Temperature sampling circuit, method, and related systems and vehicles

Abstract

The application provides a temperature sampling circuit, a method, and related systems and vehicles, and relates to the technical field of batteries. The temperature sampling circuit comprises an analog front-end module, a thermistor, a first resistor, and a controllable branch. The voltage of the thermistor reflects the temperature of a device to be measured. The thermistor and the first resistor are connected in series to form a voltage divider circuit. One end of the voltage divider circuit is connected to a power supply end, and the other end is connected to a ground. The middle voltage dividing node of the voltage divider circuit is connected to the input end of an analog-to-digital converter of the analog front-end module. The voltage of the middle voltage dividing node is sampled by the analog-to-digital converter. The controllable branch is connected in parallel with the first resistor to form a voltage dividing network. The control end of the controllable branch is connected to a general output pin of the analog front-end module. The analog front-end module controls the conduction and shutdown of the controllable branch through the general output pin, and reduces the equivalent resistance value of the voltage dividing network when the controllable branch is conducted. Through the application, the sampling accuracy of the temperature is improved.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a temperature sampling circuit, method, related system, and vehicle. Background Technology

[0002] In modern high-power applications such as electric vehicles, energy storage systems, and power tools, battery temperature directly determines the battery's charging and discharging efficiency, cycle life, and operational safety. Therefore, the Battery Management System (BMS) needs to collect battery temperature in real time to dynamically adjust charging and discharging strategies based on this temperature, promptly trigger over-temperature or under-temperature protection mechanisms, and perform battery life assessments.

[0003] Currently, the mainstream temperature sampling scheme uses a voltage divider circuit formed by connecting a negative temperature coefficient (NTC) thermistor in series with a fixed resistor. The NTC thermistor is located on one side of the battery. One end of this voltage divider circuit is connected to the reference voltage terminal of the analog front end (AFE), and the other end is grounded. The intermediate voltage divider node is electrically connected to the analog-to-digital converter (ADC) of the AFE. The ADC acquires the voltage of this intermediate voltage divider node, and the battery temperature is then calculated by back-calculating the resistance-temperature characteristic curve of the NTC thermistor.

[0004] However, in some scenarios, the accuracy of the temperature obtained in this way is relatively low. Summary of the Invention

[0005] This application provides temperature sampling circuits, methods, related systems, and vehicles to improve the accuracy of temperature sampling.

[0006] In a first aspect, this application provides a temperature sampling circuit, including: an analog front-end module AFE, a thermistor NTC, a first resistor R1, and a controllable branch, wherein the voltage of the thermistor NTC reflects the temperature of the device to be measured.

[0007] The thermistor NTC and the first resistor R1 are connected in series to form a voltage divider circuit. One end of the voltage divider circuit is connected to the power supply terminal, and the other end is grounded. The middle voltage divider node of the voltage divider circuit is connected to the input terminal of the analog-to-digital converter (ADC) of the analog front-end module AFE, and the voltage of the middle voltage divider node is collected by the ADC.

[0008] The controllable branch is connected in parallel with the first resistor R1 to form a voltage divider network. The control terminal of the controllable branch is connected to the general-purpose output pin GPO of the analog front-end module AFE. The analog front-end module AFE controls the conduction and cutoff of the controllable branch through the general-purpose output pin GPO. When the controllable branch is on, the equivalent resistance value of the voltage divider network is reduced.

[0009] In one possible embodiment, the controllable branch includes a controllable conducting element Q1 and a second resistor R2, wherein:

[0010] A controllable conducting element Q1 and a second resistor R2 are connected in series to form a controllable branch, and the control terminal of the controllable conducting element Q1 serves as the control terminal of the controllable branch.

[0011] In one possible embodiment, the temperature sampling circuit further includes: a third resistor R3 and a fourth resistor R4;

[0012] The control terminal of the controllable conducting element Q1 is connected to the general-purpose output pin GPO through the third resistor R3;

[0013] The control terminal of the controllable conducting element Q1 is also grounded through the fourth resistor R4.

[0014] In one possible embodiment, the simulated front-end module (AFE) is specifically used for:

[0015] When the voltage across the first resistor R1 is detected to be greater than the preset upper limit of voltage detection, a high-level control signal is generated and transmitted to the controllable branch through the general-purpose output pin GPO. The control signal is used to drive the controllable branch to conduct.

[0016] In one possible embodiment, the simulated front-end module (AFE) is specifically used for:

[0017] When the voltage across the first resistor R1 is detected to be less than the preset lower voltage detection limit, a low-level control signal is generated and transmitted to the controllable branch through the general-purpose output pin GPO. The control signal is used to drive the controllable branch to disconnect. The ratio of the resistance of the thermistor NTC to the resistance of the first resistor R1 is greater than or equal to a first value and less than or equal to a second value. The first value is the quotient of the voltage provided by the power supply divided by the preset upper voltage detection limit minus 1, and the second value is the quotient of the voltage provided by the power supply divided by the preset lower voltage detection limit minus 1.

[0018] In one possible embodiment, the analog front-end module (AFE) includes multiple analog-to-digital converters (ADCs), each of which has an independently configured input terminal, and the input terminals of the multiple ADCs are all connected to an intermediate voltage divider node.

[0019] The analog front-end module (AFE) is also used to determine the average voltage value of the intermediate voltage divider nodes acquired by multiple analog-to-digital converters (ADCs), and to generate control signals for the corresponding controllable branches based on the average voltage value.

[0020] In one possible embodiment, the simulated front-end module (AFE) is specifically used for:

[0021] Determine whether the absolute value of the voltage difference between any two intermediate voltage divider nodes acquired by the analog-to-digital converters (ADCs) is greater than the difference threshold. If it is greater than the difference threshold, output an alarm message to the management system. If it is less than or equal to the difference threshold, determine the average voltage value as the target voltage of the voltage divider network, and generate the control signal for the corresponding controllable branch based on the average voltage value.

[0022] In one possible embodiment, a fifth resistor R5 is also included;

[0023] The input terminals of multiple analog-to-digital converters (ADCs) are all connected to the intermediate voltage divider node through the fifth resistor R5.

[0024] In one possible embodiment, the controllable conducting element Q1 is a transistor;

[0025] The base of the transistor serves as the control terminal of the controllable conducting element Q1. The collector of the transistor is connected to the second resistor R2, and the emitter of the transistor is grounded.

[0026] In one possible embodiment, the controllable conduction element is a metal-oxide-semiconductor field-effect transistor;

[0027] The gate of the metal-oxide-semiconductor field-effect transistor serves as the control terminal of the controllable conduction element Q1, and the drain of the metal-oxide-semiconductor field-effect transistor is connected to the second resistor R2; the source of the metal-oxide-semiconductor field-effect transistor is grounded.

[0028] In one possible embodiment, the power supply terminal is the reference voltage terminal Vref of the analog front-end module AFE, or a constant voltage source terminal or a constant current source terminal.

[0029] In one possible embodiment, the number of controllable branches is multiple.

[0030] Secondly, this application provides a temperature sampling method applied to the analog front-end module (AFE) in the temperature sampling circuit provided above. The temperature sampling method includes:

[0031] The target voltage of the intermediate voltage divider node in the voltage divider circuit of the temperature sampling circuit is obtained. The target voltage is determined by the following method: determining the average voltage value of the intermediate voltage divider node collected by multiple analog-to-digital converters (ADCs) in the temperature sampling circuit, and determining the average voltage value as the target voltage.

[0032] The temperature of the device to be measured is determined based on the target voltage.

[0033] In one possible embodiment, it also includes:

[0034] Obtain the control state of the general-purpose output pin GPO in the temperature sampling circuit;

[0035] Based on the control status and the voltage of the intermediate voltage divider nodes acquired by multiple analog-to-digital converters (ADCs), the device status information in the temperature sampling circuit is determined.

[0036] Thirdly, this application provides a battery management system, including the temperature sampling circuit described above.

[0037] Fourthly, this application provides a battery system, including a battery and the battery management system described above.

[0038] Fifthly, this application provides a vehicle, including a vehicle body and the battery system described above.

[0039] Sixthly, this application provides a simulation front-end module, including: a memory and a processor;

[0040] The memory stores instructions that the computer executes;

[0041] The processor executes computer execution instructions stored in the memory, causing the processor to perform the first aspect and / or various possible implementations of the first aspect as described above.

[0042] In a seventh aspect, this application provides a computer-readable storage medium storing computer-executable instructions, which, when executed, are used to implement the first aspect and / or various possible embodiments of the first aspect.

[0043] Eighthly, this application provides a computer program product, including a computer program that, when executed, implements the first aspect and / or various possible implementations of the first aspect.

[0044] This application provides a temperature sampling circuit, method, related system, and vehicle, relating to the field of battery technology. The temperature sampling circuit includes: an analog front-end module (AFE), a thermistor NTC, a first resistor R1, and a controllable branch. The voltage of the thermistor NTC reflects the temperature of the device under test. The thermistor NTC and the first resistor R1 are connected in series to form a voltage divider circuit, with one end connected to a power supply and the other end grounded. The intermediate voltage divider node is connected to the input of the analog-to-digital converter (ADC) of the AFE, and the ADC acquires the voltage of the intermediate voltage divider node. The controllable branch is connected in parallel with the first resistor R1 to form a voltage divider network. The control terminal of the controllable branch is connected to the general-purpose output pin GPO of the AFE. The AFE controls the conduction and cutoff of the controllable branch through the general-purpose output pin GPO, reducing the equivalent resistance value of the voltage divider network when the controllable branch is on. This application forms a voltage divider circuit by connecting a thermistor and a first resistor in series, and uses an analog-to-digital converter in the analog front-end module to acquire the voltage of the intermediate voltage divider node. This converts the temperature change of the device under test into a voltage signal that can be acquired and processed. By setting a controllable branch in parallel with the first resistor, and controlling the conduction and cutoff of the controllable branch through a general-purpose output pin in the analog front-end module, the equivalent resistance value of the voltage divider network is reduced when the controllable branch is on. This allows for switching and adjustment of the electrical characteristics of the voltage divider network, thereby improving the voltage distribution of the intermediate voltage divider node over a wide temperature range and increasing the accuracy of temperature sampling. Attached Figure Description

[0045] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0046] Figure 1 A schematic diagram of the temperature sampling circuit provided in the embodiments of this application. Figure 1 ;

[0047] Figure 2 A schematic flowchart illustrating the temperature sampling method provided in this application embodiment;

[0048] Figure 3 A schematic diagram of the temperature sampling circuit provided in the embodiments of this application. Figure 2 ;

[0049] Figure 4 This is a schematic diagram of the structure of a simulated front-end module provided in an embodiment of this application.

[0050] Explanation of reference numerals in the attached figures:

[0051] AFE - Analog Front End Module; NTC - Thermistor; R1 - First Resistor; ADC - Analog-to-Digital Converter; GPO - General Purpose Output Pin; R2 - Second Resistor; Q1 - Controllable On Component; R3 - Third Resistor; R4 - Fourth Resistor; R5 - Fifth Resistor; Vref - Reference Voltage Terminal; ADC1 - First Analog-to-Digital Converter; ADC2 - ADC2; GND - Ground; 401 - Processor; 402 - Memory; 403 - Communication Interface.

