Measurement module, measurement method, measurement device, and printed circuit board

Abstract

The present disclosure provides a measurement module arranged on a circuit board, comprising: a first resistor, a first end of which is connected to a first power supply; a measurement resistor, a first end of which is connected to a second end of the first resistor and an output end of the measurement module, and a second end of which is connected to a second resistor, and which is used for measuring an environmental parameter corresponding to a circuit component to be measured, wherein a resistance value of the measurement resistor changes according to a change in the environmental parameter; and a second resistor, which is connected between the second end of the measurement resistor and a ground, and which is used for limiting a current between the second end of the measurement resistor and the ground in a case where the second end of the measurement resistor is short-circuited with a second power supply.

Description

Technical Field

[0001] This disclosure generally relates to the field of measurement, and more specifically, to a highly secure measurement module, measurement method, measurement device, and a printed circuit board on which the measurement module is disposed. Background Technology

[0002] In automotive, industrial, and consumer electronics products, there are often measuring devices that can measure environmental parameters such as temperature and humidity around certain internal components. Based on the measured values ​​of these environmental parameters, the devices can determine the actions to be taken when the corresponding environmental parameter values ​​are obtained, or determine whether these measured values ​​are within the range that allows the components to operate normally. Optionally, if the measured values ​​exceed the range, the devices can perform protective actions, thereby giving the components and products high reliability and safety.

[0003] The above measurements are usually performed using sensitive elements (such as thermistors and humidity sensors). The characteristics of these sensitive elements (such as resistance values) change with the changes in environmental parameters. They have advantages such as high sensitivity, wide operating range, small size, easy processing, and mass production. Summary of the Invention

[0004] According to one aspect of this disclosure, a measurement module disposed on a circuit board is provided. The measurement module includes: a first resistor, the first end of which is connected to a first power supply; a measuring resistor disposed adjacent to a circuit component to be measured on the circuit board, the first end of the measuring resistor being connected to a second end of the first resistor and an output terminal of the measurement module, the second end of which is connected to a second resistor and used to measure environmental parameters corresponding to the circuit component, wherein the resistance value of the measuring resistor varies according to changes in the environmental parameters; and a second resistor connected between the second end of the measuring resistor and ground, used to limit the current between the second end of the measuring resistor and ground in the event of a short circuit between the second end of the measuring resistor and the second power supply.

[0005] According to another aspect of this disclosure, a measurement method for a measurement module is also provided. The measurement module is arranged on a circuit board and includes a first resistor, a measuring resistor, and a second resistor connected in series between a first power supply and ground. A first end of the measuring resistor is connected to the first resistor and serves as the output terminal of the measurement module. The measurement method includes: reading an output voltage measurement signal from the measurement module via a controller; and determining a corresponding environmental parameter measurement value based on the output voltage measurement signal; wherein the measuring resistor is disposed adjacent to the circuit component to be measured on the circuit board, and the resistance value of the measuring resistor varies according to changes in the environmental parameters corresponding to the circuit component; and wherein, when a second end of the measuring resistor is connected to the second resistor, and the second resistor is short-circuited to a second power supply, the second resistor limits the current between the second end of the measuring resistor and ground.

[0006] According to another aspect of this disclosure, a printed circuit board is also provided. Circuit components and the aforementioned measurement module are arranged on this printed circuit board, wherein a measuring resistor in the measurement module is disposed adjacent to the circuit component to be measured, and a second resistor in the measurement module is disposed adjacent to the ground portion of the printed circuit board.

[0007] According to another aspect of this disclosure, a measuring device is also provided. The measuring device includes a measuring module and a controller as described above, wherein the controller obtains a corresponding environmental parameter measurement value based on the voltage value of a voltage measurement signal output by the measuring module. Attached Figure Description

[0008] The above and other objects, features, and advantages of this disclosure will become more apparent from the more detailed description of the embodiments thereof in conjunction with the accompanying drawings. The drawings are provided to further illustrate the embodiments of this disclosure and form part of the specification. They are used together with the embodiments of this disclosure to explain the disclosure and do not constitute a limitation thereof. In the drawings, the same reference numerals generally represent the same components or steps.

