Control circuit of vehicle-mounted high-side driving chip and chip protection device

Abstract

The utility model discloses a control circuit of a vehicle-mounted high-side driving chip and a chip protection device. The control circuit comprises a main control chip, a vehicle-mounted chip, a signal detection chip, a first switch element, a second switch element and a third switch element, the detection signal output end of the signal detection chip is electrically connected with the input end of the first switch element; the second output end of the first switch element is electrically connected with the second input end of the second switch element; the first output end of the first switch element is electrically connected with the input end of the third switch element; the fourth output end of the third switch element is electrically connected with the input end of the vehicle-mounted chip; the controlled end of the signal detection chip is electrically connected with the control end of the main control chip; and the enabling end of the main control chip is electrically connected with the first input end of the second switch element. The main control chip is monitored in real time through the signal detection chip, the abnormal data of the main control chip is prevented from influencing the post-stage load of the vehicle-mounted chip, and the data safety of the vehicle-mounted chip and the power distribution stability of the post-stage load are improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of automobile, especially a kind of control circuit and chip protection device of vehicle high side drive chip. BACKGROUND

[0002] With the continuous upgrading of automobile electronic and electrical architecture, gradually change from traditional distributed electronic and electrical architecture to new generation regional architecture, on the new regional architecture, more automobile electronic control unit needs to realize regional intelligent power distribution function, and intelligent power distribution function needs to realize current detection, I2T curve protection algorithm and other functions, to replace traditional physical fuse function. Among them, for the power distribution control of each important function area in automobile, higher functional safety level is needed to protect the chip function, to prevent data tampering.

[0003] At present, load power distribution control in market is usually realized by Efuse chip, however, due to sudden voltage fluctuation of vehicle-mounted product, MCU abnormal reset problem will occur, or enter into dead loop state, therefore, data protection is needed for Efuse chip register state, to avoid MCU abnormal reset problem or enter into dead loop state, and further cause Efuse chip post-stage important load power distribution abnormality, thereby causing major accident. SUMMARY

[0004] The utility model provides a kind of control circuit and chip protection device of vehicle high side drive chip, to realize the technical effect of improving the data security of Efuse chip register state and the power distribution stability and reliability of Efuse chip post-stage load.

[0005] In order to solve the above technical problems, the utility model embodiment provides a kind of control circuit of vehicle high side drive chip, including main control chip and vehicle chip, still including signal detection chip, first switching element, second switching element and third switching element;Wherein:

[0006] The first switching element has third input, first output and second output;

[0007] The second switching element has fifth output, first input and second input;

[0008] The third switching element has fourth input, third output and fourth output;

[0009] The detection signal output end of the signal detection chip is electrically connected with the third input of the first switching element;

[0010] The second output of the first switching element is electrically connected with the second input of the second switching element;

[0011] The first output terminal of the first switching element is electrically connected to the fourth input terminal of the third switching element;

[0012] The fifth output terminal of the second switching element is grounded;

[0013] The fourth output terminal of the third switch element is electrically connected to the input terminal of the vehicle-mounted chip;

[0014] The third output terminal of the third switching element is grounded;

[0015] The controlled end of the signal detection chip is electrically connected to the control end of the main control chip;

[0016] The enable terminal of the main control chip is electrically connected to the first input terminal of the second switch element.

[0017] The control circuit provided by the utility model includes a main control chip and an on-board chip, as well as a signal detection chip and a logic control circuit including three switch elements. Since the detection signal output end of the signal detection chip is electrically connected to the input end of the first switch element in the logic control circuit, and the enable end of the main control chip is electrically connected to the first input end of the second switch element in the logic control circuit, and the fourth output end of the third switch element in the logic control circuit is electrically connected to the input end of the on-board chip, the signal detection chip and the main control chip are electrically connected to the third switch element through the first switch element and the second switch element respectively, and the third switch element is electrically connected to the on-board chip, that is, the signal detection chip and the main control chip are electrically connected to the on-board chip through the three switch elements, and at the same time, the control end of the main control chip is electrically connected to the controlled end of the signal detection chip.