[0052] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0053] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0054] Temperature sampling is mainly used in temperature management systems to monitor the temperature of power battery modules, energy storage battery clusters or other devices to be measured, and the collected results are used for charge and discharge control, thermal management regulation and abnormal protection.

[0055] These temperature management systems typically include a thermistor sampling branch, an analog-to-digital converter (ADC), and an analog front-end module for outputting control signals to read and process the voltage at the intermediate voltage divider node (i.e., the voltage divider voltage). Currently, related technical solutions usually use a thermistor connected in series with a fixed resistor to form a voltage divider circuit. The intermediate voltage divider node in this circuit is connected to the input of the ADC, which then uses the voltage at the intermediate voltage divider node (i.e., the voltage divider voltage) to deduce the temperature of the device under test. This method is simple in structure and easy to integrate, and is therefore widely used in battery module temperature detection scenarios.

[0056] However, when the battery is under extreme ambient temperature or in a state of rapid charging and discharging heat, the traditional voltage divider circuit exposes the following shortcomings:

[0057] 1. Structural Design Defects: The resistance-temperature characteristic of the thermistor exhibits an exponentially non-linear relationship, causing the voltage at the intermediate voltage divider node to tend to saturate at extreme temperatures (such as low or high temperatures). This significantly compresses the effective range of the analog-to-digital converter (ADC), thereby reducing temperature resolution and sampling accuracy. For example, at low temperatures, the thermistor resistance is much higher than the fixed resistance, and the voltage divider voltage is close to the reference voltage, making it impossible for the ADC to distinguish subtle temperature changes. At high temperatures, the thermistor resistance is much lower than the fixed resistance, and the voltage divider voltage is close to 0V, similarly resulting in insufficient resolution of the ADC.

[0058] 2. Circuit configuration limitations: The parameters of a fixed resistor can usually only be set as a compromise for a certain temperature range, making it difficult to simultaneously ensure measurement sensitivity across the entire temperature range. Increasing the fixed resistor can improve low-temperature accuracy but will worsen high-temperature accuracy; conversely, decreasing it will also worsen high-temperature accuracy, creating an irreconcilable design contradiction.

[0059] In summary, when the battery is under extreme ambient temperature or in a state of rapid charging and discharging, the temperature sampling circuit may experience a problem where the temperature change has occurred but the voltage divider change is not obvious. This results in slow temperature recognition, increased errors, and even affects the reliability of subsequent temperature control strategies and protection decisions. Therefore, how to improve the sampling effect over a wide temperature range without significantly increasing complexity has become an important problem that needs to be solved for this type of temperature sampling circuit.

[0060] Therefore, improving the accuracy of battery temperature sampling over a wide temperature range is a technical problem that urgently needs to be solved.

[0061] To solve the above-mentioned technical problems, this application provides a temperature sampling circuit, which sets up a controllable branch in parallel with the first resistor on the basis of a voltage divider circuit composed of a thermistor and a first resistor, and controls the conduction and cutoff of the controllable branch by the general output pin of the analog front-end module, so that the equivalent resistance value of the voltage divider network can be changed as needed.

[0062] This temperature sampling circuit can still be applied to battery management system architectures, including analog front-end modules, thermistor sampling branches, and analog-to-digital converters. The analog-to-digital converters collect the voltage of intermediate voltage divider nodes. When the controllable branch is turned on, by reducing the equivalent resistance value of the voltage divider network, the voltage divider voltage is kept in a state more suitable for sampling in different temperature ranges, thus providing a foundation for improving the temperature sampling capability over a wide temperature range in the future.

[0063] The technical solution of this application and how the technical solution of this application solves the above-mentioned technical problems are described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of this application will now be described with reference to the accompanying drawings.

[0064] Figure 1A schematic diagram of the temperature sampling circuit provided in the embodiments of this application. Figure 1 ,like Figure 1 As shown, the temperature sampling circuit includes: a temperature sampling circuit comprising an analog front-end module (AFE), a thermistor (NTC), a first resistor (R1), and a controllable branch connected in parallel with the first resistor (R1). The voltage of the thermistor (NTC) is used to reflect the temperature of the device under test. The thermistor (NTC) and the first resistor (R1) are connected in series to form a voltage divider circuit. One end of the voltage divider circuit is connected to the power supply terminal, and the other end is grounded. The intermediate voltage divider node of the voltage divider circuit is connected to the input terminal of the analog-to-digital converter (ADC) of the analog front-end module (AFE). The ADC acquires the voltage of the intermediate voltage divider node. The control terminal of the controllable branch is connected to the general-purpose output pin (GPO) of the analog front-end module (AFE). The analog front-end module (AFE) controls the conduction and cutoff of the controllable branch through the general-purpose output pin (GPO). When the controllable branch is on, the equivalent resistance value of the voltage divider network is reduced.

[0065] In this embodiment, the analog front-end module (AFE) is a circuit unit used to drive, control, and digitally acquire temperature sampling signals. It includes or is connected to an analog-to-digital converter (ADC). The ADC is used to receive the analog voltage of the intermediate voltage divider node and convert it into a digital quantity for output to the subsequent control circuit.

[0066] Furthermore, the analog front-end module (AFE) provides a sampling interface in the overall circuit and outputs control levels through the general-purpose output pin (GPO) to drive the controllable branch. Its installation position is usually close to the resistor network of the temperature sampling circuit to shorten the traces and reduce parasitic interference.

[0067] The analog front-end module (AFE) can be an integrated acquisition chip, an analog front-end integrated circuit with sampling management functions, or a dedicated sampling module used in conjunction with the main controller. The connection line between the general-purpose output pin (GPO) and the input terminal of the analog-to-digital converter (ADC) should be as short as possible, and the number of pins and sampling channels of the analog front-end module (AFE) can be expanded according to the number of devices to be measured.

[0068] A thermistor (NTC) is a temperature-sensitive element used to convert the temperature change of a device under test into a resistance change. Its resistance decreases as the temperature rises and increases as the temperature falls, thereby generating a corresponding voltage change in the voltage division relationship formed with the first resistor R1.

[0069] Thermistors (NTCs) act as the temperature-sensitive element in the overall circuit. They are typically attached to the battery cell casing, tabs, module brackets, or heat dissipation interfaces to directly sense the thermal state of the device being measured. They are connected to a voltage divider network via leads or soldering. NTC thermistors can be implemented using surface-mount, leaded, or epoxy-encapsulated thermistors.

[0070] The first resistor R1 is a fixed-value resistor connected in series with the thermistor NTC. It is used to form a temperature-to-voltage voltage divider relationship together with the thermistor NTC, and to participate in setting the voltage range of the intermediate voltage divider nodes as a reference resistance unit in the voltage divider network.

[0071] The first resistor R1 is connected in series with the thermistor NTC in the circuit and then connected to the power supply terminal and the ground terminal respectively. This causes the intermediate voltage divider node to generate a voltage change corresponding to the change in the resistance value of the thermistor NTC, and provides a parallel object for the controllable branch.

[0072] The controllable branch is a switchable path connected in parallel with the first resistor R1. It is used to change the equivalent resistance value of the voltage divider network in the on state and switches the voltage division relationship through linkage with the general-purpose output pin GPO of the analog front-end module AFE. When the controllable branch is on, it reduces the equivalent resistance value of the voltage divider network and restores the original voltage division relationship when it is off.

[0073] The General Purpose Output (GPO) pin is the interface pin for output control signals from the analog front-end module (AFE). It is used to provide a conduction control level to the controllable branch to select the state of the voltage divider network. The GPO pin is electrically connected to the control terminal of the controllable branch in the circuit and can output a high or low level according to sampling requirements, thereby driving the controllable branch into the on or off state.

[0074] Based on the above analysis, it can be seen that in the operation of the temperature sampling circuit provided in this application embodiment, the thermistor NTC and the first resistor R1 first form a series voltage divider structure. One end of the voltage divider circuit is connected to the power supply terminal and the other end is grounded, so that the intermediate voltage divider node generates a corresponding voltage when the resistance value of the thermistor NTC changes with the temperature. The analog-to-digital converter ADC in the analog front-end module AFE continuously or sequentially reads the analog voltage of the intermediate voltage divider node and converts it into digital sampling results for use in temperature calculation.

[0075] Meanwhile, the analog front-end module (AFE) controls the controllable branch via the general-purpose output pin (GPO), turning it on or off. This changes the equivalent resistance of the voltage divider network connected in parallel with the first resistor R1, adjusting the voltage distribution at the intermediate voltage divider nodes to a range suitable for the analog-to-digital converter (ADC) to read, as the voltage divider network parameters change. When the controllable branch is turned off, the voltage divider network reverts to its original state where the first resistor R1 participates in the voltage division. Because the equivalent resistance of the voltage divider network can be switched under the control of the AFE, the range of voltage division can be adjusted. This prevents the voltage change caused by the thermistor (NTC) from being excessively compressed near the power supply or ground, allowing the ADC to obtain more discernible sampling results and making the input voltage used for subsequent temperature calculations more stable.

[0076] Based on the above process, when the device under test is in a wide temperature range, a rapid charging and discharging heating state, or a drastic change in ambient temperature, the temperature sampling circuit can adapt the voltage of the intermediate voltage divider node through controllable branch switching, so that the temperature change and the sampling voltage change maintain a more suitable correspondence, thereby making the temperature identification process have more consistent sampling conditions, and providing continuous and implementable voltage input for thermal management adjustment, charging and discharging control, and abnormal protection judgment.

[0077] In summary, it can be understood that the embodiments of this application, by connecting a thermistor and a first resistor in series to form a voltage divider circuit, and having the analog-to-digital converter of the analog front-end module acquire the voltage of the intermediate voltage divider node, can convert the temperature change of the device under test into a voltage signal that can be acquired and processed. By setting a controllable branch in parallel with the first resistor, and having the analog front-end module control the conduction and cutoff of the controllable branch through a general-purpose output pin, the equivalent resistance value of the voltage divider network is reduced when the controllable branch is on, which can switch and adjust the electrical characteristics of the voltage divider network, thereby improving the voltage distribution of the intermediate voltage divider node over a wide temperature range and improving the temperature sampling accuracy.

[0078] Based on the aforementioned embodiments, the controllable branch further includes a controllable conducting element Q1 and a second resistor R2, wherein: the controllable conducting element Q1 and the second resistor R2 are connected in series to form a controllable branch, and the control terminal of the controllable conducting element Q1 serves as the control terminal of the controllable branch.

[0079] Optionally, the controllable conducting element Q1 can be arranged upstream of the second resistor R2 or downstream of the second resistor R2, as long as the two are connected in series and the control terminal still serves as the control terminal of the controllable branch.

[0080] When the temperature sampling circuit is working, the analog front-end module (AFE) outputs a corresponding control signal to the control terminal of the controllable conducting element Q1 through its general-purpose output pin GPO, based on the temperature zone of the device under test. This controls whether the controllable conducting element Q1 is in a conducting or turning-off state. The temperature zone of the device under test is determined by a voltage divider.

