Temperature detection circuit of power device and power equipment
By directly mounting the temperature sensor on the TPAK device and combining it with a comparator circuit and an isolation circuit, the problems of large size and high cost of infrared sensors are solved, achieving low-cost, accurate temperature detection and space saving.
Patent Information
- Application Number
- CN202423095550.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-13
- Publication Date
- 2025-11-11
- Estimated Expiration
- 2034-12-13
AI Technical Summary
Existing TPAK devices require infrared sensors for temperature detection, which results in large size, high cost, and space consumption.
A temperature sensor packaged with a surface mount device (SMD) combines a comparator circuit and an isolation circuit. It is directly mounted on the package surface of the power device. The comparator circuit performs analog-to-digital conversion, and the isolation circuit isolates the signal, avoiding the use of an analog-to-digital converter, reducing costs and protecting the safety of subsequent circuits.
It achieves low-cost, accurate temperature detection, reduces hardware footprint, and improves detection accuracy and circuit safety.
Smart Images
Figure CN223538424U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of temperature detection technology, specifically to a temperature detection circuit and power device for a power device. Background Technology
[0002] TPAK is a type of semiconductor device package, particularly used in the packaging of power semiconductor devices, which will be referred to as power devices below. Because power devices may involve high-frequency switching, the junction temperature of the internal power device needs to be monitored during use. However, the wafer of the TAPK device is internally packaged, and the TPAK device does not include a temperature sensor.
[0003] Existing TPAK devices use infrared sensors for temperature detection, meaning the infrared sensor measures the temperature of the TPAK device. However, when measuring temperature, the infrared sensor needs to be at a certain distance from the TPAK device, resulting in disadvantages such as large size and high cost. Utility Model Content
[0004] In view of this, this application provides a temperature detection circuit and power device for power devices, which is low in cost, simple in hardware, and can reduce the space occupied.
[0005] This application provides a temperature detection circuit for a power device, comprising: a temperature sensor, a comparator circuit, and an isolation circuit; the temperature sensor is packaged as a surface mount device and is attached to the surface of the package of the power device; the output terminal of the temperature sensor is connected to the first input terminal of the comparator circuit, and the second input terminal of the comparator circuit is connected to a reference voltage; the comparator circuit is used to convert the analog voltage signal representing the temperature output by the temperature sensor into a digital signal and send it to the input terminal of the isolation circuit.
[0006] One possible implementation further includes: a controller; the comparison circuit includes a first comparator; the isolation circuit includes an isolation transformer; the output terminal of the temperature sensor is connected to the first input terminal of the first comparator, and the second input terminal of the first comparator is connected to a reference voltage; the output terminal of the first comparator is connected to the first terminal of the primary winding of the isolation transformer, the second terminal of the primary winding of the isolation transformer is grounded, the first terminal of the secondary winding of the isolation transformer is connected to the controller, and the second terminal of the secondary winding of the isolation transformer is grounded.
[0007] One possible implementation further includes: a controller; the comparison circuit includes a second comparator, a third comparator, and a fourth comparator; the isolation circuit includes a first isolation capacitor and a second isolation capacitor; the first input terminal of the second comparator and the second input terminal of the third comparator are connected to the output terminal of the temperature sensor, the second input terminal of the second comparator and the first input terminal of the third comparator are connected to the reference voltage, the output terminal of the second comparator is connected to the first input terminal of the fourth comparator through the first isolation capacitor, the output terminal of the third comparator is connected to the second input terminal of the fourth comparator through the second isolation capacitor, and the output terminal of the fourth comparator is connected to the controller.
[0008] One possible implementation further includes: a filtering circuit; the output of the temperature sensor is connected to the first input of the comparison circuit via the filtering circuit.
[0009] One possible implementation is that the reference voltage is a triangular wave reference voltage.
[0010] One possible implementation is that the digital signal output by the isolation circuit is a pulse width modulation signal.
[0011] One possible implementation is that the power device is packaged in at least one of the following: TPAK package, TO-247 package, DPAK package, or D... 2 PAK package.