[0009] Figure 1 A schematic block diagram of a measuring device according to an embodiment of the present disclosure is shown;

[0010] Figure 2 A circuit diagram of a measurement module is shown;

[0011] Figure 3 (a)-(c) show several topologies of voltage conversion circuits;

[0012] Figure 4 A circuit diagram of a measurement module according to an embodiment of the present disclosure is shown;

[0013] Figure 5(a)-(b) show the curves of the resistance of the thermistor changing with temperature;

[0014] Figure 6 A flowchart illustrating a measurement method for a measurement module according to an embodiment of the present disclosure is shown; and

[0015] Figure 7 A partial schematic diagram of a printed circuit board on which a measurement module is arranged, according to an embodiment of the present disclosure, is shown. Detailed Implementation

[0016] The technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this disclosure. All other embodiments obtained by those skilled in the art based on the embodiments of this disclosure without creative effort are within the scope of protection of this disclosure.

[0017] Although terms including ordinal numbers (such as first, second, etc.) can be used to describe various elements, structural elements are not limited by these terms. These terms are only used to distinguish one element from another. For example, without departing from the scope of this disclosure, a first structural element may be referred to as a second structural element. Similarly, a second structural element may also be referred to as a first structural element.

[0018] Figure 1 A schematic block diagram of a measuring device 100 according to an embodiment of the present disclosure is shown.

[0019] like Figure 1 As shown, the measuring device 100 includes a measuring module 101 and a controller 102.

[0020] The measurement module 101 is capable of measuring environmental parameters (e.g., temperature, humidity, etc.) of external circuit components (hereinafter collectively referred to as the circuit components to be measured), and as these environmental parameters change, the measurement module 101 provides different voltage measurement signals to the controller 102. The controller 102 receives the voltage measurement signals and calculates the corresponding environmental parameter measurement values ​​based on the voltage measurement signals.

[0021] More specifically, Figure 2 A circuit diagram of a measurement module 101 in a measuring device is shown.

[0022] like Figure 2As shown, the measurement module 101 receives a first power supply voltage signal V1 from a first external power supply. The measurement module 101 includes a first resistor R1 and a measuring resistor Rm connected in series. The connection point of the first resistor R1 and the measuring resistor Rm serves as the output terminal of the measurement module 101, used to output a voltage measurement signal Vm. In actual measurement, the measuring resistor Rm is generally placed close to the circuit component to be measured to better measure environmental parameters near the circuit component.

[0023] When the environmental parameters of the circuit component to be measured change, the resistance value of the measuring resistor Rm will change accordingly. As a result, according to the voltage divider principle, the voltage value at the connection point of the first resistor R1 and the measuring resistor Rm will also change, thereby providing the controller 102 with voltage measurement signals of different voltage values.

[0024] Figure 1 The controller 102 shown can be a microprocessor and may include an analog-to-digital converter circuit and internal logic. The analog-to-digital converter circuit converts the analog voltage value of the voltage measurement signal Vm into a digital voltage value to be provided to the internal logic. Based on the obtained digital voltage value of the voltage measurement signal, the internal logic, according to the circuit structure of the measurement module and the variation of the resistance value of the measurement resistor Rm with environmental parameters, obtains the corresponding environmental parameter measurement value.

[0025] It is worth noting that the voltage or voltage value mentioned in this application refers to the potential difference between any circuit node and the common ground. For example, the voltage value of the power supply voltage signal refers to the potential difference between the potential of the positive terminal of the power supply and the potential of the common ground (e.g., 0 potential), and the voltage value of the voltage measurement signal refers to the potential difference between the potential of the output terminal of the measurement module and the potential of the common ground.

[0026] also, Figure 2 The diagram shows that the measuring resistor Rm is a negative temperature coefficient (NTC) thermistor, and temperature measurement is described in detail at some points later in the text. However, this is just an example, and the type of environmental parameter of the circuit component to which it is to be measured can vary. Depending on the environmental parameter to be measured, the measuring resistor can also be other types of sensitive elements, such as humidity sensors.

[0027] Depending on the specific application, such as in automotive, industrial, and consumer electronics products, temperature is a crucial factor ensuring the proper functioning of their internal circuitry. These internal circuits typically include voltage conversion circuits. The power switching elements within these voltage conversion circuits are the primary heat sources; therefore, when designing and laying out the circuit board, a measuring resistor Rm needs to be placed adjacent to these power switching elements to measure their temperature and ensure the circuit functions correctly.

[0028] For ease of description, Figure 3 (a)-(c) illustrate several voltage conversion circuit topologies used in the internal circuitry of automotive, industrial, and consumer electronics products: (a) a buck converter; (b) a boost converter; and (c) a full bridge / H-bridge converter.

