PCB temperature inspection circuit

Abstract

The utility model relates to a circuit for PCB temperature inspection. The circuit comprises a first voltage acquisition circuit, a second voltage acquisition circuit, a microcontroller MCU, a temperature measurement circuit and a temperature diagnosis circuit. The first end of the first voltage acquisition circuit is electrically connected with the first end of the second voltage acquisition circuit, and the second end of the first voltage acquisition circuit is electrically connected with the microcontroller MCU; the second end of the second voltage acquisition circuit is electrically connected with the microcontroller MCU, and the third end of the second voltage acquisition circuit is electrically connected with the temperature measurement circuit; the second end of the temperature measurement circuit is electrically connected with the first end of the temperature diagnosis circuit; the second end of the temperature diagnosis circuit is electrically connected with the microcontroller MCU; the microcontroller MCU is used for processing electric signals fed back by the first voltage, the second voltage and the temperature diagnosis circuit. By adopting the technical scheme, the accuracy and the response speed of PCB temperature detection are remarkably improved, the overheating problem is avoided, the service life of components is prolonged, and the stability and the reliability of a circuit system are improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of temperature control circuits, and in particular relates to a circuit for checking PCB temperature. Background Art

[0002] Amidst the growing trend toward automotive intelligence and electrification, modern vehicle control systems are entering an era of comprehensive innovation. One of the core drivers of this transformation is the rise of the body-area microcontroller (MCU). MCUs not only play an indispensable role in vehicle electronic architectures, but also demonstrate unprecedented value in integrating complex electronic devices, optimizing vehicle safety, enhancing ride comfort, and managing energy efficiency. Crucially, the Z transistor (CU)'s ability to efficiently manage high-current loads directly impacts the stable and efficient operation of the vehicle's powertrain.

[0003] However, with the increasing electrification of vehicles, especially the widespread use of high-current drive loads, more stringent challenges are posed to the heat dissipation performance and temperature control of PCBs. High temperature environments not only accelerate the aging process of electronic components and shorten product life, but in extreme cases may cause fires, posing a direct threat to passenger safety.

[0004] Therefore, while ensuring vehicle performance and functionality, it is necessary to effectively manage the PCB temperature, conduct continuous and accurate detection of the PCB surface temperature, and detect its potential overheating risks to prevent overheating. Summary of the Invention

[0005] The purpose of this utility model: In order to overcome the defects of the prior art, the utility model provides a PCB temperature detection circuit to accurately and effectively manage the PCB temperature and detect its potential overheating risk.

[0006] The technical solution of the utility model is as follows: a circuit for checking PCB temperature, comprising a first voltage acquisition circuit, a second voltage acquisition circuit, a microcontroller MCU, a temperature measurement circuit, and a temperature diagnosis circuit; a first end of the first voltage acquisition circuit is electrically connected to a first end of the second voltage acquisition circuit, a second end of the first voltage acquisition circuit is electrically connected to the microcontroller MCU, and the first voltage acquisition circuit is used to acquire a first voltage actually input to the PCB board; a second end of the second voltage acquisition circuit is electrically connected to the microcontroller MCU, a third end of the second voltage acquisition circuit is electrically connected to the temperature measurement circuit, and the second voltage acquisition circuit is used to acquire a second voltage actually input to the PCB board; a second end of the temperature measurement circuit is electrically connected to a first end of the temperature diagnosis circuit, and the temperature measurement circuit is used to measure the temperature of a heating module; a second end of the temperature diagnosis circuit is electrically connected to the microcontroller MCU, and the temperature diagnosis circuit is used to output an electrical signal corresponding to the temperature;

[0007] The microcontroller MCU processes the electrical signal fed back by the temperature diagnosis circuit according to the first voltage and the second voltage.

