Protection circuit and regulation and control method for supporting PCB (Printed Circuit Board) level regulation parameters

Abstract

The embodiment of the invention provides a protection circuit and a regulation and control method for supporting PCB (Printed Circuit Board) level regulation parameters, the protection circuit comprises a battery protection chip, the battery protection chip is connected with a PCB and receives a characteristic signal transmitted by the PCB; wherein the characteristic signal is input through a test point deployed on the PCB; the battery protection chip is configured to obtain the characteristic signal and analyze the characteristic signal to obtain characteristic information; responding to the feature information, and adjusting parameters needing to be adjusted according to data in the feature information; the beneficial effects are that after the chip is installed on the printed circuit board, parameter adjustment can still be carried out.

Description

Technical Field

[0001] The present invention belongs to the technical field of integrated circuits, and in particular relates to a protection circuit and a control method supporting PCB board-level parameter adjustment. Background Art

[0002] At present, some internal parameters of the protection chip in the battery protection circuit of the existing electronic devices are pre-set fixed values; for example, the voltage protection threshold (for example, 4.5V) is set to a fixed value, and the protection delay time (for example, 1 second) is also set to a fixed value; it is impossible to flexibly adjust the corresponding parameters according to the needs of different application scenarios; in addition, in order to achieve higher protection accuracy, it is beneficial to achieve higher accuracy after the chip is installed in the printed circuit board. This is because during the installation process, the internal circuit of the protection chip may be affected by stress, resulting in parameter deviation (for example, the overvoltage protection threshold was originally designed to be 4.5V+ / -15mV, and the voltage deviation caused by stress may reduce the accuracy to 4.5V+ / -25mV). If the test adjustment is performed after installation on the PCB board, the accuracy can be restored to + / -15mV, and can even be adjusted to a higher accuracy (for example, + / -5mV), and higher accuracy helps to improve the safety of the battery.

[0003] Therefore, there is an urgent need for a solution that can still adjust parameters after the chip is mounted on the printed circuit board. Summary of the invention

[0004] In view of the defects in the prior art, the present invention provides a protection circuit and a control method that support PCB board-level parameter adjustment, so that parameters can still be adjusted after the chip is installed on the printed circuit board.

[0005] In a first aspect, a protection circuit supporting PCB board-level parameter adjustment includes a battery protection chip, wherein the battery protection chip is connected to a PCB board and receives a characteristic signal transmitted by the PCB board; wherein the characteristic signal is input through a test point deployed on the PCB board;

[0006] The battery protection chip is configured as:

[0007] Acquire the characteristic signal and analyze it to obtain characteristic information;

[0008] In response to the characteristic information, the parameters to be adjusted are adjusted according to the data in the characteristic information.

[0009] As a specific preferred embodiment of the present application, the battery protection chip includes a voltage input terminal and an output control terminal;

[0010] The battery protection chip is also configured as:

[0011] When the chip detects that the voltage relationship between the voltage input terminals is a set condition, the chip is triggered to enter a parameter adjustment mode, the output control terminal is controlled not to output, and the characteristic signal is received through the output control terminal.

[0012] As a specific preferred embodiment of the present application, the battery protection chip also includes a control terminal. When the chip detects that the voltage of the control terminal is lower than a preset protection threshold and lasts for more than a set time threshold, the level of the output control terminal is controlled to cut off the charging path.

[0013] As a specific preferred manner of the present application, the adjustment of the parameter to be adjusted includes increasing the parameter value or decreasing the parameter value.

[0014] As a specific preferred embodiment of the present application, the battery protection chip internally includes adjustable reference voltage sources RefA, RefB, RefC, a comparator ComD, a logic circuit, a reference voltage source VR6 and a decoder, the output control end of the logic circuit and the reference voltage source VR6 are respectively connected to the input end of the comparator ComD, the output end of the comparator ComD is connected to the decoder, and the decoder is also respectively connected to the adjustable reference voltage sources RefA, RefB and RefC to adjust the reference voltages of RefA, RefB and RefC.