[0029] In these voltage conversion circuits, power switching elements are continuously turned on and off to enable the voltage conversion circuit to output the desired voltage, and the voltage value at one end of the power switching element is equal to the voltage value of the voltage signal provided by the input power supply (second power supply V2, hereinafter also referred to as V2 to represent the voltage signal and its voltage value provided by the second power supply) at least for part of the operating period. For example, in the case of the buck converter shown in (a), the current inflow terminal of the power switching element S1 (hereinafter referred to as the first terminal and the current outflow terminal as the second terminal) is always connected to the input power supply, so the voltage value at the first terminal of the power switching element is always equal to the voltage value of the voltage signal provided by the input power supply; in the case of the boost converter shown in (b), the voltage at the first terminal of the power switching element S1 is equal to the input power supply voltage when the power switching element S1 is turned off; in the full-bridge converter shown in (c), the voltage values ​​at the first terminals of the power switching elements S1 and S2 of the upper bridge arm are always equal to the voltage value of the voltage signal provided by the input power supply.

[0030] In the voltage conversion circuit described above, since the voltage value at the first terminal of the power switching element is equal to the voltage value of the voltage signal provided by the input power supply for a long time, the temperature at the first terminal of the power switching element is the highest in the overall structure of the power switching element. Therefore, when the measuring resistor Rm is set close to the power switching element, the highest temperature value of the power switching element can be obtained by setting it close to the first terminal of the power switching element. This highest temperature value can be used to determine whether the temperature of the power switching element or the voltage conversion circuit is sufficient for it to work normally.

[0031] However, in some cases, when Figure 2When the measuring resistor Rm in the measurement module shown is positioned on the circuit board near the first terminal of the power switching element, the end of the measuring resistor Rm connected to ground may short-circuit with the first terminal of the power switching element. This can occur, for example, during salt water immersion testing of the printed circuit board containing the voltage conversion circuit (including the power switching element) and the measurement module, or due to electrochemical migration. When a short circuit occurs, the voltage signal provided by the input power supply (i.e., the second power supply) V2 applied to the first terminal of the power switching element will be applied to the end of the measuring resistor Rm connected to ground, thus directly connecting the input power supply to ground and creating a short circuit. This could damage the measurement module or even the entire circuit board, or even cause a fire with serious consequences.

[0032] The above description only refers to power switching elements in power conversion circuits; however, it should be understood that the circuit components to be measured can be of other forms.

[0033] Therefore, embodiments of this application propose an improved measurement module that can be used to replace, for example... Figure 1 The measurement module 101 in the measurement device shown prevents damage to the measurement module and the entire circuit board when a short circuit is formed between the end of the measuring resistor Rm connected to ground and the external power supply through one end of the circuit component to be measured.

[0034] Figure 4 A circuit diagram of a measurement module 401 according to an embodiment of the present disclosure is shown.

[0035] like Figure 4 As shown, the measurement module 401 includes a first resistor R1, a measuring resistor Rm, and a second resistor R2 connected in series.

[0036] Optionally, the measurement module 401 may also include an output filter capacitor Cout connected between the output terminal of the measurement module 401 and ground.

[0037] The first end of the first resistor R1 is connected to the first power supply to receive the first power supply voltage signal V1 from the first power supply, and is arranged adjacent to the circuit component to be measured on the circuit board, as described above.

[0038] The first terminal of the measuring resistor Rm is connected to the second terminal of the first resistor R1 and the output terminal of the measuring module 401 to output a voltage measurement signal Vm. The second terminal of the measuring resistor Rm is connected to the second resistor R2 and is used to measure environmental parameters corresponding to the circuit components, wherein the resistance value of the measuring resistor Rm changes according to the changes in the environmental parameters.

[0039] The second resistor R2 is connected between the second terminal of the measuring resistor Rm and ground, and is used to limit the current between the second terminal of the measuring resistor Rm and ground when the second terminal of the measuring resistor Rm is short-circuited to the second power supply.

[0040] More specifically, the measuring resistor Rm is disposed on the circuit board adjacent to the first terminal of the circuit component to be measured, and the voltage value of the first terminal of the circuit component is at least the voltage value of the power supply voltage signal V2 supplied by the second power supply during a portion of its operating period. In the event that the second terminal of the measuring resistor Rm is short-circuited to the first terminal of the circuit component, the second terminal of the measuring resistor Rm is short-circuited to the second power supply.

[0041] Alternatively, the circuit component is a power switching element in a voltage conversion circuit.

[0042] Optionally, the first power supply is the input power supply of the measurement module, and the second power supply can be the input power supply of the voltage conversion circuit, as described above. Figure 3 As shown in (a)-(c).

