Heating current detection circuit

Abstract

The embodiment of the invention provides a heating current detection circuit. The circuit comprises an amplification chip, a first resistor, a second resistor, a chip power supply module and a first output module, a first end of the first resistor is connected to a first signal end, and a second end of the first resistor is connected to a first input end of the amplification chip; a first end of the second resistor is connected to a second signal end, and a second end of the second resistor is connected to a second input end of the amplification chip; the chip power supply module is connected to the power supply end of the amplification chip; the output end of the amplification chip is connected to the first output module, and the first output module is connected to the MCU. In the embodiment of the invention, the first resistor and the second resistor can play a role in current limiting, so that overlarge current flowing into the amplification chip caused by overlarge sampling voltage and heating voltage is avoided, and the amplification chip is prevented from being damaged.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of automobile technology, and in particular to a heating current detection circuit. Background Art

[0002] With the advancement of automobile manufacturing technology, users have higher and higher requirements for automobile comfort. As an important part of the car, the seat is the main contact point between the driver and the passenger and the car. Seats with heating function can improve the driving and riding experience.

[0003] The main consideration for seat heating performance is the temperature of the seat. Too high or too low a seat temperature will affect the user's experience. In a seat heating system, the seat is usually heated by a seat heating circuit to control the seat temperature within the temperature range required by the user.

[0004] In the heating current detection circuit in the prior art, it is easy for an excessive current to flow into the amplifier chip, thereby causing damage to the amplifier chip. Summary of the invention

[0005] In view of this, an embodiment of the present application provides a heating current detection circuit for preventing damage to the amplifier chip.

[0006] A first aspect provides a heating current detection circuit, comprising: an amplifier chip, a first resistor, a second resistor, a chip power supply module and a first output module;

[0007] The first end of the first resistor is connected to the first signal end, and the second end of the first resistor is connected to the first input end of the amplifier chip; the first end of the second resistor is connected to the second signal end, and the second end of the second resistor is connected to the second input end of the amplifier chip; the chip power supply module is connected to the power supply end of the amplifier chip; the output end of the amplifier chip is connected to the first output module, and the first output module is connected to the integrated circuit chip;

[0008] The chip power supply module is used to supply power to the amplifier chip;

[0009] The amplifier chip is used to amplify the voltage drop between the sampling voltage inputted from the first input terminal and the heating voltage inputted from the second input terminal, so as to output the amplified voltage drop;

[0010] The first output module is used to output a first output voltage to the integrated circuit chip according to the amplified voltage drop voltage, so that the integrated circuit chip generates a heating current according to the first output voltage.

[0011] In a possible implementation, the heating current detection circuit further includes: a first capacitor;

[0012] A first terminal of the first capacitor is connected to the first input terminal, and a second terminal of the first capacitor is connected to the second input terminal.

[0013] In a possible implementation, the heating current detection circuit further includes: a second output module, and the output end of the amplifier chip is also connected to the second output module;

[0014] The second output module is used to output a second output voltage according to the amplified voltage drop voltage.

[0015] In a possible implementation, the first output module includes: a third resistor;

[0016] A first end of the third resistor is connected to the output end, a second end of the third resistor is connected to a first output node, and the first output node is connected to the integrated circuit chip.

[0017] In a possible implementation, the first output module further includes: a second capacitor;

[0018] A first terminal of the second capacitor is connected to the first voltage terminal, and a second terminal of the second capacitor is connected to the first output node.

[0019] In a possible implementation, the first output module further includes: a third capacitor;

[0020] A first terminal of the third capacitor is connected to the first voltage terminal, and a second terminal of the third capacitor is connected to the output terminal.

[0021] In a possible implementation, the second output module further includes: a fourth resistor;

[0022] A first end of the fourth resistor is connected to the output end, and a second end of the fourth resistor is connected to the second output node.

[0023] In a possible implementation, the second output module further includes: a fifth resistor;

[0024] A first end of the fifth resistor is connected to the output end, and a second end of the fifth resistor is connected to the first voltage end.

[0025] In a possible implementation, the second output module further includes: a fourth capacitor;

[0026] A first terminal of the fourth capacitor is connected to the second output node, and a second terminal of the fourth capacitor is connected to the first voltage terminal.