[0012] One possible implementation further includes: a controller; the output of the isolation circuit is connected to the controller; the controller is also used to provide operating power to the comparison circuit, the isolation circuit and the temperature sensor.
[0013] One possible implementation is that the comparison circuit and the isolation circuit are integrated inside the motor control chip.
[0014] This application also provides a power device, including a power device and the temperature detection circuit described above;
[0015] The temperature detection circuit is used to detect the temperature of the power device.
[0016] The temperature detection circuit for power devices provided in this application embodiment can utilize surface-mount devices (SMT) packages, directly attaching to the surface of the power device's package housing to directly sense the device's temperature. Furthermore, it employs a comparator circuit for analog-to-digital conversion, eliminating the need for an analog-to-digital converter and saving costs. Additionally, an isolation circuit is used for signal isolation, protecting subsequent circuitry. Therefore, the temperature detection circuit provided in this application embodiment is low-cost, simple in hardware, can directly contact the power device, provides accurate detection results, and reduces space requirements. Attached Figure Description
[0017] Figure 1A This is a schematic diagram of a temperature detection circuit for a power device provided in an embodiment of this application;
[0018] Figure 1B A schematic diagram of another temperature detection circuit for a power device is provided for embodiments of this application;
[0019] Figure 2 A schematic diagram of a temperature detection circuit for another power device provided in an embodiment of this application;
[0020] Figure 3 A schematic diagram of a temperature detection circuit for another power device provided in an embodiment of this application;
[0021] Figure 4 A schematic diagram of a temperature detection circuit for another power device provided in an embodiment of this application;
[0022] Figure 5 This is a schematic diagram of a power device provided in an embodiment of this application. Detailed Implementation
[0023] The embodiments of this application do not specifically limit the application scenarios of power devices, but can be applied to power equipment that performs power conversion, such as power equipment for motors, power equipment for photovoltaics, or power equipment for energy storage, etc.
[0024] Since power devices perform switching actions during operation, their temperature can sometimes rise significantly, necessitating temperature detection. The temperature detection circuit provided in this application can be attached to the power device's package, directly contacting the package surface. The temperature sensor can directly sense the temperature of the package housing, unlike infrared temperature sensors which require a certain distance from the housing. This not only leads to inaccurate temperature detection but also occupies space, making installation inconvenient in scenarios with limited semiconductor hardware space.
[0025] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the embodiments of this application will be further described in detail below with reference to the accompanying drawings and specific implementation methods.
[0026] See Figure 1A The figure is a schematic diagram of a temperature detection circuit for a power device provided in an embodiment of this application.
[0027] The temperature detection circuit for the power device provided in this application includes: a temperature sensor 100, a comparator circuit 10, and an isolation circuit 20.
[0028] The temperature sensor 100 is in SMT package and is attached to the surface of the power device package.
[0029] It should be understood that the embodiments of this application do not specifically limit the number of power devices included in a package, and may include one power device or multiple power devices.
[0030] The output terminal of the temperature sensor 100 is connected to the first input terminal of the comparator circuit 10, and the second input terminal of the comparator circuit 10 is connected to a reference voltage (not shown in the figure). The comparator circuit 10 is used to convert the analog voltage signal representing the temperature output by the temperature sensor into a digital signal and send it to the input terminal of the isolation circuit 20.
[0031] The temperature detection circuit for power devices provided in this application embodiment can be packaged using SMT (Surface Mount Technology) and directly attached to the surface of the power device's package housing to directly sense the device's temperature. Furthermore, it uses a comparator circuit for analog-to-digital conversion, eliminating the need for an analog-to-digital converter (ADC) and saving costs. Additionally, an isolation circuit is used for signal isolation, protecting subsequent circuitry. Therefore, the temperature detection circuit provided in this application embodiment is low-cost, simple in hardware, can directly contact the power device, provides accurate detection results, and reduces space requirements.
[0032] See Figure 1B The figure is a schematic diagram of a temperature detection circuit for another power device provided in an embodiment of this application.