[0018] Therefore, when the main control chip sends a control signal to the first input terminal of the second switch element in the logic control circuit, the signal detection chip will simultaneously receive the detection signal from the main control chip through the controlled terminal and determine whether the main control chip is in an abnormal state based on the received detection signal. In other words, it will determine whether the control signal sent by the main chip to the second switch element is a control signal output under normal conditions based on the detection signal. If the signal detection chip determines that the main control chip is in an abnormal state based on the detection signal, the detection signal it outputs to the first switch element in the logic control circuit will, together with the control signal output by the main control chip, adjust the third switch element, thereby adjusting the state of the on-board chip, so that the register state of the on-board chip is adjusted to prohibit writing, thereby ensuring the latching function of important signals.

[0019] Through real-time monitoring of the master control chip by the signal detection chip, when the master control chip is abnormal, the signal detection chip output signal can be adjusted, so that the register state of the vehicle chip is adjusted accordingly, so as to avoid the abnormal data generated by the abnormal master control chip affecting the load distribution of the subsequent load to be protected by the vehicle chip, and improve the data security of the register state of the vehicle chip and the stability and reliability of the load distribution of the subsequent load of the vehicle chip.

[0020] As a preferred example, the first switch element is a triode or a MOS tube;

[0021] The second switch element is a triode or a MOS tube;

[0022] The third switch element is a triode or a MOS tube.

[0023] The three switch elements provided by the utility model can be triodes or MOS tubes. The detection signal and the control signal sent by the signal detection chip and the master control chip can control the voltage difference between the base and the emitter of the triode to control the signal conduction state of the three switch elements, or control the voltage difference between the gate and the source of the MOS tube to control the signal conduction state of the three switch elements. By controlling the signal conduction state of the three switch elements, the signal transmission state of the logic circuit containing the three switch elements can be adjusted. In the case where the master control chip is in an abnormal state, the conduction state of the three switch elements is controlled to ensure that the abnormal control signal sent by the master control chip will not be written into the vehicle chip, thereby improving the data security of the register state of the vehicle chip and the stability and reliability of the load distribution of the subsequent load to be protected by the vehicle chip.

[0024] As a preferred example, the first switch element is a PNP type triode, the second switch element is an NPN type triode, and the third switch element is an NPN type triode.

[0025] By adjusting the triode or MOS tube type of the three switch elements and the electrical connection mode of the three switch elements, the transmission control of the control signal sent by the master control chip and the detection signal sent by the signal detection chip can be realized, so as to ensure that the signals input to the vehicle chip through the three switch elements are normal signals, and abnormal signals are blocked from being input to the vehicle chip, thereby improving the data security of the vehicle chip and the detection efficiency and processing efficiency of the system for abnormal signals.

[0026] As a preferred example, it also includes a first input resistor; wherein:

[0027] One end of the first input resistor is electrically connected to the third input end of the first switch element, and the other end is electrically connected to the second output end of the first switch element.

[0028] By the first input resistor electrically connected between the input end of the first switch element and the second output end, the tiny current input to the first switch element is avoided to cause the first switch element to be adjusted to the conducting state, thereby affecting the data security and normal operation of the vehicle chip.

[0029] As a preferred example, a second input resistor is further included; wherein:

[0030] One end of the second input resistor is electrically connected to the fifth output end of the second switch element, and the other end is electrically connected to the first input end of the second switch element.

[0031] By the second input resistor electrically connected between the output end of the second switch element and the first input end, the tiny current input to the second switch element is avoided to cause the second switch element to be adjusted to the conducting state, thereby affecting the normal signal transmission of the second switch element and the data security of the vehicle chip.

[0032] As a preferred example, a third input resistor is further included; wherein:

[0033] One end of the third input resistor is electrically connected to the third output end of the third switch element, and the other end is electrically connected to the fourth input end of the third switch element.

