Single cell monitoring chip, system, and method

Abstract

The present disclosure provides a single cell monitoring chip, system and method. The chip is used for monitoring a single cell and is self-powered by the single cell, and is integrated with: a voltage detection circuit connected to a positive electrode of the single cell and used for detecting a positive electrode voltage of the single cell; a boost circuit having an input end receiving the positive electrode voltage and used for boosting the positive electrode voltage to obtain a boosted voltage; and a first low-dropout linear regulator having an input end connected to the positive electrode of the single cell via a first switch and connected to an output end of the boost circuit via a second switch, and having an output end used for powering circuits in the chip, in a case where the positive electrode voltage is greater than or equal to a threshold voltage, the first switch is turned on and the second switch is turned off, the first low-dropout linear regulator receives the positive electrode voltage as a power supply voltage, and in a case where the positive electrode voltage is less than the threshold voltage, the first switch is turned off and the second switch is turned on, the first low-dropout linear regulator receives the boosted voltage as the power supply voltage.

Description

Technical Field

[0001] This disclosure belongs to the field of battery monitoring technology, and in particular relates to a single-cell monitoring chip, a single-cell monitoring system, and a single-cell monitoring method. Background Technology

[0002] With the rapid development of new energy vehicles, energy storage systems, and various electronic devices, the safety and reliability of battery systems are receiving increasing attention. Real-time and accurate monitoring of individual cells (single batteries) has become a crucial means of ensuring battery safety, extending lifespan, and optimizing energy management within battery systems.

[0003] In existing technologies, single-cell monitoring solutions typically suffer from the following technical problems. First, single-cell monitoring chips struggle to achieve true self-powering. Most existing monitoring chips rely on external power supplies or additional power management modules, which not only increases system complexity and cost but also reduces overall reliability. External power supply becomes particularly unsuitable when internal space within the battery pack is limited or when power consumption and reliability requirements are high. Second, single-cell voltage ranges are relatively wide (typically operating from 1.2V to above 4.2V). When the cell voltage drops to a low level, the monitoring chip struggles to maintain stable operation. Especially when the cell voltage falls below a certain threshold, if the voltage cannot be effectively boosted to provide stable power to the monitoring circuit and wireless transmission module, monitoring functions and wireless data transmission will be interrupted or fail, severely impacting the real-time performance of the battery management system. Third, the design of the reference voltage source contains inherent contradictions. Reference voltage sources used for voltage detection, boost control, and low-dropout linear regulator feedback require a wide voltage input range to provide a reference voltage even when the cell voltage is extremely low. The reference voltage source used for high-precision measurements in analog-to-digital converters requires high accuracy and a small temperature coefficient to ensure the accuracy of the monitoring data. Existing solutions struggle to meet both of these different requirements simultaneously, often necessitating trade-offs between wide range and high accuracy, which limits system performance.

[0004] Furthermore, existing single-cell monitoring solutions have shortcomings in integrating multi-parameter monitoring (voltage, temperature, current, pressure, and electrochemical impedance spectroscopy (EIS), etc.) and powering external wireless circuits. In particular, when the cell voltage is in the low-voltage range, how to achieve self-powering while stably powering the external wireless transmission module and performing advanced monitoring functions such as EIS has become a pressing technical challenge.

[0005] Therefore, how to design a single-cell monitoring chip that can be directly powered by the monitored single cell without the need for an external power source; can still stably power the internal circuitry and external wireless circuitry when the cell voltage varies over a wide range (especially as low as 1.2V); and can reasonably resolve the contradiction between the wide range and high precision of the reference voltage source, and achieve the integration of multi-parameter monitoring and wireless transmission functions, has become a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0006] This disclosure provides a single-cell monitoring chip, a single-cell monitoring system, and a single-cell monitoring method.

[0007] According to one aspect of this disclosure, a single-cell monitoring chip is provided, the chip being used to monitor a single cell and self-powered by the single cell, the chip integrating: a voltage detection circuit connected to the positive terminal of the single cell and used to detect the positive voltage of the single cell; a direct supply path, the input terminal of the direct supply path being connected to the positive voltage; a boost path, the input terminal of the boost path being connected to the positive voltage and including a boost circuit, the boost circuit receiving the positive voltage and used to boost the positive voltage to obtain a raised voltage; and a first low-dropout linear regulator connected to the output terminal of the direct supply path and the output terminal of the boost path, wherein when the voltage detection circuit detects that the positive voltage is greater than or equal to a threshold voltage, the direct supply path directly provides the positive voltage to the first low-dropout linear regulator, and when the voltage detection circuit detects that the positive voltage is less than the threshold voltage, the boost path provides the raised voltage to the first low-dropout linear regulator.

