Chip protection circuit, controller and vehicle

Abstract

The invention relates to a chip protection circuit, a controller and a vehicle, and the circuit comprises a first external diode and a second external diode which are connected with the input pin of a chip, and the cathode of the first external diode is connected to the external power supply end of the chip. An anode of the first external diode is respectively connected with an input pin of the chip and a cathode of the second external diode, the first external diode is conducted when an input voltage of the chip is greater than a first preset voltage, and the input voltage is clamped at a sum value of the first preset voltage and a forward conduction voltage of the first external diode; the anode of the second external diode is grounded, the second external diode is conducted when the input voltage is smaller than the second preset voltage, and the input voltage is clamped at the reverse conduction voltage value of the second external diode. Therefore, the problems that a simple signal processing circuit can only restrain part of interference, the chip cannot be protected in the case of overvoltage and negative voltage, and the chip is damaged are solved, and the diode can protect the chip from being damaged in the case of overvoltage and negative voltage.

Description

Technical Field

[0001] The present application relates to the field of chip protection technology, and in particular to a chip protection circuit, a controller, and a vehicle. Background Art

[0002] In the field of automotive electronic control systems, microcontrollers (MCUs), with their powerful logical computing capabilities, high integration, and programmability, have become the core components of various controllers. Currently, the signal processing flow for these control systems typically follows this process: external input signals, such as switching quantities, analog quantities, and frequency quantities, are first processed by simple signal circuits before being sent to the MCU's pins for sampling and further processing. This traditional signal processing approach met basic system requirements for a period of time and ensured the normal operation of the control system.

[0003] However, as system demands increase, the vehicle's electromagnetic environment deteriorates, leading to an increase in electrical faults. Simple signal processing circuits are now showing significant limitations. When the system encounters sudden overvoltage or negative pressure events, simple signal processing circuits can only partially suppress interference. In such situations, they fail to protect the chip, causing damage and ultimately failure of the entire control system. This severely impacts vehicle safety and reliability, posing an urgent need for solutions. Summary of the Invention

[0004] The present application provides a chip protection circuit, a controller, and a vehicle to solve the problem that a simple signal processing circuit can only suppress part of the interference and cannot protect the chip from sudden overvoltage and negative pressure conditions, resulting in chip damage.

[0005] A first aspect embodiment of the present application provides a chip protection circuit, comprising: a diode group connected to the input pin of the chip to be protected, the diode group comprising a first external diode and a second external diode, wherein the cathode of the first external diode is connected to the external power supply end of the chip to be protected, the anode of the first external diode is connected to the input pin of the chip to be protected and the cathode of the second external diode, respectively, the first external diode is used to turn on when the input voltage of the chip to be protected is greater than a first preset voltage, and clamp the input voltage to the sum of the first preset voltage and the forward conduction voltage of the first external diode; the anode of the second external diode is connected to the ground end, and the second external diode is used to turn on when the input voltage is less than the second preset voltage, and clamp the input voltage to the reverse conduction voltage value of the second external diode.

[0006] Optionally, when the input voltage of the chip to be protected is greater than the first preset voltage, the first diode inside the chip to be protected is turned off; when the input voltage of the chip to be protected is less than a second preset voltage, the second diode inside the chip to be protected is turned off.

[0007] Optionally, the power of the first external diode and the power of the second external diode are both greater than the larger power of the first diode and the second diode.

[0008] Optionally, the first external diode and the second external diode are both Schottky diodes.

[0009] Optionally, a conduction speed of the first external diode and a conduction speed of the second external diode are both greater than a faster conduction speed of the first diode and the second diode.

[0010] Optionally, when the input voltage of the chip to be protected is greater than the second preset voltage and the input voltage of the chip to be protected is less than the first preset voltage, the forward voltage of the first external diode is less than the forward voltage of the first diode, and the forward voltage of the second external diode is less than the forward voltage of the second diode.

[0011] Optionally, the above-mentioned chip protection circuit also includes: a filter circuit, the first end of the filter circuit is connected to the anode of the first external diode, and the second end of the filter circuit is connected to the connection node between the anode of the first external diode and the cathode of the second external diode.

[0012] Optionally, the filtering circuit includes: a resistor, a first capacitor and a second capacitor, one end of the resistor is connected to one end of the capacitor, one end of the resistor and one end of the first capacitor are both connected to the anode of the first external diode and the cathode of the second external diode, the other end of the first capacitor is connected to the anode of the second external diode, the other end of the resistor is connected to one end of the second capacitor, and the other end of the second capacitor is connected to the ground terminal of the chip to be protected.