[0034] By the third input resistor electrically connected between the output end of the third switch element and the fourth input end, the tiny current input to the third switch element is avoided to cause the third switch element to be adjusted to the conducting state, thereby affecting the normal signal transmission of the third switch element and the data security of the vehicle chip.

[0035] As a preferred example, a first resistor is further included; wherein:

[0036] One end of the first resistor is electrically connected to the fourth output end of the third switch element, and the other end is electrically connected to a constant voltage source.

[0037] The first resistor is electrically connected between the fourth output end of the third switch element, i.e., the collector of the third transistor, and the constant voltage source, which serves as the pull-up resistor of the third switch element, i.e., the third transistor, to improve the stability of the circuit and avoid the adverse effects of false operation on the vehicle chip.

[0038] As a preferred example, a second resistor is further included; wherein:

[0039] One end of the second resistor is electrically connected to the fourth output end of the third switch element, and the other end is electrically connected to the input end of the vehicle chip.

[0040] The second resistor is electrically connected to the fourth output end of the third switch element, i.e., the fourth triode, between the collector of the triode and the vehicle-mounted chip, and functions to limit the current and protect the input pin of the vehicle-mounted chip, thereby improving the safety and stability of the vehicle-mounted chip and the rear load to be protected by the vehicle-mounted chip, and ensuring the data safety of the register state of the vehicle-mounted chip and the unchangeability of the data stored in the vehicle-mounted chip.

[0041] As a preferred example, the signal detection chip is a watchdog chip.

[0042] The watchdog chip is a common hardware device in an embedded system, which functions to monitor the system running state and perform corresponding processing when a fault or an exception occurs, and in the utility model, as a signal detection chip, whether the system, i.e., the master control chip, is normally running is judged by checking whether a specific signal output by the master control chip is received within a preset time interval, so as to ensure the reliability and stability of the complete system running.

[0043] Correspondingly, the utility model embodiment further provides a kind of chip protection device of automobile distribution system, including the control circuit of vehicle-mounted high-side drive chip, signal switching module, current sampling resistance and load interface of any one described above;Wherein:

[0044] The input end of the signal switching module is electrically connected to the output end of the vehicle-mounted chip;

[0045] The sixth output end of the signal switching module is electrically connected to the constant voltage source through the current sampling resistance;

[0046] The seventh output end of the signal switching module is grounded through the load interface.

[0047] In order to further ensure the safety of the rear load of the vehicle-mounted chip, the utility model further electrically connects a signal switching module between the vehicle-mounted chip and the rear load, and the signal switching module is electrically connected to an external voltage source through a current sampling resistance, so as to ensure the safety and stability of the current output by the vehicle-mounted chip, improve the reliability and stability of the chip protection device, and also ensure the safety and stability of the load electrically connected to the signal switching module.

[0048] The rear power distribution load of the vehicle-mounted chip is protected once by the vehicle-mounted chip and the control circuit, and the signal switching module and the current sampling resistance cooperate to protect the load twice, so as to avoid power distribution abnormalities and also avoid the adverse effects caused by current abnormalities. BRIEF DESCRIPTION OF DRAWINGS

[0049] Figure 1 : the structure schematic view of one embodiment of the control circuit of vehicle-mounted high-side drive chip provided by the utility model;

[0050] Figure 2 Figure 1 is a structural schematic diagram of one embodiment of the chip protection device of the vehicle-mounted high-side drive chip provided by the present application;

[0051] Figure 3 Figure 2 is a circuit principle diagram of one embodiment of the control circuit of the vehicle-mounted high-side drive chip provided by the present application;

[0052] Among them, 101, main control chip; 102, signal detection chip; 103, first switching element; 104, second switching element; 105, third switching element; 106, vehicle-mounted chip; 107, signal switching module; 108, current sampling resistor; 109, load interface; 1, control end; 2, enable end; 3, controlled end; 4, detection signal output end; 5, third input end; 6, first output end; 7, second output end; 8, first input end; 9, second input end; 10, fifth output end; 11, fourth input end; 12, third output end; 13, fourth output end; 14, input end of vehicle-mounted chip; 15, output end of vehicle-mounted chip; 16, input end of signal switching module; 17, sixth output end; 18, seventh output end. DETAILED DESCRIPTION

[0053] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, 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 those skilled in the art without creative labor fall within the scope of protection of the present application.