[0043] Optionally, when the vehicle uses a 12V power supply system, the voltage values ​​of the power supply voltage signals output by the first power supply and the second power supply are equal, and both are 12V.

[0044] The following is combined with Figure 4 This describes the working process of the measurement module 401.

[0045] The measurement module 401 operates normally when the second terminal of the measuring resistor Rm is not short-circuited to the first terminal of the circuit component to be measured. Let the voltage value of the first power supply voltage signal V1 provided by the first power supply be V1, the resistance value of the first resistor R1 be R1, the resistance value of the measuring circuit Rm be Rm (which varies with environmental parameters (e.g., temperature)), and the resistance value of the second resistor R2 be R2, then the voltage value of the voltage measurement signal Vm (denoted by Vm) is:

[0046]

[0047] Then, the measurement module outputs the voltage measurement signal Vm to the controller via its output terminal, so that the controller can obtain the corresponding environmental parameter measurement value based on the voltage measurement signal Vm.

[0048] The controller obtains the corresponding environmental parameter measurements based on the voltage measurement signal Vm, including:

[0049] From equation (1), we can see that:

[0050]

[0051] Then, based on the correspondence between the measured resistance value Rm and environmental parameters (e.g., ... Figure 5(a)-(b) show the temperature-resistance curves of the thermistor as the resistance changes with temperature, and the environmental parameter measurements at this time are obtained.

[0052] When the second terminal of the measuring resistor Rm is short-circuited to the first terminal of the circuit component under test, and the voltage at the first terminal of the circuit component is equal to the voltage value of the second power supply voltage signal V2 (denoted as V2) provided by the second power supply, then the second power supply voltage signal V2 is applied to the first terminal of the second resistor R2. That is, the voltage at the first terminal of the second resistor R2 is V2, and the second terminal of the second resistor is grounded. In other words, when the second terminal of the measuring resistor Rm is short-circuited to the first terminal of the circuit component under test, it does not cause a short circuit between the second power supply and ground. Instead, it creates a loop between the second power supply and ground through the second resistor R2, meaning the voltage difference across the second resistor R2 is V2. This ensures that even if the second terminal of the measuring resistor Rm is short-circuited to the first terminal of the circuit component under test, thus preventing a short circuit between the second power supply and ground, the second resistor R2 prevents this short circuit, thereby ensuring the safety of the measurement module and the entire circuit board, providing protection.

[0053] The following describes the issues to consider when selecting a second resistor, assuming that the resistance value of the measured resistor is also constant when the environmental parameters are constant.

[0054] Factor 1: When the second terminal of the measuring resistor Rm is short-circuited with the second power supply, an excessive surge current flowing through the second resistor will cause abnormal changes in the resistance value of the second resistor, thereby affecting the measurement accuracy. In fact, an excessive surge current may even cause the circuit to overheat and catch fire, thus causing safety problems.

[0055] When adopting such Figure 4When the measurement module 401 is shown, if the second terminal of the measuring resistor Rm is short-circuited to the second power supply, as described above, the second resistor R2 prevents a short circuit between the second power supply and ground. In this case, if a second resistor R2 with a larger resistance value is selected, the surge current flowing through the second resistor R2 (I = V2 / R2) will be smaller; conversely, if a second resistor R2 with a smaller resistance value is selected, the surge current flowing through the second resistor R2 will be larger. When the surge current flowing through the second resistor R2 is too large, even if it does not damage the measurement module and the entire circuit board, it will make the resistance value of the second resistor R2 very large, which will affect the accuracy of the final measured environmental parameter value. This is because, according to equation (2), the measured environmental parameter value is obtained through the correspondence with the resistance value of the measuring resistor. The resistance value of the measuring resistor is related to the resistance value of the second resistor. After the resistance value of the second resistor R2 changes significantly (for example, from 100 ohms to 150 ohms), when the environmental parameter is measured by the measurement module 401, the internal logic of the controller still calculates according to the theoretical value of the second resistor. Therefore, the difference between the actual resistance value and the theoretical value of the second resistor will eventually lead to the inaccuracy of the measured environmental parameter value, thus affecting the measurement accuracy.

[0056] Factor 2: The resistance value of the second resistor did not change abnormally, but the inherent resistance error will affect the measurement accuracy. This inherent resistance error exists in both the first and second resistors. However, to better analyze the impact of the second resistor's resistance error on measurement accuracy, the following assumes that the resistance value of the first resistor is the theoretical value. However, those skilled in the art should understand that the measurement error caused by the resistance error in the first resistor will be superimposed on the measurement error caused by the resistance error in the second resistor, thus affecting the overall measurement accuracy.