[0008] Furthermore, the input terminal of the first low-dropout linear regulator is connected to the positive terminal of the individual battery cell via a first switch of the direct supply path, and is connected to the output terminal of the boost circuit of the boost path via a second switch. The output terminal of the first low-dropout linear regulator is used to supply power to the circuit within the chip. When the positive voltage is greater than or equal to a threshold voltage, the first switch is turned on and the second switch is turned off, and the first low-dropout linear regulator receives the positive voltage as the power supply voltage. When the positive voltage is less than the threshold voltage, the first switch is turned off and the second switch is turned on, and the first low-dropout linear regulator receives the boosted voltage as the power supply voltage.

[0009] According to this technical solution, existing single-cell monitoring chips struggle to operate stably when the cell voltage drops and typically require an external power supply. This solution addresses this by incorporating a voltage detection circuit, a boost circuit, and a first low-dropout linear regulator with first and second switches. This allows for automatic switching between direct power and boost paths based on the cell voltage, enabling the chip to be directly powered by the monitored single cell without external power. Even when the cell voltage falls below a threshold, it can still provide stable power to the internal circuitry through boosting, thus resolving the technical problem of unreliable operation of the monitoring chip in low-voltage scenarios.

[0010] According to at least one embodiment of this disclosure, the chip further integrates a second low-dropout linear regulator, which is connected to the output terminal of the direct supply path and the output terminal of the boost path. When the voltage detection circuit detects that the positive voltage is greater than or equal to the threshold voltage, the direct supply path directly provides the positive voltage to the second low-dropout linear regulator. When the voltage detection circuit detects that the positive voltage is less than the threshold voltage, the boost path provides the boosted voltage to the second low-dropout linear regulator.

[0011] Furthermore, the input terminal of the second low-dropout linear regulator is connected to the positive terminal of the single cell via a third switch, and to the output terminal of the boost circuit via a fourth switch. The output terminal of the second low-dropout linear regulator is used to power circuits outside the chip. When the positive voltage is greater than or equal to a threshold voltage, the third switch is turned on and the fourth switch is turned off, and the second low-dropout linear regulator receives the positive voltage as its power supply voltage. When the positive voltage is less than the threshold voltage, the third switch is turned off and the fourth switch is turned on, and the second low-dropout linear regulator receives the boost voltage as its power supply voltage.

[0012] In existing solutions, the monitoring chip and wireless transmission module are typically powered separately, and wireless transmission is prone to failure when the battery voltage drops. This technical solution adds a second low-dropout linear regulator with a third and fourth switch, which is dedicated to powering the chip's external circuitry and shares a boost path with the first low-dropout linear regulator. This achieves unified self-powered management of the monitoring chip's internal circuitry and external wireless circuitry, solving the technical problem of unstable wireless transmission in the low-voltage range.

[0013] According to at least one embodiment of this disclosure, the chip further integrates a first bandgap reference voltage generation circuit. The input terminal of the first bandgap reference voltage generation circuit receives the positive voltage. The first bandgap reference voltage generation circuit operates directly under the positive voltage. The first bandgap reference voltage generation circuit has a wide voltage input range and generates a low-precision output voltage to provide to the voltage detection circuit, the boost circuit, the first low-dropout linear regulator, and the second low-dropout linear regulator.

[0014] The reference voltage used for power control and threshold detection needs to have a wide input voltage range to provide a stable reference even when the cell voltage is extremely low (the LDO is not yet effectively operating). Existing single references struggle to balance wide range and control reliability. This technical solution sets up a first bandgap reference voltage generation circuit directly connected to the positive terminal of the cell, which has a wide voltage input range and operates directly at the positive terminal voltage. It provides a reference for the voltage detection circuit, boost circuit, and two low-dropout linear regulators, solving the technical problem of unreliable reference for control logic in the low-voltage range.

[0015] According to at least one embodiment of this disclosure, the chip has a minimum operating voltage of 1.2V and a threshold voltage of 2.3V.

[0016] The chip in this technical solution has a minimum operating voltage of 1.2V and a threshold voltage of 2.3V, achieving stable operation within a wide voltage range of 1.2V to 4.2V, which significantly improves the applicability and reliability of single-cell monitoring.

[0017] According to at least one embodiment of the present disclosure, the chip further includes a signal acquisition circuit for acquiring multiple measurement signals of the single cell, the measurement signals including at least one or more of the voltage signal, temperature signal, current signal, pressure signal and electrochemical impedance spectroscopy signal of the single cell.

[0018] According to at least one embodiment of this disclosure, the signal acquisition circuit includes: a multiplexer that connects to the plurality of measurement signals to measure the plurality of measurement signals respectively; an analog-to-digital converter that receives the measurement signals from the multiplexer and converts the measurement signals into digital signals; and a digital circuit that receives the digital signals from the analog-to-digital converter, processes the digital signals to obtain a processed signal, and provides the processed signal to the digital interface of the chip.