[0008] Furthermore, the first voltage acquisition circuit includes a first power supply terminal VBAT1, a transistor Q1, a resistor R2, a resistor R3, a resistor R5, a resistor R7, and a capacitor C1; the emitter of the transistor Q1 is electrically connected to the first power supply terminal VBAT1, the collector of the transistor Q1 is electrically connected to the first end of the resistor R2, and the base of the transistor Q1 is electrically connected to the first end of the resistor R7; the second end of the resistor R2 is electrically connected to the first end of the resistor R5 and the first end of the capacitor C1, and is electrically connected to a microcontroller MCU, and the microcontroller MCU is used to collect the first voltage; the first end and the second end of the resistor R3 are connected in parallel to the emitter and base of the transistor Q1; the second end of the resistor R5 and the second end of the capacitor C1 are connected to the ground end; the second end of the resistor R7 is electrically connected to the first end of the second voltage acquisition circuit.

[0009] Furthermore, the second voltage acquisition circuit includes a second power supply terminal VPP1, a transistor Q2, a resistor R1, a resistor R4, a resistor R6, a resistor R8, and a capacitor C2; the emitter of the transistor Q2 is electrically connected to the second power supply terminal VPP1, the collector of the transistor Q2 is electrically connected to the first end of the resistor R1, and the base of the transistor Q2 is electrically connected to the first end of the resistor R8; the second end of the resistor R1 is electrically connected to the first end of the resistor R6 and the first end of the capacitor C2, and is electrically connected to the microcontroller MCU, and the microcontroller MCU is used to collect the second voltage; the first and second ends of the resistor R4 are connected in parallel to the emitter and base of the transistor Q2; the second end of the resistor R6 and the second end of the capacitor C2 are connected to the ground end, and the second end of the resistor R8 is electrically connected to the second end of the resistor R7.

[0010] Furthermore, the temperature measurement circuit includes: a thermistor RT1, a resistor R9, and a resistor R12; a first end of the thermistor RT1 is electrically connected to the second power supply terminal VPP1, and a second end of the thermistor RT1 is electrically connected to the first end of the resistor R9; the resistor R9 is electrically connected to the first end of the resistor R12 and the temperature diagnosis circuit, and the other end of the resistor R12 is connected to the ground terminal.

[0011] Furthermore, the temperature diagnostic circuit includes: an operational amplifier, a resistor R10, a resistor R11, a resistor R14, a capacitor C3, a capacitor C4 and a third power supply terminal VPP2; the non-inverting input terminal of the operational amplifier is electrically connected to the first end of the resistor R10 and the first end of the capacitor C3, the inverting input terminal is electrically connected to the first end of the resistor R14, the output terminal is electrically connected to the first end of the resistor R11 and the second end of the resistor R14, the positive power supply terminal is connected to the ground terminal, and the negative power supply terminal is electrically connected to the first end of the capacitor C4 and the third power supply terminal VPP2; the resistor R10 is electrically connected to the second end of the temperature measurement circuit, the second end of the resistor R11 is electrically connected to the microcontroller MCU; the second end of the capacitor C3 is connected to the ground terminal, and the second end of the capacitor C4 is connected to the ground terminal.

[0012] Furthermore, the temperature measurement circuit also includes a driving circuit, the first end of the driving circuit is electrically connected to the first end of the first voltage acquisition circuit and the first end of the second voltage acquisition circuit respectively; the driving circuit is used to control the first voltage acquisition circuit and / or the second voltage acquisition circuit to perform voltage acquisition.

[0013] Furthermore, the driving circuit includes a transistor bias circuit with a transistor Q3, the collector of the transistor Q3 is electrically connected to the first end of the first voltage acquisition circuit and the first end of the second voltage acquisition circuit, the emitter is connected to the ground end, and the base is electrically connected to the enable control end.

[0014] Furthermore, the temperature measurement circuit further includes: an energy-saving circuit, a first end of the energy-saving circuit being electrically connected to a third end of the temperature measurement circuit, and the energy-saving circuit being used to reduce a static current of the temperature measurement circuit.

[0015] Furthermore, the energy-saving circuit includes: a transistor MOS1, a Zener diode Z1, a Zener diode Z2, a resistor R13 and a fourth power supply terminal V0, the gate of the transistor MOS1 is electrically connected to the first end of the resistor R13, the source is electrically connected to the temperature measurement circuit, and the drain is connected to the ground terminal; the second end of the resistor R13 is electrically connected to the fourth power supply terminal V0, the cathode of the Zener diode Z1 is electrically connected to the first end of the resistor R13 and the gate of the transistor MOS1, the anode is electrically connected to the anode of the Zener diode Z2, and the cathode of the Zener diode Z2 is electrically connected to the drain of the transistor MOS1 and the ground terminal respectively.

