Voltage regulation circuit and battery management system

Abstract

The application provides a voltage regulating circuit and a battery management system. The voltage regulating circuit comprises: a bias current generation module configured to generate a bias current related to a voltage variation range of a power supply end according to a voltage value of the power supply end; a plurality of current modulation modules, each of which has a first modulation branch and a second modulation branch coupled with each other, each second modulation branch has a preset modulation coefficient, and the first modulation branch and the second modulation branch are configured to modulate a difference between a first current input to the first modulation branch and a second current output to a next current modulation module from the second modulation branch according to the preset modulation coefficient when the bias current varies, so as to generate a modulation current on the second modulation branch, and the bias current is input to the first modulation branch of the first current modulation module; and a voltage generation module configured to adjust a reference current to generate an output voltage. The above technical solution can improve the stability of the output voltage.

Description

Technical Field

[0001] This invention relates to the field of power management technology, and more particularly to a voltage regulation circuit and a battery management system. Background Technology

[0002] Battery Management System (BMS) is a key technology for ensuring the safe and efficient operation of batteries. It plays a vital role in many fields such as electric vehicles (EVs), energy storage systems, drones, and power tools.

[0003] In actual operation, fluctuations in the power supply cause changes in the output voltage of the battery management system, which will seriously affect the stability of operation.

[0004] Therefore, how to provide technical solutions to improve the stability of output voltage has become an urgent problem to be solved. Summary of the Invention

[0005] In view of this, the present invention provides a voltage regulation circuit and a battery management system that can improve the stability of the output voltage.

[0006] This invention provides a voltage regulation circuit coupled to a power supply terminal, comprising:

[0007] A bias current generation module is used to generate a bias current related to the voltage variation range of the power supply terminal based on the voltage value of the power supply terminal.

[0008] A multi-stage current modulation module is provided, wherein each stage of the current modulation module is sequentially coupled, and the first stage current modulation module is coupled to the bias current generation module. Each stage of the current modulation module has a first modulation branch and a second modulation branch coupled to each other. Each second modulation branch has a preset modulation coefficient. The first modulation branch and the second modulation branch in any stage of the current modulation module are used to modulate the difference between the first current input to the first modulation branch and the second current output to the next stage current modulation module according to the preset modulation coefficient when the bias current changes, so as to generate a modulation current in the second modulation branch and input it to the first modulation branch of the next stage current modulation module through the second modulation branch. The second modulation branch of the last stage of the current modulation module outputs a reference current, wherein the bias current is input to the first modulation branch of the first stage current modulation module.

[0009] The voltage generation module, coupled to the last-stage current modulation module, is used to adjust the reference current to generate the output voltage.

[0010] Optionally, each current modulation module includes: a first bipolar transistor and a second bipolar transistor disposed on the first modulation branch; a third bipolar transistor, a fourth bipolar transistor, and a current output resistor disposed on the second modulation branch; and a first current mirror unit connected to the second modulation branch, wherein:

[0011] The first bipolar transistor, the second bipolar transistor, the third bipolar transistor, and the fourth bipolar transistor constitute a current modulation unit of each stage of the current modulation module. The base current of the first bipolar transistor is different from that of the fourth bipolar transistor. The current modulation unit is used to generate a modulation current in the second modulation branch when the bias current changes, based on the current difference between the first current and the second current, and the ratio between the current difference and the collector current of the second bipolar transistor and the preset modulation coefficient. The preset modulation coefficient is the current amplification factor of the third bipolar transistor.

[0012] The first current mirroring unit is used to mirror the modulation current on the corresponding second modulation branch to generate a first mirrored current, and the first mirrored current of the last stage current modulation module is the reference current.

[0013] Optionally, the first bipolar transistor, the second bipolar transistor, the third bipolar transistor, and the fourth bipolar transistor in different levels of current modulation modules are matched, and the current output resistors in different levels of current modulation modules are matched.

[0014] Optionally, the base of the first bipolar transistor is connected to the base of the third bipolar transistor and the collector of the first bipolar transistor, respectively, and the emitter of the first bipolar transistor is connected to the base of the fourth bipolar transistor and the collector of the second bipolar transistor, respectively.

[0015] The base of the second bipolar transistor is connected to the emitter of the third bipolar transistor and the collector of the fourth bipolar transistor, respectively. The emitter of the second bipolar transistor is connected to the second terminal of the current output resistor and grounded.

[0016] The collector of the third bipolar transistor is connected to the first current mirror unit;

[0017] The emitter of the fourth bipolar transistor is connected to the first terminal of the current output resistor.

[0018] Optionally, the first current mirror unit includes a first mirror transistor and a second mirror transistor. The control terminal of the first mirror transistor is connected to the control terminal of the second mirror transistor, the second terminal of the first mirror transistor, and the second modulation branch, respectively. The first terminal of the first mirror transistor and the first terminal of the second mirror transistor are connected and connected to the power supply terminal. The second terminal of the second mirror transistor is used to output the first mirror current.

[0019] Optionally, the voltage generation module includes: a second mirror unit and a voltage generation unit, wherein:

[0020] The second mirror unit is coupled to the last stage current modulation module and the voltage generation unit respectively, and is used to mirror the reference current back to the voltage generation unit;

[0021] The voltage generation unit is used to adjust the reference current, convert the type of the reference current, generate the output voltage, and output the output voltage.