[0081] When the controllable conducting element Q1 is turned on, current flows through the controllable branch formed by the second resistor R2 and the controllable conducting element Q1. This allows the second resistor R2 and the first resistor R1 to participate in the equivalent calculation of the voltage divider network, thereby reducing the equivalent resistance value of the voltage divider network and adjusting the voltage range of the intermediate voltage divider nodes. This makes it easier for the analog-to-digital converter (ADC) to acquire signals with more significant changes within its effective range. When the controllable conducting element Q1 is turned off, the controllable branch is cut off, the second resistor R2 exits the voltage divider network, and the voltage division relationship returns to its original state.

[0082] Since the controllable conducting element Q1 is directly controlled by the general output pin GPO of the analog front-end module AFE, its control logic can be flexibly switched according to the temperature range, sampling strategy or system calibration results. It can achieve dynamic correction of the voltage divider under different temperature ranges without significantly increasing the number of additional sampling channels or complex analog conditioning circuits.

[0083] Therefore, the embodiments of this application can maintain the simplicity of the temperature sampling circuit while enabling the temperature sampling to obtain a more suitable voltage distribution over a wide temperature range, reducing the range compression problem caused by the voltage divider approaching the power supply terminal or ground terminal in extreme temperature regions, thereby improving sampling resolution and reducing temperature measurement error.

[0084] Based on the aforementioned embodiments, the temperature sampling circuit further includes: a third resistor R3 and a fourth resistor R4; the control terminal of the controllable conducting element Q1 is connected to the general output pin GPO through the third resistor R3; the control terminal of the controllable conducting element Q1 is also grounded through the fourth resistor R4.

[0085] In this embodiment, the third resistor R3 and the fourth resistor R4 constitute an external resistor network for driving and biasing the control terminal of the controllable conducting element Q1. The third resistor R3 limits and isolates the control signal from the general-purpose output pin GPO, preventing damage to the controllable conducting element Q1 due to overcurrent. The fourth resistor R4 stably pulls the control terminal of the controllable conducting element Q1 to ground when the general-purpose output pin GPO is in a low-level, high-impedance, or failed state, thus keeping the controllable conducting element Q1 in the off state. This external resistor network achieves a balance between pull-down strength and static power consumption through resistance matching (e.g., the resistance of the fourth resistor R4 is much larger than that of the third resistor R3), thereby improving the anti-interference capability of the control terminal of the controllable conducting element Q1 and avoiding false triggering caused by external noise or transient interference.

[0086] The third resistor R3 is usually electrically connected to the controllable conducting element Q1 through wires, traces, or pads. The fourth resistor R4 is connected at one end to the control terminal node of the controllable conducting element Q1, and the other end is grounded to form a reference constraint on the control terminal potential.

[0087] This connection method enables the controllable branch to obtain more stable driving conditions during switching and reduces the risk of false triggering caused by external interference, harness coupling or transient changes in the general output pin GPO.

[0088] The resistance values ​​of the third resistor R3 and the fourth resistor R4 can be matched according to the output capability of the general-purpose output pin GPO, the input characteristics of the controllable conducting element Q1 control terminal, and the required pull-down strength. Typically, the third resistor R3 is used to limit the transient current flowing into the control terminal, and the fourth resistor R4 is used to provide a weak pull-down or steady-state bias. Therefore, the resistance value of the fourth resistor R4 can generally be set to be several times greater than or equal to the resistance value of the third resistor R3, so as to reduce static power consumption while ensuring turn-off reliability.

[0089] When the temperature sampling circuit is working, the analog front-end module (AFE) outputs a control signal to the control terminal of the controllable conducting element Q1 through the general-purpose output pin GPO. This control signal is applied to the control terminal of the controllable conducting element Q1 after being current-limited by the third resistor R3, so that the controllable conducting element Q1 can be turned on when needed. This allows the controllable branch connected in parallel with the first resistor R1 to be connected to the voltage divider network, reducing the equivalent resistance value of the voltage divider network and changing the voltage division relationship formed by the thermistor NTC and the first resistor R1, so that the voltage of the intermediate voltage divider node is in a range that is more conducive to the sampling of the analog-to-digital converter (ADC). When the controllable conducting element outputs a low level or is in a high-impedance state, the fourth resistor R4 stably pulls the control terminal of the controllable conducting element Q1 to the ground, so that the controllable conducting element Q1 quickly returns to the off state, preventing the controllable branch from being continuously turned on when it does not need to participate in the voltage division.

[0090] Since the third resistor R3 limits and isolates the control signal, and the fourth resistor R4 provides a definite default bias to the control terminal, the control network can maintain high switching consistency and anti-misoperation capability under conditions of controllable conduction element switching, power-on reset, abnormal power failure or external interference, making the switching action of the controllable branch more reliable and helping to maintain the stable operation of the temperature sampling circuit over a wide temperature range.

[0091] Based on the above analysis, it can be seen that the embodiments of this application can not only improve the driving conditions of the controllable conducting element Q1, but also improve the switching accuracy of the voltage divider network in different temperature zones, thereby providing a basis for improving the available dynamic range of the sampling voltage, reducing temperature recognition lag and sampling error.

[0092] In one possible implementation, the analog front-end module (AFE) is specifically used to: generate a high-level control signal when the voltage of the first resistor R1 is detected to be greater than the preset voltage detection upper limit, and transmit it to the controllable branch through the general-purpose output pin GPO. The control signal is used to drive the controllable branch to conduct.

[0093] In some possible implementations, the analog front-end module (AFE) can be an integrated analog front-end chip, a data acquisition chip with comparator function, a temperature monitoring chip with programmable logic, or a module composed of an analog sampling front-end and control logic. Internally, it can integrate a voltage comparison unit, a logic judgment unit, and a general-purpose output drive unit. The input terminal of its analog-to-digital converter (ADC) is electrically connected to the intermediate voltage divider node to acquire the voltage divider voltage in real time. The general-purpose output pin (GPO) is used as a control output interface and connected to the control terminal of the controllable branch, thereby forming a closed-loop control relationship between voltage monitoring and branch regulation.

[0094] During operation, the analog front-end module (AFE) continuously samples or calculates the voltage state corresponding to the first resistor R1. When the detected voltage exceeds the preset upper limit, it indicates that the current voltage divider is approaching or exceeding the effective range boundary of the analog-to-digital converter (ADC). At this time, the internal control logic of the AFE outputs a high-level control signal, which is transmitted to the controllable branch via the general-purpose output pin GPO to drive the controllable branch to conduct, enabling the parallel branch to work and changing the equivalent resistance value of the voltage divider network. At this point, the equivalent resistance value R of the voltage divider network... parallel =R1×R2 / (R1+R2), the corresponding voltage divider voltage V=Vref×R parallel / (R NTC +R parallel ).

[0095] It should be noted that the control action is triggered when the voltage value of the first resistor R1 reaches or exceeds the upper limit threshold. This upper limit threshold can be pre-configured according to design requirements to adapt to different battery temperature zones, different power supply voltage conditions, and different sampling accuracy requirements. The high-level control signal can be defined as the drive level corresponding to the high logic level output by the general-purpose output pin GPO. Its voltage amplitude matches the standard output logic level of the analog front-end module AFE to ensure reliable driving of the controllable conducting elements in the controllable branch into the conducting state.

[0096] Optionally, the judgment logic inside the analog front-end module (AFE) can be implemented directly by a hardware comparator, or it can be implemented by the embedded firmware after periodic sampling and threshold comparison. When the trigger condition is met, a high level is output.

[0097] The above control method enables the analog front-end module (AFE) to no longer passively read the voltage divider result, but to actively adjust the equivalent resistance of the voltage divider network according to the sampling state, thereby pulling the voltage of the intermediate voltage divider node back to the more suitable detection range of the analog-to-digital converter (ADC) (such as 1.0V-2.0V), so that the ADC can complete the sampling with better range utilization.

[0098] Based on the above analysis, when the voltage divider network approaches the upper limit of the range under high temperature conditions, the analog front-end module (AFE) triggers a high-level output and drives the controllable branch to conduct by setting a preset voltage detection upper limit. This can effectively suppress the range compression problem caused by excessively high sampling voltage, thereby improving the resolution, stability and wide temperature adaptability of temperature sampling, and enhancing the reliability of subsequent thermal management control and abnormal protection judgment.

[0099] In one possible implementation, the analog front-end module (AFE) is specifically used to: generate a low-level control signal when the voltage of the first resistor R1 is detected to be less than a preset lower voltage detection limit, and transmit it to the controllable branch through the general-purpose output pin GPO. The control signal is used to drive the controllable branch to disconnect. The ratio of the resistance of the thermistor NTC to the resistance of the first resistor R1 is greater than or equal to a first value and less than or equal to a second value. The first value is the quotient of the voltage provided by the power supply divided by the preset upper voltage detection limit minus 1, and the second value is the quotient of the voltage provided by the power supply divided by the preset lower voltage detection limit minus 1.

[0100] When the voltage related to the first resistor R1 acquired by the analog-to-digital converter (ADC) is lower than the preset lower voltage detection limit, the analog front-end module (AFE) outputs a low-level control signal, keeping the general-purpose output pin GPO at a low level. This puts the control terminal of the controllable branch under a shutdown drive condition, thereby disconnecting the controllable branch. Here, the first and second values ​​are used to limit the resistance ratio of the thermistor NTC to the first resistor R1 to be within a temperature window that can be effectively identified by the ADC. The first value corresponds to the relationship between the preset upper voltage detection limit and the voltage value provided by the power supply, and the second value corresponds to the relationship between the preset lower voltage detection limit and the voltage value provided by the power supply. This ensures that the voltage divider voltage is not further reduced in the low voltage range and that the voltage sampling result remains within the effective and accurate detection range of the ADC.

[0101] When the controllable branch is disconnected, the first resistor R1 no longer forms a low equivalent resistance together with the parallel branch. The voltage division relationship returns to the basic state dominated by the thermistor NTC and the first resistor R1, preventing the sampled voltage division from getting too close to the ground terminal. At this time, the voltage division voltage V = Vref × R1 / (R NTC +R1).

[0102] Once the temperature monitoring state is entered, the analog front-end module (AFE) will continuously sample and compare the voltage divider voltage related to the first resistor R1. When the voltage divider voltage is detected to be lower than the preset voltage detection lower limit, the analog front-end module (AFE) will immediately generate a low-level control signal and transmit it to the controllable branch via the general-purpose output pin GPO to disconnect the controllable branch, thereby preventing the voltage divider network from continuing to decrease due to the parallel conduction channel.

[0103] At the same time, the ratio of the resistance of the thermistor NTC to the resistance of the first resistor R1 is limited to between the first and second values, so that the corresponding voltage division relationship is within the window (e.g., 2.0V-3.0V) that the analog-to-digital converter (ADC) can effectively distinguish. Even at low temperatures or near extreme temperatures, the sampling voltage will not approach the power supply or ground terminal excessively and lose its effective range.

[0104] Based on the above control process, it can be seen that the embodiments of this application can maintain the voltage stability of the intermediate voltage divider node by cutting off the controllable branch in the low voltage range, avoid the quantization error caused by the further decrease of the voltage divider voltage, and keep the sampling result of the analog-to-digital converter (ADC) within the resolvable range by using the range constraint of the resistance ratio, thereby improving the temperature sampling accuracy and control reliability over a wide temperature range.