[0015] As a specific preferred embodiment of the present application, the output control terminal is further connected to the protection device through a switch device; wherein the switch device is associated with a corresponding threshold voltage;

[0016] The characteristic signal corresponds to a high level voltage and a low level voltage, and both the high level voltage and the low level voltage are lower than the threshold voltage to prevent the switch device from being mistakenly turned on.

[0017] In a second aspect, a control method supporting PCB board-level parameter adjustment is applied to a protection circuit supporting PCB board-level parameter adjustment described in the first aspect, and the control method includes:

[0018] Receiving a characteristic signal transmitted by a PCB board; wherein the characteristic signal is input through a test point deployed on the PCB board;

[0019] Acquire the characteristic signal and analyze it to obtain characteristic information;

[0020] In response to the characteristic information, the parameters to be adjusted are adjusted according to the data in the characteristic information.

[0021] As a specific preferred embodiment of the present application, the control method further comprises:

[0022] When the chip detects that the voltage relationship between the voltage input terminals is a set condition, the chip is triggered to enter a parameter adjustment mode, the output control terminal is controlled not to output, and the characteristic signal is received through the output control terminal.

[0023] As a specific preferred embodiment of the present application, the control method further comprises:

[0024] The output control terminal is also connected to the protection device through a switch device; wherein the switch device is associated with a corresponding threshold voltage;

[0025] The characteristic signal corresponds to a high level voltage and a low level voltage, and both the high level voltage and the low level voltage are lower than the threshold voltage to prevent the switch device from being mistakenly turned on.

[0026] It can be seen from the above technical scheme that the present invention provides a protection circuit and control method that supports PCB board-level parameter adjustment, by adding a test point on the printed circuit board, and transmitting the characteristic signal from this test point to the battery protection chip; then parsing the characteristic signal to obtain characteristic information; and adjusting the parameters to be adjusted according to the data in the characteristic information; thereby achieving parameter adjustment after the chip is installed on the printed circuit board, which is convenient for flexible adjustment according to the needs of different application scenarios; at the same time, it can meet the adjustment to a higher precision, thereby helping to improve the safety of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for the specific embodiments or the description of the prior art. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn according to the actual scale.

[0028] Figure 1 A circuit diagram of a battery protection circuit provided by the prior art.

[0029] Figure 2 A connection diagram of a protection circuit supporting PCB board-level parameter adjustment provided by an embodiment of the present invention.

[0030] Figure 3 A schematic diagram of the internal connection of a protection circuit supporting PCB board-level parameter adjustment provided by an embodiment of the present invention;

[0031] Figure 4 A flow chart of a control method supporting PCB board-level parameter adjustment provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0032] The embodiments of the technical solution of the present invention will be described in detail below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and are therefore only used as examples, and the protection scope of the present invention cannot be limited thereto. It should be noted that, unless otherwise specified, the technical terms or scientific terms used in this application should be the common meanings understood by those skilled in the art to which the present invention belongs.

[0033] It should be understood that when used in this specification and the appended claims, the terms "include" and "comprises" indicate the presence of described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0034] It should also be understood that the terms used in this specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the specification of the present invention and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include plural forms.

[0035] As used in this specification and the appended claims, the term "if" may be interpreted as "when" or "upon" or "in response to determining" or "in response to detecting," depending on the context. Similarly, the phrases "if it is determined" or "if [described condition or event] is detected" may be interpreted as meaning "upon determination" or "in response to determining" or "upon detection of [described condition or event]" or "in response to detecting [described condition or event]," depending on the context.

[0036] It should be noted that, unless otherwise specified, the technical terms in this embodiment have the common meanings understood in the relevant technical field.