[0022] Optionally, the second mirror unit includes: a fifth bipolar transistor and a sixth bipolar transistor, wherein:

[0023] The base of the fifth bipolar transistor is connected to the base of the sixth bipolar transistor and the collector of the sixth bipolar transistor, respectively. The collector of the fifth bipolar transistor is connected to the current modulation module and the voltage generation unit of the last stage, respectively. The emitter of the fifth bipolar transistor is connected to the emitter of the sixth bipolar transistor and grounded.

[0024] Optionally, the voltage generation unit includes a gating switch and a first conversion resistor, wherein the control terminal of the gating switch is connected to the second mirror unit, the first terminal of the gating switch is connected to the power supply terminal, and the second terminal of the gating switch is connected to the first terminal of the first conversion resistor and serves as the output terminal;

[0025] The second end of the first conversion resistor is connected to the second mirror unit.

[0026] Optionally, the voltage generation unit further includes: a reference voltage branch located between the selector switch and the conversion resistor, the reference voltage branch including a second conversion resistor and a seventh bipolar transistor, wherein the first end of the second conversion resistor is coupled to the second end of the selector switch, the second end of the second conversion resistor is connected to the collector and base of the seventh bipolar transistor respectively, and the emitter of the seventh bipolar transistor is connected to the first end of the first conversion resistor.

[0027] Optionally, the voltage regulation circuit further includes at least one of the following:

[0028] The first capacitor is coupled to the input terminal of the voltage generation unit and the output terminal of the last stage current modulation module, respectively.

[0029] An output capacitor coupled between the output terminal of the voltage generation unit and ground.

[0030] Optionally, the bias current generation module includes a bias resistor.

[0031] Accordingly, the present invention also provides a battery management system, including a voltage regulation circuit as described in any of the foregoing examples.

[0032] Compared with the prior art, the technical solution of the embodiments of the present invention has the following advantages:

[0033] The voltage regulation circuit provided in this embodiment of the invention generates a bias current that is related to the voltage variation range of the power supply terminal. When the voltage variation range of the power supply terminal is large, the bias current variation range is also large. By enabling each second modulation branch in the multi-stage current modulation module to have a preset modulation coefficient, the first and second modulation branches in any stage of the current modulation module can, according to the preset modulation coefficient, modulate the difference between the first current input to the first modulation branch and the second current output to the next stage current modulation module. Through multiple modulations, the influence of the voltage variation range of the power supply terminal on the reference current can be gradually reduced. In other words, by adjusting the changing bias current in multiple stages based on the preset modulation coefficient, the influence of voltage variations at the power supply terminal on the reference current output by the final stage current modulation module can be greatly suppressed, resulting in higher stability of the reference current and thus improving the stability of the output voltage. Attached Figure Description

[0034] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments of the present invention or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1 This is a schematic diagram of a voltage regulation circuit according to an embodiment of the present invention;

[0036] Figure 2 This is a schematic diagram of the structure of a current modulation module in an embodiment of the present invention;

[0037] Figure 3 This is a schematic diagram illustrating the derivation principle of a multi-level suppression principle in an embodiment of the present invention;

[0038] Figure 4 This is a schematic diagram of the specific structure of a voltage regulation circuit in an embodiment of the present invention. Detailed Implementation

[0039] As described in the background section, when power supply fluctuations occur, the output voltage of the battery management system changes. This is because the voltage regulation circuit in the existing solution uses a bipolar transistor, which directly ignores the base current when determining the generated reference current. This approach is satisfactory when the circuit power consumption is high, the temperature variation range of the power supply is small, and the current gain of the bipolar transistor is large. However, when one of the above three conditions is not met, the reference current deviates significantly, resulting in greater variations in the output voltage under PVT (i.e., process, voltage, and temperature), thus failing to meet the output requirements.

[0040] For example, when the voltage change at the power supply terminal is more than 10 times (e.g., the voltage change range at the power supply terminal is 10V to 100V), and the current gain of the bipolar transistor is small, the base current of the two bipolar transistors will be inconsistent. The existing solution ignores the base current when the base current of the two bipolar transistors is the same, and infers that the reference current is not affected by the voltage change at the power supply terminal. However, in practical applications, the inventors found that if the base current is ignored directly, the reference current will follow the voltage change at the power supply terminal, and the stability of the output voltage will be poor.

[0041] To address the aforementioned technical problems, this invention provides a voltage regulation circuit coupled to a power supply terminal, comprising: a bias current generation module for generating a bias current related to the voltage variation range of the power supply terminal based on the voltage value of the power supply terminal; and a multi-stage current modulation module, wherein each stage of the current modulation module is sequentially coupled, and the first stage current modulation module in the multi-stage current modulation module is coupled to the bias current generation module, wherein each stage of the current modulation module has a first modulation branch and a second modulation branch coupled to each other, and each second modulation branch has a preset modulation coefficient, wherein the first modulation branch and the second modulation branch in any stage of the current modulation module are used to adjust the bias current generation module based on the voltage variation range of the power supply terminal; When the bias current changes, the difference between the first current input to the first modulation branch and the second current output to the next-stage current modulation module on the second modulation branch is modulated according to the preset modulation coefficient, so as to generate a modulation current on the second modulation branch and input it to the first modulation branch of the next-stage current modulation module. The second modulation branch of the last-stage current modulation module outputs a reference current, wherein the bias current is input to the first modulation branch of the first-stage current modulation module. A voltage generation module, coupled to the last-stage current modulation module, is used to adjust the reference current and generate an output voltage.