[0054] Embodiment one

[0055] Please refer to Figure 1 Figure 1 is a structural schematic diagram of one embodiment of the control circuit of the vehicle-mounted high-side drive chip provided by the present application, comprising a main control chip 101 and a vehicle-mounted chip 106, further comprising a signal detection chip 102, a first switching element 103, a second switching element 104 and a third switching element 105; wherein:

[0056] The first switching element 103 has a third input end 5, a first output end 6 and a second output end 7;

[0057] The second switching element 104 has a fifth output end 10, a first input end 8 and a second input end 9;

[0058] The third switching element 105 has a fourth input end 11, a third output end 12 and a fourth output end 13;

[0059] The detection signal output end 4 of the signal detection chip 102 is electrically connected with the third input end 5 of the first switch element 103.

[0060] The second output end 7 of the first switch element 103 is electrically connected with the second input end 9 of the second switch element 104.

[0061] The first output end 6 of the first switch element 103 is electrically connected with the fourth input end 11 of the third switch element 105.

[0062] The fifth output end 10 of the second switch element 104 is grounded.

[0063] The fourth output end 13 of the third switch element 105 is electrically connected with the input end 14 of the vehicle-mounted chip 106.

[0064] The third output end 12 of the third switch element 105 is grounded.

[0065] The control end 3 of the signal detection chip 102 is electrically connected with the control end 1 of the master control chip 101.

[0066] The enable end 2 of the master control chip 101 is electrically connected with the first input end 8 of the second switch element 104.

[0067] The control circuit comprises the master control chip 101 and the vehicle-mounted chip 106, and the signal detection chip 102 and a logic control circuit comprising three switch elements. The detection signal output end 4 of the signal detection chip 102 is electrically connected with the input end 5 of the first switch element 103 in the logic control circuit, the enable end 2 of the master control chip 101 is electrically connected with the first input end 8 of the second switch element 104 in the logic control circuit, and the fourth output end 13 of the third switch element 105 in the logic control circuit is electrically connected with the input end 14 of the vehicle-mounted chip 106, so that the signal detection chip 102 and the master control chip 101 are electrically connected with the third switch element 105 through the first switch element 103 and the second switch element 104, the third switch element 105 is electrically connected with the vehicle-mounted chip 106, the signal detection chip 102 and the master control chip 101 are electrically connected with the vehicle-mounted chip 106 through the three switch elements, and the control end 1 of the master control chip 101 is in an electrical connection relationship with the control end 3 of the signal detection chip 102.

[0068] Therefore, when the master chip 101 sends a control signal to the first input end 8 of the second switch element 104 in the logic control circuit, the signal detection chip 102 receives a detection signal from the master chip 101 through the controlled end 3 synchronously, and determines whether the master chip 101 is in an abnormal state at this time according to the received detection signal, that is, whether the control signal sent by the master chip 101 to the second switch element 104 at this time is a control signal output in a normal state. When the signal detection chip 102 determines that the master chip 101 is in an abnormal state at this time, the detection signal output by the signal detection chip 102 to the first switch element 103 in the logic control circuit will be adjusted together with the control signal output by the master chip 101 to the third switch element 105, so as to adjust the state of the vehicle-mounted chip 106, so that the register state of the vehicle-mounted chip 106 is adjusted to be prohibited from being written, thereby ensuring the latch function of the important signal.