[0027] In a possible implementation, the chip power supply module includes: a magnetic bead, a fifth capacitor and a sixth capacitor;

[0028] The first end of the magnetic bead is connected to the second voltage end, and the second end of the magnetic bead is connected to the third output node;

[0029] A first end of the fifth capacitor is connected to the third output node, and a second end of the fifth capacitor is connected to the first voltage end;

[0030] A first end of the sixth capacitor is connected to the third output node, and a second end of the sixth capacitor is connected to the first voltage end;

[0031] The third output node is connected to a power supply terminal of the amplifier chip.

[0032] In the technical solution provided in the embodiment of the present application, the heating circuit detection circuit includes an amplifier chip, a first resistor, a second resistor, a chip power supply module and a first output module. The chip power supply module is used to power the amplifier chip. The amplifier chip is used to amplify the voltage drop between the sampling voltage input at the first input end and the heating voltage input at the second input end to output the amplified voltage drop. The first output module is used to output a first output voltage to the integrated circuit chip according to the amplified voltage drop, so that the integrated circuit chip generates a heating current according to the first output voltage. In the embodiment of the present application, the first resistor and the second resistor can play a current limiting role, avoiding excessive current flowing into the amplifier chip due to excessive sampling voltage and heating voltage, thereby avoiding damage to the amplifier chip. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0034] Figure 1 A schematic diagram of the structure of a heating current detection circuit provided in an embodiment of the present application;

[0035] Figure 2 A schematic diagram of the structure of a chip power supply module provided in an embodiment of the present application. DETAILED DESCRIPTION

[0036] In order to better understand the technical solution of the present application, the embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0037] It should be clear that the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0038] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. The singular forms "a", "said" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings.

[0039] It should be understood that the term "and / or" used in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0040] Figure 1 A schematic diagram of a heating current detection circuit provided in an embodiment of the present application is shown in FIG. Figure 2 A schematic diagram of the structure of a chip power supply module provided in an embodiment of the present application is shown in FIG. Figure 1 and Figure 2 As shown, the heating current detection circuit includes: an amplifier chip, a first resistor R1, a second resistor R2, a chip power supply module and a first output module. The first end of the first resistor R1 is connected to the first signal end, and the second end of the first resistor R1 is connected to the first input end IN+ of the amplifier chip; the first end of the second resistor R2 is connected to the second signal end, and the second end of the second resistor R2 is connected to the second input end IN- of the amplifier chip; the chip power supply module is connected to the power supply end of the amplifier chip; the output end OUT of the amplifier chip is connected to the first output module, and the first output module is connected to the integrated circuit chip.

[0041] The chip power supply module is used to power the amplifier chip; the amplifier chip is used to amplify the voltage drop between the sampling voltage input at the first input terminal and the heating voltage input at the second input terminal to output the amplified voltage drop; the first output module is used to output the first output voltage MCU_HEAT1_ADC to the integrated circuit chip according to the amplified voltage drop voltage, so that the integrated circuit chip can generate a heating current according to the first output voltage MCU_HEAT1_ADC.

[0042] In the embodiment of the present application, the heating current detection circuit further includes: a first capacitor C1, a first end of the first capacitor C1 is connected to the first input end IN+, and a second end of the first capacitor C1 is connected to the second input end IN-.

[0043] like Figure 1 As shown, the ground terminal GND of the amplifier chip is connected to the first voltage terminal, and the reference terminal REF of the amplifier chip is connected to the first voltage terminal. As an optional solution, the amplifier chip may include an amplifier A, a sixth resistor R11, a seventh resistor R12, an eighth resistor R13 and a ninth resistor R14. The first end of the sixth resistor R11 is connected to the first input terminal IN+, the second end of the sixth resistor R11 is connected to the positive input terminal of the amplifier A, the first end of the seventh resistor R12 is connected to the positive input terminal of the amplifier A, the second end of the seventh resistor R12 is connected to the reference terminal REF, the first end of the eighth resistor R13 is connected to the second input terminal IN-, the second end of the eighth resistor R13 is connected to the negative input terminal of the amplifier A, the first end of the ninth resistor R14 is connected to the negative input terminal of the amplifier A, the second end of the ninth resistor R14 is connected to the output terminal OUT, and the output terminal of the amplifier A is connected to the output terminal OUT.