[0016] The beneficial effects of the present invention are that two voltage acquisition circuits and one temperature measurement circuit are used to significantly improve the accuracy and response speed of PCB temperature detection, and potential overheating risks can be detected in the temperature measurement circuit in a timely manner to avoid the resulting overheating problems, extend the service life of components, and improve the stability and reliability of the circuit system. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A schematic diagram of the structure of a circuit for checking PCB temperature provided by an embodiment of the present utility model;

[0018] Figure 2 One of the circuit diagrams of a PCB temperature detection circuit provided by an embodiment of the present utility model;

[0019] Figure 3 This is a second circuit diagram of a PCB temperature detection circuit provided by an embodiment of the present utility model.

[0020] In the figure: 1. First voltage acquisition circuit; 2. Second voltage acquisition circuit; 3. Temperature measurement circuit; 4. Temperature diagnosis circuit; 5. Microcontroller MCU; 6. Drive circuit; 7. Energy-saving circuit. DETAILED DESCRIPTION

[0021] The following will clearly and completely describe the technical solutions in this embodiment with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0022] It should be noted that in the description of the present invention, all directional indications (such as up, down, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0023] In addition, the terms "first," "second," and so on, used in this utility model are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the technical features being described. In the description of this utility model, "several" means at least two, such as two or three, unless otherwise specifically defined.

[0024] In addition, the technical solutions between the various embodiments of the present invention can be combined with each other, but it must be based on the fact that technical personnel in this field can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by this utility model.

[0025] like Figure 1-3 As shown, the embodiment of the present utility model provides a circuit for checking PCB temperature. Figure 1 A circuit for checking PCB temperature is provided in an embodiment of the present invention. Figure 1 As shown, it includes a first voltage acquisition circuit 1, a second voltage acquisition circuit 2, a microcontroller MCU5, a temperature measurement circuit 3 and a temperature diagnosis circuit 4.

[0026] The first end of the first voltage acquisition circuit 1 is electrically connected to the first end of the second voltage acquisition circuit 2 , and the second end of the first voltage acquisition circuit 1 is electrically connected to the microcontroller MCU5 . The first voltage acquisition circuit 1 is used to acquire the first voltage.

[0027] The second end of the second voltage acquisition circuit 2 is electrically connected to the microcontroller MCU5 , and the third end of the second voltage acquisition circuit 2 is electrically connected to the temperature measurement circuit 3 . The second voltage acquisition circuit 2 is used to acquire the second voltage.

[0028] The first power terminal VBAT1 is the vehicle power terminal voltage, and the second power terminal VPP1 is the product supply voltage obtained after filtering the power supply. Both are DC voltages and remain stable under normal working conditions. The first voltage and the second voltage are the actual input voltage values ​​of the first power terminal VBAT1 and the second power terminal VPP1, respectively. They are compared with the input voltages of the first power terminal VBAT1 and the second power terminal VPP1 to serve as a reference for the input voltage of the thermistor RT1 of the subsequent temperature measurement circuit 3, thereby preventing errors in subsequent temperature calculations caused by fluctuations in the PCB board input voltage.

[0029] In one embodiment, a dual power supply voltage acquisition mechanism (collecting the first voltage and the second voltage) is used, and combined with a precise voltage processing algorithm in the microcontroller MCU5 to process the collected voltage data and then calculate the average value of the voltage collection. There are no specific restrictions on the calculation method of the average value.

[0030] The second end of the temperature measurement circuit 3 is electrically connected to the first end of the temperature diagnosis circuit 4 . The temperature measurement circuit 3 is used to measure the temperature of the heating module.

[0031] Among them, the temperature measurement circuit 3 should be arranged within 10 mm from the heating area, that is, near the high-temperature area, for example, within 10 mm from the vehicle-mounted high-power driver chip. The closer the distance, the better, because the closer to the chip, the closer the measurement point is to the center of the heating area.