[0042] Using the voltage regulation circuit in the above embodiments, the bias current generation module generates a bias current related to the voltage variation range of the power supply terminal. When the voltage variation range of the power supply terminal is large, the bias current variation range is also large. By enabling each second modulation branch in the multi-stage current modulation module to have a preset modulation coefficient, the first and second modulation branches in any stage of the current modulation module can, according to the preset modulation coefficient, modulate the difference between the first current input to the first modulation branch and the second current output to the next stage current modulation module. Through multiple modulations, the influence of the voltage variation range of the power supply terminal on the reference current can be gradually reduced. In other words, by adjusting the changing bias current in multiple stages based on the preset modulation coefficient, the influence of voltage variations at the power supply terminal on the reference current output by the final stage current modulation module can be greatly suppressed, resulting in higher stability of the reference current and thus improving the stability of the output voltage.

[0043] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described below with reference to the accompanying drawings.

[0044] For ease of understanding, the following example uses a voltage regulation circuit with two current modulation modules to illustrate the structure and working principle of the voltage regulation circuit in this embodiment of the invention.

[0045] This invention provides a voltage regulation circuit, such as Figure 1 The diagram shown illustrates the structure of a voltage regulation circuit according to the present invention. The voltage regulation circuit may include:

[0046] The bias current generation module 110 is used to generate a bias current related to the voltage variation range of the power supply terminal based on the voltage value of the power supply terminal VDD.

[0047] A multi-stage current modulation module (e.g., a first-stage current modulation module 121 and a second-stage current modulation module 122) is provided, with each stage of the current modulation module sequentially coupled (e.g., the first-stage current modulation module 121 and the second-stage current modulation module 122 are coupled together, and the second-stage current modulation module 122 and the third-stage current modulation module are coupled together). The first-stage current modulation module 121 is coupled to the bias current generation module 110. Each stage of the current modulation module has a first modulation branch S1 and a second modulation branch S2 that are mutually coupled. Each second modulation branch S2 has a preset modulation coefficient β. The current modulation coefficient β is determined by the specific modulation level of each stage. The first modulation branch S1 and the second modulation branch S2 in the current modulation module are used to modulate the difference between the first current input to the first modulation branch S1 and the second current output to the next stage current modulation module according to the preset modulation coefficient β when the bias current changes, so as to generate a modulation current in the second modulation branch S2 and input it to the first modulation branch S1 of the next stage current modulation module through the second modulation branch S2. The second modulation branch S2 of the last stage current modulation module outputs a reference current, wherein the bias current is input to the first modulation branch S1 of the first stage current modulation module 121.

[0048] The voltage generation module 130 is coupled to the last-stage current modulation module and is used to adjust the reference current to generate an output voltage.

[0049] Specifically, when the voltage of the power supply terminal VDD fluctuates within a certain range, the bias current generated by the bias current generation module 110 varies with the voltage range of the power supply terminal VDD. The range of the bias current is large, and the value of the bias current is unstable.

[0050] The current in the first modulation branch S1 of the first-stage current modulation module 121 is the bias current. After modulation by the first modulation branch S1 and the second modulation branch S2 of the first-stage current modulation module 121, the current difference between the first modulation branch S1 and the second modulation branch S2 is affected by the power supply VDD to be 1 / β of the original value. After modulation by the first modulation branch S1 and the second modulation branch S2 of the second-stage current modulation module 122, the current difference between the first modulation branch S1 and the second modulation branch S2 is further reduced by the power supply VDD, and the degree of reduction is related to β. Since the current difference between the first modulation branch S1 and the second modulation branch S2 affects the reference current output by the last-stage current modulation module, the influence of the power supply VDD change on the reference current is reduced through multi-stage suppression, and the reference current is more stable.

[0051] In other words, the impact of voltage changes at the power supply terminal VDD on the voltage regulation circuit gradually decreases. With the addition of more cascaded current modulation modules, the influence of power supply terminal VDD on the voltage regulation circuit becomes 1 / β of its original value. n When n (where n is the number of current modulation modules) is large enough, the effect of voltage changes at the power supply terminal VDD on the voltage regulation circuit can be ignored. This results in higher stability of the reference current, thereby improving the stability of the output voltage.

[0052] It should be noted that, firstly, Figure 1 The illustrated voltage regulation circuit structure is for illustrative purposes only, intended to show that multi-stage current modulation modules can be configured to reduce the impact of power supply voltage variations on the output voltage; secondly, Figure 1 This invention uses a two-stage current modulation module as an example. In practical applications, more stages of current modulation modules can be set up. The present invention does not impose any limit on the number of current modulation modules.

[0053] In this embodiment, bias current generation modules with different structures can be used to convert the voltage at the power supply terminal into the corresponding bias current.

[0054] As an optional example, the bias current generation module may include a bias resistor, wherein a first end of the bias resistor is connected to a power supply terminal, and a second end of the bias resistor is connected to a first-stage current modulation module to provide bias current.

[0055] By using a bias resistor as the bias current generation module, the structure is simple and the overall size of the voltage regulation circuit can be reduced.

[0056] In this embodiment, the bias resistor is generally large in value, which can reduce the impact of power supply voltage changes on the reference current, thereby enabling a more stable output voltage to power other devices, circuits or components.