[0057] The actual resistance value of the selected resistor generally has a certain error compared to the theoretical value, and this error is unavoidable. For example, a resistor with a theoretical value of 100 ohms may have an actual resistance value between 98 ohms and 102 ohms, a resistor with a theoretical value of 20 ohms may have an actual resistance value between 19.6 ohms and 20.4 ohms, and so on. That is, the actual resistance value of the selected resistor is between its theoretical value (referred to as R2r in the following text) * (1 ± 2%). Therefore, for the same environmental parameters (e.g., temperature), the resistance value Rm of the measuring resistor is constant. As mentioned earlier, it is assumed that the resistance value of the first resistor is also a theoretical value (which also has errors in reality). However, since the resistance value of the selected second resistor may be any value within the range of R2r*(1±2%), the actual voltage value Vm of the voltage measurement signal transmitted from the measurement module to the controller will also be a value within the corresponding range. However, the internal logic of the controller calculates the environmental parameter value based on the theoretical value R2r of the second resistor. Therefore, the calculated resistance value of the measuring resistor, which is based on the actual voltage value Vm (based on the actual resistance value of the second resistor) but calculated according to the theoretical value R2r of the second resistor, may not be accurate. This results in the environmental parameter value being inaccurate, i.e., there is a measurement accuracy error.

[0058] The following is a brief analysis of the difference in environmental parameter measurements caused by selecting a second resistor with a theoretical resistance value of 20 ohms and 100 ohms when the measurement module is used to measure the environmental parameters of the same circuit component.

[0059] When a second resistor with a theoretical value of 20 ohms is selected, and the actual resistance of the second resistor is 19.6 ohms, the voltage value of the voltage measurement signal obtained by the controller is Vm1. Based on equation (2), it can be known that the actual resistance value Rm of the measuring resistor should be:

[0060]

[0061] However, the controller's internal logic still calculates the resistance of the second resistor as 20 ohms, using the following formula:

[0062]

[0063] Based on equations (3) and (4), it can be seen that since the actual resistance value of the second resistor is 0.4 ohms smaller than the theoretical value used by the controller in the calculation, the calculated resistance value Rm' of the measuring resistor should be 0.4 ohms smaller than the actual resistance value Rm of the measuring resistor. Therefore, the environmental parameter value obtained by the internal logic of the controller based on the voltage value Vm1 of the voltage measurement signal (the correspondence between the resistance value Rm of the measuring resistor and the environmental parameter value) has a certain error with the actual environmental parameter value.

[0064] When selecting a second resistor with a theoretical value of 100 ohms, since the ratio of the resistance value error to the theoretical value is generally fixed (for example, 1% in good condition, but 2.4% in bad condition; this article takes 2% as an example), the actual resistance value of the selected second resistor is between 98 ohms and 102 ohms.

[0065] Based on similar analysis, when the actual resistance of the second resistor is 98 ohms, the voltage value of the voltage measurement signal obtained by the controller is Vm2. Based on equation (2), the actual resistance value Rm of the measuring resistor should be:

[0066]

[0067] However, the controller's internal logic still calculates the resistance of the second resistor as 100 ohms, using the following formula:

[0068]

[0069] Based on equations (5) and (6), it can be seen that since the actual resistance value of the second resistor is 2 ohms smaller than the theoretical value used by the controller in the calculation, the calculated resistance value Rm' of the measuring resistor should be 2 ohms smaller than the actual resistance value Rm of the measuring resistor. Therefore, the environmental parameter value obtained by the internal logic of the controller based on the voltage value Vm2 of the voltage measurement signal (the correspondence between the resistance value Rm of the measuring resistor and the environmental parameter value) has a certain error with the actual environmental parameter value.

[0070] Since the measurement module measures the environmental parameters of the same circuit component, the actual resistance values ​​Rm of the measuring resistor in equations (3) and (5) should be equal when the theoretical values ​​are 20 ohms and 100 ohms. However, when the second resistor with a theoretical value of 20 ohms is selected, the error of the calculated resistance value Rm′ relative to Rm is smaller than the error of the calculated resistance value Rm″ relative to Rm when the second resistor with a theoretical value of 100 ohms is selected. In other words, the larger the resistance value of the second resistor (i.e., the larger the theoretical value of the second resistor), the greater the measurement error, and the lower the accuracy of the measurement module.

