that the second current I3 remains stable, thereby making the output current I out2 Stay stable;

[0101] Optional, output current I out2 Maintaining stability means that the coefficient η used to characterize the stability of the output current is less than a threshold value, indicating that the output current is stable, for example:

[0102] When the first current I2 undergoes a first change, the third current I4 is adjusted to a first value, and the corresponding output current I out2 is the second value;

[0103] When the first current I2 undergoes a second change, the third current I4 is adjusted to a third value, and the corresponding output current I out2 is the fourth value;

[0104] The coefficient n is determined based on the second value and the fourth value, wherein the coefficient n satisfies:

[0105]

[0106] When the coefficient η is less than the threshold, the output current I is determined out2 Stable; among them, I out2_A is the second value, I out2_B is the fourth value, the VCC A is the value of the power supply voltage corresponding to the first change of the first current, the VCC B is the value of the power supply voltage corresponding to the second change of the first current.

[0107] Optionally, the coefficient η can also be calculated using formula (9).

[0108]

[0109] Among them, I out2_max is the output current I when the first current I2 changes out2 The maximum value, I out2_min When the first current I2 changes, the output current I out2 The minimum value of VCC _max is the maximum value of the power supply voltage corresponding to the change of the first current I2, VCC _min is the minimum value of the power supply voltage corresponding to when the first current I2 changes.

[0110] When the operating voltage range of the power supply voltage VCC is determined, the third current I4 can be adjusted according to the value of the first current I2, so as to minimize the output current I out2 The difference between the maximum and minimum values ​​reduces the coefficient of change of the current with the power supply voltage, thereby improving the stability of the output voltage.

[0111] The embodiment of the present invention simulates the current source circuit with the compensation module and the current source circuit without the compensation module respectively, and the output current curve is as follows: Fig.10 As shown. Curve 1001 is the output current when there is a compensation module, and curve 1002 is the output current when there is no compensation module. It can be clearly seen that compared with the case without the compensation module, the bias current I generated by the current source circuit with the compensation module added out2 The change with the power supply voltage is very small. When the power supply voltage is in the range of 2.8-5.5V, the output current I out2 The maximum and minimum values ​​of the current source circuit with compensation module are 6.041uA and 5.005uA respectively, so the coefficient of variation of the output current with the power supply voltage is (6.041-5.005) / (5.5-2.8)=0.38uA / V; the output current I out2 The maximum and minimum values ​​of the output current are 5.238uA and 5.005uA respectively. The coefficient of change of the output current with the power supply voltage η can be calculated by formula 8 as (5.238-5.005) / (5.5-2.8)=0.08uA / V. It can be seen that when the power supply voltage changes by 1V within the working range, the output current I out2 The current changes by only 0.08uA, which is smaller than the current change of the uncompensated module.

[0112] See also Fig.11 Based on the same inventive concept, an embodiment of the present invention provides an electronic device, including:

[0113] Circuit board 1101; and

[0114] The current source circuit 1102 integrated on the circuit board is as described above. Figures 2 to 8 Any of the current source circuits provided in .

[0115] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A method for stabilizing electric current, characterized in that: Applied to a current source circuit, the current source circuit includes a power interface, a compensation module, a first path and a second path, the compensation module is connected between the power interface and a first node, the first node is a node between a first module and a second module on the first path, the first path and the second path are both connected between the power interface and a ground point, the method includes: When the power interface is connected to the power supply voltage, a first current, a second current and a third current are generated; the first current is the current flowing through the second module; the second current is the current flowing through the first module; the third current is the current flowing through the compensation module; wherein the first current is the sum of the second current and the third current; When the first current changes, adjusting the third current so that the second current remains stable; Wherein, the compensation module comprises a first transistor, a source and a gate of the first transistor are connected to the power interface, and a drain of the first transistor is connected to the first node; The first module includes a second transistor, a source of the second transistor is connected to the power interface, and a gate and a drain of the second transistor are connected to the first node; The second module includes a third transistor and a second resistor, the drain of the third transistor is connected to the first node, the gate of the third transistor is connected to the power interface, the source of the third transistor is connected to the second resistor, and the other end of the second resistor is connected to the ground point.

2. The method according to claim 1, characterized in that Before the step of adjusting the third current so that the second current remains stable when the first current changes, the method further comprises: generating an output current, wherein the output current is a current on the second path; and the output current is positively correlated with the second current; When the first current changes, adjusting the third current so that the second current remains stable includes: When the first current changes, the third current is adjusted so that the output current remains stable.