[0069] Through the real-time monitoring of the master chip 101 by the signal detection chip 102, when the master chip 101 generates an abnormality, the register state of the vehicle-mounted chip 106 can be adjusted by adjusting the signal output by the signal detection chip 102, so as to avoid the influence of abnormal data generated by the master chip 101 on the load distribution of the subsequent stage to be protected by the vehicle-mounted chip 106, and improve the data security of the register state of the vehicle-mounted chip 106 and the stability and reliability of the load distribution of the subsequent stage to be protected by the vehicle-mounted chip 106.

[0070] In the embodiment, the first switch element 103 is a triode or a MOS tube.

[0071] The second switch element 104 is a triode or a MOS tube.

[0072] The third switch element 105 is a triode or a MOS tube.

[0073] The three switch elements provided by the utility model can be triodes or MOS tubes. The detection signal and the control signal sent by the signal detection chip 102 and the master chip 101 can control the voltage difference between the base and the emitter of the triode, so as to control the signal conduction state of the three switch elements, or can control the voltage difference between the gate and the source of the MOS tube, so as to control the signal conduction state of the three switch elements. By controlling the signal conduction state of the three switch elements, the signal transmission state of the logic circuit containing the three switch elements can be adjusted, that is, the conduction state of the three switch elements is controlled when it is determined that the master chip 101 is in an abnormal state, so as to ensure that the abnormal control signal sent by the master chip 101 will not be written into the vehicle-mounted chip 106, thereby improving the data security of the register state of the vehicle-mounted chip 106 and the stability and reliability of the load distribution of the subsequent stage to be protected by the vehicle-mounted chip 106.

[0074] In this embodiment, if Figure 2 As shown, the first switching element 103 is Figure 2 The first transistor Q1 and the first input resistor electrically connected between the emitter and the base of the first transistor Q1, the second switch element 104 are shown. Figure 2 The second transistor Q2 and the third switch element 105 are shown Figure 2 The third transistor Q3, the first resistor electrically connected between the collector of Q3 and the external voltage source, and the first resistor electrically connected between the collector of the third transistor Q3 and the on-board chip are shown. Figure 2 A second resistor is shown between the eFuse chips.

[0075] Specifically, in this embodiment, the first switch element 103 is a PNP transistor, the second switch element 104 is an NPN transistor, and the third switch element 105 is an NPN transistor.

[0076] By adjusting the transistor or MOS tube type of the three switching elements and the electrical connection method of the three switching elements, the transmission control of the control signal issued by the main control chip 101 and the detection signal issued by the signal detection chip 102 can be achieved, ensuring that the signals input to the on-board chip 106 through the three switching elements are all normal signals, blocking abnormal signals from being input to the on-board chip 106, improving the data security of the on-board chip 106, and also improving the system's detection efficiency and processing efficiency of abnormal signals.

[0077] Furthermore, the control circuit of this embodiment further includes a first input resistor; wherein:

[0078] One end of the first input resistor is electrically connected to the third input end 5 of the first switch element 103 , and the other end of the first input resistor is electrically connected to the second output end 7 of the first switch element 103 .

[0079] By electrically connecting the first input resistor to the input terminal 5 and the second output terminal 7 of the first switching element 103, it is prevented that a small current is input into the first switching element 103, causing the first switching element 103 to be adjusted to the on state, thereby affecting the data security in the on-board chip 106 and the normal operation of the on-board chip 106.

[0080] Depend on Figure 2 It can be seen that the first switch element 103 includes a first transistor Q1 and Figure 2 As shown, the first input resistor is electrically connected between the emitter and the base of the first transistor Q1. Figure 2 As shown, the emitter of the first transistor Q1 also serves as the input terminal 5 of the first switch element 103 and the signal detection chip 102. Figure 2 The detection signal output terminal 4 of the watchdog chip is shown as Figure 2The OUT end is electrically connected, and the base of the first transistor Q1 is electrically connected with the second output end 7 of the first switch element 103 and the collector of the second transistor Q2 in the second switch element 104.