[0071] On the other hand, when the theoretical value of the second resistor to be selected is determined (e.g., a theoretical value of 100 ohms with an error of 2 ohms), the measurement accuracy of the measurement module is analyzed as environmental parameters change when this second resistor is used.

[0072] Taking NTC as an example for measuring resistance, the temperature-resistance curve of NTC is as follows: Figure 5 As shown in (a). From Figure 5As can be seen in (a), the lower the temperature, the greater the resistance value of the measured resistor; the higher the temperature, the smaller the resistance value of the measured resistor; and the absolute value of the slope of the temperature-resistance curve gradually decreases.

[0073] At low temperatures, the actual resistance value Rm of the measured resistor is relatively large. Therefore, due to the error between the actual and theoretical resistance values ​​of the second resistor (taking 2 ohms as an example), the error between the calculated measured value Rm' and the actual resistance value Rm is 2 ohms. According to the characteristics of the NTC temperature-resistance curve, the 2-ohm error between the calculated measured value Rm' and the actual resistance value Rm results in a relatively small error between the measured temperature and the actual temperature. Figure 5 As shown in (a), the temperature corresponding to the calculated resistance value Rm1' of the measured resistor is t2, and the temperature corresponding to the actual resistance value Rm1 of the measured resistor is t1.

[0074] At high temperatures, the actual resistance value Rm of the measured resistor is smaller. Therefore, due to the error between the actual and theoretical resistance values ​​of the second resistor (taking 2 ohms as an example), the error between the calculated measured value Rm' and the actual resistance value Rm is 2 ohms. According to the characteristics of the NTC temperature-resistance curve, the 2-ohm error between the calculated measured value Rm' and the actual resistance value Rm results in a relatively large error between the measured temperature and the actual temperature. Figure 5 As shown in (a), the temperature corresponding to the calculated resistance value Rm2' is t3, and the temperature corresponding to the actual resistance value Rm2 is t4. Figure 5 As can be seen from (a), the temperature measurement error (t4-t3) under high temperature conditions is greater than the temperature measurement error (t2-t1) under low temperature conditions.

[0075] Therefore, as can be seen from the above analysis, for any theoretical value of the second resistance, as the temperature increases, the error between the actual resistance value and the theoretical value of the second resistance has a significant impact on the error between the temperature value corresponding to the actual resistance value of the measured resistance and the temperature value corresponding to the calculated resistance value of the measured resistance. Thus, the larger the measurement error, the lower the accuracy of the measurement module.

[0076] Of course, the above analysis is based on the case where the measuring resistor Rm is an NTC resistor. Different situations may arise when the measuring resistor Rm is another type of sensitive element, for example... Figure 5As shown in (b), when a measuring resistor whose resistance value changes linearly with temperature is used, as the temperature increases, the error between the actual resistance value and the theoretical value of the second resistor has the same effect on the error between the temperature value corresponding to the actual resistance value of the measuring resistor and the temperature value corresponding to the calculated resistance value of the measuring resistor (the slope of the curve is the same, the same Y-axis distance corresponds to the same X-axis distance, that is, t2-t1 and t4-t3 are equal). The accuracy of this measuring module is constant.

[0077] In summary, when selecting the resistance value of the second resistor, since a smaller resistance value generally leads to higher measurement accuracy, it is desirable to choose a second resistor with a (theoretically) smaller resistance value to improve measurement accuracy (its inherent resistance error has less impact on the measured value). However, if a second resistor with too small a resistance value is selected, when the second terminal of the measuring resistor is short-circuited to the second power supply, the surge current flowing through the second resistor will be too large, causing abnormal changes in the resistance value (e.g., from 100 ohms to 150 ohms), which will also affect measurement accuracy. In fact, excessive surge current may even cause the circuit to overheat and catch fire, thus rendering the second resistor ineffective for protection. Furthermore, using a second resistor with a larger resistance value results in lower measurement accuracy compared to choosing a smaller resistance value. Therefore, the required accuracy and the voltage of the second power supply must be considered when selecting the resistance value of the second resistor.

[0078] For example, it is generally ensured that the current flowing through the second resistor is around 0.5A. For instance, when the voltage of the second power supply is 12V, a second resistor with a theoretical value of 22 ohms can be selected, and when the voltage of the second power supply is 48V, a second resistor with a theoretical value of 100 ohms can be selected.

[0079] According to another aspect of this disclosure, a measurement method for a measurement module is also provided. Figure 6 A flowchart of a measurement method 600 for a measurement module according to an embodiment of the present disclosure is shown.