[0105] Currently, existing solutions use single-channel analog-to-digital converters (ADCs) for data acquisition, lacking redundancy verification mechanisms. When the ADC malfunctions or the voltage divider circuit malfunctions (such as open circuits or short circuits), it cannot be identified and alarmed in a timely manner, posing a safety hazard. For example, a single-channel ADC may experience abnormal sampling values ​​due to changes in the thermistor resistance at high temperatures, but the management system cannot determine whether it is a normal temperature rise or a sensor malfunction, potentially triggering protection mechanisms falsely or missing dangerous conditions.

[0106] To address this issue, this application introduces a redundant acquisition architecture, namely, multiple analog-to-digital converters (ADCs). Specifically, the analog front-end module (AFE) includes multiple ADCs, each with its own independently configured input terminal, and all input terminals of the multiple ADCs are connected to intermediate voltage divider nodes. The AFE also determines the average voltage value of the intermediate voltage divider nodes acquired by the multiple ADCs and generates control signals for the corresponding controllable branches based on the average voltage value.

[0107] In this embodiment, when the input terminals of multiple analog-to-digital converters (ADCs) are all connected to the intermediate voltage divider node, the input terminals can be connected to the intermediate node of the voltage divider network composed of the thermistor and the first resistor through parallel wiring, thereby enabling each ADC to read the same voltage divider voltage synchronously or nearly synchronously. After obtaining the voltage sampling results of each ADC, the analog front-end module (AFE) averages the multiple voltage sampling values. The resulting average voltage value serves as a more representative voltage characterization of the intermediate voltage divider node. Furthermore, based on the average voltage value, it generates control signals for the corresponding controllable branches to drive the controllable branches to turn on or off.

[0108] The average voltage value can be obtained by arithmetic average, weighted average or moving average. The specific method can be set according to the sampling frequency, temperature change rate and filtering requirements. The control signal can be output to the control terminal of the controllable branch through the general output pin to realize the dynamic adjustment of the equivalent resistance of the voltage divider network.

[0109] In one possible implementation, multiple analog-to-digital converters (ADCs) can be configured with two, three, or more channels, each with an independent input port to maintain good sampling stability even under conditions of rapid battery temperature changes or strong electromagnetic interference. Within the analog front-end module (AFE), buffer registers, digital filtering modules, or control logic units can be configured to temporarily store the sampling results of each ADC and perform averaging operations. The averaged voltage value is then compared with a preset threshold to generate the corresponding control signal.

[0110] Since multiple analog-to-digital converters (ADCs) share the same intermediate voltage divider node, their wiring connections are usually implemented using a short-path parallel connection method to reduce the impact of lead resistance and parasitic capacitance on sampling accuracy.

[0111] When the temperature sampling circuit is started, the analog front-end module (AFE) first enables multiple analog-to-digital converters (ADCs) to synchronously sample the voltage of the intermediate voltage divider node or sample it sequentially within a short time window. The voltage sample values ​​output by each ADC are aggregated in the digital domain to form an average voltage value. The AFE then determines whether the operating state of the controllable branch needs to be changed based on the relationship between the average voltage value and the preset upper and lower threshold values, and generates corresponding control signals through the general-purpose output pins to output to the controllable branch.

[0112] Since the average voltage value is determined by the results of multiple sampling channels, compared with direct sampling by a single analog-to-digital converter (ADC), it can effectively reduce the impact of transient interference, voltage ripple, and deviation of a single sampling channel on the control criteria, making the conduction and cut-off actions of the controllable branch closer to the real voltage state of the intermediate voltage divider node.

[0113] Based on the above analysis, it can be seen that the embodiments of this application achieve stable identification of the voltage divider node by combining redundant sampling of the multi-analog-to-digital converter (ADC) with average value determination, and provide a more reliable driving basis for the controllable branch, thereby improving the temperature sampling accuracy and control reliability over a wide temperature range.

[0114] Furthermore, existing technologies struggle to achieve self-diagnosis of the temperature sampling circuit status through hardware or software linkage. For example, they cannot effectively detect common faults such as switch failure, open or short circuits in voltage divider resistors, leading to the blind output of incorrect temperature values ​​when abnormalities occur, thus posing a potential threat to the operational safety of the battery system.

[0115] To address this issue, this application embodiment uses an analog front-end module (AFE) to perform circuit self-diagnosis on the temperature sampling circuit based on the collected voltages of intermediate voltage divider nodes. Specifically, in one possible implementation, the analog front-end module (AFE) is used to: determine whether the absolute value of the difference between the voltages of any two analog-to-digital converters (ADCs) collected by the intermediate voltage divider nodes is greater than a difference threshold; if it is greater than the difference threshold, output an alarm message to the management system; if it is less than or equal to the difference threshold, determine the average voltage value as the target voltage of the voltage divider network, and generate a control signal for the corresponding controllable branch based on the average voltage value.

[0116] In this embodiment, the intermediate voltage divider node voltages acquired by the analog-to-digital converter can correspond to multiple sampling channels. The analog front-end module (AFE) performs a consistency comparison on any two voltage sample values ​​and judges the absolute value of the resulting difference with a preset difference threshold. This difference threshold can be set according to the noise level of the temperature sampling circuit, the quantization accuracy of the analog-to-digital converter (ADC), and the allowable error range, so that it can effectively distinguish between normal sampling fluctuations and abnormal deviations.

[0117] When the absolute value of the difference between the sampling results of any two voltage dividers exceeds the difference threshold, the analog front-end module (AFE) can determine that there are abnormalities such as ADC channel abnormality, abnormal drift, input open circuit, poor contact, channel mismatch, poor soldering of voltage divider nodes, or external interference in the corresponding sampling link. It will then send alarm information to the management system via the communication interface so that the management system can execute fault recording, power limiting control, or further protection strategies.

[0118] When the absolute value of the difference between the voltage divider sampling results of any two channels is less than or equal to the difference threshold, the analog front-end module (AFE) considers that the sampling results of the voltage divider voltage of each channel are consistent. Then, it averages the sampling values ​​of multiple analog-to-digital converters (ADCs) and determines the average voltage value as the target voltage of the voltage divider network. Based on this, it generates the control signal of the corresponding controllable branch, thereby driving the controllable branch to turn on or off while ensuring the sampling reliability.

[0119] It should be noted that the aforementioned difference threshold is a reference voltage boundary used in the temperature sampling circuit to determine whether the sampling results of the multi-channel analog-to-digital converter (ADC) meet the consistency conditions. The function of this difference threshold is to perform mutual verification of the multi-channel sampled values, preventing malfunctions of a single ADC due to noise, bias error, or transient interference. Simultaneously, it triggers an alarm promptly when the sampling results of the voltage divider show significant deviations, thus balancing safety and control accuracy. Furthermore, this difference threshold should be greater than the typical amplitude of the ADC quantization noise and short-term random fluctuations, while being less than the upper limit of the allowable sampling error. For example, it can be set to several times one or more minimum resolution voltage units to achieve a balance between false alarm rate and sensitivity.

[0120] The average voltage value is a representative voltage obtained by averaging, weighting, or filtering the voltages of intermediate voltage divider nodes collected by multiple analog-to-digital converters (ADCs). It serves as the input reference for the voltage divider network control strategy, enabling the analog front-end module (AFE) to determine the operating state of the controllable branch based on a more representative voltage value after confirming the consistency of the sampling results from each channel. This reduces the impact of single-point sampling errors on the control results.

[0121] The alarm message is an abnormal indication signal output by the analog front-end module (AFE) to the management system when it detects that the difference between the sampling results of any two analog-to-digital converters (ADCs) exceeds the limit. Its purpose is to promptly report sampling inconsistencies, channel faults, or voltage divider network anomalies so that the management system can take protective measures. This alarm message can be sent to the management system via the communication interface through the analog front-end module (AFE), and can further carry additional information such as the faulty channel number, the over-limit amplitude, the timestamp of occurrence, and the current temperature zone. Furthermore, the alarm message can be represented as a digital communication frame, status bit, error code, or interrupt request signal, and can be implemented using serial messages, parallel flags, or event triggering methods under different bus protocols.

[0122] Based on the above analysis, it can be seen that by combining the difference threshold judgment with the average voltage value control, the analog front-end module (AFE) can prioritize fault isolation during abnormal sampling and generate control signals with more stable average results during normal sampling. This improves the reliability and consistency of the temperature sampling link over a wide temperature range and reduces the risk of miscontrol caused by single-path deviation.

[0123] Based on the aforementioned embodiments, a fifth resistor R5 is further included; the input terminals of multiple analog-to-digital converters (ADCs) are all connected to the intermediate voltage divider node through the fifth resistor R5.

[0124] In this embodiment, the fifth resistor R5 is a current-limiting isolation element connected in series between the intermediate voltage divider node and the input terminal of the analog-to-digital converter (ADC) to reduce the direct load effect of the ADC input terminal on the intermediate voltage divider node while maintaining the transmission of the voltage divider signal.

[0125] Since multiple analog-to-digital converters (ADCs) typically correspond to different sampling channels, and each sampling channel generates different charging and discharging currents during the sampling and holding moment, the fifth resistor R5 can limit the transient current at each input terminal and buffer disturbances caused by channel switching, sampling capacitor charging, and external electromagnetic coupling, thereby improving the voltage stability of the intermediate voltage divider node and reducing the measurement deviation introduced by the coupling at the input terminal of the ADC.

[0126] Furthermore, the fifth resistor R5 is placed between the intermediate voltage divider node and the input terminals of each analog-to-digital converter (ADC). The input terminals of multiple ADCs can be connected to the same intermediate voltage divider node via independent fifth resistors R5, or they can be led out from a common node in a branch wiring structure and then connected in series with the corresponding fifth resistors R5 to the input terminals of each ADC.

[0127] Optionally, the fifth resistor R5 can be placed on the side close to the ADC pin inside the analog front-end module AFE to shorten the length of the high-impedance sampling path, or it can be placed on the side close to the voltage divider circuit to form a centralized layout with the thermistor sampling branch.

[0128] Furthermore, the fifth resistor R5 can be implemented using any of the following methods: surface mount resistor, precision thin-film resistor, or array resistor network. Surface mount resistors facilitate miniaturization, precision thin-film resistors improve resistance consistency and temperature drift stability, and array resistor networks are suitable for matching designs when multiple analog-to-digital converters (ADCs) are synchronously connected. In different implementation scenarios, the fifth resistor R5 can also adopt common package sizes to adapt to the different requirements of space, power consumption, and assembly processes in battery management systems. The resistance value of the fifth resistor R5 can typically be set from several ohms to tens of kiloohms, specifically determined by the ADC input capacitance, sampling period, allowable settling time, and voltage divider network source impedance. When high sampling speed is required, a smaller resistance value can be selected for the fifth resistor R5 to reduce the RC time constant. When the battery management system prioritizes interference immunity and input protection, the resistance value can be appropriately increased to improve isolation.

[0129] It is understandable that the fifth resistor R5 is not only used to suppress the transient pull of the ADC input on the intermediate voltage divider node, but also to form a low-pass filter characteristic together with the internal sampling capacitor of the ADC input terminal, thereby attenuating high-frequency noise to a certain extent and further improving the stability of the sampling results.