[0037] Figure 1 It is a battery protection circuit built into electronic equipment in the prior art, for example a laptop computer, which includes a protection chip Prot, resistors R1-R2, resistor Rvdd, capacitors C1-C2, capacitor Cvdd, battery cells BAT1-BAT2, fuse Fuse, and power MOSFET tube MNCO. Figure 1 It is implemented by connecting 2 cells in series (it can also be used for 3 or 4 or more cells in series). R1 ​​and C1 form a filter and voltage regulator function to make the voltage input to the VC1 pin of the chip Prot more stable; similarly, R2 and C2 form a filter and voltage regulator function; Rvdd and Cvdd form a filter and voltage regulator function, and the VDD pin supplies power to the chip. VC1~VC2 pins are used as voltage input to detect the cell voltage.

[0038] When the chip Prot detects that any cell voltage is overvoltage (for example, the cell voltage is greater than the overvoltage protection threshold, which is 4.5V in a design example), and the detection lasts longer than the protection delay time (for example, 1 second in a design example), the protection chip Prot sets CO to a high level, drives MNCO to turn on, blows the fuse, and cuts off the charging path.

[0039] When overvoltage does not occur, the battery cell can be charged by connecting a charger to the P+ and P- terminals. PTC is a positive temperature coefficient resistor, and the capacitor Cctl is used to filter and stabilize the voltage. When the battery temperature is too high, the resistance value of the PTC resistor increases, and after voltage division with the internal resistor, the voltage of the CTL node becomes lower. When it is lower than the overtemperature protection threshold, the protection chip Prot will set CO to a high level, drive MNCO to conduct, blow the fuse Fuse, and cut off the charging path.

[0040] A protection circuit supporting PCB board-level parameter adjustment is provided in an embodiment of the present invention. Figure 2 , including a battery protection chip, the battery protection chip is connected to the PCB board and receives a characteristic signal transmitted by the PCB board; wherein the characteristic signal is input through a test point deployed on the PCB board;

[0041] The battery protection chip is configured as:

[0042] Acquire the characteristic signal and analyze it to obtain characteristic information;

[0043] In response to the characteristic information, the parameters to be adjusted are adjusted according to the data in the characteristic information.

[0044] It should be noted that this embodiment only describes some circuits related to the present invention, and actual applications also include circuit modules that implement other functions, which are omitted here to simplify the description;

[0045] The battery protection chip is represented by Prot, the test point is represented by Test, the voltage input terminal is VC1~VC2 pins, the output control terminal is represented by CO pin, and the control terminal is CTL pin.

[0046] In this embodiment, by inputting a triangle wave or a sine wave or other waveform (including a superposition or modulated signal of multiple waveforms) as the characteristic signal at the test point Test, a corresponding battery protection chip is constructed to identify the characteristic information contained in the corresponding waveform, and adjust the parameters according to the characteristic information; wherein, the characteristic information can be represented by dynamically changing the high level time, or low level time, or frequency, or amplitude, or rising edge time, or falling edge time of the waveform; in the implementation method, the above-mentioned characteristics of the waveform can be used to generate the code, and the corresponding battery protection chip Prot needs to design a decoding circuit, and the decoding circuit here is the subsequent decoder.

[0047] The battery protection chip includes a voltage input terminal and an output control terminal;

[0048] The battery protection chip is also configured as:

[0049] When the chip detects that the voltage relationship between the voltage input terminals is the set condition, the chip is triggered to enter the parameter adjustment mode, the output control terminal is controlled not to output, and the characteristic signal is received through the output control terminal; the set condition here is the subsequent example of detecting that the VC2 voltage is greater than the VC1 voltage.

[0050] During implementation, the output control terminal is also connected to the protection device through a switch device; wherein the switch device is associated with a corresponding threshold voltage; wherein the switch device is represented by MNCO, and the protection device is represented by Fuse;

[0051] The characteristic signal corresponds to a high level voltage and a low level voltage, and both the high level voltage and the low level voltage are lower than the threshold voltage to prevent the switch device from being mistakenly turned on.

[0052] Figure 2 This is an implementation provided by the present invention (here is an application solution of 2 battery cells connected in series, and in other designs, it can also be an application situation of 3 or 4 or more battery cells connected in series, which does not affect the principle of the present invention). Figure 1 In contrast, a test point Test is added at the CO node on the printed circuit board, and a signal can be input to the chip Prot from this test point. The test signal (i.e., characteristic signal) can be input to control the parameter adjustment of the protection chip.