[0019] According to at least one embodiment of the present disclosure, the chip further integrates a second bandgap reference voltage generation circuit, the second bandgap reference voltage generation circuit being connected to the first low-dropout linear regulator, and the output voltage of the first low-dropout linear regulator serving as the power supply voltage of the second bandgap reference voltage generation circuit.

[0020] According to at least one embodiment of the present disclosure, the output voltage of the second bandgap reference voltage generation circuit has high accuracy and a small temperature coefficient, and serves as the reference voltage for the analog-to-digital converter.

[0021] The accuracy and temperature coefficient of the reference voltage of the analog-to-digital converter (ADC) directly affect the accuracy and consistency of the monitoring data. This technical solution further limits the output of the second bandgap reference voltage generation circuit to have high accuracy and a small temperature coefficient, and uses it as the reference voltage for the ADC. This solves the technical problem that the accuracy of ADC measurement is greatly affected by battery voltage fluctuations, and significantly improves the accuracy and temperature stability of the monitoring results.

[0022] According to at least one embodiment of this disclosure, the power supply voltage of the multiplexer, analog-to-digital converter, and digital circuit is the output voltage of the first bandgap reference voltage generating circuit.

[0023] This technical solution limits the power supply voltage of the multiplexer, analog-to-digital converter, and digital circuit to the output of the first bandgap reference voltage generation circuit (i.e., the voltage after being regulated by the first low-dropout linear regulator), thereby achieving power domain isolation between the precision measurement circuit and the wide-range control circuit, and improving the overall anti-interference capability and operational reliability of the system.

[0024] According to another aspect of this disclosure, a single-cell monitoring system is provided, comprising: a chip as described in any of the preceding claims; and a wireless circuit, wherein the output voltage of a second bandgap reference voltage generation circuit is used as the power supply voltage of the wireless circuit, and the wireless circuit receives the processed signal through the digital interface.

[0025] According to another aspect of this disclosure, a power management method for a single-cell monitoring chip is provided, applied to the aforementioned single-cell monitoring chip. The method includes: the voltage detection circuit detecting the positive voltage of the single cell in real time; when the positive voltage is greater than or equal to a threshold voltage, controlling the first switch to be turned on and the second switch to be turned off, so that the first low-dropout linear regulator directly receives the positive voltage as a power supply voltage; when the positive voltage is less than the threshold voltage, controlling the first switch to be turned off and the second switch to be turned on, starting the boost circuit to boost the positive voltage, and making the first low-dropout linear regulator receive the boosted voltage as a power supply voltage; wherein, the method uses a first bandgap reference voltage generation circuit to provide a reference voltage to the voltage detection circuit, the first low-dropout linear regulator, and the boost circuit.

[0026] According to at least one embodiment of this disclosure, the method further includes: controlling the third switch and the fourth switch such that the second low-dropout linear regulator directly receives the positive voltage as a power supply voltage when the positive voltage is greater than or equal to a threshold voltage, and receives the increased voltage as a power supply voltage when the positive voltage is less than the threshold voltage. Attached Figure Description

[0027] The accompanying drawings illustrate exemplary embodiments of the present disclosure and, together with the description thereof, serve to explain the principles of the present disclosure. These drawings are included to provide a further understanding of the present disclosure and are incorporated in and constitute a part of this specification.

[0028] Figure 1 A schematic block diagram of a single-cell monitoring system according to one embodiment of the present disclosure is shown.

[0029] Figure 2 A schematic block diagram of a single-cell monitoring system according to one embodiment of the present disclosure is shown.

[0030] Figure 3 A schematic diagram of the direct supply path of a single-cell monitoring system according to one embodiment of the present disclosure is shown.

[0031] Figure 4 A schematic diagram of the boost path of a single-cell monitoring system according to one embodiment of the present disclosure is shown.

[0032] Figure 5 A flowchart of a single-cell monitoring method according to one embodiment of the present disclosure is shown.

[0033] Figure 6 A flowchart of a single-cell monitoring method according to one embodiment of the present disclosure is shown. Detailed Implementation

[0034] The present disclosure will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the disclosure. Furthermore, it should be noted that, for ease of description, only the parts relevant to the present disclosure are shown in the accompanying drawings.

[0035] It should be noted that, where there is no conflict, the embodiments and features described in this disclosure can be combined with each other. The technical solutions of this disclosure will now be described in detail with reference to the accompanying drawings and embodiments.