[0032] In one embodiment, the temperature measurement circuit 3 includes a thermistor RT1 .

[0033] A second terminal of the temperature diagnosis circuit 4 is electrically connected to the microcontroller MCU5 , and the temperature diagnosis circuit 4 is configured to output an electrical signal corresponding to the temperature.

[0034] Among them, the temperature diagnosis circuit 4 processes the output signal of the temperature measurement circuit 3, and the output electrical signal can be a voltage value. For the collected voltage value, its processing process has an isolation function and a suppression effect on common-mode interference. This isolation measure can effectively block any electrical connection that may exist with other circuits.

[0035] The microcontroller MCU5 can process the first voltage, the second voltage, and the electrical signal fed back by the temperature diagnosis circuit 4 .

[0036] Among them, with the help of a dual power supply voltage acquisition mechanism (collecting the first voltage and the second voltage), and in the microcontroller MCU5, it is combined with a precise voltage processing algorithm to process the collected voltage data, and then calculate the average value of the voltage acquisition; on this basis, the average value is intelligently compared and analyzed with the voltage generated by the temperature diagnosis circuit 4.

[0037] In one embodiment, the first and second voltages collected by the microcontroller MCU5 are first used to calculate an average value of the voltage collection. Then, the voltage value of the temperature diagnostic circuit 4 is obtained. The two collected voltage values ​​are processed using a specific conversion method to obtain the actual resistance value of thermistor RT1 in the temperature measurement circuit 3. On this basis, the actual temperature of the PCB is further calculated based on the temperature curve characteristics of thermistor RT1, thereby achieving accurate monitoring of the PCB temperature and providing critical temperature data support for the stable operation of the system.

[0038] The technical solution provided by the embodiment of the present utility model, by combining a dual power supply voltage acquisition mechanism with a sophisticated voltage processing algorithm, achieves high-precision temperature calculation of the high-temperature area of ​​the PCB board, effectively ensuring the accuracy and reliability of the temperature calculation, and providing strong temperature monitoring support for the stable operation of the PCB board under complex working conditions.

[0039] Based on the above embodiments, Figure 2 This is one of the circuit diagrams of an embodiment of the present utility model. The first voltage acquisition circuit includes a first power supply terminal VBAT1, a transistor Q1, a resistor R2, a resistor R3, a resistor R5, a resistor R7, and a capacitor C1. The transistor Q1 is a PNP transistor. The emitter of the transistor Q1 is electrically connected to the first power supply terminal VBAT1, the collector is electrically connected to the first end of the resistor R2, and the base is electrically connected to the first end of the resistor R7.

[0040] The second end of the resistor R2 is electrically connected to the first end of the resistor R5 and the first end of the capacitor C1, and is electrically connected to the microcontroller MCU5. The microcontroller MCU5 is used to collect the first voltage. The first and second ends of the resistor R3 are connected in parallel to the emitter and base of the transistor Q1. The second end of the resistor R5 and the second end of the capacitor C1 are connected to the ground end. The second end of the resistor R7 is electrically connected to the first end of the second voltage collection circuit 2.

[0041] The first power supply terminal VBAT1 may be a vehicle power supply terminal voltage, and the input voltage range is a wide voltage range of 9V to 16V. This wide voltage input characteristic can adapt to various complex working conditions.

[0042] The resistor R5, capacitor C1, and ground terminal are used to increase bias stability. A properly designed ground connection can provide a decoupling function and effectively filter out spikes in the power supply signal.

[0043] The technical solution provided by the embodiment of the present utility model helps to further improve the stability of the entire acquisition system, ensure the quality of signals and the accuracy of data during the acquisition process, provide a reliable basis for subsequent analysis and processing, reduce acquisition errors and data fluctuations caused by interference, and ensure that the acquisition system can operate stably even in complex electromagnetic environments.