[0057] In some other embodiments, the bias current generation module may also be other devices capable of converting voltage into current.

[0058] In this embodiment, in order to reduce the influence of the power supply voltage on the reference current, the structures of the first modulation branch and the second modulation branch can be adaptively adjusted.

[0059] For example, combining Figure 1 See Figure 2 The diagram shown is a structural schematic of a current modulation module, as follows: Figure 2 As shown, each current modulation module (e.g., the first-stage current modulation module 121 and the second-stage current modulation module 122) includes: a first bipolar transistor Q1 and a second bipolar transistor Q2 disposed on the first modulation branch S1, a third bipolar transistor Q3, a fourth bipolar transistor Q4 and a current output resistor R2 disposed on the second modulation branch S2, and a first current mirror unit CM1 connected to the second modulation branch S2.

[0060] In this embodiment, the first bipolar transistor Q1, the second bipolar transistor Q2, the third bipolar transistor Q3, and the fourth bipolar transistor Q4 constitute the current modulation unit of each stage of the current modulation module. The base current of the first bipolar transistor Q1 is different from that of the fourth bipolar transistor Q4. Therefore, when determining the reference current, the difference in base current between the first bipolar transistor Q1 and the fourth bipolar transistor Q4 cannot be ignored. As a result, when the voltage at the power supply terminal changes, the reference current changes.

[0061] Based on this, the current modulation unit is used to generate a modulation current in the second modulation branch when the bias current changes (or can be considered as a change in the power supply terminal), according to the current difference between the first current and the second current, and the ratio between the current difference and the collector current of the second bipolar transistor and the preset modulation coefficient, wherein the preset modulation coefficient is the current amplification factor of the third bipolar transistor.

[0062] Specifically, for any current modulation module, the current difference between the first current and the second current can be modulated by the first bipolar transistor Q1, the second bipolar transistor Q2, the third bipolar transistor Q3, and the fourth bipolar transistor Q4. During the modulation process, the preset modulation coefficient β is the current amplification factor of the third bipolar transistor Q3. This reduces the influence of power supply VDD while making the bias current on the first modulation branch S1 and the current on the second modulation branch S2 tend to be the same (the difference between the two is very small, close to 0). As a result, the final output reference current is not affected by power supply VDD, and the reference current is more stable.

[0063] In this case, the first current mirror unit can be used to mirror the modulation current on the corresponding second modulation branch to generate the first mirror current, and the first mirror current of the last stage current modulation module is the reference current.

[0064] For example, the first current mirror unit CM1 can mirror the current in the second modulation branch of the first-stage current modulation module, the first current mirror unit CM1_A can mirror the current in the second modulation branch of the second-stage current modulation module, and so on. The last first current mirror unit can mirror the current in the second modulation branch of the last-stage current modulation module to serve as the reference current output.

[0065] In this embodiment, the first bipolar transistor Q1, the second bipolar transistor Q2, the third bipolar transistor Q3, and the fourth bipolar transistor Q4 in different stages of the current modulation module are matched, and the current output resistors R2 in different stages of the current modulation module are matched, so that each stage of the current modulation module has the same characteristics (e.g., temperature change characteristics, resistance change characteristics). This can reduce the error caused by the differences between the current modulation modules at each stage and further improve the stability of the output voltage.

[0066] It should be noted that the matching in this embodiment refers to the following: the first bipolar transistor Q1 in different levels of current modulation modules is the same, the second bipolar transistor Q2 in different levels of current modulation modules is the same, the third bipolar transistor Q3 in different levels of current modulation modules is the same, the fourth bipolar transistor Q4 in different levels of current modulation modules is the same, and the current output resistor R2 in different levels of current modulation modules is the same. Here, "same" means that the bipolar transistors are of the same type, the current output resistor R2 is of the same type, the temperature coefficient / temperature dependence is the same, the manufacturing process is the same, the wafer is the same, the manufacturing time is the same, and / or the position layout is the same. This matching mechanism can compensate for process variations and provide the same component temperature dependence.

[0067] In this embodiment, the connection relationship between the first modulation branch S1 and the second modulation branch S2 is as follows:

[0068] The base of the first bipolar transistor Q1 is connected to the base of the third bipolar transistor Q3 and the collector of the first bipolar transistor Q1, respectively. The emitter of the first bipolar transistor Q1 is connected to the base of the fourth bipolar transistor Q4 and the collector of the second bipolar transistor Q2, respectively.

[0069] The base of the second bipolar transistor Q2 is connected to the emitter of the third bipolar transistor Q3 and the collector of the fourth bipolar transistor Q4, respectively. The emitter of the second bipolar transistor Q2 is connected to the second terminal of the current output resistor R2 and grounded.

[0070] The collector of the third bipolar transistor Q3 is connected to the first current mirror unit CM1;

[0071] The emitter of the fourth bipolar transistor Q4 is connected to the first terminal of the current output resistor R2.

[0072] It should be noted that the collector of the first bipolar transistor Q1 in different stages of the current modulation module is connected to different structures.

[0073] For example, in the first-stage current modulation module, the collector of the first bipolar transistor Q1 is connected to the output terminal of the bias current generation module 110, for example, the collector of the first bipolar transistor Q1 is connected to the first terminal of the bias resistor R1; while in the other stages of the current modulation module, the collector of the first bipolar transistor Q1 is connected to the output terminal of the first mirror unit CM1 of the previous stage of the current modulation module.