[0036] Unless otherwise stated, the exemplary implementations / embodiments shown are to be understood as providing exemplary features of various details that provide ways in which the technical concepts of this disclosure can be implemented in practice. Therefore, unless otherwise stated, the features of various implementations / embodiments may be additionally combined, separated, interchanged and / or rearranged without departing from the technical concepts of this disclosure.

[0037] Existing single-cell monitoring solutions mainly suffer from the following technical problems: it is difficult to achieve direct self-powering from the monitored cell, usually requiring an additional external power supply or a complex power management module; the monitoring chip becomes unstable when the cell voltage drops; there is a contradiction in the design of the reference voltage source, making it difficult to balance the requirements of wide input range control with high precision and low temperature coefficient measurement; and multi-parameter monitoring functions are difficult to integrate in low-voltage self-powered scenarios.

[0038] This disclosure provides a single-cell monitoring chip and a single-cell monitoring system, which realize various functions such as self-powered stability monitoring of a single cell under a wide voltage range.

[0039] Figure 1 A framework diagram of a single-cell monitoring system according to one embodiment of the present disclosure is shown. The single-cell monitoring system 10 may include a single-cell monitoring chip 100. The single-cell monitoring chip 100 is used to monitor a single cell, for example, it can monitor one or any one of N lithium battery cells connected in series, where N > 1. The single-cell monitoring chip 100 receives the voltage of the positive terminal of the single cell 200 as its power supply voltage, without the need for other voltages or voltage sources, as will be described in detail below. Furthermore, the single-cell monitoring chip can collect and process multiple monitoring signals from the single cell, and provide the processed signals to the wireless circuit 300 of the single-cell monitoring system 10. The wireless circuit 300 can transmit the signals to other devices. As an example, the single-cell monitoring chip 100 and the wireless circuit 300 of the single-cell monitoring system 10 may be disposed inside the battery pack or on the surface of the battery pack.

[0040] Figure 2A framework diagram of a single-cell monitoring system according to a further embodiment of the present disclosure is shown. Figure 2 The single-cell monitoring chip 100 of this application, shown in a dashed box, is integrated into a single semiconductor chip. The single-cell monitoring chip 100 can be connected to the positive terminal of a single cell 200 via pins, thus providing the power supply voltage to the single-cell monitoring chip 100 without requiring an additional voltage source. Figure 2 As shown, the positive voltage VBAT of a single battery cell 200 can be connected through pin 1 of the single-cell monitoring chip 100. Additionally, the temperature sensor (NTC) 500 and the current sampling resistor 400 can also be connected through other pins of the single-cell monitoring chip 100 to receive temperature and current monitoring signals. Of course, according to the technical solution of this disclosure, if it is necessary to receive other monitoring signals, corresponding pins can also be used to provide them to the single-cell monitoring chip 100.

[0041] The single-cell monitoring chip 100 integrates a voltage detection circuit 110, a boost circuit 120, a first low-dropout linear regulator (LDO) 130, a second low-dropout linear regulator (LDO) 140, a first bandgap reference voltage generation circuit 150, a second bandgap reference voltage generation circuit 160, a multiplexer 170, an analog-to-digital converter 180, a digital circuit 190, and a switching network. The entire chip achieves high integration, reducing system size, parasitic parameters, and failure rates. Furthermore, it can be powered by the monitored single cell 200, thus achieving self-powering functionality while monitoring.

[0042] The voltage detection circuit 110 receives the positive voltage VBAT of a single cell 200 for real-time detection of the positive voltage VBAT of the single cell 200. The voltage detection circuit 110 can adopt existing detection circuit forms; for example, it may include a voltage divider resistor network and a comparator. As an example, when using a voltage divider resistor network and a comparator, the first reference voltage generated by the first bandgap reference voltage generation circuit 150 described herein can be used as the reference voltage, without the need for other reference voltage generators. For example, the voltage divider resistors proportionally reduce VBAT and feed it to one end of the comparator, while the other end of the comparator receives the first reference voltage from the first bandgap reference voltage generation circuit 150.

[0043] The single-cell monitoring chip 100 includes both a direct power supply path and a boost path. Figure 2 The direct supply path is shown in dashed lines. Figure 3The boost path is shown as a dashed line. During the discharge process of the battery cell, the cell voltage will continuously decrease. If it falls below a certain voltage, the positive terminal voltage of the cell will not be able to meet the power supply voltage requirements of the single-cell monitoring chip 100. In the technical solution disclosed herein, two power supply paths are provided: a direct power supply path and a boost path.