[0013] A second aspect of the present application provides a controller, comprising the chip protection circuit as described in the above embodiment.

[0014] A third aspect of the present application provides a vehicle, comprising a controller as described in the above embodiment.

[0015] In the above embodiment, the cathode of a first external diode is connected to an external power supply terminal of the chip to be protected, and the anode of the first external diode is connected to an input pin of the chip to be protected and the cathode of a second external diode, respectively. The first external diode conducts when the input voltage of the chip to be protected is greater than a first preset voltage, clamping the input voltage to the sum of the first preset voltage and the forward conduction voltage of the first external diode. The anode of the second external diode is connected to a ground terminal, and the second external diode conducts when the input voltage is less than the second preset voltage, clamping the input voltage to the reverse conduction voltage of the second external diode. This solves the problem that a simple signal processing circuit can only suppress partial interference and cannot protect the chip from sudden overvoltage and negative voltage conditions, resulting in chip damage. By adding a diode to the signal processing circuit and utilizing the diode's unidirectional conductivity, the diode can clamp the voltage to the withstand voltage range of the chip pin in overvoltage and negative voltage conditions, thus preventing damage to the protection chip. Within the normal voltage range, the diode does not affect the signal processing circuit and signal acquisition function, and does not reduce acquisition accuracy.

[0016] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which: Figure 1 It is a schematic diagram of the structure of the chip protection circuit in the related art; Figure 2 A schematic diagram of the structure of a chip protection circuit provided according to an embodiment of the present application; Figure 3 This is a schematic diagram of a chip protection circuit design according to a specific embodiment of the present application; Figure 4 A schematic diagram of the structure of a controller provided according to an embodiment of the present application; Figure 5 A schematic structural diagram of a vehicle provided according to an embodiment of the present application. DETAILED DESCRIPTION

[0018] The following describes in detail embodiments of the present application, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0019] The following describes a chip protection circuit, controller, and vehicle according to an embodiment of the present application with reference to the accompanying drawings. In response to the problem that the simple signal processing circuit mentioned in the above background technology can only suppress part of the interference and cannot protect the chip in the face of sudden overvoltage and negative voltage conditions, resulting in chip damage, the present application provides a chip protection circuit, in which the cathode of a first external diode is connected to the external power supply terminal of the chip to be protected, the anode of the first external diode is connected to the input pin of the chip to be protected and the cathode of the second external diode respectively, the first external diode is turned on when the input voltage of the chip to be protected is greater than a first preset voltage, and the input voltage is clamped to the sum of the first preset voltage and the forward conduction voltage of the first external diode; the anode of the second external diode is connected to the ground terminal, the second external diode is turned on when the input voltage is less than the second preset voltage, and the input voltage is clamped to the reverse conduction voltage value of the second external diode. In this way, the problem that a simple signal processing circuit can only suppress part of the interference and cannot protect the chip in the face of sudden overvoltage and negative voltage, resulting in chip damage, is solved. A diode is added to the signal processing circuit. By utilizing the unidirectional conductivity of the diode, in the case of overvoltage and negative voltage, the diode can clamp the voltage to the withstand voltage range of the chip pin, protecting the chip from damage. In the normal voltage range, the diode does not affect the signal processing circuit and signal acquisition function, and will not reduce the acquisition accuracy.

[0020] A typical first-order RC processing circuit is as follows: Figure 1 As shown, the first-order RC processing circuit includes a circuit and a chip internal protection architecture. The chip internal protection architecture includes: diode D1 and diode D2. Diode D1 is connected to the external power supply terminal of the chip, such as VCC; diode D2 is connected to the ground supply terminal of the chip, such as GND. The protection principle of the first-order RC processing circuit is as follows: The unidirectional conductivity of the diode is used in combination with the connection method of the diode to form voltage clamping protection: When the circuit is over-voltage, the chip input voltage Vin> external power supply voltage VCC, diode D1 is turned on, and the chip pin input voltage is clamped at VCC + V D1 constant; When the circuit has a negative voltage, the chip's input voltage Vin is less than 0V, and the diode D2 is turned on. The diode D2 clamps the chip pin's input voltage at -V D2 constant.

[0021] If 0V<Vin<VCC, diodes D1 and D2 are cut off, and the chip pin input voltage = Vin. Within this range, the chip pin relies on its own diode protection to clamp the external input voltage Ui at -V D2 and VCC+V D1 The chip security is guaranteed.