[0033] The temperature detection circuit provided in this application embodiment may further include a controller 30.
[0034] The embodiments of this application do not specifically limit the type of controller 30. For example, it may include a microcontroller or microprocessor, or a microcontroller and peripheral circuits, or a microprocessor and peripheral circuits, etc.
[0035] It should be understood that the embodiments of this application do not specifically limit the physical form of the comparison circuit 10, the isolation circuit 20, and the controller 30. In one possible implementation, the comparison circuit 10 and the isolation circuit 20 can be constructed using analog circuits respectively. In another possible implementation, the comparison circuit 10 and the isolation circuit 20 can also be integrated into a single control chip and implemented by a single control chip.
[0036] For example, the control chip can be the MCCGD3160. The MCCGD3160 is an automotive-grade driver chip, i.e., a motor control chip; it has a large drive current (15A), low drive impedance, and a wide drive voltage range, which can meet the needs of driving power devices such as IGBTs and SiCs; in addition, it integrates other functional circuits, such as analog signal isolation sampling, temperature protection or warning, desaturation protection, chip undervoltage protection, overcurrent and short circuit protection, etc. The comparison circuit and isolation circuit in the embodiments of this application can be implemented by the analog signal isolation sampling in the control chip. For example, for temperature detection of power devices driven by vehicles, the analog signal isolation sampling function of the control chip MCCGD3160 can be reused, and it is not necessary to set up a separate comparison circuit and isolation circuit.
[0037] This application does not specifically limit the package type of the power device. For example, the package may include at least one of the following: TPAK package, TO-247 package, DPAK package, or D... 2 PAK package. For ease of understanding, the following explanation uses DPAK package as an example.
[0038] It should be understood that the embodiments of this application do not use an analog-to-digital converter to convert the sampled analog signal into a digital signal, but rather use a comparator circuit to convert the analog signal into a digital signal.
[0039] This application incorporates an isolation circuit to isolate the primary high voltage from the secondary low voltage. Even if the TPAK device is damaged, such as when the casing ruptures, the temperature detection circuit can still be isolated by the high and low voltages through the isolation circuit, preventing it from affecting the controller and protecting the entire circuit, thus enhancing safety.
[0040] The temperature detection circuit for power devices provided in this application embodiment can be SMT packaged and directly attached to the surface of the power device's package housing to directly sense the device's temperature. Furthermore, it uses a comparator circuit for analog-to-digital conversion, eliminating the need for an analog-to-digital converter (ADC) and saving costs. Additionally, an isolation circuit is used for signal isolation, protecting the safety of subsequent circuits, such as the controller. Therefore, the temperature detection circuit provided in this application embodiment is low-cost, simple in hardware, can directly contact the power device, provides accurate detection results, and reduces the space it occupies.
[0041] The following description, in conjunction with the accompanying drawings, illustrates how the comparison circuit and isolation circuit provided in the embodiments of this application are implemented using analog circuits.
[0042] See Figure 2 The figure is a schematic diagram of a temperature detection circuit for another power device provided in an embodiment of this application.
[0043] The temperature detection circuit provided in this embodiment includes a first comparator U1 in the comparison circuit and an isolation transformer 21 in the isolation circuit. The first input terminal of the first comparator U1 is connected to the output terminal of the temperature sensor. For ease of understanding, Figure 2 The temperature sensor is equivalent to a sensing resistor Rt. The first terminal of the sensing resistor Rt is connected to a first resistor R1, and the second terminal of the first resistor R1 is connected to a power supply (taken as an example, 5V). The first resistor R1 serves as a current limiter and voltage divider. The second terminal of the sensing resistor Rt is grounded.
[0044] To improve the quality of signal acquisition, the temperature detection circuit also includes a filtering circuit, and the output of the temperature sensor is connected to the first input of the comparison circuit through the filtering circuit.