[0081] Since the first switch element 103 in the embodiment is a PNP type transistor, Figure 2 The current direction of the first transistor Q1 is from the emitter to the base. The basic condition for the conduction of the PNP type transistor is that the voltage (Veb) between the base (B) and the emitter (E) is less than the conduction voltage. The conduction voltage is between -0.6V and -0.7V in the normal operation state, so when the base voltage is about 0.7V lower than the emitter voltage, the first transistor Q1 provided in the embodiment, which is a PNP type transistor, will be turned on. In actual application, when the base (B) of the PNP type transistor is connected to a low level, the transistor will be in a conduction state, and the transistor will allow current to flow from the emitter to the collector.

[0082] In the embodiment, when the first transistor Q1 and the signal detection chip, i.e. Figure 2 The emitter of the OUT end of the watchdog chip, which is electrically connected, receives a high-level detection signal when the watchdog chip WD_OUT outputs a high level. Figure 2 When the first transistor Q1 of the first switch element 103 is in a conduction state, i.e., the first transistor Q1 allows current to flow from the emitter to the collector, i.e., current flows from the first switch element 103 to the third switch element 105.

[0083] Further, the control circuit in the embodiment further includes a second input resistor; wherein:

[0084] One end of the second input resistor is electrically connected with the fifth output end 10 of the second switch element 104, and the other end is electrically connected with the first input end 8 of the second switch element 104.

[0085] Through the second input resistor electrically connected between the output end 10 and the first input end 8 of the second switch element 104, it is avoided that a small current input to the second switch element 104 causes the second switch element 104 to be adjusted to a conduction state, which affects the normal signal transmission of the second switch element 104, and further affects the data security of the vehicle-mounted chip 106.

[0086] As shown in the figure, Figure 2 It can be seen that the second switch element 104 includes a second transistor Q2, and as shown in the figure, Figure 2 The base of the second transistor Q2 is electrically connected with the first input end 8 of the second switch element 104 and the enable end 2 of the MCU chip, i.e. Figure 2 The enable end 2 of the MCU chip, i.e. Figure 2The base of the first transistor Q1 is electrically connected to the EN end, and the emitter of the second transistor Q2 is grounded. Figure 2 The base of the first transistor Q1 is electrically connected to the EN end, and the emitter of the second transistor Q2 is grounded.

[0087] Since the second switch element 104 is an NPN transistor, the current of the second transistor Q2 flows from the collector to the emitter. The conduction of the NPN transistor involves the base (B), the collector (C) and the emitter (E), and the conduction condition is that the voltage between the base and the emitter (Vbe) is greater than the conduction voltage, which is between 0.6V and 0.7V in normal operation. Therefore, when the base voltage of the second transistor Q2 is higher than the emitter voltage and reaches the conduction voltage, a large current will flow between the collector and the emitter.

[0088] In this embodiment, when the second transistor Q2 and the main control chip 101 are in the conduction state, the base of the first transistor Q1 is electrically connected to the EN end of the MCU chip, and the control signal received by the base is high, that is, the MCU_EN output by the main control chip (MCU chip) is high. Figure 2 The base of the first transistor Q1 is electrically connected to the EN end of the MCU chip, and the control signal received by the base is high, that is, the MCU_EN output by the main control chip (MCU chip) is high. Figure 2 When the base of the first transistor Q1 is electrically connected to the EN end of the MCU chip, and the control signal received by the base is high, that is, the MCU_EN output by the main control chip (MCU chip) is high, and the collector of the second transistor Q2 is also in the conduction state, that is, the first transistor Q1 in the first switch element 103 is also in the conduction state, then the second switch element 104 is also in the conduction state. Figure 2 When the base of the first transistor Q1 is electrically connected to the EN end of the MCU chip, and the control signal received by the base is high, that is, the MCU_EN output by the main control chip (MCU chip) is high, and the collector of the second transistor Q2 is also in the conduction state, that is, the first transistor Q1 in the first switch element 103 is also in the conduction state, then the second switch element 104 is also in the conduction state.