[0044] Further, if Figure 2 The second voltage acquisition circuit 2 includes a second power supply terminal VPP1, a transistor Q2, a resistor R1, a resistor R4, a resistor R6, a resistor R8, and a capacitor C2. The transistor Q2 is a PNP transistor. The emitter of the transistor Q2 is electrically connected to the second power supply terminal VPP1, the collector is electrically connected to the first end of the resistor R1, the base is electrically connected to the first end of the resistor R8, the second end of the resistor R1 is electrically connected to the first end of the resistor R6 and the first end of the capacitor C2, and is electrically connected to the microcontroller MCU5. The microcontroller MCU5 is used to collect the second voltage. The first and second ends of the resistor R4 are connected in parallel to the emitter and base of the transistor Q2. The second end of the resistor R6 and the second end of the capacitor C2 are connected to the ground end. The second end of the resistor R8 is electrically connected to the second end of the resistor R7.

[0045] The second power supply terminal VPP1 is a product power supply voltage obtained after filtering the power supply, and has a wide input voltage range of 9V to 16V. This wide voltage input characteristic can adapt to various complex working conditions.

[0046] The resistor R6, capacitor C2, and ground terminal are used to increase bias stability. A properly designed ground connection can provide a decoupling function and effectively filter out spikes in the power supply signal.

[0047] The technical solution provided by the embodiment of the present utility model helps to further improve the stability of the entire acquisition system, ensure the quality of signals and the accuracy of data during the acquisition process, provide a reliable basis for subsequent analysis and processing, reduce acquisition errors and data fluctuations caused by interference, and ensure that the acquisition system can operate stably even in complex electromagnetic environments.

[0048] Further, if Figure 3 As shown, the temperature measurement circuit 3 includes a thermistor RT1, a resistor R9, and a resistor R12. The first end of the thermistor RT1 is electrically connected to the second power supply terminal VPP1, and the second end is electrically connected to the first end of the resistor R9. The thermistor RT1 is used for temperature acquisition. The resistor R9 is electrically connected to the first end of the resistor R12 and the temperature diagnosis circuit 4. The other end of the resistor R12 is connected to the ground terminal.

[0049] Thermistor RT1 is a high-precision negative temperature coefficient (NTC) thermistor, a semiconductor resistor device that is very sensitive to temperature changes. Its resistance value is negatively correlated with temperature, meaning that as the temperature increases, the resistance value decreases; conversely, as the temperature decreases, the resistance value increases. Thermistor RT1 should be located within 10 mm of the heating area, that is, near the high-temperature area. The closer the distance, the better, because the closer the measurement point is to the center of the heating area, the closer it is to the chip.

[0050] Among them, resistor R9 and resistor R12 perform the voltage dividing function in the circuit. Their role is to reduce the collected voltage according to a specific ratio, so that the voltage value falls within the voltage range that can be collected by the microcontroller MCU5, avoiding data collection errors or damage to the MCU caused by the voltage being too high beyond the collection range.

[0051] Further, if Figure 3 The temperature diagnosis circuit includes: an operational amplifier, a resistor R10, a resistor R11, a resistor R14, a capacitor C3, a capacitor C4 and a third power supply terminal VPP2: the non-inverting input terminal of the operational amplifier U1A is electrically connected to the first end of the resistor R10 and the first end of the capacitor C3, the inverting input terminal is electrically connected to the first end of the resistor R14, the output terminal is electrically connected to the first end of the resistor R11 and the second end of the resistor R14, the positive power supply terminal is connected to the ground terminal, the negative power supply terminal is electrically connected to the first end of the capacitor C4 and the third power supply terminal VPP2, the resistor R10 is electrically connected to the second end of the temperature measurement circuit 3, the second end of the resistor R11 is electrically connected to the microcontroller MCU5, the second end of the capacitor C3 is connected to the ground terminal, and the second end of the capacitor C4 is connected to the ground terminal.

[0052] Among them, the operational amplifier U1A in the temperature diagnosis circuit 4 processes the output signal of the temperature measurement circuit 3. The output signal can be a voltage value. Its processing process has an isolation function and a suppression effect on common-mode interference. This isolation measure can effectively block any electrical connection that may exist with other circuits.