[0044] The direct supply path refers to the path where the positive voltage VBAT of a single battery cell 200 is directly used as the power supply voltage of the single-cell monitoring chip 100, such as... Figure 3 As shown. In the direct supply path, the positive voltage of a single cell 200 is used as the power supply voltage for the first low-dropout linear regulator 130 and the second low-dropout linear regulator 140. For example, the first low-dropout linear regulator 130 can be connected to the positive voltage of a single cell 200 via a first switch S1, and the connection or disconnection of the positive voltage of the single cell 200 can be controlled by turning the first switch S1 on and off; the second low-dropout linear regulator 140 can be connected to the positive voltage of a single cell 200 via a third switch S3, and the connection or disconnection of the positive voltage of the single cell 200 can be controlled by turning the third switch S3 on and off. The on / off state of the first switch S1 and the third switch S3 can be controlled based on the results detected by the voltage detection circuit 110. When the voltage detection circuit 110 detects that the positive voltage VBAT of a single cell 200 is greater than or equal to the threshold voltage, the first switch S1 and the third switch S3 are turned on. When the voltage detection circuit 110 detects that the positive voltage VBAT of a single cell 200 is less than the threshold voltage, the first switch S1 and the third switch S3 are turned off. In this way, when the positive voltage VBAT of a single cell 200 meets the power supply voltage requirements of the single cell monitoring chip 100, the single cell monitoring chip 100 is directly powered by the positive voltage VBAT of the single cell 200.

[0045] The boost path refers to the path where the positive voltage VBAT of a single battery cell 200 is increased before being supplied to the first low-dropout linear regulator 130 and the second low-dropout linear regulator 140 as their power supply voltage. For example... Figure 4As shown, a boost circuit 120 can be provided in the boost path. The boost circuit 120 can take the form of a charge pump step-up converter, a boost converter, a flyback boost converter (flyback isolated boost switching power supply), a four-switch buck-boost converter, or other existing boost circuits. In the scheme of this application, the first low-dropout linear regulator 130 and the second low-dropout linear regulator 140 share a boost circuit 120, thus forming one boost path from the positive terminal of a single cell 200, through the boost circuit 120, to the first low-dropout linear regulator 130; and another boost path from the positive terminal of a single cell 200, through the boost circuit 120, to the second low-dropout linear regulator 140. A switch can also be provided in the boost path to control the conduction or disconnection of the boost path. Figure 4 As shown, the first low-dropout linear regulator 130 is provided with a second switch S2, and the second low-dropout linear regulator 140 is provided with a fourth switch S4. It should be noted that the first to fourth switches are merely one specific form; those skilled in the art can, according to actual conditions, provide other forms of on / off control elements or other numbers of switches, etc., and transistor switches, etc., can also be selected. This disclosure does not impose limitations on the technical solution.

[0046] The on / off state of the second switch S2 and the fourth switch S4 can be controlled based on the results detected by the voltage detection circuit 110. When the voltage detection circuit 110 detects that the positive voltage VBAT of a single cell 200 is less than the threshold voltage, the second switch S2 and the fourth switch S4 are turned on. When the voltage detection circuit 110 detects that the positive voltage VBAT of a single cell 200 is greater than or equal to the threshold voltage, the second switch S2 and the fourth switch S4 are turned off. In this way, when the positive voltage VBAT of a single cell 200 does not meet the power supply voltage requirements of the single cell monitoring chip 100, the boosted voltage of the positive voltage VBAT of the single cell 200 is used as the power supply for the single cell monitoring chip 100.

[0047] Furthermore, in the technical solution disclosed herein, the first low-dropout linear regulator 130 and the second low-dropout linear regulator 140 can be selected from existing low-dropout linear regulators 130. The first low-dropout linear regulator 130 can be used to power devices within the single-cell monitoring chip 100, for example in... Figure 2 All devices are shown within the dashed box. The output VDDBT of the second low-dropout linear regulator 140 can be used to power devices other than the single-cell monitoring chip 100, for example... Figure 2The wireless circuit 300 shown can also supply power to other external devices if other external devices are present.

[0048] According to the technical solution disclosed herein, the single-cell monitoring chip 100 can be fully self-powered by the positive voltage of a single cell 200, without any external power supply. Even when the positive voltage of a single cell 200 does not meet the power supply voltage requirements of the single-cell monitoring chip 100, it can still be powered by the positive voltage of a single cell 200. This not only powers the internal components of the single-cell monitoring chip 100 but also powers its external components. As an example in the technical solution disclosed herein, the threshold voltage can be 2.3V, and the minimum operating voltage of the single-cell monitoring chip 100 can be 1.2V. That is, within the voltage range of the positive voltage of a single cell 200 (1.2V to 2.3V), power can be supplied through a boost path; while within the voltage range of the positive voltage of a single cell 200 above 2.3V, power can be supplied directly through a direct power supply path.