[0089] In this embodiment, only when the second transistor Q2 included in the second switch element 104 is in the conduction state, the first transistor Q1 included in the first switch element 103 can be adjusted to be in the conduction state, that is, if the second transistor Q2 is in the cut-off state, the first transistor Q1 must be in the cut-off state; if the second transistor Q2 is in the conduction state, the first transistor Q1 may be in the conduction state or in the cut-off state. Whether the first transistor Q1 is in the conduction state or not needs to be referred to not only the conduction state of the second transistor Q2, but also the level of the detection signal output by the watchdog chip WD_OUT end. Therefore, the signal detection chip 102, that is, the watchdog chip can realize the adjustment of the conduction state of the first switch element 103 and the third switch element 105 in the logic control circuit. Figure 2 The signal detection chip 102, that is, the watchdog chip can realize the adjustment of the conduction state of the first switch element 103 and the third switch element 105 in the logic control circuit.

[0090] Further, the control circuit provided in the embodiment further comprises a third input resistor.

[0091] One end of the third input resistor is electrically connected to the third output end 12 of the third switch element 105, and the other end is electrically connected to the fourth input end 11 of the third switch element 105.

[0092] By the third input resistor electrically connected between the output end 12 and the fourth input end 11 of the third switch element 105, the third switch element 105 is prevented from being adjusted to the conducting state due to the input of a small current, which affects the normal signal transmission of the third switch element 105 and further affects the data security of the vehicle-mounted chip 106.

[0093] Further, the control circuit provided by the embodiment further comprises a first resistor, wherein:

[0094] One end of the first resistor is electrically connected to the fourth output end 13 of the third switch element 105, and the other end is electrically connected to the constant voltage source.

[0095] The first resistor is electrically connected between the fourth output end 13 of the third switch element 105, i.e., the collector of the third transistor, and the constant voltage source, which serves as the pull-up resistor of the third switch element 105, i.e., the third transistor, to improve the stability of the circuit and avoid the adverse effects of false operation on the vehicle-mounted chip 106.

[0096] Further, the control circuit provided by the embodiment further comprises a second resistor, wherein:

[0097] One end of the second resistor is electrically connected to the fourth output end 13 of the third switch element 105, and the other end is electrically connected to the input end 14 of the vehicle-mounted chip 106.

[0098] The second resistor is electrically connected between the fourth output end 13 of the third switch element 105, i.e., the collector of the third transistor, and the vehicle-mounted chip 106, which serves to limit the current and protect the input pin of the vehicle-mounted chip 106, thereby improving the safety and stability of the vehicle-mounted chip 106 and the rear load to be protected, and ensuring the data security of the register state of the vehicle-mounted chip 106 and the unchangeability of the memory data in the vehicle-mounted chip 106.

[0099] The third transistor Q3 in the third switch element 105 is used as a circuit signal switch, which controls the transmission of signals in the third switch element 105. The first resistor connected between the collector of the third transistor Q3 and the constant voltage source is used as a pull-up resistor of the transistor, which can improve the stability of the circuit and avoid the adverse effects of false operation on the vehicle chip. The second resistor is connected between the collector of the third transistor Q3 and the vehicle chip, i.e. between the fourth output end 13 of the third switch element 105 and the vehicle chip, which limits the current and protects the input pin of the vehicle chip, improves the safety and stability of the vehicle chip and the load behind it, and ensures the data safety of the register state of the vehicle chip and the unchangeability of the stored data in the vehicle chip.