[0053] Among them, resistor R11 mainly plays the role of protecting the microcontroller MCU5 in the circuit. It can prevent abnormal current or voltage from damaging the microcontroller MCU5 and ensure that the microcontroller MCU5 operates stably under normal electrical environments. Resistor R14 has the function of compensating bias current. By adjusting the current distribution in the circuit, it effectively reduces the impact of bias current on circuit performance, thereby improving the accuracy and stability of the entire circuit operation. Resistor R10 and capacitor C3 are responsible for protecting the operational amplifier U1A in the circuit. At the same time, the circuit composed of the two also has an RC filtering function. In terms of protecting the operational amplifier U1A, they can effectively prevent abnormal voltage and current shocks from damaging the amplifier, ensuring that the operational amplifier U1A operates stably and reliably. As for the filtering function, this RC filtering circuit can selectively process signals of different frequencies and suppress interference signals outside a specific frequency range, thereby improving the purity of the amplifier input signal, optimizing the performance of the operational amplifier U1A, and reducing signal distortion caused by noise interference.

[0054] In one embodiment, the average value of the voltage collected by the microcontroller MCU5 at the first power supply terminal VBAT1 and the second power supply terminal VPP1 is calculated. The voltage value of the temperature diagnosis circuit 4 is then obtained. These two collected voltage values ​​are processed using a specific conversion method to obtain the actual resistance value of thermistor RT1 in the temperature measurement circuit 3. On this basis, the actual temperature of the PCB is further calculated based on the temperature curve characteristics of thermistor RT1. This achieves accurate monitoring of the PCB temperature and provides critical temperature data support for the stable operation of the system.

[0055] Furthermore, if Figure 1 and Figure 2 The temperature measurement circuit also includes a driving circuit 6, a first end of the driving circuit 6 is electrically connected to the first end of the first voltage acquisition circuit 1 and the first end of the second voltage acquisition circuit 2, respectively. The driving circuit 6 acts as a control switch to control the first voltage acquisition circuit 1 and / or the second voltage acquisition circuit 2 to perform voltage acquisition.

[0056] Furthermore, the driving circuit 6 is a transistor bias circuit including a transistor Q3, the collector of the transistor Q3 is electrically connected to the first end of the first voltage acquisition circuit and the first end of the second voltage acquisition circuit, the emitter is connected to the ground end, and the base is connected to the enable control end.

[0057] Among them, the driving circuit 6 has a simple control switch function, and its enable end EN can receive an input control signal from the microcontroller MCU5. The specific source of the input control signal is not limited in the utility model. It can be received by the microcontroller MCU5 or obtained by other means. The signal is an enable control signal. Through the driving circuit 6, the acquisition function of the first voltage acquisition circuit 1 and / or the second voltage acquisition circuit 2 can be turned on, thereby realizing the acquisition operation of the corresponding data, providing an effective control mechanism for the data acquisition link of the entire system, and ensuring the orderliness and operability of the acquisition process.

[0058] Further, if Figure 1 The temperature measurement circuit also includes an energy-saving circuit 7, a first end of the energy-saving circuit 7 is electrically connected to the third end of the temperature measurement circuit 3, and the energy-saving circuit 7 is used to reduce the static current of the temperature measurement circuit.

[0059] The energy-saving circuit includes a transistor MOS1, a Zener diode Z1, a Zener diode Z2, a resistor R13, and a fourth power supply terminal V0. The gate of the transistor MOS1 is electrically connected to the first end of the resistor R13, the source is electrically connected to the temperature measurement circuit 3, and the drain is connected to the ground terminal. The second end of the resistor R13 is electrically connected to the fourth power supply terminal V0. The cathode of the Zener diode Z1 is electrically connected to the first end of the resistor R13 and the gate of the transistor MOS1, and the anode is electrically connected to the anode of the Zener diode Z2. The cathode of the Zener diode Z2 is electrically connected to the drain of the transistor MOS1 and the ground terminal.

[0060] Among them, this solution introduces the transistor MOS1 control strategy: when the product is in sleep mode, the temperature measurement circuit can be automatically shut down with the help of the intelligent control mechanism of transistor MOS1. This control method effectively reduces the static current consumption of the product from the source.