[0074] In this embodiment, by configuring the parameters of the first bipolar transistor Q1, the second bipolar transistor Q2, the third bipolar transistor Q3, and the fourth bipolar transistor Q4, the bias current can be made to be similar to the current on the collector of the third bipolar transistor Q3.

[0075] In one specific embodiment, the first bipolar transistor Q1, the second bipolar transistor Q2, and the third bipolar transistor Q3 have the same effective size, and are all smaller than the effective size of the fourth bipolar transistor Q4. The effective size can refer to the area of ​​the bipolar transistor (wherein, the effective size can refer to the size of the component on the semiconductor die, for example, the effective size of the bipolar transistor can be increased by stacking multiple bipolar transistors with a common base, collector, and emitter in parallel).

[0076] In one alternative example, the ratio of the first bipolar transistor Q1, the second bipolar transistor Q2, the third bipolar transistor Q3, and the fourth bipolar transistor Q4 is 1:1:1:8.

[0077] It should be noted that, firstly, Figure 2 This explanation uses an example where the first bipolar transistor Q1, the second bipolar transistor Q2, the third bipolar transistor Q3, and the fourth bipolar transistor Q4 are NPN type. In some other embodiments, the first bipolar transistor Q1, the second bipolar transistor Q2, the third bipolar transistor Q3, and the fourth bipolar transistor Q4 can also be PNP type. This invention does not impose specific limitations on the type of bipolar transistor. Secondly, the ratio between the first bipolar transistor Q1, the second bipolar transistor Q2, the third bipolar transistor Q3, and the fourth bipolar transistor Q4 can be other values, and this embodiment does not impose any limitations on this.

[0078] In this embodiment, the first current mirror unit CM1 may include a first mirror transistor M1 and a second mirror transistor M2. The control terminal of the first mirror transistor M1 is connected to the control terminal of the second mirror transistor M2, the second terminal of the first mirror transistor M1, and the second modulation branch S2 (e.g., the collector of the third bipolar transistor Q3). The first terminal of the first mirror transistor M1 and the first terminal of the second mirror transistor M2 are connected and connected to the power supply terminal VDD. The second terminal of the second mirror transistor M2 is used to output the first mirror current.

[0079] It should be noted that the structure connected to the second terminal of the second mirror transistor M2 in different stages of the current modulation module is different.

[0080] For example, the second terminal of the second mirror transistor M2 in the last stage current modulation module is connected to the voltage generation module 130, while the second terminal of the second mirror transistor M2 in other stage current modulation modules is connected to the first modulation branch S1 in the next stage current modulation module.

[0081] Specifically, by using a mirror module CM1 composed of a first mirror transistor M1 and a second mirror transistor M2, the current on the second modulation branch S2 can be mirrored to generate a current with a corresponding mirror coefficient.

[0082] In an optional embodiment, the mirroring coefficient between the first mirror transistor M1 and the second mirror transistor M2 is 2, so the current output by the second mirror transistor M2 is twice the current on the second modulation branch S2.

[0083] It should be noted that, firstly, Figure 2The illustrated structure of the mirror module CM1 is for illustrative purposes only. In practical applications, more mirror transistors can be used, and this embodiment of the invention does not limit this; secondly, Figure 2 The first mirror transistor M1 and the second mirror transistor M2 shown are both PMOS transistors. In some other embodiments, the first mirror transistor M1 and the second mirror transistor M2 can both be NMOS transistors. The embodiments of the present invention do not limit the type of the first mirror transistor M1 and the second mirror transistor M2. Third, the mirror coefficient between the first mirror transistor M1 and the second mirror transistor M2 is also for illustrative purposes. Different mirror coefficients can be used in different application scenarios.

[0084] Therefore, the current modulation module with the above structure can reduce the influence of the power supply VDD on the reference current.

[0085] To facilitate understanding of the multi-level suppression principle in the embodiments of the present invention, the following examples will be used for illustration.

[0086] See Figure 3 The diagram shown illustrates the derivation principle of a multi-level suppression principle in this invention. Figure 3 As shown, the derivation process is as follows:

[0087]

[0088] As can be deduced above, the difference between I0 and I1 will be divided by β and reflected between IB_Q4 and IB_Q1. The value of I0 changes with the power supply terminal VDD. The above method can suppress the temperature influence of the power supply terminal VDD to a certain extent. However, when the power supply voltage changes by more than 10 times (10V-100V) and I1 or β is small, this difference cannot be ignored, which makes the stability of the reference current worse.

[0089] Furthermore, I1 consists of two parts: the first part is a constant, and the second part is affected by I0, which is related to the power supply VDD. Therefore, I1 is affected by the power supply VDD. By dividing the difference between I0 and I1 by β, suppressing the difference by a factor of β, and then taking the logarithm, the influence of the power supply VDD can be further reduced.

[0090] Similarly, after two stages, the second part is further suppressed by a factor of β, and the suppression capability is related to β. In this way, even if the power supply voltage changes by more than 10 times, the influence of VDD at the power supply terminal can be significantly reduced.