[0080] In step 601, the controller reads the output voltage measurement signal of the measurement module, and in step 602, the corresponding environmental parameter measurement value is determined based on the voltage measurement signal.

[0081] The measurement module employing the above measurement method is arranged on a circuit board and includes a first resistor R1, a measuring resistor Rm, and a second resistor R2 connected in series between a first power supply and ground. The first end of the measuring resistor Rm is connected to the first resistor R1 and serves as the output terminal of the measurement module. The measuring resistor Rm is positioned adjacent to the circuit component to be measured on the circuit board, and its resistance value varies according to changes in the environmental parameters corresponding to the circuit component. The second end of the measuring resistor Rm is connected to the second resistor R2, and when the second end of the measuring resistor Rm is short-circuited to the second power supply, the second resistor R2 limits the current between the second end of the measuring resistor Rm and ground.

[0082] More specifically, the measuring resistor Rm is disposed adjacent to the first terminal of the circuit component to be measured, the voltage value of the first terminal of the circuit component being at least the voltage value of the power supply voltage signal provided by the second power supply during a portion of its operating period; and in the event that the second terminal of the measuring resistor Rm is short-circuited to the first terminal of the circuit component, the second terminal of the measuring resistor Rm is short-circuited to the second power supply.

[0083] Optionally, the resistance value of the second resistor R2 is determined based on the required measurement accuracy and the voltage value of the power supply voltage signal provided by the first power supply.

[0084] Optionally, the measurement module can serve as a reference. Figure 4 The measurement module 400 is described.

[0085] According to another aspect of this disclosure, a printed circuit board is also provided. Figure 7 A partial schematic diagram of a printed circuit board according to an embodiment of the present disclosure is shown.

[0086] The printed circuit board contains the circuit components to be measured, as well as references. Figure 4 The measurement module 401 is described. On the printed circuit board, the measuring resistor Rm in the measurement module 401 is disposed adjacent to the circuit component to be measured, and the second resistor R2 in the measurement module 401 is disposed adjacent to the ground portion of the printed circuit board.

[0087] Optionally, a power converter is also arranged on the printed circuit board, and the circuit component to be measured is a power switching element in the power converter. (See reference...) Figure 3 As described in (a)-(c), the voltage value at the first terminal of the power switching element is at least the voltage value of the power supply voltage signal provided by the second power supply during a portion of its operating period, and in the event that the second terminal of the measuring resistor Rm is short-circuited to the first terminal of the power switching element, the second terminal of the measuring resistor Rm is short-circuited to the second power supply, but the second power supply and ground can be prevented from forming a short circuit through the second resistor Rm.

[0088] The printed circuit board also has a controller connected to the output of the measurement module 401. The controller calculates the corresponding environmental parameter measurement value based on the voltage value of the voltage measurement signal output by the measurement module 401.

[0089] Through the various embodiments of this disclosure, damage to the measurement module and the entire circuit board can be avoided when a short circuit is formed between the end of the measured resistor connected to ground and the external power supply, thereby improving the reliability and safety of the measurement process.

[0090] While the subject matter has been described in detail with respect to various specific exemplary embodiments, each example is provided by way of explanation rather than limitation. Those skilled in the art, upon receiving the foregoing understanding, will readily make changes, variations, and equivalents to such embodiments. Therefore, the invention does not exclude the inclusion of such modifications, variations, and / or additions to the subject matter that will be obvious to those skilled in the art. For example, features illustrated or described as part of one embodiment may be used with another embodiment to produce yet another embodiment. Therefore, it is intended that this disclosure cover such changes, variations, and equivalents.

[0091] Specifically, although the accompanying drawings of this disclosure depict steps performed in a specific order for illustrative and discussion purposes, the methods of this disclosure are not limited to the specific illustrated order or arrangement. Without departing from the scope of this disclosure, the various steps of the described methods may be omitted, rearranged, combined, and / or adjusted in various ways.

[0092] Unless otherwise defined, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. It should also be understood that terms such as those defined in a common dictionary shall be interpreted as having a meaning consistent with their meaning in the context of the relevant art, and not as having an idealized or highly formalized meaning, unless expressly defined herein.

[0093] The foregoing description is intended to illustrate the present disclosure and should not be construed as limiting it. While several exemplary embodiments of the present disclosure have been described, those skilled in the art will readily understand that many modifications may be made to the exemplary embodiments without departing from the novel teachings and advantages of the present disclosure. Therefore, all such modifications are intended to be included within the scope of the present disclosure as defined by the claims. It should be understood that the foregoing description is intended to illustrate the present disclosure and should not be construed as limiting it to the specific embodiments disclosed, and modifications to the disclosed embodiments and other embodiments are intended to be included within the scope of the appended claims. The present disclosure is defined by the claims and their equivalents.