[0022] Although the diodes D1 and D2 inside the chip can provide protection, due to the limited power of the diodes themselves, their conduction current is generally less than 3mA. Otherwise, the diodes will burn out, causing the chip pins to lose protection and be damaged. Therefore, there is a risk. Based on the typical circuit architecture, the current formula of the diodes is as follows: Diode D1 current: I D1 =(Ui-VCC-V D1 ) / R1, Ui>VCC Diode D2 current: I D2 =(Ui-V D2 ) / R1, Ui<0V Among them, R1, VCC, V D1 , V D2 They are all fixed values, only Ui is a variable. It can be seen from the formula that when Ui is too high or too low, the diode current will increase.

[0023] Since the external input voltage Ui comes from an external power supply and is transmitted through the wiring harness, interference may occur on Ui, and even surge high voltage and reverse negative voltage may occur. Resistor R1 and capacitor C1 form a low-pass filter circuit, which can only absorb high-frequency fluctuation components. It has no protection or attenuation effect on long-term surges and negative voltages of more than milliseconds. Then, the surge high voltage and reverse negative voltage directly act on diodes D1 and D2, turning on the corresponding diodes and forming diode current at the same time. The duration and amplitude of the overvoltage and negative voltage on Ui cannot be predicted, so it is very likely to cause excessive diode current, causing diode damage, and then causing the chip to lose protection and be broken down by overvoltage and negative voltage.

[0024] Therefore, the diodes integrated inside the chip do play a clamping protection function, but due to its own power limitations, it is risky to rely solely on the internal diodes of the chip to achieve protection. This application uses external diodes on the chip to achieve clamping protection, and higher-power diodes can be designed on the PCB to cope with more complex interference.

[0025] Specifically, Figure 2 A schematic diagram of a chip protection circuit provided in an embodiment of the present application.

[0026] like Figure 2As shown, the chip protection circuit 10 includes: a diode group connected to the input pin of the chip to be protected, the diode group including a first external diode D3 and a second external diode D4, wherein the cathode of the first external diode D3 is connected to the external power supply terminal of the chip to be protected, and the anode of the first external diode D3 is connected to the input pin of the chip to be protected and the cathode of the second external diode D4, respectively. The first external diode D3 is configured to be turned on when the input voltage Vin of the chip to be protected is greater than a first preset voltage, and clamp the input voltage Vin to the sum of the first preset voltage and the forward conduction voltage of the first external diode D3; the anode of the second external diode D4 is connected to the ground terminal GND, and the second external diode D4 is configured to be turned on when the input voltage Vin is less than the second preset voltage, and clamp the input voltage Vin to the reverse conduction voltage value of the second external diode D4.

[0027] The first preset voltage is the voltage VCC of the external power supply terminal, and the second preset voltage is 0V.

[0028] Optionally, in some embodiments, the chip protection circuit 10 further includes: a filter circuit, wherein a first end of the filter circuit is connected to the anode of the first external diode D3, and a second end of the filter circuit is connected to a connection node between the anode of the first external diode D3 and the cathode of the second external diode D4.

[0029] Optionally, in some embodiments, the filtering circuit includes: a resistor R1, a first capacitor C1 and a second capacitor C2, one end of the resistor R1 is connected to one end of the capacitor, one end of the resistor R1 and one end of the first capacitor C1 are both connected to the anode of the first external diode D3 and the cathode of the second external diode D4, the other end of the first capacitor C1 is connected to the anode of the second external diode D4, the other end of the resistor R1 is connected to one end of the second capacitor C2, and the other end of the second capacitor C2 is connected to the ground terminal GND of the chip to be protected.

[0030] It should be noted that if Figure 2 As shown, the first end of the filter circuit is one end of the resistor R1 and one end of the first capacitor C1, and the second end of the filter circuit is the other end of the first capacitor C1.

[0031] like Figure 2As shown, a diode group is added outside the input pin of the chip to be protected. The diode group consists of a first external diode D3 and a second external diode D4. The connection method of the diode group is the same as that of the first diode D1 and the second diode D2 inside the chip. The cathode of the first external diode D3 is connected to the external power supply end of the chip to be protected, and the anode of the first external diode D3 is connected to the input pin of the chip to be protected and the cathode of the second external diode D4 respectively. The anode of the second external diode D4 is connected to the ground terminal GND. The clamping protection principle is consistent with that of the first diode D1 and the second diode D2 inside the chip.