[0049] The single-cell monitoring chip 100 also integrates a first bandgap reference voltage generation circuit 150. The first bandgap reference voltage generation circuit 150 employs a wide voltage input range and can generate a relatively low-precision output voltage. The first bandgap reference voltage generation circuit 150 is connected to the positive terminal voltage of the single cell 200, meaning its power supply voltage is the positive terminal voltage of the single cell 200. Thus, the first bandgap reference voltage generation circuit 150 can directly operate at the positive terminal voltage of the single cell 200, generating a relatively low-precision reference voltage to provide to the voltage detection circuit 110, the boost circuit 120, the first low-dropout linear regulator 130, and the second low-dropout linear regulator 140, etc., thereby serving as the reference voltage for these devices. For example, the voltage detection circuit 110 can use this reference voltage as a reference voltage to compare with the positive terminal voltage of the single cell 200, etc.

[0050] The single-cell monitoring chip 100 also integrates a second bandgap reference voltage generation circuit 160. The power supply voltage of the second bandgap reference voltage generation circuit 160 is the output voltage of the first bandgap reference voltage generation circuit 150, rather than the positive electrode voltage of a single cell 200. The large fluctuations in the positive electrode voltage of a single cell 200 can affect the accuracy and low temperature drift characteristics of the reference voltage generated by the bandgap reference voltage generation circuit. In the technical solution of this disclosure, the power supply voltage of the second bandgap reference voltage generation circuit 160 adopts the output voltage (VDDA / VDDD) of the first low-dropout linear regulator 130, thereby utilizing the characteristics of high accuracy and low temperature drift. The first bandgap reference voltage generation circuit 150 directly uses the positive electrode voltage of a single cell 200. This allows the first bandgap reference voltage generation circuit 150 to be directly powered on when the single-cell monitoring chip 100 is de-energized (e.g., the positive electrode voltage of a single cell 200 is less than 1.2V) and then re-energized, thus providing a reference voltage for the boost circuit 120, allowing the entire single-cell monitoring chip 100 to resume normal operation. The output voltage (reference voltage) provided by the second bandgap reference voltage generation circuit 160 is used to provide a reference voltage for the signal acquisition circuit integrated in the single-cell monitoring chip 100, especially for the analog-to-digital converter in the signal acquisition circuit. The output of the first low-dropout linear regulator 130 provides a stable power supply to the second bandgap reference voltage generation circuit 160, which is crucial for achieving high-precision analog-to-digital conversion.

[0051] The following reference Figure 2 A detailed description of the signal acquisition circuit is provided.

[0052] The signal acquisition circuit includes a multiplexer (MUX) 170, an analog-to-digital converter (ADC) 180, and a digital input / output (DIG) circuit 190. The multiplexer 170 connects multiple measurement signals to perform separate measurements on each signal. The ADC 180 receives the measurement signals from the multiplexer 170 and converts them into digital signals. The DIG circuit 190 receives the digital signals from the ADC 180, processes them to obtain a processed signal, and provides the processed signal to the chip's digital interface.

[0053] Multiplexer 170 has multiple inputs connected to the cell voltage divider signal, the temperature sensor (NTC 500) output signal, the voltage signal across the current sampling resistor 400 (cell current detection signal), the pressure sensor output signal (not shown), and electrochemical impedance spectroscopy (EIS) related signals (not shown). Multiplexer 170 can be time-division switched to provide these signals to the inputs of analog-to-digital converter 180. With the support of the reference voltage provided by the second bandgap reference voltage generation circuit 160, analog-to-digital converter 180 converts the analog signals into digital signals and sends them to digital circuit 190. Digital circuit 190 filters, calibrates, and calculates these digital signals (including EIS AC impedance calculation), ultimately obtaining monitoring results such as voltage, temperature, current, pressure, and EIS, which are then transmitted to external wireless circuit 300 via a digital interface. The digital circuit 190 is the data processing and control center of the entire monitoring chip (e.g., in the form of a microcontroller), responsible for the conversion from the initial analog-to-digital converter output data to the final monitoring result, EIS calculation, wireless data packaging, and some power management auxiliary logic.

[0054] When the cell voltage VBAT is greater than or equal to 2.3V, the voltage detection circuit 110 controls the switch to allow the first low-dropout linear regulator 130 and the second low-dropout linear regulator 140 to draw power directly from VBAT. The boost circuit 120 can be turned off or bypassed to reduce power consumption. At this time, both the first bandgap reference voltage generation circuit 150 and the second bandgap reference voltage generation circuit 160 operate normally, and the multi-parameter monitoring and wireless transmission functions operate normally, with the system in a high-efficiency direct supply mode. When the cell voltage drops below 2.3V, the voltage detection circuit 110 switches its state, the boost circuit 120 starts, and the two low-dropout linear regulators are powered by the boost voltage. The first bandgap reference voltage generation circuit 150 remains operational throughout the process, providing the necessary reference for low-voltage detection and boost control, thereby ensuring that the chip can still complete monitoring and wireless transmission tasks even at voltages as low as 1.2V, avoiding system failure due to insufficient LDO input.