[0091] It should be noted that: First, in the above example, IE_Q1 represents the emitter current of the first bipolar transistor Q1, IE_Q3 represents the emitter current of the third bipolar transistor Q3, IB_Q4 represents the base current of the fourth bipolar transistor Q4, IB_Q1 represents the base current of the first bipolar transistor Q1, IC_Q1 represents the collector current of the first bipolar transistor Q1, and IC_Q2 represents the collector current of the second bipolar transistor Q2; Second, to distinguish the bipolar transistors, mirror transistors, and current output resistors in different stages of the voltage modulation module, different labels are used for illustration. For example, the labels for the first bipolar transistor include: Q1 and Q1_A; Third, V T This represents the thermal voltage of a bipolar transistor. This represents the ratio of the effective size of the first bipolar transistor Q3 to the effective size of the second bipolar transistor Q4.

[0092] In summary, the multi-stage current modulation module greatly suppresses the impact of voltage changes at the power supply end on the reference current output by the last-stage current modulation module, making the reference current tend to a constant value.

[0093] In this embodiment, the temperature characteristics of the reference current can also be controlled, wherein the temperature phase characteristics of the reference current depend on the temperature characteristics (dV) of the thermal voltage. T The temperature characteristics of the current output resistance (dR2 / dT) and the temperature characteristics of the thermal voltage are usually positive, i.e., they change in the positive direction with temperature. Therefore, the temperature characteristics of the current modulation module used to generate the reference current can be at least one of the following: a PTAT current generator that is proportional to the absolute temperature, a CTAT current generator that is complementary to the absolute temperature, and a current generator that is independent of the absolute temperature.

[0094] In one alternative example, if the current output resistance is independent of temperature, the current modulation module can be a PTAT current generator.

[0095] In this embodiment, combined with Figures 1 to 3 See Figure 4 The diagram shows a specific structure of a voltage regulation module. The voltage generation module 130 may include: a second mirror unit CM2 and a voltage generation unit UG, wherein:

[0096] The second mirror unit CM2 is coupled to the last stage current modulation module (e.g., the second stage current modulation module 122) and the voltage generation unit UG, respectively, and is used to mirror the reference current back to the voltage generation unit UG;

[0097] The voltage generation unit UG is used to adjust the reference current, convert the type of the reference current, generate the output voltage Vout, and output the output voltage Vout.

[0098] Specifically, the second mirror unit CM2 can mirror the reference current output by the last stage current modulation module and transmit it to the voltage generation unit UG. The voltage generation unit UG can then adjust the reference current, change the type of the reference current, and generate an output voltage Vout to power the external circuit.

[0099] In some optional embodiments, the second mirror unit CM2 includes a fifth bipolar transistor Q5 and a sixth bipolar transistor Q6, wherein: the base of the fifth bipolar transistor Q5 is connected to the base and collector of the sixth bipolar transistor Q6, respectively; the collector of the fifth bipolar transistor Q5 is connected to the last stage current modulation module (e.g., the second stage current modulation module 122) and the voltage generation unit UG, respectively; and the emitter of the fifth bipolar transistor Q5 is connected to the emitter of the sixth bipolar transistor Q6 and grounded.

[0100] In other words, the fifth bipolar transistor Q5 and the sixth bipolar transistor Q6 can mirror the reference current, thereby drawing the mirrored reference current to the voltage generation unit UG.

[0101] In some embodiments, the effective sizes of the fifth bipolar transistor Q5 and the sixth bipolar transistor Q6 may be different (wherein, the effective size may refer to the size of the component on the semiconductor die, for example, the effective size of the bipolar transistor may be increased by stacking multiple bipolar transistors having a common base, collector and emitter in parallel).

[0102] In one specific embodiment, the effective size ratio between the fifth bipolar transistor Q5 and the sixth bipolar transistor Q6 is 1:4, that is, the mirror factor between the fifth bipolar transistor Q5 and the sixth bipolar transistor Q6 is 4, then the mirror reference current = 4 * reference current.

[0103] It is understandable that, firstly, the mirror coefficient between the fifth bipolar transistor Q5 and the sixth bipolar transistor Q6 can also be other values; secondly, in this embodiment, the fifth bipolar transistor Q5 and the sixth bipolar transistor Q6 are NPN type for illustration, but in some other embodiments, the fifth bipolar transistor Q5 and the sixth bipolar transistor Q6 can also be PNP type.

[0104] In this embodiment, the voltage generation unit UG may include a gating switch M3 and a first conversion resistor R3. The control terminal of the gating switch M3 is connected to the second mirror unit CM2 (e.g., the collector of the fifth bipolar transistor Q5). The first terminal of the gating switch M3 is connected to the power supply terminal VDD. The second terminal of the gating switch M3 is connected to the first terminal of the first conversion resistor R3 and serves as the output terminal. The second terminal of the first conversion resistor R3 is connected to the second mirror unit CM2 (e.g., the collector and base of the sixth bipolar transistor Q6).

[0105] Specifically, when the selector switch M3 is turned on, the second mirror unit CM2 can mirror the reference current, so that the mirror current can flow through the first conversion resistor R3. After conversion by the first conversion resistor R3, the output voltage Vout can be obtained.

[0106] Furthermore, in this embodiment, the sixth bipolar transistor Q6 is connected across a diode, such that the collector-emitter voltage of the sixth bipolar transistor Q6 is the same as the base-emitter voltage. Thus, the collector-emitter voltage can include a fixed bandgap voltage and a CTAT voltage component that is complementary to the absolute temperature. As a result, the sixth bipolar transistor Q6 has a fixed bandgap voltage of approximately 1.25V. Therefore, the output voltage Vout, in addition to including the voltage across the first switching resistor R3, also has an additional fixed bandgap voltage of 1.25V.