[0053] In one implementation, a square wave signal may be input at the test point Test, the period of the square wave signal (e.g., designed to be 20 microseconds), the duty cycle is 50% (i.e., the high level time is, for example, 10 microseconds), the high level voltage of the square wave is a voltage value lower than the threshold voltage of MNCO (e.g., the threshold voltage of MNCO is 1V, the high level voltage of the square wave needs to be lower than 1V, in a design example, it may be 0.8V, or 0.6V, or 0.4V), the low level voltage of the square wave may be 0V, or other voltage values ​​lower than the high level voltage, such as 0.1V or -0.2V). The feature here is that both the high level voltage and the low level voltage of the square wave need to be lower than the threshold voltage of MNCO, so as to prevent MNCO from being opened by mistake, thereby accidentally blowing the fuse Fuse. This square wave can be detected by chip Prot, and Prot can identify the information in this square wave. It can control chip Prot to enter parameter adjustment mode according to the identification feature information, and adjust the parameters to be adjusted according to the data in this square wave serial signal (including but not limited to protection threshold, protection delay time, over-temperature protection threshold). The adjustment may include increasing the parameter value or decreasing the parameter value.

[0054] Furthermore, the battery protection chip also includes a control terminal. When the chip detects that the voltage of the control terminal is lower than a preset protection threshold and lasts longer than a set time threshold, the level of the output control terminal is controlled to cut off the charging path.

[0055] In this embodiment, the battery protection chip includes adjustable reference voltage sources RefA, RefB, RefC, a comparator ComD, a logic circuit, a reference voltage source VR6 and a decoder.

[0056] The output control terminal of the logic circuit and the reference voltage source VR6 are respectively connected to the input terminal of the comparator ComD, the output terminal of the comparator ComD is connected to the decoder, and the decoder is also respectively connected to the adjustable reference voltage sources RefA, RefB and RefC to adjust the reference voltages of RefA, RefB and RefC.

[0057] Reference Figure 3, specifically including voltage-dividing resistors R1a and R1b (for dividing the voltage between VC1 and VC2, i.e., the voltage of the first battery cell BAT1), voltage-dividing resistors R2a and R2b (for dividing the voltage between VC2 and VSS, i.e., the voltage of the battery cell BAT2), adjustable reference voltage sources RefA, RefB, RefC, comparators ComA, ComB, ComC, ComD, ComT, oscillator OSC, logic circuit Logic, reference voltage source VR6, decoder Decode, voltage regulator LDO, inverter inva, switch SW1, and resistor Rt. LDO converts the VDD voltage into a lower voltage to power Logic and Decode.

[0058] When adjusting the board-level parameters, VC2 needs to be connected to a higher voltage than VC1. When the comparator ComT detects that the VC2 voltage is greater than the VC1 voltage, its output test becomes high, indicating that the chip enters the test mode (i.e., parameter adjustment mode). The signal after the inverter inva becomes low, and the control switch SW1 is disconnected. At this time, the Logic module does not output a signal to the CO port. The CO port can receive input signals (i.e., characteristic signals) from the outside, and the high and low levels of this waveform must be lower than Figure 2 The threshold voltage of MNCO in the circuit can avoid the situation where MNCO is mis-conducted. VR6 can be set to the voltage between the high level and the low level of the corresponding waveform (the middle voltage is a voltage greater than the low level and less than the high level, which is used to distinguish between the high level and the low level). After passing through the comparator ComD, its output signal COD is a shaped logic signal. The logic signal is input to the decoder (Decode module) for decoding, and the programmed parallel data signal (three groups of programming data signals DA0~DA2, DB0~DB2, DC0~DC2) is generated and stored. Then, the reference voltages of RefA, RefB, and RefC are adjusted respectively through the three groups of programming data signals. The oscillator OSC generates a clock signal CK to provide a clock for the logic circuit Logic and the decoding circuit Decode.