[0044] like Figure 1 As shown, pin 1 of the amplifier chip is the reference terminal REF, pin 2 of the amplifier chip is the ground terminal GND, pin 3 of the amplifier chip is the power supply terminal V+, pin 4 of the amplifier chip is the first input terminal IN+, and pin 5 of the amplifier chip is the second input terminal IN-.

[0045] like Figure 1 As shown, the first signal terminal is used to input the sampling voltage HEAT1_SAMPLY, and the second signal terminal is used to input the heating voltage HEAT1+. In the embodiment of the present application, as an optional solution, the heating voltage output circuit includes a sampling resistor, the first signal terminal and the second signal terminal are respectively connected to the two ends of the sampling resistor, the first signal terminal can be used to collect the sampling voltage HEAT1_SAMPLY at one end of the sampling resistor, and the second signal terminal is used to collect the heating voltage HEAT1+ at the other end of the sampling resistor.

[0046] In the embodiment of the present application, the heating current detection circuit further includes: a second output module, the output terminal OUT of the amplifier chip is also connected to the second output module. The second output module is used to output a second output voltage HEAT1_comparator according to the amplified voltage drop voltage.

[0047] like Figure 1 As shown, the first output module includes: a third resistor R3, a first end of the third resistor R3 is connected to the output end OUT, a second end of the third resistor R3 is connected to the first output node TP1, and the first output node TP1 is connected to the integrated circuit chip.

[0048] As an optional solution, the first output module further includes: a second capacitor C2, a first end of the second capacitor C2 is connected to the first voltage terminal IN+, and a second end of the second capacitor C2 is connected to the first output node TP1.

[0049] As an optional solution, the first output module further includes: a third capacitor C3, a first end of the third capacitor C3 is connected to the first voltage terminal IN+, and a second end of the third capacitor C3 is connected to the output terminal OUT.

[0050] like Figure 1 As shown, the second output module further includes: a fourth resistor R4, a first end of the fourth resistor R4 is connected to the output end OUT, and a second end of the fourth resistor R4 is connected to the second output node TP2.

[0051] As an optional solution, the second output module further includes: a fifth resistor R5, a first end of the fifth resistor R5 is connected to the output end OUT, and a second end of the fifth resistor R5 is connected to the first voltage end IN+.

[0052] As an optional solution, the second output module further includes: a fourth capacitor C4, a first end of the fourth capacitor C4 is connected to the second output node TP4, and a second end of the fourth capacitor C4 is connected to the first voltage terminal IN+.

[0053] like Figure 2 As shown, the chip power supply module includes: a magnetic bead FB1, a fifth capacitor C5 and a sixth capacitor C6. The first end of the magnetic bead FB1 is connected to the second voltage terminal U1, and the second end of the magnetic bead FB1 is connected to the third output node TP3; the first end of the fifth capacitor C5 is connected to the third output node TP3, and the second end of the fifth capacitor C5 is connected to the first voltage terminal; the first end of the sixth capacitor C6 is connected to the third output node TP3, and the second end of the sixth capacitor C6 is connected to the first voltage terminal; the third output node TP3 is connected to the power supply terminal V+ of the amplifier chip.

[0054] In the present application embodiment, for example, Figure 1 and Figure 2 As shown, the first voltage terminal can be the ground terminal GND, the ground terminal of the amplifier chip is connected to the ground terminal GND, the reference terminal REF of the amplifier chip is connected to the ground terminal GND, the second end of the fifth resistor R5 is connected to the ground terminal GND, the second end of the fourth capacitor C4 is connected to the ground terminal GND, the second end of the fifth capacitor C5 is connected to the ground terminal GND, and the second end of the sixth capacitor C6 is connected to the ground terminal GND.

[0055] As an optional solution, the integrated circuit chip may include a microcontroller unit (MCU). In the embodiment of the present application, the integrated circuit chip is described as an MCU.

[0056] Combine the following Figure 1 and Figure 2 , the working principle of the heating current detection circuit provided in the embodiment of the present application is described in detail.