[0107] In this embodiment, the properties (or types) of the fifth bipolar transistor Q5, the sixth bipolar transistor Q6, and the first switching resistor R3 can be the same as those of the first bipolar transistor Q1, the second bipolar transistor Q2, the third bipolar transistor Q3, the fourth bipolar transistor Q4, and the current output resistor R2, respectively.

[0108] In other words, the current output resistor R2 is matched with the first conversion resistor R3, and the fifth bipolar transistor Q5 and the sixth bipolar transistor Q6 are matched with the first bipolar transistor Q1, the second bipolar transistor Q2, the third bipolar transistor Q3, and the fourth bipolar transistor Q4.

[0109] The matching illustrated here refers to the following: bipolar transistors, resistors of the same type, the same temperature coefficient / temperature dependence, the same manufacturing process, the same wafer, the same manufacturing time, and / or the same location layout. This matching mechanism can compensate for process variations and provide the same component temperature dependence.

[0110] Thus, the output voltage Vout of the voltage generation unit UG is insensitive to temperature changes, and because the bipolar transistors and resistors shared by the output and feedback branches are matched, the output branch can provide a highly accurate output voltage Vout that is insensitive to any changes in the process or environment.

[0111] In this embodiment, the selector switch M3 can have a rated voltage higher than the maximum value of the voltage operating range of the power supply terminal VDD, which can improve the stability of the circuit operation.

[0112] In one embodiment, the gating switch M3 is an NMOS transistor; in some other embodiments, the gating switch M3 may also be a PMOS transistor.

[0113] In this embodiment, the voltage generation unit UG may further include a reference voltage module branch located between the selector switch M3 and the conversion resistor R3, so that the value of the output voltage Vout can be adjusted while keeping the original circuit structure unchanged.

[0114] In one specific embodiment, the reference voltage module branch may include a second switching resistor R4 and a seventh bipolar transistor Q7, wherein the first end of the second switching resistor R4 is coupled to the second end of the gating switch M3, the second end of the second switching resistor R4 is connected to the collector and base of the seventh bipolar transistor Q7 respectively, and the emitter of the seventh bipolar transistor Q7 is connected to the first end of the first switching resistor R3.

[0115] It should be noted that there can be multiple branches of the reference voltage module; secondly, the seventh bipolar transistor Q7 in the reference voltage module branch is matched with the first bipolar transistor Q1, and the second conversion resistor R4 is matched with the first conversion resistor R3.

[0116] In some optional examples of the present invention, the voltage regulation circuit may further include a first capacitor C1 coupled to the input terminal of the voltage generation unit UG and the output terminal of the last stage current modulation module (e.g., the second stage current modulation module 122), so as to provide a stable current value for the voltage regulation circuit.

[0117] Specifically, the first terminal of the first capacitor C1 is connected to the control terminal of the selector switch M4 and the collector of the fifth bipolar transistor Q5, respectively, and the second terminal of the first capacitor C1 is grounded.

[0118] In some optional embodiments of the present invention, the voltage regulation circuit may further include an output capacitor C2 coupled between the output terminal of the voltage generation unit UG and ground, which can improve the stability of the output voltage Vout.

[0119] Specifically, the first terminal of the output capacitor C2 is connected to the second terminal of the selector switch M4, and the second terminal of the output capacitor C2 is grounded.

[0120] In some embodiments, the capacitance values ​​of the first capacitor C1 and the output capacitor C2 can be in the picofarad range and can be integrated on a chip to maintain the stability of the output voltage in response to load changes.

[0121] It should be noted that the above description of multiple embodiments provided by the present invention may combine or cross-reference the various optional methods described in each embodiment without conflict, thereby extending to a variety of possible embodiments, all of which can be considered as embodiments disclosed or invented by the present invention.

[0122] In practical implementation, the above voltage regulation circuit can be applied to various batteries and corresponding devices. The following is an application example in a battery management system.

[0123] This invention also provides a battery management system, including the voltage regulation circuit described in any of the foregoing embodiments.

[0124] It should be noted that the term "an embodiment" or "embodiment" as used in this invention refers to a specific feature, structure, or characteristic that can be included in at least one implementation of the invention. Furthermore, in the description of this invention, terms such as "first," "second," etc., 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. Thus, a feature defined with terms such as "first," "second," etc., may explicitly or implicitly include one or more of that feature. Moreover, terms such as "first," "second," etc., are used to distinguish similar objects and are not necessarily used to describe a specific order or indicate importance. It is understood that such terms can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in an order other than that illustrated or described.

[0125] While the embodiments of the present invention have been disclosed above, the present invention is not limited thereto. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the present invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. A voltage regulation circuit, coupled to a power supply terminal, characterized in that, include: A bias current generation module is used to generate a bias current related to the voltage variation range of the power supply terminal based on the voltage value of the power supply terminal. A multi-stage current modulation module is provided, with each stage of the current modulation module sequentially coupled. The first-stage current modulation module is coupled to the bias current generation module. Each stage of the current modulation module has a first modulation branch and a second modulation branch coupled to each other. Each second modulation branch has a preset modulation coefficient. The first and second modulation branches in any stage of the current modulation module are used, according to the preset modulation coefficient, to modulate the difference between the first current input to the first modulation branch and the second current output to the next-stage current modulation module from the second modulation branch, so as to generate a current in the second modulation branch when the bias current changes. The current modulation module generates a modulation current and inputs it to the first modulation branch of the next-stage current modulation module through the second modulation branch. The second modulation branch of the last-stage current modulation module outputs a reference current. The bias current is input to the first modulation branch of the first-stage current modulation module. Each current modulation module includes a second bipolar transistor disposed on the first modulation branch. When the bias current changes, the current modulation module generates the modulation current on the second modulation branch according to the current difference between the first current and the second current, and the ratio between the current difference and the collector current of the second bipolar transistor and the preset modulation coefficient. The voltage generation module, coupled to the last-stage current modulation module, is used to adjust the reference current to generate the output voltage.