[0130] Based on the above analysis, when the temperature sampling circuit is started and enters the temperature sampling state, the voltage at the intermediate voltage divider node forms a corresponding voltage divider result under the combined action of the thermistor, the first resistor, and the controllable branch. Multiple analog-to-digital converters (ADCs) then acquire the voltage at this node through the fifth resistor R5. During the sampling and holding process of the ADCs, the fifth resistor R5 limits the charging current to avoid a significant jump in the voltage at the intermediate voltage divider node caused by the instantaneous loading of the sampling capacitor. At the same time, it reduces the coupling interference between multiple ADCs connected in parallel. Therefore, the voltage divider can be made closer to the temperature change state truly reflected by the thermistor, thereby improving the temperature sampling stability and consistency over a wide temperature range.

[0131] Based on the aforementioned embodiments, the controllable conducting element Q1 is further defined as a transistor; the base of the transistor serves as the control terminal of the controllable conducting element Q1, the collector of the transistor is connected to the second resistor R2, and the emitter of the transistor is grounded.

[0132] For example, the transistor can be an NPN bipolar transistor, or a PNP transistor in reverse configuration when the circuit polarity is adjusted accordingly, or a composite transistor structure with equivalent switching function; its packaging can be of different levels to adapt to different management system board space and assembly processes.

[0133] When the temperature sampling circuit is started, the analog front-end module controls the base drive of the transistor according to the temperature sampling state corresponding to the intermediate voltage divider node. The control signal output from the general output pin is applied to the base of the transistor through the third resistor, and the fourth resistor provides a pull-down bias so that the transistor can obtain sufficient base bias and enter the conduction state when it needs to be turned on. At this time, a low-resistance path is formed between the collector and emitter. The branch where the second resistor is located is connected to the voltage divider network, thereby changing the equivalent resistance value after the first resistor and the controllable branch are connected in parallel, so that the voltage of the intermediate voltage divider node is kept in a range that is easier for the analog-to-digital converter to collect.

[0134] When the control signal is removed (when the control signal is low), the base potential of the transistor returns to the cutoff bias under the action of the fourth resistor, the collector and emitter are disconnected, the controllable branch exits the voltage divider network, and the temperature sampling circuit returns to the original voltage divider state.

[0135] Since the transistor controls the connection of the second resistor in a low-side switching manner, its conduction and cutoff responses can work in conjunction with the detection logic of the analog front-end module, thereby dynamically adjusting the distribution range of the sampling voltage in different temperature zones, reducing the probability of the voltage at the voltage divider node approaching the power supply or ground, and thus improving the effective range utilization of the analog-to-digital converter and increasing the sensitivity and resolution of temperature sampling over a wide temperature range.

[0136] Based on the above analysis, it can be seen that the embodiments of this application utilize transistors as controlled conduction elements with simple structure, fast response speed and easy drive, so as to make the conduction switching of controllable branches more stable and help reduce the deviation and hysteresis of temperature sampling under extreme temperature conditions.

[0137] Based on the aforementioned embodiments, the controllable conduction element is a metal-oxide-semiconductor field-effect transistor; the gate of the metal-oxide-semiconductor field-effect transistor serves as the control terminal of the controllable conduction element Q1, the drain of the metal-oxide-semiconductor field-effect transistor is connected to the second resistor R2; and the source of the metal-oxide-semiconductor field-effect transistor is grounded.

[0138] For example, the metal-oxide-semiconductor field-effect transistor can be an N-channel enhancement-mode metal-oxide-semiconductor field-effect transistor, a logic-level metal-oxide-semiconductor field-effect transistor, or a low-threshold metal-oxide-semiconductor field-effect transistor, in order to adapt to the output level and drive capability of different analog front-end modules; its package can be a common low-power device package, or it can be selected according to heat dissipation and installation space.

[0139] Furthermore, to make the impact of the controllable branch on the equivalent resistance of the voltage divider network more controllable, the on-resistance of the metal-oxide-semiconductor (MOSFET) should generally be much smaller than the values ​​of the second and first resistors, ensuring that its influence on the equivalent resistance of the voltage divider network when it is turned on is negligible. For example, if both the second and first resistors are on the order of 10kΩ, the on-resistance of the MOSFET should be less than 100Ω to avoid interference from its own voltage drop on the voltage divider accuracy. This design contrasts with the transistor approach: the base-emitter voltage drop (approximately 0.7V) of a transistor directly affects the voltage of the voltage divider node, while the on-resistance of the MOSFET has less interference with the voltage, thus requiring resistance matching to optimize the voltage divider accuracy. Simultaneously, its gate charge and switching speed should match the drive capability of the general-purpose output pins of the analog front-end module to ensure that the branch can respond promptly when the control signal switches.

[0140] This controllable conduction element uses gate voltage to control conduction. Compared with the current drive method using transistors, it can further reduce drive losses and reduce the impact of conduction voltage drop on voltage division accuracy, thus making it easier for the voltage divider network to maintain a voltage range suitable for ADC sampling in different temperature zones.

[0141] Upon startup, the analog front-end module determines whether the voltage divider corresponding to the current temperature is within the effective detection range of the analog-to-digital converter (ADC) based on the sampling results of the intermediate voltage divider node. It then applies a control level to the gate of the metal-oxide-semiconductor (MOSFET) through a general-purpose output pin. When the second resistor branch needs to be activated, the gate voltage rises above the threshold, the MOSFET is turned on, and the second resistor forms a low-side path to ground via its drain and source. This allows the controllable branch to be connected in parallel with the first resistor, reducing the equivalent resistance of the voltage divider network and thus altering the voltage distribution of the intermediate voltage divider node. This causes the sampled voltage to fall back into a range more suitable for the ADC to read. When this branch is no longer needed for voltage division, the control signal is removed, the MOSFET is turned off, the second resistor branch is disconnected, and the voltage divider network returns to its original operating state.

[0142] Based on the above-described process, it can be seen that the embodiments of this application can achieve rapid switching of parallel branches by voltage drive without significantly increasing circuit complexity. Due to the low on-state voltage drop and low control loss of the metal-oxide-semiconductor field-effect transistor, the switching process of the voltage divider network is more stable, which helps to improve the temperature sampling accuracy and stability over a wide temperature range and reduce sampling errors under high temperature, low temperature or rapid temperature change conditions.

[0143] In one possible implementation, the power supply terminal is the reference voltage terminal Vref of the analog front-end module AFE, or a constant voltage source terminal or a constant current source terminal.

[0144] The power supply terminal is located at one end of the series voltage divider link between the thermistor NTC and the first resistor R1, and is connected to the power reference inside or outside the analog front-end module AFE. In one possible embodiment, the reference voltage terminal Vref can be directly output to the voltage divider circuit as the voltage divider excitation source. In another possible embodiment, the constant voltage source terminal can be provided by a bandgap reference, a low dropout linear regulator, or other voltage regulator reference chip, with an output of 3.3V, 5V, or other stable voltages that meet the sampling accuracy requirements. In yet another possible embodiment, the constant current source terminal can provide a constant current from microamps to milliamps through a current mirror, a constant current source chip, or a current output circuit controlled by an operational amplifier to adapt to different thermistor NTC resistance ranges and temperature detection methods.

[0145] When the voltage of the power supply terminal is related to that of the intermediate voltage divider node, it is necessary to ensure that its output stability, ripple level and load regulation meet the sampling requirements of the analog-to-digital converter (ADC) and are coordinated with the resistance range of the first resistor R1 and the thermistor NTC within the target temperature range, so that the intermediate voltage divider node can generate continuous and distinguishable voltage changes when the temperature changes.

[0146] Upon startup, the power supply first provides a stable excitation to the voltage divider circuit composed of the thermistor NTC and the first resistor R1, causing the intermediate voltage divider node to generate a corresponding voltage as the temperature changes and input to the analog-to-digital converter (ADC) of the analog front-end module (AFE) for sampling. Since the power supply can use any of the following: reference voltage terminal Vref, constant voltage source terminal, or constant current source terminal, its output characteristics can be matched according to the circuit architecture, thereby ensuring that the voltage of the voltage divider node remains within the identifiable range under low temperature, high temperature, or rapid temperature change scenarios.

[0147] Based on this stable excitation, the analog front-end module (AFE) can accurately read the voltage divider at different operating points. Furthermore, it works with controllable branches to adjust the equivalent resistance of the voltage divider network, preventing the sampled voltage from consistently approaching the upper or lower limits of the analog-to-digital converter (ADC). Consequently, changes in the thermistor (NTC) resistance can be more fully mapped to changes in node voltage, reducing sensitivity loss at temperature edges due to voltage compression, improving the consistency and distinguishability of temperature sampling over a wide temperature range, and providing a more reliable input basis for subsequent charge / discharge control, thermal management adjustments, and anomaly protection judgments.

[0148] In one possible implementation, the number of controllable branches is multiple.

[0149] The configuration of multiple controllable branches allows the temperature sampling circuit to selectively change the voltage division relationship according to different temperature ranges, different ADC range boundaries, or different sampling accuracy requirements, thereby avoiding the problem that a single branch cannot simultaneously take into account the sampling sensitivity of low and high temperature ranges over a wide temperature range.

[0150] In one possible embodiment, multiple controllable branches are connected in parallel with the first resistor between the voltage divider node and ground. Alternatively, they can be arranged at the other end of the first resistor according to the actual circuit layout and maintain an equivalent parallel relationship with the voltage divider network. The input, control, and output terminals of each controllable branch correspond to the general output pins, control logic, and voltage divider node of the analog front-end module.

[0151] Multiple controllable branches can be implemented in the form of discrete devices arranged in parallel, integrated switch arrays, or modular plug-in arrangements. Each branch can include a controllable conducting element and a resistor connected in series with it. Different implementation forms can also be adopted, such as metal-oxide-semiconductor field-effect transistors with resistors, transistors with resistors, analog switches with resistors, or digital potentiometer branches.

[0152] The selection of materials and devices for the aforementioned controllable branches can be adjusted according to the requirements of withstand voltage, power consumption and response speed. For example, silicon-based metal-oxide-semiconductor field-effect transistors, bipolar transistors, thin film resistors or thick film resistors can be used. The resistance parameters of each controllable branch can be set to equal value, segmented weight or progressive binary weight, so as to form a multi-level adjustment mode that combines coarse and fine adjustment.

[0153] The number of controllable branches mentioned above is typically matched to the target temperature range coverage, the effective input range of the analog-to-digital converter (ADC), and the allowable sampling error. As the number of branches increases, the equivalent resistance of each individual controllable branch can be set to decrease or increase in predetermined steps to ensure that the parallel equivalent resistance formed when multiple controllable branches are active remains within a predetermined range suitable for temperature sampling. For example, fewer controllable branches can be enabled in the low-temperature range to maintain a higher voltage divider, while more controllable branches can be enabled in the high-temperature range to reduce the equivalent resistance and expand the effective sampling range of the ADC. This multi-level adjustment mode allows the voltage divider network to adapt to sampling requirements across the entire temperature range, avoiding the limitation of a single branch failing to achieve both high and low temperature accuracy.

[0154] When the temperature sampling circuit is working, the analog front-end module first samples and judges the voltage of the intermediate voltage divider node, and determines the number of branches to be activated based on the control strategy of multiple controllable branches. When the temperature change causes the voltage of the voltage divider node to deviate from the target sampling range, the analog front-end module outputs control signals to one or more controllable branches through the general-purpose output pin, so as to turn the corresponding controllable branch on or off, thereby changing the parallel equivalent resistance value corresponding to the first resistor, and thus redistributing the voltage relationship between the thermistor and the voltage divider network.