[0057] In the chip power supply module, the second voltage terminal U1 can provide a second voltage, for example, the second voltage can be 3.3V, then the power supply voltage SAMPLE_VDD of the third output node TP3 is the second voltage that can be provided by the second voltage terminal U1. The magnetic bead FB1 can eliminate high-frequency noise in the circuit. The fifth capacitor C5 and the sixth capacitor C6 can filter the power supply voltage SAMPLE_VDD so that the power supply voltage SAMPLE_VDD is maintained at the second voltage, that is, the power supply voltage SAMPLE_VDD is maintained at 3.3V, so that the power supply voltage SAMPLE_VDD is more stable and the waveform of the power supply voltage SAMPLE_VDD is better. The third output node TP3 outputs the power supply voltage SAMPLE_VDD to the power supply terminal V+ of the amplifier chip to power the amplifier chip. As an optional solution, when the entire seat circuit fails, the magnetic beads can be removed from the chip power supply module. At this time, the second voltage terminal U1 and the third output node TP3 in the chip power supply module are disconnected, and the chip power supply module no longer supplies power to the amplifier chip. At this time, if the fault of the circuit other than the heating current detection circuit in the seat circuit is eliminated, it is determined that the heating current detection circuit has failed, thereby achieving the purpose of quickly troubleshooting.

[0058] The first signal terminal inputs the sampling voltage HEAT1_SAMPLY to the first input terminal IN+ of the amplifier chip, and the second signal terminal inputs the heating voltage HEAT1+ to the second input terminal IN- of the amplifier chip. The amplifier chip amplifies the voltage drop between the sampling voltage HEAT1_SAMPLY and the heating voltage HEAT1+, and outputs the amplified voltage drop through the output terminal OUT of the amplifier chip, wherein the voltage drop is the difference between the sampling voltage HEAT1_SAMPLY and the heating voltage HEAT1+.

[0059] The first resistor R1 can limit the voltage of the first input terminal of the amplifier chip, and the second resistor R2 can limit the voltage of the second input terminal of the amplifier chip, thereby avoiding excessive current flowing into the amplifier chip due to excessive sampling voltage HEAT1_SAMPLY and heating voltage HEAT1+, thereby avoiding damage to the amplifier chip. In order to avoid affecting the amplification factor of the amplifier chip, the resistance values ​​of the first resistor R1 and the second resistor R2 can be set to smaller resistance values. For example, the first resistor R1 and the second resistor R2 can both be selected to have a resistance value of less than 50Ω.

[0060] The first output module can output the first output voltage MCU_HEAT1_ADC to the MCU according to the amplified voltage drop. Specifically, the voltage of the output terminal OUT of the amplifier chip is the amplified voltage drop, that is, the voltage of pin 6 is the amplified voltage drop, and the MCU reads the voltage of the first output node TP1 to obtain the first output voltage MCU_HEAT1_ADC. In the first output module, the third resistor R3 can play a current limiting role, thereby achieving the purpose of protecting the MCU; the third capacitor C3 is an optional device, and the third capacitor C3 can perform voltage stabilization and filtering on the amplified voltage drop; the second capacitor C2 can perform voltage stabilization and filtering on the first output voltage MCU_HEAT1_ADC.

[0061] Then, the MCU divides the first output voltage MCU_HEAT1_ADC by the amplification factor to obtain a voltage difference; divides the voltage difference by the resistance of the pre-stored sampling resistor to obtain a heating current; determines whether the heating current is greater than a preset threshold value, and if it is determined that the heating current is less than or equal to the preset threshold value, it is determined that the heating is normal; if it is determined that the heating current is greater than the preset threshold value, it is determined that the heating is overcurrent. In the embodiment of the present application, the heating current can be the current of the heating wire of the seat, and the current state of the heating wire can be effectively detected by the heating current detection circuit. After determining that the heating is overcurrent, the subsequent software and hardware protection can be used to avoid long-term heating overcurrent.

[0062] The second output module outputs the second output voltage HEAT1_comparator according to the amplified voltage drop. Specifically, the voltage of the output terminal OUT of the amplifier chip is the amplified voltage drop, that is, the voltage of pin 6 is the amplified voltage drop, and the hardware protection circuit reads the voltage of the second output node TP2 to obtain the second output voltage HEAT1_comparator. In the second output module, the fourth resistor R4 can play a current limiting role, thereby achieving the purpose of protecting the MCU; the fifth resistor R5 is an optional device, and the fifth resistor R5 can clamp the amplified voltage drop, or it can be said that the fifth resistor R5 can stabilize the amplified voltage drop; the fourth capacitor C4 can stabilize and filter the second output voltage HEAT1_comparator. In the embodiment of the present application, as an optional solution, the second output voltage HEAT1_comparator can be used for hardware circuit protection, so that the hardware protection circuit can perform hardware circuit protection according to the second output voltage HEAT1_comparator.