2. The voltage regulation circuit according to claim 1, characterized in that, Each current modulation module further includes: a first bipolar transistor disposed on the first modulation branch, a third bipolar transistor, a fourth bipolar transistor, and a current output resistor disposed on the second modulation branch, and a first current mirror unit connected to the second modulation branch, wherein: The first bipolar transistor, the second bipolar transistor, the third bipolar transistor, and the fourth bipolar transistor constitute a current modulation unit of each stage of the current modulation module. The base current of the first bipolar transistor is different from that of the fourth bipolar transistor. The current modulation unit is used to generate a modulation current in the second modulation branch when the bias current changes, based on the current difference between the first current and the second current, and the ratio between the current difference and the collector current of the second bipolar transistor and the preset modulation coefficient. The preset modulation coefficient is the current amplification factor of the third bipolar transistor. The first current mirroring unit is used to mirror the modulation current on the corresponding second modulation branch to generate a first mirrored current, and the first mirrored current of the last stage current modulation module is the reference current.

3. The voltage regulation circuit according to claim 2, characterized in that, The first bipolar transistor, the second bipolar transistor, the third bipolar transistor, and the fourth bipolar transistor in different levels of current modulation modules are matched, and the current output resistors in different levels of current modulation modules are matched.

4. The voltage regulation circuit according to claim 2, characterized in that, The base of the first bipolar transistor is connected to the base of the third bipolar transistor and the collector of the first bipolar transistor, respectively; the emitter of the first bipolar transistor is connected to the base of the fourth bipolar transistor and the collector of the second bipolar transistor, respectively. The base of the second bipolar transistor is connected to the emitter of the third bipolar transistor and the collector of the fourth bipolar transistor, respectively. The emitter of the second bipolar transistor is connected to the second terminal of the current output resistor and grounded. The collector of the third bipolar transistor is connected to the first current mirror unit; The emitter of the fourth bipolar transistor is connected to the first terminal of the current output resistor.

5. The voltage regulation circuit according to claim 2, characterized in that, The first current mirror unit includes a first mirror transistor and a second mirror transistor. The control terminal of the first mirror transistor is connected to the control terminal of the second mirror transistor, the second terminal of the first mirror transistor, and the second modulation branch, respectively. The first terminal of the first mirror transistor and the first terminal of the second mirror transistor are connected and connected to the power supply terminal. The second terminal of the second mirror transistor is used to output the first mirror current.

6. The voltage regulation circuit according to claim 1, characterized in that, The voltage generation module includes: a second mirror unit and a voltage generation unit, wherein: The second mirror unit is coupled to the last stage current modulation module and the voltage generation unit respectively, and is used to mirror the reference current back to the voltage generation unit; The voltage generation unit is used to adjust the reference current, convert the type of the reference current, generate the output voltage, and output the output voltage.

7. The voltage regulation circuit according to claim 6, characterized in that, The second mirror unit includes: a fifth bipolar transistor and a sixth bipolar transistor, wherein: The base of the fifth bipolar transistor is connected to the base of the sixth bipolar transistor and the collector of the sixth bipolar transistor, respectively. The collector of the fifth bipolar transistor is connected to the current modulation module and the voltage generation unit of the last stage, respectively. The emitter of the fifth bipolar transistor is connected to the emitter of the sixth bipolar transistor and grounded.

8. The voltage regulation circuit according to claim 6, characterized in that, The voltage generation unit includes a gating switch and a first conversion resistor. The control terminal of the gating switch is connected to the second mirror unit, the first terminal of the gating switch is connected to the power supply terminal, and the second terminal of the gating switch is connected to the first terminal of the first conversion resistor and serves as the output terminal. The second end of the first conversion resistor is connected to the second mirror unit.

9. The voltage regulation circuit according to claim 8, characterized in that, The voltage generation unit further includes a reference voltage branch located between the gating switch and the switching resistor. The reference voltage branch includes a second switching resistor and a seventh bipolar transistor. The first end of the second switching resistor is coupled to the second end of the gating switch. The second end of the second switching resistor is connected to the collector and base of the seventh bipolar transistor, respectively. The emitter of the seventh bipolar transistor is connected to the first end of the first switching resistor.

10. The voltage regulation circuit according to claim 6, characterized in that, It also includes at least one of the following: The first capacitor is coupled to the input terminal of the voltage generation unit and the output terminal of the last stage current modulation module, respectively. An output capacitor coupled between the output terminal of the voltage generation unit and ground.

11. The voltage regulation circuit according to claim 1, characterized in that, The bias current generation module includes a bias resistor.

12. A battery management system, characterized in that, Includes the voltage regulation circuit as described in any one of claims 1 to 11.

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