[0155] Since multiple controllable branches can provide multi-level switchable equivalent resistance values, the temperature sampling circuit can flexibly select the state of single branch conduction, dual branch parallel conduction, or more branches coordinated conduction in different temperature ranges, so that the voltage of the voltage divider node is kept within the effective detection range of the analog-to-digital converter (ADC) as much as possible, avoiding the phenomenon of voltage approaching the power supply terminal or ground terminal and causing range compression under extreme low temperature or high temperature conditions.

[0156] Therefore, this scheme can improve the availability of voltage sampling over a wide temperature range and improve the resolution and stability of temperature derivation, thereby enhancing the management system's ability to identify temperature measurement devices and the reliability of subsequent thermal management control.

[0157] Figure 2 This is a schematic flowchart illustrating the temperature sampling method provided in an embodiment of this application. Figure 2 As shown, the temperature sampling method includes:

[0158] S201: Obtain the target voltage of the intermediate voltage divider node in the voltage divider circuit of the temperature sampling circuit. The target voltage is determined by: determining the average voltage value of the voltage of the intermediate voltage divider node collected by multiple analog-to-digital converters in the temperature sampling circuit, and determining the average voltage value as the target voltage.

[0159] In this step, the analog front-end module, serving as the execution carrier of the temperature sampling method, is deployed within the temperature sampling link of the battery management system and forms electrical or signal connections with the temperature sampling circuit, multiple analog-to-digital converters (ADCs), and voltage divider circuits. The temperature sampling circuit forms the basis for voltage division sampling and voltage acquisition of the device under test. Specifically, it constructs a voltage divider network through the thermistor branch and its matching resistor branch corresponding to the device under test, creating intermediate voltage divider nodes for data acquisition. The voltage divider circuit converts the resistance change of the device under test into a voltage change at the intermediate voltage divider node, which is the sampling output point in the voltage divider network. Multiple ADCs jointly read the voltage at this node. Multiple ADCs perform multi-channel sampling at the same intermediate voltage divider node, and the average voltage value characterizes the combined value of multiple sampling results. The target voltage is the final sampling result determined by this average voltage value.

[0160] In practical implementation, the analog front-end module first controls the temperature sampling circuit to enter a stable sampling state. In one possible embodiment, the device to be measured is the battery in the battery module. In this embodiment, a thermistor is placed on one side of the battery, and the thermistor and the first resistor are connected in series to form a voltage divider branch. The intermediate connection point constitutes an intermediate voltage divider node, which is connected to the input terminals of two or more analog-to-digital converters (ADCs). Before starting sampling, the analog front-end module maintains a stable power supply to the voltage divider network and triggers multiple ADCs to perform sampling after a preset setup time, so that each ADC acquires the instantaneous voltage value of the intermediate voltage divider node within the same sampling window. For each ADC, the acquired digital quantity is first converted into a corresponding voltage value. The conversion can be performed according to the reference voltage and quantization bit depth of the ADC. If the output code value of the i-th ADC is Di, the reference voltage is Vref, and the resolution is N bits, then the sampling voltage of that ADC can be expressed as Vi = Di × Vref / 2^N. After the analog front-end module summarizes the voltage values ​​of each channel, it calculates the average voltage value according to Vavg=(V1+V2+…+Vn) / n, where n is the number of analog-to-digital converters participating in this calculation, and Vavg is the average voltage value. This average voltage value is then determined as the target voltage.

[0161] In another possible embodiment, multiple analog-to-digital converters (ADCs) do not sample strictly simultaneously. Instead, the analog front-end module triggers them sequentially at adjacent sampling times according to a preset timing sequence. However, each sampling corresponds to the same intermediate voltage divider node, and the interval between adjacent samplings is set within a time range where the voltage change at the voltage divider node is negligible. After receiving the sampling results, the analog front-end module performs validity checks on the sampled values. Validity checks can include range checks, consistency checks, and exception code checks. Range checks are used to confirm that each sampled value is within the resolvable range of the ADC. Consistency checks are used to compare whether the difference between each sampled value is less than a preset deviation threshold. Exception code checks are used to exclude invalid sampled values ​​caused by open circuits, short circuits, or interface anomalies.

[0162] When at least a preset number of valid samples are obtained, the analog front-end module only averages the valid samples and uses the resulting average voltage value as the target voltage. If there are insufficient valid samples, the analog front-end module can restart the current sampling round.

[0163] In another possible embodiment, the analog front-end module performs a consistency check on the voltages collected by multiple analog-to-digital converters before determining the average voltage value. Specifically, the deviation between the voltage sample value of each channel and the preliminary average value can be calculated first. Then, voltage sample values ​​with deviations greater than a preset threshold are removed, and the remaining sample values ​​are averaged again to obtain a corrected average voltage value as the target voltage. The threshold setting can be determined by combining the analog-to-digital converter resolution, the reference voltage fluctuation range, and the allowable error of temperature sampling. For example, the deviation threshold can be set to 0.5% to 2% of the full-scale voltage to control the impact of abnormal channels on the target voltage.

[0164] Furthermore, if there are fixed offset differences in the front-end channels of each analog-to-digital converter, the analog front-end module can also pre-store calibration coefficients for each channel and perform channel compensation processing before averaging, so that the sampling results of different analog-to-digital converters are under a unified benchmark.

[0165] In this step, the target voltage is not directly taken from a single analog-to-digital converter (ADC), but rather the voltage of the same intermediate voltage divider node is jointly characterized by multiple ADCs.

[0166] Based on the above analysis, it can be seen that within the wide operating temperature range of the voltage divider circuit, the voltage of the intermediate voltage divider node may exhibit discrete changes due to the influence of analog-to-digital converter channel offset, instantaneous noise, reference source fluctuations, and sampling time jitter. By calculating the average voltage value of the acquisition results from multiple analog-to-digital converters and determining it as the target voltage, the single-channel sampling error can be smoothed without changing the basic architecture of the temperature sampling circuit. This allows the target voltage to more accurately represent the actual potential of the intermediate voltage divider node, providing a stable input for subsequent temperature conversion.

[0167] S202: Determine the temperature of the device to be measured based on the target voltage.

[0168] In this step, the device to be measured is the object whose temperature is being measured, corresponding to the temperature-sensitive element in the voltage divider circuit or the actual device thermally coupled to that temperature-sensitive element. The analog front-end module performs temperature conversion processing based on the target voltage obtained in S201. Since the resistance relationship of the voltage divider circuit is known, a correspondence can be pre-established between the temperature of the device to be measured and the target voltage, and the analog front-end module outputs the temperature value of the device to be measured accordingly.

[0169] In practical implementation, the simulation front-end module stores the correspondence between target voltage and temperature. This correspondence can be established during the calibration phase. The establishment process includes: selecting the actual temperature values ​​of the device under test at multiple known temperature points, recording the voltage of the intermediate voltage divider node of the voltage divider circuit at the corresponding temperature points, forming a temperature-voltage mapping table, and writing this mapping table into a storage area accessible to the simulation front-end module. During operation, after reading the target voltage, the simulation front-end module searches for the temperature range corresponding to the target voltage in the mapping table. If the target voltage is exactly the same as a certain voltage point in the table, the corresponding temperature is directly output. If the target voltage is between two adjacent voltage points, the temperatures corresponding to these two voltage points are interpolated to obtain the temperature value of the device under test. The interpolation method can be linear interpolation, that is, when the target voltage is Vt and it is between Vx and Vy, and the corresponding temperatures are Tx and Ty respectively, the temperature can be calculated as T = Tx + (Vt - Vx) × (Ty - Tx) / (Vy - Vx).

[0170] In one possible embodiment, the correspondence is implemented using a functional relationship. For scenarios where a thermistor is used as the temperature measurement device, the simulation front-end module first calculates the equivalent resistance of the thermistor based on the target voltage, and then calculates the temperature based on the functional relationship between the thermistor resistance and temperature. If the voltage divider circuit consists of a supply voltage Vin, a fixed resistor R1, and a thermistor Rt, with the intermediate voltage divider node connected between them, then depending on whether the thermistor is on the pull-up or pull-down side, the simulation front-end module calls the corresponding voltage divider inverse calculation formula to calculate Rt. For example, in a connection where the fixed resistor R1 is connected to the power supply and the thermistor Rt is grounded, and the target voltage of the intermediate voltage divider node is Vt, then Rt can be calculated as Rt = R1 × Vt / (Vin - Vt). After obtaining Rt, the simulation front-end module can call the pre-stored thermistor characteristic equation to calculate the temperature. After completing the calculation, the simulation front-end module converts the absolute temperature to Celsius and outputs it.

[0171] In another possible embodiment, the analog front-end module incorporates correction parameters when determining the temperature based on the target voltage. These correction parameters may include the actual value of the voltage divider supply, the measured resistance of the fixed resistor, the reference voltage offset of the analog-to-digital converter, and a thermal coupling correction due to the mounting location of the device under test. The analog front-end module obtains these correction parameters during production testing or system calibration and incorporates them into temperature calculations during operation.

[0172] After this step is completed, the analog front-end module outputs the determined temperature of the device to be measured to the subsequent processing unit of the management system for thermal management adjustment and abnormal protection judgment and invocation. In one possible embodiment, the analog front-end module writes the temperature value into a register, which is periodically read by the main control chip; in another possible embodiment, the analog front-end module directly sends the temperature value to the control logic via the internal bus.

[0173] Based on the above analysis, it can be seen that by using the target voltage obtained by S201 as a unified input and performing conversion according to the pre-established correspondence between target voltage and temperature, the voltage information in the voltage divider circuit can be stably converted into the temperature information of the device under test. Especially under the condition that the dispersion of the target voltage has been reduced by averaging multiple analog-to-digital converters, the consistency between the subsequent temperature conversion result and the actual state of the intermediate voltage divider node is higher, thus making the temperature identification results over a wide temperature range more usable.

[0174] Based on the above analysis, this application provides a temperature sampling method, including: acquiring the target voltage of the intermediate voltage divider node in the voltage divider circuit of the temperature sampling circuit, wherein the target voltage is obtained by determining the average voltage value of the voltages of the intermediate voltage divider node collected by multiple analog-to-digital converters and determining the average voltage value as the target voltage; and determining the temperature of the device to be measured based on the target voltage. In this application, the analog front-end module relies on multiple analog-to-digital converters to perform sampling, verification, and averaging processing on the same intermediate voltage divider node, and then converts the obtained target voltage into a temperature value according to a preset mapping relationship or functional relationship, so that the temperature sampling method can be adapted to the thermistor voltage divider sampling scenario in the battery management system.

[0175] Based on the aforementioned embodiments, the method further includes: acquiring the control state of the general output pin GPO in the temperature sampling circuit; and determining the device status information in the temperature sampling circuit based on the control state and the voltage of the intermediate voltage divider node acquired by multiple analog-to-digital converters (ADCs).