[0061] Specifically, the fourth power terminal V0, serving as the product's 5V supply voltage, is turned off when the product is in sleep mode. However, the voltage at the second power terminal VPP1 cannot be turned off in this state. This design aims to reduce the circuit's quiescent current, thereby optimizing the product's energy consumption. After power-on, this circuit is normally open and requires no separate control. The drain of transistor MOS1 is grounded, maintaining its voltage at 0V. This series of designs forms part of a quiescent current control solution and is of great significance for improving the product's energy efficiency in sleep and other modes. This helps reduce unnecessary energy loss, meets the high energy-saving and environmental protection requirements of modern electronic products, and contributes to enhancing the product's market competitiveness and sustainable development capabilities.

[0062] In a specific embodiment:

[0063] The first power supply terminal VBAT1 = 14V, the second power supply terminal VPP1 = 13.7V, the resistor R1 = 3.32K, the resistor R6 = 7.68K, VMOS1 dS =0.2V, V Q2 =0.12V, resistor R9=2K, resistor R12=1K;

[0064] Among them, VMOS1 dS is the drain voltage of transistor MOS1, V Q2 is the voltage of transistor Q2;

[0065] In the second voltage acquisition circuit 2, the processing calculation formula of the second voltage is:

[0066]

[0067] In the first voltage acquisition circuit 1 , the calculation formula for processing the voltage of the first power supply terminal VBAT1_DLAG_AD is the same as the calculation method in the second voltage acquisition circuit 2 , and will not be repeated here.

[0068] In the temperature diagnosis circuit 4, the voltage processing calculation formula is:

[0069]

[0070] The collected voltage data is processed by collecting the second power supply terminal VPP1_DLAG_AD and the first power supply terminal VBAT1_DLAG_AD and combining them with a precise voltage processing algorithm in the microcontroller MCU5 to calculate an average value of the collected voltages. This average value is then intelligently compared and analyzed with the voltage at the second power supply terminal VPP1_TEMP generated by the temperature diagnostic circuit 4 to avoid inaccurate measurements caused by voltage instability. The actual resistance value of the thermistor RT1 and the temperature curve characteristics are then used to further calculate the actual temperature of the PCB, thereby achieving accurate monitoring of the PCB temperature.

Claims

1. A circuit for checking PCB temperature, characterized in that: It includes a first voltage acquisition circuit, a second voltage acquisition circuit, a microcontroller MCU, a temperature measurement circuit and a temperature diagnosis circuit; The first end of the first voltage acquisition circuit is electrically connected to the first end of the second voltage acquisition circuit, the second end of the first voltage acquisition circuit is electrically connected to the microcontroller MCU, and the first voltage acquisition circuit is used to acquire the first voltage actually input to the PCB board; The second end of the second voltage acquisition circuit is electrically connected to the microcontroller MCU, the third end of the second voltage acquisition circuit is electrically connected to the temperature measurement circuit, and the second voltage acquisition circuit is used to collect the second voltage actually input to the PCB board; The second end of the temperature measurement circuit is electrically connected to the first end of the temperature diagnosis circuit, and the temperature measurement circuit is used to measure the temperature of the heating module; The second end of the temperature diagnosis circuit is electrically connected to the microcontroller MCU, and the temperature diagnosis circuit is used to output an electrical signal corresponding to the temperature; The microcontroller MCU processes the electrical signal fed back by the temperature diagnosis circuit according to the first voltage and the second voltage.

2. A PCB temperature detection circuit according to claim 1, characterized in that: The first voltage acquisition circuit includes a first power supply terminal VBAT1, a transistor Q1, a resistor R2, a resistor R3, a resistor R5, a resistor R7, and a capacitor C1; The emitter of the transistor Q1 is electrically connected to the first power supply terminal VBAT1, the collector of the transistor Q1 is electrically connected to the first end of the resistor R2, and the base of the transistor Q1 is electrically connected to the first end of the resistor R7; The second end of the resistor R2 is electrically connected to the first end of the resistor R5 and the first end of the capacitor C1, and is also electrically connected to a microcontroller MCU, and the microcontroller MCU is used to collect the first voltage; The first end and the second end of the resistor R3 are connected in parallel to the emitter and the base of the transistor Q1; The second end of the resistor R5 and the second end of the capacitor C1 are connected to the ground end; The second end of the resistor R7 is electrically connected to the first end of the second voltage acquisition circuit.