[0032] Specifically, the first external diode D3 is turned on when the input voltage Vin of the chip to be protected is greater than the first preset voltage VCC, clamping the input voltage Vin to the voltage between the first preset voltage VCC and the forward conduction voltage +V D3 The sum of .

[0033] The second external diode D4 is turned on when the input voltage Vin of the chip to be protected is less than the second preset voltage 0V, and clamps the input voltage Vin to the reverse conduction voltage value -V of the second external diode D4. D4 , that is to say: When overvoltage occurs in the circuit, the input voltage Vin of the chip to be protected is greater than the first preset voltage VCC, and the first external diode D3 is turned on to clamp the input voltage of the pin of the chip to be protected at VCC+V D3 constant.

[0034] When negative voltage appears in the circuit, the input voltage Vin of the chip to be protected is less than the second preset voltage 0V, and the second external diode D4 is turned on to clamp the input voltage of the pin of the chip to be protected at -V D4 constant.

[0035] Optionally, in some embodiments, when the input voltage Vin of the chip to be protected is greater than the second preset voltage and the input voltage Vin of the chip to be protected is less than the first preset voltage, the turn-on voltage of the first external diode D3 is less than the turn-on voltage of the first diode D1, and the turn-on voltage of the second external diode D4 is less than the turn-on voltage of the second diode D2.

[0036] It can be understood that when the second preset voltage 0V is less than the input voltage Vin and less than the first preset voltage VCC, the first external diode D3 and the second external diode D4 are not necessarily turned on. However, the turn-on voltage of the first external diode D3 and the second external diode D4 is smaller than the turn-on voltage of the first diode D1 and the second diode D2 inside the chip, so that the first external diode D3 and the second external diode D4 are both turned on within a smaller voltage range, thereby protecting the first diode D1 and the second diode D2.

[0037] Optionally, in some embodiments, when the input voltage Vin of the chip to be protected is greater than a first preset voltage, the first diode D1 inside the chip to be protected is cut off; when the input voltage Vin of the chip to be protected is less than a second preset voltage, the second diode D2 inside the chip to be protected is cut off.

[0038] It can be understood that the forward voltage of the first diode D1 and the second diode D2 inside the chip is 0.7V. If the forward voltage of the first external diode D3 and the second external diode D4 is smaller, the first external diode D3 and the second external diode D4 will be turned on first. The clamping voltage formed causes the first diode D1 and the second diode D2 to be non-conductive. That is, when an overvoltage occurs in the circuit, the first diode D1 cannot be turned on, and only the first external diode D3 is turned on. When a negative voltage occurs in the circuit, the second diode D2 cannot be turned on, and only the second external diode D4 is turned on. When an overvoltage or negative voltage interference occurs in the circuit, only the first external diode D3 or the second external diode D4 is turned on. The clamping protection function is completely implemented by the first external diode D3 and the second external diode D4, thereby avoiding damage to the diodes D1 and D2 inside the chip.

[0039] Optionally, in some embodiments, the power of the first external diode D3 and the power of the second external diode D4 are both greater than the larger power of the first diode D1 and the second diode D2.

[0040] Optionally, in some embodiments, the first external diode D3 and the second external diode D4 are both Schottky diodes.

[0041] Optionally, in some embodiments, the conduction speed of the first external diode D3 and the conduction speed of the second external diode D4 are both greater than the faster conduction speed of the first diode D1 and the second diode D2.

[0042] It is understandable that the first external diode D3 and the second external diode D4 are selected from diode models with higher power, that is, the power of the first external diode D3 and the power of the second external diode D4 are both greater than the larger power of the first diode D1 and the second diode D2, so that the first external diode D3 and the second external diode D4 can protect against interference with greater energy. If power diodes are selected, the conduction current can reach 2A.

[0043] The conduction speeds of the first external diode D3 and the second external diode D4 are both greater than the faster conduction speed of the first diode D1 and the second diode D2. The first external diode D3 and the second external diode D4 are selected to have faster conduction speeds to protect the chip from higher-frequency interference. For example, Schottky diodes have nanosecond-level conduction and recovery times, which react faster than the internal diodes of the chip and activate the clamping protection function earlier.

[0044] In the specific design, such as Figure 3 As shown in the figure, external diodes are used for clamping protection in the controller unit's input circuit. Diodes D400 and D401 replace the internal diodes on the microcontroller pins for clamping protection. Diodes D400 and D401 are Schottky diodes, which offer fast recovery and provide faster clamping protection. Furthermore, their breakover voltage is 0.3V, preventing overcurrent damage to the internal diodes on the microcontroller pins.