[0055] This application achieves stable self-powered monitoring and wireless transmission of a single battery cell over a wide voltage range (especially the low-voltage range) through the coordinated operation of the aforementioned components. Simultaneously, the isolation design of the dual-bandgap reference power supply ensures the reliability of power control and the high accuracy of ADC measurements, significantly improving the overall performance and reliability of the single-cell monitoring system. The two LDOs provide power domain isolation for the internal circuitry and external wireless circuitry, further enhancing the system's flexibility and anti-interference capabilities. The continuous operation of the first bandgap reference voltage generation circuit 150 in the low-voltage range is another key factor in maintaining operation even at extremely low voltages, such as a single battery cell's positive terminal voltage as low as 1.2V.

[0056] According to a further embodiment of this disclosure, a single-cell monitoring method is also provided, which is applied to the single-cell monitoring chip described above.

[0057] Figure 5 A single-cell monitoring method according to one embodiment is shown. The method includes steps 510 to 530.

[0058] In step 510, the voltage detection circuit monitors the positive voltage of a single cell in real time. In step 520, it is determined whether the positive voltage is greater than or equal to a threshold voltage. If the positive voltage is greater than or equal to the threshold voltage, the process proceeds to step 530, where the first switch is turned on and the second switch is turned off, allowing the first low-dropout linear regulator to directly receive the positive voltage as its power supply voltage. If the positive voltage is less than the threshold voltage, the process proceeds to step 540, where the first switch is turned off and the second switch is turned on, activating the boost circuit to boost the positive voltage, and allowing the first low-dropout linear regulator to receive the increased voltage as its power supply voltage.

[0059] Figure 6 A single-cell monitoring method according to one embodiment is shown. The method includes steps 610 to 630.

[0060] In step 610, the voltage detection circuit monitors the positive voltage of a single cell in real time. In step 620, it is determined whether the positive voltage is greater than or equal to a threshold voltage. If the positive voltage is greater than or equal to the threshold voltage, the process proceeds to step 630, where the first and third switches are turned on, and the second and fourth switches are turned off, allowing the first and second low-dropout linear regulators to directly receive the positive voltage as the power supply voltage. If the positive voltage is less than the threshold voltage, the process proceeds to step 640, where the first and third switches are turned off, and the second and fourth switches are turned on, activating the boost circuit to boost the positive voltage, and allowing the first and second low-dropout linear regulators to receive the boosted voltage as the power supply voltage.

[0061] Other specific details in the technical solution of the method disclosed herein can be referred to the previous description, and for the sake of brevity, they will not be described in detail here.

[0062] In the description of this specification, the references to terms such as "one embodiment / mode," "some embodiments / modes," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment / mode or example is included in at least one embodiment / mode or example of this disclosure. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment / mode or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments / modes or examples. Furthermore, without contradiction, those skilled in the art can combine and integrate the different embodiments / modes or examples described in this specification, as well as the features of different embodiments / modes or examples.

[0063] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this disclosure, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0064] Those skilled in the art should understand that the above embodiments are merely for illustrating the present disclosure and are not intended to limit the scope of the disclosure. Those skilled in the art can make other changes or modifications based on the above disclosure, and these changes or modifications still fall within the scope of the present disclosure.

Claims

1. A single cell monitoring chip for monitoring a single cell and being self-powered by the single cell, characterized in that, The chip integrates: A voltage detection circuit is connected to the positive terminal of the individual battery cell and is used to detect the positive terminal voltage of the individual battery cell. A direct supply path, wherein the input terminal of the direct supply path is connected to the positive voltage; A boost path, wherein the input terminal of the boost path is connected to the positive voltage and includes a boost circuit, the boost circuit receiving the positive voltage and boosting the positive voltage to obtain a higher voltage; The first low-dropout linear regulator is connected to the output terminal of the direct supply path and the output terminal of the boost path. When the voltage detection circuit detects that the positive voltage is greater than or equal to the threshold voltage, the direct supply path directly provides the positive voltage to the first low-dropout linear regulator. When the voltage detection circuit detects that the positive voltage is less than the threshold voltage, the boost path provides the boosted voltage to the first low-dropout linear regulator.

2. The single-cell monitoring chip as described in claim 1, characterized in that, The input terminal of the first low-dropout linear regulator is connected to the positive terminal of the single cell via a first switch in the direct supply path, and is connected to the output terminal of the boost circuit in the boost path via a second switch. The output terminal of the first low-dropout linear regulator is used to supply power to the circuitry within the chip. When the positive voltage is greater than or equal to a threshold voltage, the first switch is turned on and the second switch is turned off, and the first low-dropout linear regulator receives the positive voltage as the power supply voltage. When the positive voltage is less than the threshold voltage, the first switch is turned off and the second switch is turned on, and the first low-dropout linear regulator receives the boosted voltage as the power supply voltage.