Claims

1. A measurement module arranged on a circuit board, comprising: A first resistor, the first end of which is connected to a first power source; A measuring resistor is provided, wherein a first terminal of the measuring resistor is connected to a second terminal of a first resistor and an output terminal of the measuring module, and a second terminal of the measuring resistor is connected to a first terminal of a second resistor. The measuring resistor is disposed adjacent to a first terminal of a circuit component to be measured on a circuit board and is used to measure environmental parameters of the circuit component, wherein the resistance value of the measuring resistor varies according to changes in the environmental parameters. The second resistor, with its second terminal connected to ground; The first terminal of the circuit assembly is connected to a second power source. When the measuring resistor is short-circuited to the first terminal of the circuit assembly, the second resistor limits the current from the first terminal of the circuit assembly to ground.

2. The measurement module according to claim 1, wherein, The voltage value at the first terminal of the circuit component is the voltage value of the power supply voltage signal provided by the second power source at least during a portion of its operating period.

3. The measurement module according to claim 1 or 2, wherein, The second power source is the same as the first power source.

4. The measurement module according to claim 1 or 2, wherein, The first and second power sources are batteries.

5. The measurement module according to claim 1 or 2, wherein, The circuit component is a power switching element.

6. The measurement module according to claim 1, wherein, The environmental parameters are temperature or humidity.

7. The measurement module according to claim 6, wherein, The measuring resistor is a positive temperature coefficient thermistor or a negative temperature coefficient thermistor.

8. The measurement module according to claim 1, wherein, The measurement module is a temperature measurement module used in automobiles or electronic products.

9. The measurement module according to claim 1, further comprising: A filter capacitor is placed between the output terminal of the measurement module and ground.

10. The measurement module according to claim 1, wherein, The output terminal of the measurement module outputs a voltage measurement signal to the controller, so that the controller can obtain the corresponding environmental parameter measurement value based on the voltage measurement signal.

11. The measurement module according to claim 1, wherein, The resistance value of the second resistor is determined based on the required measurement accuracy and the magnitude of the surge current flowing through the second resistor.

12. A measurement method for a measurement module, the measurement module being arranged on a circuit board and including a first resistor, a measuring resistor, and a second resistor connected in series between a first power supply and ground, wherein a first end of the measuring resistor is connected to the first resistor and serves as an output terminal of the measurement module, comprising: The controller reads the output voltage measurement signal of the measurement module. as well as The corresponding environmental parameter measurement values ​​are determined based on the output voltage measurement signal; The measuring resistor is arranged adjacent to the first terminal of the circuit component to be measured on the circuit board, and the resistance value of the measuring resistor varies according to changes in the environmental parameters of the circuit component; and The first terminal of the circuit assembly is connected to a second power source. When the measuring resistor is short-circuited to the first terminal of the circuit assembly, the second resistor limits the current from the first terminal of the circuit assembly to ground.

13. The measurement method according to claim 12, wherein, The voltage value at the first terminal of the circuit component is the voltage value of the power supply voltage signal provided by the second power source at least during a portion of its operating period.

14. The measurement method according to claim 12, wherein, The resistance value of the second resistor is determined based on the required measurement accuracy and the magnitude of the surge current flowing through the second resistor.

15. A printed circuit board having circuit components arranged thereon, and a measurement module as described in any one of claims 1-11, wherein, The measuring resistor in the measuring module is disposed adjacent to the circuit component to be measured, and the second resistor in the measuring module is disposed adjacent to the ground portion of the printed circuit board.

16. The printed circuit board according to claim 15, wherein, A controller is also arranged on it, which obtains the corresponding environmental parameter measurement value based on the voltage value of the voltage measurement signal output by the measurement module.

17. The printed circuit board according to claim 15, wherein, A power converter is also arranged on it, and the circuit assembly is a power switching element in the power converter.

18. The printed circuit board according to claim 17, wherein, The voltage value at the first terminal of the power switching element is at least the voltage value of the power supply voltage signal provided by the second power supply during a portion of its operating period.

19. A measuring device comprising a measuring module and a controller as described in any one of claims 1-11, wherein the controller obtains a corresponding environmental parameter measurement value based on the voltage value of a voltage measurement signal output by the measuring module.

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