3. A PCB temperature detection circuit according to claim 2, characterized in that: The second voltage acquisition circuit includes a second power supply terminal VPP1, a transistor Q2, a resistor R1, a resistor R4, a resistor R6, a resistor R8, and a capacitor C2: The emitter of the transistor Q2 is electrically connected to the second power supply terminal VPP1, the collector of the transistor Q2 is electrically connected to the first end of the resistor R1, and the base of the transistor Q2 is electrically connected to the first end of the resistor R8; The second end of the resistor R1 is electrically connected to the first end of the resistor R6 and the first end of the capacitor C2, and is also electrically connected to the microcontroller MCU, and the microcontroller MCU is used to collect the second voltage; The first end and the second end of the resistor R4 are connected in parallel to the emitter and base of the transistor Q2; The second end of the resistor R6 and the second end of the capacitor C2 are connected to the ground end; The second end of the resistor R8 is electrically connected to the second end of the resistor R7.

4. A circuit for checking PCB temperature according to claim 1, characterized in that: The temperature measurement circuit includes: a thermistor RT1, a resistor R9 and a resistor R12; The first end of the thermistor RT1 is electrically connected to the second power supply terminal VPP1, and the second end of the thermistor RT1 is electrically connected to the first end of the resistor R9; The resistor R9 is electrically connected to a first end of the resistor R12 and the temperature diagnosis circuit. The other end of the resistor R12 is connected to the ground.

5. The circuit for checking PCB temperature according to claim 1, characterized in that: The temperature diagnosis circuit includes: an operational amplifier, a resistor R10, a resistor R11, a resistor R14, a capacitor C3, a capacitor C4 and a third power supply terminal VPP2; The operational amplifier has a non-inverting input terminal electrically connected to the first end of the resistor R10 and the first end of the capacitor C3, an inverting input terminal electrically connected to the first end of the resistor R14, an output terminal electrically connected to the first end of the resistor R11 and the second end of the resistor R14, a positive power terminal electrically connected to the ground terminal, and a negative power terminal electrically connected to the first end of the capacitor C4 and the third power terminal VPP2; The resistor R10 is electrically connected to the second end of the temperature measurement circuit, and the second end of the resistor R11 is electrically connected to the microcontroller MCU; The second end of the capacitor C3 is connected to the ground, and the second end of the capacitor C4 is connected to the ground.

6. A circuit for checking PCB temperature according to claim 1, characterized in that: The temperature measurement circuit further includes: a driving circuit; The first end of the driving circuit is electrically connected to the first end of the first voltage acquisition circuit and the first end of the second voltage acquisition circuit respectively; The driving circuit is used to control the first voltage acquisition circuit and / or the second voltage acquisition circuit to perform voltage acquisition.

7. A circuit for checking PCB temperature according to claim 6, characterized in that: The driving circuit is a transistor bias circuit including a transistor Q3; The collector of the transistor Q3 is electrically connected to the first end of the first voltage acquisition circuit and the first end of the second voltage acquisition circuit, the emitter is connected to the ground end, and the base is connected to the enable control end.

8. The circuit for checking PCB temperature according to claim 1, characterized in that: The temperature measurement circuit further includes: an energy-saving circuit; The first end of the energy-saving circuit is electrically connected to the third end of the temperature measurement circuit; The energy-saving circuit is used to reduce the static current of the temperature measurement circuit.

9. A circuit for checking PCB temperature according to claim 8, characterized in that: The energy-saving circuit includes: a transistor MOS1, a voltage-stabilizing diode Z1, a voltage-stabilizing diode Z2, a resistor R13 and a fourth power supply terminal V0; The gate of the transistor MOS1 is electrically connected to the first end of the resistor R13, the source is electrically connected to the temperature measurement circuit, and the drain is connected to the ground end; The second end of the resistor R13 is electrically connected to the fourth power supply end V0; The cathode of the voltage stabilizing diode Z1 is electrically connected to the first end of the resistor R13 and the gate of the transistor MOS1, and the anode is electrically connected to the anode of the voltage stabilizing diode Z2; The cathode of the voltage stabilizing diode Z2 is electrically connected to the drain of the transistor MOS1 and the ground terminal respectively.

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