3. The chip as described in claim 2, characterized in that, The chip also integrates a second low-dropout linear regulator, which is connected to the output of the direct supply path and the output of the boost path. When the voltage detection circuit detects that the positive voltage is greater than or equal to the threshold voltage, the direct supply path directly provides the positive voltage to the second low-dropout linear regulator. When the voltage detection circuit detects that the positive voltage is less than the threshold voltage, the boost path provides the boosted voltage to the second low-dropout linear regulator.

4. The chip as described in claim 3, characterized in that, The input terminal of the second low-dropout linear regulator is connected to the positive terminal of the single cell via a third switch, and to the output terminal of the boost circuit via a fourth switch. The output terminal of the second low-dropout linear regulator is used to power circuits outside the chip. When the positive voltage is greater than or equal to a threshold voltage, the third switch is turned on and the fourth switch is turned off, and the second low-dropout linear regulator receives the positive voltage as its power supply voltage. When the positive voltage is less than the threshold voltage, the third switch is turned off and the fourth switch is turned on, and the second low-dropout linear regulator receives the boost voltage as its power supply voltage.

5. The chip as described in claim 4, characterized in that, Optionally, the chip further integrates a first bandgap reference voltage generation circuit. The input terminal of the first bandgap reference voltage generation circuit receives the positive voltage. The first bandgap reference voltage generation circuit operates directly under the positive voltage. The first bandgap reference voltage generation circuit has a wide voltage input range and generates a low-precision output voltage to provide power to the voltage detection circuit, the boost circuit, the first low-dropout linear regulator, and the second low-dropout linear regulator. Optionally, the chip has a minimum operating voltage of 1.2V and a threshold voltage of 2.3V. Optionally, the chip further includes a signal acquisition circuit for acquiring multiple measurement signals of the single cell, wherein the measurement signals include at least one or more of the voltage signal, temperature signal, current signal, pressure signal, and electrochemical impedance spectroscopy signal of the single cell.

6. The chip as described in any one of claims 1 to 5, characterized in that, The signal acquisition circuit includes: A multiplexer, which connects the plurality of measurement signals to measure the plurality of measurement signals separately; An analog-to-digital converter (ADC) that receives measurement signals from the multiplexer and converts the measurement signals into digital signals; and A digital circuit that receives a digital signal from the analog-to-digital converter, processes the digital signal to obtain a processed signal, and provides the processed signal to the digital interface of the chip.

7. The chip as described in any one of claims 1 to 6, characterized in that, Optionally, the chip further integrates a second bandgap reference voltage generation circuit, which is connected to the first low-dropout linear regulator, and the output voltage of the first low-dropout linear regulator serves as the power supply voltage for the second bandgap reference voltage generation circuit. Optionally, the output voltage of the second bandgap reference voltage generation circuit has high accuracy and a small temperature coefficient, and serves as the reference voltage for the analog-to-digital converter. Optionally, the power supply voltage of the multiplexer, analog-to-digital converter, and digital circuit is the output voltage of the first bandgap reference voltage generation circuit.

8. A single-cell monitoring system, characterized in that, include: The chip as described in claim 7; as well as The wireless circuit uses the output voltage of the second bandgap reference voltage generation circuit as the power supply voltage of the wireless circuit, and the wireless circuit receives the processed signal through the digital interface.

9. A power management method for a single-cell monitoring chip, characterized in that, The method, applied to the single-cell monitoring chip according to any one of claims 1 to 8, comprises: The voltage detection circuit detects the positive voltage of the individual battery cell in real time; When the positive voltage is greater than or equal to the threshold voltage, the first switch is turned on and the second switch is turned off, so that the first low-dropout linear regulator directly receives the positive voltage as the power supply voltage. When the positive voltage is less than the threshold voltage, the first switch is turned off and the second switch is turned on, the boost circuit is started to boost the positive voltage, and the first low dropout linear regulator receives the boosted voltage as the power supply voltage. The method uses the first bandgap reference voltage generation circuit to provide a reference voltage to the voltage detection circuit, the first low-dropout linear regulator, and the boost circuit.

10. The method as described in claim 9, characterized in that, The method further includes: controlling the third switch and the fourth switch so that the second low-dropout linear regulator directly receives the positive voltage as the power supply voltage when the positive voltage is greater than or equal to the threshold voltage, and receives the increased voltage as the power supply voltage when the positive voltage is less than the threshold voltage.

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