[0176] In its implementation, after receiving the control state of the General Purpose Output (GPO) pin, the analog front-end module can perform correlation analysis between this control state and the intermediate voltage divider node voltages of multiple analog-to-digital converters (ADCs). If the control state indicates that the controllable branch is in a conducting state, the intermediate voltage divider node voltage should fall within a preset voltage range corresponding to this conducting state; if the control state indicates that the controllable branch is in a de-conducting state, the intermediate voltage divider node voltage should satisfy another preset range. Based on the matching relationship between the control state and the sampling voltages of each ADC, combined with threshold judgment or table lookup comparison, the analog front-end module can output the corresponding device status information.

[0177] For example, if the voltage divider values ​​collected by multiple analog-to-digital converters (ADCs) are abnormally high when the controllable conducting element Q1 is off, it may indicate that the first resistor R1 is open; if the voltage divider values ​​collected by multiple ADCs are no different from those in the off state when the controllable conducting element Q1 is on, it may indicate that the controllable conducting element Q1 is faulty or that the second resistor R2 is open.

[0178] To reduce the impact of sampling deviation of a single analog-to-digital converter (ADC) on the judgment result, the consistency of multiple ADC acquisition values ​​can be checked first, and then the device is determined to be abnormal based on the average value, maximum and minimum value differences or deviations.

[0179] During operation, the control status of the general purpose output pin (GPO) first reflects the control intention of the analog front-end module for the controllable branch, while the intermediate voltage divider node voltages collected by multiple analog-to-digital converters (ADCs) reflect the actual response status of the current voltage divider network. Together, they constitute the basis for determining the operating status of the internal devices in the temperature sampling circuit. By jointly analyzing the control status and the sampled voltage, normal conduction, normal shutdown, and abnormal conduction states can be distinguished, and corresponding device status information can be output.

[0180] By adopting the above method, the device status information no longer depends on a single voltage value, but is determined by combining the control status of the general output pin GPO with the sampling results of multiple analog-to-digital converters (ADCs). This makes the status identification results of the temperature sampling circuit more complete and can provide a basis for subsequent temperature sampling correction, fault diagnosis, and abnormal protection.

[0181] In this embodiment, the temperature sampling method is applied to the analog front-end module (AFE) in the temperature sampling circuit. During sampling, the AFE first reads the voltage of the intermediate voltage divider node in the voltage divider circuit of the temperature sampling circuit, and receives voltage data from multiple analog-to-digital converters (ADCs) that have acquired data from this intermediate voltage divider node. For each sampling result output by the multiple ADCs, the AFE summarizes and calculates the voltage values ​​to obtain the average voltage value of the corresponding intermediate voltage divider node, and determines this average voltage value as the target voltage. Subsequently, the AFE determines the temperature of the device under test based on the correspondence between the target voltage and the temperature of the device under test. The temperature result can be calculated according to the parameters of the voltage divider circuit, the electrical characteristic parameters of the device under test, and the resistance or equivalent electrical quantity corresponding to the target voltage.

[0182] While sampling the temperature, the analog front-end module (AFE) also reads the control state of the general-purpose output pin (GPO) in the temperature sampling circuit and processes it together with the intermediate voltage divider node voltages acquired by multiple analog-to-digital converters (ADCs). When the GPO is in different control states, the AFE determines the device status information in the temperature sampling circuit according to the sampling results of the intermediate voltage divider node voltages under the corresponding control states. The device status information is determined based on the matching relationship between the control states and the sampling voltages of each ADC. During the determination process, the sampling results of multiple ADCs are compared and synthesized to output the corresponding device status information.

[0183] Next, taking a battery as the device to be tested and two analog-to-digital converters as an example, we will explain how to test the temperature of a battery, combining the temperature sampling method and temperature sampling circuit provided in the above embodiments. Figure 3 A schematic diagram of the temperature sampling circuit provided in the embodiments of this application. Figure 2 Battery temperature testing includes the following steps:

[0184] Step 1: After the temperature sampling circuit is powered on, the analog front-end module (AFE) needs to complete a self-test. After the AFE completes the self-test, the general-purpose output pin GPO outputs a low level by default. At this time, the controllable conducting element Q1 is turned off, and the battery management system enters the low-temperature mode. The first analog-to-digital converter (ADC1) and the second analog-to-digital converter (ADC2) begin periodically sampling the intermediate voltage divider node of the voltage divider circuit.

[0185] Step 2: Read the sampled values ​​from the first analog-to-digital converter (ADC1) and the second analog-to-digital converter (ADC2), and average the sampled values ​​to obtain the average voltage value V. avg According to V avg With preset threshold V th_low and V th_highBased on the comparison results, determine the current temperature range of the battery:

[0186] If V avg <V th_low If the area is determined to be in a high-temperature zone, proceed to step three.

[0187] If V avg >V th_high If the temperature is determined to be in the low-temperature range, proceed to step four.

[0188] If V th_low ≤V avg ≤V th_high If the current mode is deemed appropriate, maintain the existing state and proceed to step five.

[0189] Step 3: Switch to High Temperature Mode: The general-purpose output pin GPO outputs a high-level control signal, driving the controllable conducting element Q1 to conduct. The second resistor R2 is connected in parallel to the voltage divider network. Wait for stabilization time t. settle After (usually in milliseconds), the sampled values ​​of the first analog-to-digital converter ADC1 and the second analog-to-digital converter ADC2 are reread.

[0190] Step 4: Switch to Low Temperature Mode: The general-purpose output pin GPO outputs a low-level control signal, turning off the controllable conducting element Q1, disconnecting the controllable branch, and only the first resistor R1 participates in voltage division. Wait for stabilization time t. settle Then, the sampled values ​​of the first analog-to-digital converter ADC1 and the second analog-to-digital converter ADC2 are read again.

[0191] Step 5, Temperature Calculation and Output: Based on the state of the controllable conducting element Q1 (e.g., on or off), select the corresponding voltage divider formula and the thermistor NTC lookup table parameters, and calculate the temperature from V. avg Calculate the resistance R of the thermistor NTC. NTC Then, the battery temperature T is calculated by looking up a table or by the Steinhart-Hart equation, and the calculated temperature value is output to the main control module (BatteryManagement System Master Control Module, abbreviated as BMS).

[0192] Step Six: Anomaly Detection: Within each sampling period, compare the difference |V| between the sampled values ​​of the first analog-to-digital converter ADC1 and the second analog-to-digital converter ADC2. ADC1 -V ADC2 If the difference exceeds ΔV max If an abnormality is detected, the fault code is recorded and reported to the BMS. If an abnormality occurs N times consecutively, a hardware fault alarm is triggered.

[0193] One point needs to be clarified: in V th_low and V th_highAn appropriate hysteresis range is set between these two thresholds to prevent frequent switching at the switching threshold.

[0194] In summary, the above scheme significantly improves the accuracy and reliability of battery temperature sampling through an adaptive range switching mechanism and a dual-path redundant acquisition architecture. Firstly, dynamically switching the equivalent resistance value of the voltage divider network solves the problem of sampling accuracy degradation under extreme temperatures caused by the nonlinear characteristics of the thermistor (NTC), ensuring that the voltage of the voltage divider node remains within the optimal sampling range of the analog-to-digital converter (ADC) across the entire temperature range. Test data shows that temperature sampling accuracy is significantly improved by more than 50% over a wide temperature range of −40°C to 85°C.

[0195] Secondly, the redundant acquisition of multi-channel analog-to-digital converters (ADCs) not only reduces random noise by averaging, but also achieves circuit self-diagnosis by comparing the differences in the sampled values ​​of any two ADCs, enabling timely identification of abnormal conditions such as ADC faults, open circuits / short circuits, etc.

[0196] In addition, by controlling the output state of the general-purpose output pin GPO through software algorithms, hardware faults such as failure of the controllable conducting element Q1 switch, open circuit of the second resistor R2, or short circuit of the fifth resistor R5 can be further diagnosed, thus avoiding the output of incorrect temperature values.

[0197] The above design achieves high-precision sampling and redundancy verification across the entire temperature range with a small number of external components without the need for additional dedicated chips. It has low hardware costs and is simple to implement, making it suitable for scenarios with extremely high battery safety requirements, such as electric vehicles and energy storage systems.

[0198] Furthermore, the temperature sampling method and temperature sampling circuit provided in the above embodiments can also be applied to other devices besides batteries. When applied to other devices besides batteries, the analog front-end module (AFE) needs to be replaced with a corresponding control chip.

[0199] Furthermore, the resistor used in the temperature sampling circuit described above can be replaced with a digital potentiometer with a resistance value. This digital potentiometer dynamically adjusts the resistance value through the serial peripheral interface (SPI) or inter-integrated circuit (I2C) interface of the analog front-end module to achieve a continuously adjustable voltage division ratio without segmented switching.

[0200] This application also provides a battery management system, including the temperature sampling circuit described above.

[0201] This battery management system integrates a temperature sampling circuit into the battery temperature monitoring link. A voltage divider signal is generated through a thermistor sampling branch, and the voltage at the intermediate voltage divider node is acquired by an analog-to-digital converter (ADC). Because the temperature sampling circuit incorporates a controllable branch connected in parallel with the first resistor in the voltage divider formed by the thermistor and the first resistor, and this controllable branch is turned on or off by the general-purpose output pin of the analog front-end module, the equivalent resistance of the voltage divider network can be adjusted according to different temperature ranges. This prevents the voltage divider voltage from excessively approaching the power supply or ground terminal in low or high temperature ranges, thereby expanding the effective range of the ADC and making voltage changes over a wide temperature range more easily and accurately identified, thus improving temperature resolution and sampling accuracy.

[0202] Therefore, this battery management system can more reliably support charge and discharge control, thermal management regulation, and abnormal protection in applications such as power battery modules and energy storage battery clusters.

[0203] Furthermore, embodiments of this application also provide a battery system, including a battery and the battery management system provided above.

[0204] The battery management system in this battery system can work in conjunction with the battery to sample the temperature of battery modules, energy storage battery clusters, or other devices under temperature measurement, and use the sampling results for charge / discharge control, thermal management adjustment, and anomaly protection. Because the battery management system employs a temperature sampling scheme based on a thermistor voltage divider circuit and adjustable equivalent resistance values ​​via controllable branches, the voltage at the voltage divider nodes is more suitable for analog-to-digital converter acquisition within different temperature ranges. This improves voltage utilization and temperature resolution over a wide temperature range, thereby enhancing the accuracy and timeliness of temperature identification in low-temperature, high-temperature, and rapid charge / discharge heating scenarios. Therefore, it helps to enhance the reliability of the battery system's temperature control strategy and safety protection judgment.

[0205] Furthermore, embodiments of this application provide a vehicle, including a vehicle body and the battery system described above.

[0206] The vehicle body carries and mounts the aforementioned battery system. The temperature sampling circuit within the battery system monitors the temperature of the power battery module, energy storage battery cluster, or other devices to be measured. Because the battery system incorporates a controllable branch based on the voltage divider formed by the thermistor and the first resistor, and its conduction and cutoff are controlled by the analog front-end module, the equivalent resistance of the voltage divider network can be adjusted according to the temperature range. This allows the analog-to-digital converter to obtain a more suitable sampling voltage over a wider temperature range. This reduces the impact of effective range compression in extreme temperature zones, enabling the vehicle to more accurately identify battery temperature changes even under conditions of low-temperature start-up, high-temperature operation, and rapid charging / discharging. This improves the reliability of thermal management control, charge / discharge control, and fault protection, thus enhancing overall vehicle operational safety.