3. The method according to claim 1 or 2, characterized in that When the first current changes, adjusting the third current so that the second current remains stable includes: When the first current increases by M, the third current is adjusted to increase by M so that the second current remains stable; or, When the first current decreases by M, the third current is adjusted to decrease by M so that the second current remains stable.

4. The method according to claim 1, characterized in that The third current is a current flowing through the compensation module, including: The third current is a current flowing through the first transistor.

5. The method according to claim 2, characterized in that The second path includes a third module, the third module includes a fourth transistor and a fifth transistor, the source of the fourth transistor is connected to the power interface, the fourth transistor and the second transistor have a common gate; the drain of the fourth transistor is connected to the gate and drain of the fifth transistor, and the source of the fifth transistor is connected to the ground point; The output current is positively correlated with the second current, including: the output current satisfies: Wherein, W3 and L3 are the width and length of the second transistor, W4 and L4 are the width and length of the fourth transistor, I3 is the second current, and I out2 is the output current; when the width and length of the second transistor and the fourth transistor are determined, the output current is positively correlated with the second current.

6. The method according to claim 1, characterized in that The power supply voltage further includes a sixth transistor and a seventh transistor, the drain of the sixth transistor is connected to the power interface, the sixth transistor and the third transistor have a common gate, the source of the sixth transistor is connected to the emitter of the seventh transistor, and the base and collector of the seventh transistor are connected to the ground point; The first current is a current flowing through the third transistor in the second module, satisfying: Among them, the V be is the voltage between the base and emitter of the seventh transistor, the V gs1 is the voltage between the gate and source of the sixth transistor, the V th2 is the turn-on voltage of the third transistor, R2 is the resistance of the second resistor, I2 is the first current; V be and the V th2 is a fixed value, the V gs1 will change with the change of the power supply voltage, and the I2 will change with the V gs1 changes have occurred.

7. The method according to claim 2, characterized in that When the first current changes, adjusting the third current so that the output current is stable includes: When the first current undergoes a first change, adjusting the third current to a first value, and the corresponding output current to a second value; When the first current undergoes a second change, the third current is adjusted to a third value, and the corresponding output current is a fourth value; A coefficient n is determined based on the second value and the fourth value, and the coefficient n satisfies: When the coefficient η is less than the threshold, the output current I is determined out2 Stable; wherein said I out2_A is the second value, the I out2_B is the fourth value, the VCC A is the value of the power supply voltage corresponding to the first change of the first current, the VCC B is the value of the power supply voltage corresponding to the second change of the first current.

8. A current source circuit, characterized in that: include: Power interface, used to connect to the power supply; A compensation module, one end of which is connected to the power interface, and the other end of which is connected to the first node; A first path, wherein the first path is a path between the power interface and a ground point; The first node is a node between the first module and the second module on the first path; A second path, the second path is another path between the power interface and the grounding point, and the second path includes a third module; When the power interface is connected to the power supply voltage, a first current, a second current and a third current are generated; the first current is the current flowing through the second module; the second current is the current flowing through the first module; the third current is the current flowing through the compensation module; wherein the first current is the sum of the second current and the third current; When the first current changes, adjusting the third current so that the second current remains stable; Wherein, the compensation module comprises a first transistor, a source and a gate of the first transistor are connected to the power interface, and a drain of the first transistor is connected to the first node; The first module includes a second transistor, a source of the second transistor is connected to the power interface, and a gate and a drain of the second transistor are connected to the first node; The second module includes a third transistor and a second resistor, the drain of the third transistor is connected to the first node, the gate of the third transistor is connected to the power interface, the source of the third transistor is connected to the second resistor, and the other end of the second resistor is connected to the ground point; The third module includes a fourth transistor and a fifth transistor; the source of the fourth transistor is connected to the power interface, and the fourth transistor and the second transistor have a common gate; the drain of the fourth transistor is connected to the gate and drain of the fifth transistor, and the source of the fifth transistor is connected to the ground point.

9. The current source circuit according to claim 8, characterized in that: The current source circuit also includes a first resistor; one end of the first resistor is connected to the power interface, and the other end is connected to the gate of the first transistor.

10. The current source circuit according to claim 8, characterized in that: The current source circuit further includes: a sixth transistor and a seventh transistor; The drain of the sixth transistor is connected to the power interface, and the sixth transistor and the third transistor have a common gate; the source of the sixth transistor is connected to the emitter of the seventh transistor; and the base and collector of the seventh transistor are connected to the ground point.

11. An electronic device, characterized in that: include: Circuit boards; as well as, A current source circuit integrated on the circuit board, wherein the current source circuit is the current source circuit as described in any one of claims 8 to 10.

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