[0045] According to the chip protection circuit proposed in the embodiment of the present application, the cathode of a first external diode is connected to the external power supply terminal of the chip to be protected, and the anode of the first external diode is connected to the input pin of the chip to be protected and the cathode of the second external diode, respectively. The first external diode is turned on when the input voltage of the chip to be protected is greater than a first preset voltage, clamping the input voltage to the sum of the first preset voltage and the forward conduction voltage of the first external diode. The anode of the second external diode is connected to the ground terminal, and the second external diode is turned on when the input voltage is less than the second preset voltage, clamping the input voltage to the reverse conduction voltage of the second external diode. This solves the problem that a simple signal processing circuit can only suppress partial interference and cannot protect the chip in the face of sudden overvoltage and negative voltage conditions, resulting in chip damage. By adding a diode to the signal processing circuit and utilizing the unidirectional conductivity of the diode, the diode can clamp the voltage to the withstand voltage range of the chip pin in the case of overvoltage and negative voltage, thus preventing damage to the chip. Within the normal voltage range, the diode does not affect the signal processing circuit and signal acquisition function, and does not reduce acquisition accuracy.

[0046] The second embodiment of the present application provides a controller 20, such as Figure 4 As shown, it includes the chip protection circuit 10 according to the above embodiment.

[0047] A third embodiment of the present application provides a vehicle 30, such as Figure 5 As shown, it includes the controller 20 as described in the above embodiment.

[0048] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or N embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0049] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of technical features indicated. Thus, a feature specified as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of this application, "N" means at least two, for example, two, three, etc., unless otherwise specifically defined.

Claims

1. A chip protection circuit, characterized in that: include: A diode group connected to the input pin of the chip to be protected, the diode group including a first external diode and a second external diode, wherein: The cathode of the first external diode is connected to the external power supply terminal of the chip to be protected, and the anode of the first external diode is connected to the input pin of the chip to be protected and the cathode of the second external diode respectively. The first external diode is configured to be turned on when the input voltage of the chip to be protected is greater than a first preset voltage, and clamp the input voltage to the sum of the first preset voltage and the forward conduction voltage of the first external diode; The anode of the second external diode is connected to the ground terminal. The second external diode is used to conduct when the input voltage is less than a second preset voltage and clamp the input voltage at a reverse conduction voltage value of the second external diode.

2. The chip protection circuit according to claim 1, characterized in that: When the input voltage of the chip to be protected is greater than the first preset voltage, the first diode inside the chip to be protected is turned off; when the input voltage of the chip to be protected is less than the second preset voltage, the second diode inside the chip to be protected is turned off.

3. The chip protection circuit according to claim 2, characterized in that: The power of the first external diode and the power of the second external diode are both greater than the larger power of the first diode and the second diode.

4. The chip protection circuit according to claim 3, characterized in that: The first external diode and the second external diode are both Schottky diodes.

5. The chip protection circuit according to claim 3, characterized in that: The conduction speed of the first external diode and the conduction speed of the second external diode are both greater than the faster conduction speed of the first diode and the second diode.

6. The chip protection circuit according to claim 5, characterized in that: When the input voltage of the chip to be protected is greater than the second preset voltage and the input voltage of the chip to be protected is less than the first preset voltage, the forward voltage of the first external diode is less than the forward voltage of the first diode, and the forward voltage of the second external diode is less than the forward voltage of the second diode.

7. The chip protection circuit according to claim 6, characterized in that: Also includes: A filter circuit, wherein a first end of the filter circuit is connected to the anode of the first external diode, and a second end of the filter circuit is connected to a connection node between the anode of the first external diode and the cathode of the second external diode.

8. The chip protection circuit according to claim 7, characterized in that: The filtering circuit comprises: a resistor, a first capacitor, and a second capacitor, One end of the resistor is connected to one end of the capacitor, one end of the resistor and one end of the first capacitor are both connected to the anode of the first external diode and the cathode of the second external diode, the other end of the first capacitor is connected to the anode of the second external diode, the other end of the resistor is connected to one end of the second capacitor, and the other end of the second capacitor is connected to the ground terminal of the chip to be protected.

9. A controller, characterized in that: include: The chip protection circuit according to any one of claims 1 to 8.

10. A vehicle, characterized in that: include: The controller as claimed in claim 9.

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