[0045] For example, one implementation of the filter circuit may include a second resistor R2 and a first capacitor C1. The first terminal of the second resistor R2 is connected to the first terminal of the sensing resistor Rt, and the second terminal of the second resistor R2 is connected to the first input terminal of the first comparator U1. The first terminal of the first capacitor C1 is connected to the second terminal of the second resistor R2, and the second terminal of the first capacitor C1 is grounded.
[0046] The output of the first comparator U1 is connected to the first terminal of the primary winding of the isolation transformer 21. The second terminal of the primary winding of the isolation transformer 21 is grounded to GND. The first terminal of the secondary winding of the isolation transformer 21 is connected to the controller 30, and the second terminal of the secondary winding of the isolation transformer 21 is grounded to GND1. It should be understood that, in order to better achieve isolation between the primary and secondary signals of the isolation transformer 21, the primary and secondary windings are not connected to the same ground.
[0047] To improve the signal's anti-interference capability, a triangular wave reference voltage is used. The voltage signal Uin acquired at the first input terminal of the first comparator U1 is compared with the triangular wave reference voltage to generate a square wave signal. After passing through the isolation circuit 21, the square wave signal outputs a pulse width modulation signal Vout to the controller 30.
[0048] It should be understood that the controller 30 samples a square wave signal, and the temperature is identified by the duty cycle of the sampled square wave signal.
[0049] Figure 2The isolation circuit shown is implemented using a transformer. Alternatively, the isolation circuit can also be implemented using a capacitor. A detailed description is provided below with reference to the attached diagram.
[0050] See Figure 3 The figure is a schematic diagram of a temperature detection circuit for another power device provided in an embodiment of this application.
[0051] The temperature detection circuit for the power device provided in this application includes a comparison circuit comprising a second comparator U2, a third comparator U3, and a fourth comparator U4; and an isolation circuit comprising a first isolation capacitor C2 and a second isolation capacitor C3.
[0052] The temperature sensor and filter circuit are not described in detail in this embodiment; please refer to [link to relevant documentation]. Figure 2 The corresponding description.
[0053] The first input terminal of the second comparator U2 and the second input terminal of the third comparator U3 are connected to the output terminal of the temperature sensor. The second input terminal of the second comparator U2 and the first input terminal of the third comparator U3 are connected to the reference voltage. The output terminal of the second comparator U2 is connected to the first input terminal of the fourth comparator U4 through the first isolation capacitor C2. The output terminal of the third comparator U3 is connected to the second input terminal of the fourth comparator U4 through the second isolation capacitor C3. The output terminal of the fourth comparator U4 is connected to the controller 30.
[0054] Since the reference voltage is a triangular wave reference voltage, the output signal Vout-P of the second comparator U2 is a square wave signal. Similarly, the output signal Vout-N of the third comparator U3 is a square wave signal. Vout-P and Vout-N are a set of mutually inverted PWM signals.
[0055] The signal Vout-P1, isolated by the first isolation capacitor C2, is also a square wave signal. The signal Vout-N1, isolated by the second isolation capacitor C3, is also a square wave signal. Vout-P1 and Vout-N1 are also a pair of PWM signals that are opposite to each other.
[0056] The output signal Vout of the fourth comparator U4 is also a square wave signal, i.e., a PWM signal.
[0057] It should be understood that the controller 30 samples a square wave signal, and the temperature is identified by the duty cycle of the sampled square wave signal.
[0058] See Figure 4 The figure is a schematic diagram of a temperature detection circuit for another power device provided in an embodiment of this application.
[0059] The temperature detection circuit for the power device provided in this application embodiment, the controller 30 is also used to provide operating power to the comparator circuit 10, the isolation circuit 20 and the temperature sensor 100.
[0060] Since the temperature sensor, comparator circuit, and isolation circuit require a power supply to operate, in order to simplify the circuit connections, the controller can be used directly to provide power to the temperature sensor, comparator circuit, and isolation circuit, eliminating the need for a separate power supply and thus simplifying the circuit design.
[0061] Based on the temperature detection circuit of the power device provided in the above embodiments, this application also provides a power device, which will be described in detail below with reference to the accompanying drawings.