[0063] In the technical solution provided in the embodiment of the present application, the heating circuit detection circuit includes an amplifier chip, a first resistor, a second resistor, a chip power supply module and a first output module. The chip power supply module is used to power the amplifier chip. The amplifier chip is used to amplify the voltage drop between the sampling voltage input at the first input end and the heating voltage input at the second input end to output the amplified voltage drop. The first output module is used to output a first output voltage to the MCU according to the amplified voltage drop voltage, so that the MCU can generate a heating current according to the first output voltage. In the embodiment of the present application, the first resistor and the second resistor can play a current limiting role, avoiding excessive current flowing into the amplifier chip due to excessive sampling voltage and heating voltage, thereby avoiding damage to the amplifier chip.

[0064] In the technical solution provided in the embodiment of the present application, magnetic beads are arranged in the chip power supply module. When the entire seat circuit fails, the magnetic beads can be removed from the chip power supply module. At this time, if the fault of the circuit other than the heating current detection circuit in the seat circuit is eliminated, it is determined that the heating current detection circuit has failed, thereby achieving the purpose of quickly troubleshooting.

[0065] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. A heating current detection circuit, characterized in that: include: Amplifying chip, a first resistor, a second resistor, a chip power supply module and a first output module; The first end of the first resistor is connected to the first signal end, and the second end of the first resistor is connected to the first input end of the amplifier chip; the first end of the second resistor is connected to the second signal end, and the second end of the second resistor is connected to the second input end of the amplifier chip; the chip power supply module is connected to the power supply end of the amplifier chip; the output end of the amplifier chip is connected to the first output module, and the first output module is connected to the integrated circuit chip; The chip power supply module is used to supply power to the amplifier chip; The amplifier chip is used to amplify the voltage drop between the sampling voltage inputted from the first input terminal and the heating voltage inputted from the second input terminal, so as to output the amplified voltage drop; The first output module is used to output a first output voltage to the integrated circuit chip according to the amplified voltage drop voltage, so that the integrated circuit chip generates a heating current according to the first output voltage.

2. The circuit according to claim 1, characterized in that The heating current detection circuit further includes: a first capacitor; A first terminal of the first capacitor is connected to the first input terminal, and a second terminal of the first capacitor is connected to the second input terminal.

3. The circuit according to claim 1, characterized in that The heating current detection circuit further includes: a second output module, and the output end of the amplifier chip is also connected to the second output module; The second output module is used to output a second output voltage according to the amplified voltage drop voltage.

4. The circuit according to claim 1, characterized in that The first output module includes: a third resistor; A first end of the third resistor is connected to the output end, a second end of the third resistor is connected to a first output node, and the first output node is connected to the integrated circuit chip.

5. The circuit according to claim 4, characterized in that The first output module further includes: a second capacitor; A first terminal of the second capacitor is connected to the first voltage terminal, and a second terminal of the second capacitor is connected to the first output node.

6. The circuit according to claim 4 or 5, characterized in that The first output module further includes: a third capacitor; A first terminal of the third capacitor is connected to the first voltage terminal, and a second terminal of the third capacitor is connected to the output terminal.

7. The circuit according to claim 3, characterized in that The second output module further includes: a fourth resistor; A first end of the fourth resistor is connected to the output end, and a second end of the fourth resistor is connected to the second output node.

8. The circuit according to claim 7, characterized in that The second output module further includes: a fifth resistor; A first end of the fifth resistor is connected to the output end, and a second end of the fifth resistor is connected to the first voltage end.

9. The circuit according to claim 8, characterized in that The second output module further includes: a fourth capacitor; A first terminal of the fourth capacitor is connected to the second output node, and a second terminal of the fourth capacitor is connected to the first voltage terminal.

10. The circuit according to claim 1, characterized in that The chip power supply module includes: a magnetic bead, a fifth capacitor and a sixth capacitor; The first end of the magnetic bead is connected to the second voltage end, and the second end of the magnetic bead is connected to the third output node; A first end of the fifth capacitor is connected to the third output node, and a second end of the fifth capacitor is connected to the first voltage end; A first end of the sixth capacitor is connected to the third output node, and a second end of the sixth capacitor is connected to the first voltage end; The third output node is connected to a power supply terminal of the amplifier chip.

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