[0207] This application provides a temperature sampling device, which includes:

[0208] The acquisition module is used to acquire the target voltage of the intermediate voltage divider node in the voltage divider circuit of the temperature sampling circuit. The target voltage is determined by: determining the average voltage value of the voltage of the intermediate voltage divider node collected by multiple analog-to-digital converters in the temperature sampling circuit, and determining the average voltage value as the target voltage.

[0209] The determination module is used to determine the temperature of the device under test based on the target voltage.

[0210] The temperature sampling device provided in this embodiment can execute the method provided in the above method embodiment. Its implementation principle and technical effect are similar, and will not be described in detail here.

[0211] It should be noted that the division of the various modules in the above device is merely a logical functional division. In actual implementation, they can be fully or partially integrated into a single physical entity, or they can be physically separated. Furthermore, these modules can be implemented entirely in software via processing element calls; they can be fully implemented in hardware; or some modules can be implemented by processing element calls to software, while others are implemented in hardware. For example, a processing module can be a separate processing element, or it can be integrated into a chip within the device. Alternatively, it can be stored as program code in the device's memory, and its functions can be called and executed by a processing element. The implementation of other modules is similar. Moreover, these modules can be fully or partially integrated together, or they can be implemented independently. The processing element here can be an integrated circuit with signal processing capabilities. During implementation, each step of the above method or each of the above modules can be completed through integrated logic circuits in the hardware of the processor element or through software instructions.

[0212] For example, these modules can be one or more integrated circuits configured to implement the above methods, such as one or more Application Specific Integrated Circuits (ASICs), one or more Digital Signal Processors (DSPs), or one or more Field Programmable Gate Arrays (FPGAs). As another example, when a module is implemented using processing element scheduler code, the processing element can be a general-purpose processor, such as a Central Processing Unit (CPU) or other processor capable of calling program code. Furthermore, these modules can be integrated together as a System-On-a-Chip (SOC).

[0213] Figure 4 This is a schematic diagram of the structure of a simulated front-end module provided in one embodiment of this application. Figure 4 As shown, the analog front-end module provided in this application embodiment may include: a processor 401, and a memory 402 communicatively connected to the processor, wherein:

[0214] The memory stores instructions that the computer executes;

[0215] The processor executes computer execution instructions stored in memory to implement the method described in the foregoing method embodiments.

[0216] It should be understood that processor 401 can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), etc. A general-purpose processor can be a microprocessor or any conventional processor. The steps of the method disclosed in the application can be directly manifested as execution by a hardware processor, or execution by a combination of hardware and software modules within the processor. Memory 402 may include high-speed random access memory (RAM), and may also include non-volatile memory (NVM), such as at least one disk storage device, or a USB flash drive, external hard drive, read-only memory, disk, or optical disc, etc.

[0217] Optionally, the analog front-end module may also include a communication interface 403. In specific implementations, if the communication interface 403, memory 402, and processor 401 are implemented independently, they can be interconnected via a bus to complete communication. The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus, etc. Buses can be categorized as address buses, data buses, control buses, etc., but this does not imply that there is only one bus or one type of bus.

[0218] Optionally, in a specific implementation, if the communication interface 403, memory 402 and processor 401 are integrated on a single chip, then the communication interface 403, memory 402 and processor 401 can communicate through an internal interface.

[0219] This application also provides a computer-readable storage medium storing computer-executable instructions, which, when executed, are used to implement the methods described in any of the foregoing embodiments.

[0220] It is understood that the computer-readable storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as Static Random Access Memory (SRAM), Electrically Erasable Programmable Read Only Memory (EEPROM), Erasable Programmable Read Only Memory (EPROM), Programmable Read Only Memory (PROM), Read Only Memory (ROM), magnetic storage, flash memory, magnetic disk, or optical disk. The readable storage medium can be any available medium accessible to a general-purpose or special-purpose computer.

[0221] An exemplary computer-readable storage medium is coupled to a processor, enabling the processor to read information from and write information to the computer-readable storage medium. Of course, the computer-readable storage medium can also be a component of the processor. The processor and the computer-readable storage medium can reside in an ASIC. Alternatively, the processor and the computer-readable storage medium can exist as discrete components in an electronic device.

[0222] The integrated modules implemented as software functional modules described above can be stored in a computer-readable storage medium. These software functional modules, stored in a computer-readable storage medium, include several instructions to cause an electronic device (which may be a personal computer, server, or network device, etc.) or processor to execute some steps of the methods described in the various embodiments of this application.

[0223] This application also provides a computer program product, including a computer program that, when executed, implements the method described in any of the foregoing embodiments.

[0224] It should be noted that, for the sake of simplicity, the foregoing method embodiments are all described as a series of actions. However, those skilled in the art should understand that this application is not limited to the described order of actions, as some steps may be performed in other orders or simultaneously according to this application. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are all optional embodiments, and the actions and modules involved are not necessarily essential to this application.

[0225] It should be further noted that although the steps in the flowchart are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowchart may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the sub-steps or stages of other steps.

[0226] In the above embodiments, the descriptions of each embodiment have their own emphasis. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments. The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combination of these technical features does not contradict each other, it should be considered within the scope of this specification.

[0227] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this application are indicated by the following claims.

[0228] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. A temperature sampling circuit, characterized by, include: The system includes an analog front-end module (AFE), a thermistor (NTC), a first resistor (R1), and a controllable branch, wherein the voltage of the thermistor (NTC) reflects the temperature of the device under test. The thermistor (NTC) is connected in series with the first resistor (R1) to form a voltage divider circuit. One end of the voltage divider circuit is connected to the power supply terminal, and the other end is grounded. The intermediate voltage divider node of the voltage divider circuit is connected to the input terminal of the analog-to-digital converter (ADC) of the analog front-end module (AFE), and the voltage of the intermediate voltage divider node is acquired by the analog-to-digital converter (ADC). The controllable branch is connected in parallel with the first resistor (R1) to form a voltage divider network. The control terminal of the controllable branch is connected to the general purpose output pin (GPO) of the analog front-end module (AFE). The analog front-end module (AFE) controls the conduction and cutoff of the controllable branch through the general purpose output pin (GPO). When the controllable branch is on, the equivalent resistance value of the voltage divider network is reduced.

2. The temperature sampling circuit of claim 1, wherein, The controllable branch includes a controllable conducting element (Q1) and a second resistor (R2), wherein: The controllable conducting element (Q1) and the second resistor (R2) are connected in series to form the controllable branch, and the control terminal of the controllable conducting element (Q1) serves as the control terminal of the controllable branch.

3. The temperature sampling circuit of claim 2, wherein, The temperature sampling circuit also includes a third resistor (R3) and a fourth resistor (R4). The control terminal of the controllable conducting element (Q1) is connected to the general-purpose output pin (GPO) through the third resistor (R3); The control terminal of the controllable conducting element (Q1) is also grounded through the fourth resistor (R4).

4. The temperature sampling circuit of any one of claims 1 to 3, wherein, The analog front-end module (AFE) is specifically used for: When the voltage of the first resistor (R1) is detected to be greater than the preset voltage detection upper limit, a high-level control signal is generated and transmitted to the controllable branch through the general purpose output pin (GPO). The control signal is used to drive the controllable branch to conduct.

5. The temperature sampling circuit according to any one of claims 1 to 3, characterized in that, The analog front-end module (AFE) is specifically used for: When the voltage across the first resistor (R1) is detected to be less than a preset lower voltage detection limit, a low-level control signal is generated and transmitted to the controllable branch through the general purpose output pin (GPO). The control signal is used to drive the controllable branch to disconnect. The ratio of the resistance of the thermistor (NTC) to the resistance of the first resistor (R1) is greater than or equal to a first value and less than or equal to a second value. The first value is the quotient of the voltage provided by the power supply divided by the preset upper voltage detection limit minus 1, and the second value is the quotient of the voltage provided by the power supply divided by the preset lower voltage detection limit minus 1.

6. The temperature sampling circuit according to any one of claims 1 to 3, characterized in that, The analog front-end module (AFE) includes multiple analog-to-digital converters (ADCs), and each ADC has an independently configured input terminal. The input terminals of the multiple ADCs are all connected to the intermediate voltage divider node. The analog front-end module (AFE) is also used to determine the average voltage value of the voltage of the intermediate voltage divider node collected by the plurality of analog-to-digital converters (ADCs), and generate a control signal corresponding to the controllable branch based on the average voltage value.

7. The sampling circuit according to claim 6, characterized in that, The analog front-end module (AFE) is specifically used for: Determine whether the absolute value of the difference between the voltages of any two analog-to-digital converters (ADCs) at the intermediate voltage divider nodes is greater than a difference threshold; if it is greater than the difference threshold, output an alarm message to the management system. If the average voltage value is less than or equal to the difference threshold, the average voltage value is determined as the target voltage of the voltage divider network, and a control signal corresponding to the controllable branch is generated based on the average voltage value.

8. The temperature sampling circuit according to claim 6, characterized in that, It also includes the fifth resistor (R5); The input terminals of the plurality of analog-to-digital converters (ADCs) are all connected to the intermediate voltage divider node via a fifth resistor (R5).

9. The sampling circuit according to claim 2 or 3, characterized in that, The controllable conducting element (Q1) is a transistor; The base of the transistor serves as the control terminal of the controllable conducting element (Q1), the collector of the transistor is connected to the second resistor (R2), and the emitter of the transistor is grounded.

10. The sampling circuit according to claim 2 or 3, characterized in that, The controllable conduction element is a metal-oxide-semiconductor field-effect transistor; The gate of the metal-oxide-semiconductor field-effect transistor serves as the control terminal of the controllable conduction element (Q1), and the drain of the metal-oxide-semiconductor field-effect transistor is connected to the second resistor (R2); the source of the metal-oxide-semiconductor field-effect transistor is grounded.

11. The temperature sampling circuit according to any one of claims 1 to 3, characterized in that, The power supply terminal is the reference voltage terminal (Vref) of the analog front-end module (AFE), or a constant voltage source terminal or a constant current source terminal.

12. The temperature sampling circuit according to any one of claims 1 to 3, characterized in that, The number of controllable branches is multiple.

13. A temperature sampling method, characterized in that, An analog front-end module (AFE) applied in a temperature sampling circuit as described in any one of claims 6 to 12, the temperature sampling method comprising: The target voltage of the intermediate voltage divider node in the voltage divider circuit of the temperature sampling circuit is obtained, wherein the target voltage is determined by: determining the average voltage value of the voltage of the intermediate voltage divider node collected by multiple analog-to-digital converters (ADCs) in the temperature sampling circuit, and determining the average voltage value as the target voltage; Based on the target voltage, the temperature of the device to be measured is determined.

14. The temperature sampling method according to claim 13, characterized in that, Also includes: Obtain the control state of the general purpose output pin (GPO) in the temperature sampling circuit; Based on the control state and the voltage of the intermediate voltage divider node acquired by the plurality of analog-to-digital converters (ADCs), the device state information in the temperature sampling circuit is determined.

15. A battery management system, characterized in that, Includes the temperature sampling circuit as described in any one of claims 1 to 12.

16. A battery system, characterized in that, Includes a battery and a battery management system as described in claim 15.

17. A vehicle, characterized in that, Includes the vehicle body and the battery system as described in claim 16.

Images