[0062] See Figure 5 This figure is a schematic diagram of a power device provided in an embodiment of this application.
[0063] The power device provided in this application includes a power device 1000 and a temperature detection circuit 2000 described in the above embodiments;
[0064] Temperature detection circuit 2000 is used to detect the temperature of power device 1000.
[0065] The power device provided in this application embodiment allows for temperature detection of the power device. The temperature sensor can be directly attached to the surface of the power device's package to directly sense its temperature. Furthermore, a comparator circuit is used for analog-to-digital conversion, eliminating the need for an analog-to-digital converter (ADC) and saving costs. Additionally, an isolation circuit is used for signal isolation, protecting subsequent circuits, such as the controller. Since the temperature sensor is in direct contact with the power device, the detection results are accurate. Moreover, when the power device includes multiple power devices, multiple temperature sensors are correspondingly included. Even with a large number of power devices, the temperature sensor, being attached to the power device, does not occupy space, thus reducing the overall size of the power device.
[0066] It should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.
[0067] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims
1. A temperature detection circuit for a power device, characterized in that, include: Temperature sensor, comparator circuit, and isolation circuit; The temperature sensor is packaged as a surface mount device and is attached to the surface of the package of the power device. The output terminal of the temperature sensor is connected to the first input terminal of the comparator circuit, and the second input terminal of the comparator circuit is connected to the reference voltage. The comparison circuit is used to convert the analog voltage signal representing temperature output by the temperature sensor into a digital signal and send it to the input terminal of the isolation circuit.
2. The temperature detection circuit according to claim 1, characterized in that, Also includes: Controller; The comparison circuit includes a first comparator; the isolation circuit includes an isolation transformer; The output terminal of the temperature sensor is connected to the first input terminal of the first comparator, and the second input terminal of the first comparator is connected to the reference voltage; the output terminal of the first comparator is connected to the first terminal of the primary winding of the isolation transformer, the second terminal of the primary winding of the isolation transformer is grounded, the first terminal of the secondary winding of the isolation transformer is connected to the controller, and the second terminal of the secondary winding of the isolation transformer is grounded.
3. The temperature detection circuit according to claim 1, characterized in that, Also includes: Controller; The comparison circuit includes a second comparator, a third comparator, and a fourth comparator; the isolation circuit includes a first isolation capacitor and a second isolation capacitor. The first input terminal of the second comparator and the second input terminal of the third comparator are connected to the output terminal of the temperature sensor. The second input terminal of the second comparator and the first input terminal of the third comparator are connected to the reference voltage. The output terminal of the second comparator is connected to the first input terminal of the fourth comparator through the first isolation capacitor. The output terminal of the third comparator is connected to the second input terminal of the fourth comparator through the second isolation capacitor. The output terminal of the fourth comparator is connected to the controller.
4. The temperature detection circuit according to any one of claims 1-3, characterized in that, Also includes: Filtering circuit; The output of the temperature sensor is connected to the first input of the comparator circuit via the filter circuit.
5. The temperature detection circuit according to any one of claims 1-3, characterized in that, The reference voltage is a triangular wave reference voltage.
6. The temperature detection circuit according to claim 5, characterized in that, The digital signal output by the isolation circuit is a pulse width modulation signal.
7. The temperature detection circuit according to any one of claims 1-3, characterized in that, The power device is packaged in at least one of the following: TPAK package, TO-247 package, DPAK package, or D... 2 PAK package.
8. The temperature detection circuit according to claim 1, characterized in that, Also includes: Controller; The output of the isolation circuit is connected to the controller; The controller is also used to provide operating power to the comparator circuit, the isolation circuit, and the temperature sensor.
9. The temperature detection circuit according to any one of claims 1-3, characterized in that, The comparison circuit and the isolation circuit are integrated inside the motor control chip.
10. A power device, characterized in that, Includes power devices and the temperature detection circuit according to any one of claims 1-9; The temperature detection circuit is used to detect the temperature of the power device.