[0059] When programming is complete, connect the battery (such as Figure 2 As shown), the VC2 voltage is lower than the VC1 voltage, the output test of the comparator ComT becomes a low level, and its output signal is a high level after inva, controlling SW1 to turn on, and the chip performs normal protection functions.

[0060] When the chip performs normal protection function, the comparator ComA compares the voltage difference between VC1 and VC2 (which is equal to the voltage of the battery cell BAT1) and the voltage divided by resistors R1a and R1b with the reference voltage VRA. If it is greater than the reference voltage VRA (indicating that the voltage of the battery cell BAT1 has abnormally over-voltage and should not be used), the comparator output COA becomes high level and is input to the Logic module for timing. If the over-voltage state continues to exceed the protection delay time, after passing through SW1, CO is made high level to control Figure 2 MNCO is turned on, causing the fuse to blow, thereby achieving the protection function (prohibiting further use). Similarly, comparator ComB compares the voltage difference between VC2 and VSS (which is equal to the voltage of the battery cell BAT2) and the divided voltage (divided by resistors R2a and R2b) with the reference voltage VRB. If it is greater than the reference voltage VRB (indicating that the voltage of the battery cell BAT2 has been abnormally over-voltage and should not be used), the comparator output COB becomes a high level and is input to the Logic module for timing. If the overvoltage state continues to exceed the protection delay time, after passing through SW1, CO is set to a high level to control Figure 2 MNCO is turned on, causing the fuse to blow, thereby achieving a protection function (prohibiting further use).

[0061] When the protection chip is in normal use, if the battery is abnormally hot inside, the positive temperature coefficient resistor PTC (such as Figure 2 The resistance value of the resistor PTC increases, and the resistor PTC is divided by the internal resistor Rt. If this divided voltage value is lower than the reference voltage value VRC (the output signal of the RefC module), it means that the battery temperature exceeds the over-temperature protection threshold, and the output CoC of the comparator ComC becomes high level and is output to the Logic module for timing. If the over-temperature state continues to exceed the over-temperature protection delay time, after passing through SW1, CO is made high level, and the control Figure 2 MNCO is turned on, causing the fuse to blow, thereby achieving the protection function (prohibiting further use). If the protection chip is in normal working condition, neither the battery cell overvoltage nor the battery cell overtemperature occurs, the high level of CO will not be triggered, and the fuse will not be blown, and normal operation will continue.

[0062] The above scheme adds a test point on the printed circuit board, and transmits the characteristic signal to the battery protection chip from the test point; then analyzes the characteristic signal to obtain characteristic information; and adjusts the parameters to be adjusted according to the data in the characteristic information; thereby achieving parameter adjustment after the chip is installed on the printed circuit board, which is convenient for flexible adjustment according to the needs of different application scenarios; at the same time, it can meet the adjustment to a higher accuracy, thereby helping to improve the safety of the battery.

[0063] Reference Figure 4 Based on the same inventive concept, a control method supporting PCB board-level parameter adjustment is provided, characterized in that it is applied to the protection circuit supporting PCB board-level parameter adjustment as described above, and the control method includes:

[0064] S101, receiving a characteristic signal transmitted by a PCB board; wherein the characteristic signal is input through a test point deployed on the PCB board;

[0065] S102, acquiring the characteristic signal and analyzing it to obtain characteristic information;

[0066] S103: respond to the characteristic information and adjust the parameters required to be adjusted according to the data in the characteristic information.

[0067] In this embodiment, the control method further includes:

[0068] When the chip detects that the voltage relationship between the voltage input terminals is a set condition, the chip is triggered to enter a parameter adjustment mode, the output control terminal is controlled not to output, and the characteristic signal is received through the output control terminal.

[0069] Furthermore, the control method further comprises:

[0070] The output control terminal is also connected to the protection device through a switch device; wherein the switch device is associated with a corresponding threshold voltage;

[0071] The characteristic signal corresponds to a high level voltage and a low level voltage, and both the high level voltage and the low level voltage are lower than the threshold voltage to prevent the switch device from being mistakenly turned on.

[0072] It should be noted that for a more specific description of the workflow of the method embodiment, please refer to the aforementioned protection circuit embodiment part, which will not be repeated here.

[0073] After the protection chip is installed on the printed circuit board, parameters can still be adjusted, including but not limited to the adjustment of the protection threshold, protection delay time, and over-temperature protection threshold; it is convenient to flexibly adjust according to the needs of different application scenarios; at the same time, it can be adjusted to a higher precision, which helps to improve the safety of the battery.

[0074] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. These modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and specification of the present invention.

Claims

1. A protection circuit supporting PCB board-level parameter adjustment, including a battery protection chip, characterized in that: The battery protection chip is connected to the PCB board and receives a characteristic signal transmitted by the PCB board; wherein the characteristic signal is input through a test point deployed on the PCB board; The battery protection chip is configured as follows: Acquire the characteristic signal and analyze it to obtain characteristic information; In response to the characteristic information, the parameters to be adjusted are adjusted according to the data in the characteristic information.

2. A protection circuit supporting PCB board-level parameter adjustment according to claim 1, characterized in that: The battery protection chip includes a voltage input terminal and an output control terminal; The battery protection chip is also configured as: When the chip detects that the voltage relationship between the voltage input terminals is a set condition, the chip is triggered to enter a parameter adjustment mode, the output control terminal is controlled not to output, and the characteristic signal is received through the output control terminal.

3. A protection circuit supporting PCB board-level parameter adjustment according to claim 2, characterized in that: The battery protection chip also includes a control terminal. When the chip detects that the voltage of the control terminal is lower than a preset protection threshold and lasts longer than a set time threshold, the chip controls the level of the output control terminal to cut off the charging path.

4. A protection circuit supporting PCB board-level parameter adjustment according to claim 1, characterized in that: The adjusting of the parameter to be adjusted includes increasing the parameter value or decreasing the parameter value.

5. A protection circuit supporting PCB board-level parameter adjustment according to any one of claims 1 to 4, characterized in that: The battery protection chip includes adjustable reference voltage sources RefA, RefB, RefC, a comparator ComD, a logic circuit, a reference voltage source VR6 and a decoder. The output control end of the logic circuit and the reference voltage source VR6 are respectively connected to the input end of the comparator ComD, the output end of the comparator ComD is connected to the decoder, and the decoder is also respectively connected to the adjustable reference voltage sources RefA, RefB and RefC to adjust the reference voltages of RefA, RefB and RefC.

6. A protection circuit supporting PCB board-level parameter adjustment according to claim 5, characterized in that: The output control terminal is also connected to the protection device through a switch device; wherein the switch device is associated with a corresponding threshold voltage; The characteristic signal corresponds to a high level voltage and a low level voltage, and both the high level voltage and the low level voltage are lower than the threshold voltage to prevent the switch device from being mistakenly turned on.

7. A control method supporting PCB board-level parameter adjustment, characterized in that: The protection circuit supporting PCB board-level parameter adjustment as claimed in claim 2, wherein the control method comprises: Receiving a characteristic signal transmitted by a PCB board; wherein the characteristic signal is input through a test point deployed on the PCB board; Acquire the characteristic signal and analyze it to obtain characteristic information; In response to the characteristic information, the parameters to be adjusted are adjusted according to the data in the characteristic information.

8. A control method supporting PCB board-level parameter adjustment according to claim 7, characterized in that: The control method further comprises: When the chip detects that the voltage relationship between the voltage input terminals is a set condition, the chip is triggered to enter a parameter adjustment mode, the output control terminal is controlled not to output, and the characteristic signal is received through the output control terminal.

9. A control method supporting PCB board-level parameter adjustment according to claim 8, characterized in that: The control method further comprises: The output control terminal is also connected to the protection device through a switch device; wherein the switch device is associated with a corresponding threshold voltage; The characteristic signal corresponds to a high level voltage and a low level voltage, and both the high level voltage and the low level voltage are lower than the threshold voltage to prevent the switch device from being mistakenly turned on.

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