[0100] By Figure 2 The third switch element 105 includes a third transistor Q3, a second resistor connected between the collector of the third transistor Q3 and the constant voltage source, and a third resistor connected between the third transistor Q3 and the input end 14 of the EFUSE chip and EFUSE_HWLO. Figure 2 The base of the third transistor Q3 is connected to the collector of the first transistor Q1 of the first switch element 103, and the emitter of the third transistor Q3 is grounded. Figure 2

[0101] Since the third switch element 105 is an NPN transistor, the current flow of the third transistor Q3 is from the collector to the emitter. The conduction of the NPN transistor involves the base (B), the collector (C) and the emitter (E), and the main condition for conduction is that the voltage between the base and the emitter (Vbe) should be greater than the conduction voltage, which is between 0.6V and 0.7V in normal operation. Therefore, when the base voltage of the third transistor Q3 is higher than the emitter voltage and reaches the conduction voltage, a large current will flow between the collector and the emitter.

[0102] In this embodiment, when the base of the third transistor Q3 is connected to the collector of the first transistor Q1 and receives the high-level signal transmitted by the first transistor Q1 when both the first transistor Q1 and the second transistor Q2 are in the conduction state, the third transistor Q3 will be adjusted to the conduction state. Therefore, the original state of the vehicle chip corresponds to the input end 14 of the EFUSE chip and EFUSE_HWLO. Figure 2 Figure 2 ​​EFUSE_HWLO is high, and will be pulled low, i.e. the register state of the EFUSE chip is adjusted to the write-allowed state.

[0103] In the embodiment, the signal detection chip 102 is a watchdog chip.

[0104] The watchdog chip, as a common hardware device in embedded systems, monitors the system running state and performs corresponding processing when a fault or exception occurs. In the utility model, as the signal detection chip 102, it judges whether the system, i.e. the master control chip 101, is normally running by checking whether a specific signal output by the master control chip 101 is received within a preset time interval to ensure the reliability and stability of the complete system running.

[0105] Therefore, as shown in the figure, the master control chip 101, i.e. the MCU chip, will send a fixed frequency PWM to the watchdog chip (for detecting whether the MCU is normally working) through the pin WD (which can also be a normal I / O port simulation) according to the characteristics of the watchdog chip, and the watchdog chip will determine the output level by monitoring the PWM signal to confirm whether the MCU is working normally. If it is determined that the MCU is working normally, it outputs a high level (since the later stage of the control circuit provided in the embodiment needs a high level, therefore the output is a high level, on the contrary, if the watchdog model outputs a low level, the logic control circuit needs to perform a level inversion on it, such as adding a NOT gate). Correspondingly, WD_OUT = H. Figure 2

[0106] Specifically, when the watchdog chip WD_OUT outputs a high level, and the master control chip, i.e. the MCU chip, outputs MCU_EN as a low level, it indicates that the watchdog chip and the master control chip, i.e. the MCU chip, are normally fed, i.e. the control end 1 of the master control chip outputs a normal high level signal, and the controlled end 3 of the watchdog chip, i.e. the IN end, receives a normal high level signal. Figure 2 Figure 2 Figure 2

[0107] ​​​​Correspondingly, when the watchdog chip WD_OUT outputs a high level and the main control chip 101, i.e., the MCU chip outputs MCU_EN at a high level, it indicates that the main control chip 101, i.e., the MCU chip and the watchdog chip are feeding the dog normally, i.e., the control terminal 1 of the main control chip 101, i.e., Figure 2 The WD terminal output is a normal high level signal, and the controlled terminal 3 of the watchdog chip is Figure 3 The signal received by the IN terminal is a normal high level signal, and the main control chip 101, ie, MCU, has an EFUSE operation requirement, ie, it pulls up the EN pin level, then the onboard chip 106 Figure 3 The corresponding EFUSE_HWLO is low, and the EFUSE register allows writing. At this time, the second transistor Q2 in the control circuit is in the on state, and the first transistor Q1 is also adjusted to the on state, so the corresponding third transistor Q3 is also in the on state, that is, the pin HWLO of the vehicle chip 106 is pulled low, and the EFUSE register allows writing.

[0108] In addition, when the main control chip 101 is Figure 3 When the MCU software shown runs away or is in an abnormal state, the main control chip 101, i.e., the MCU, cannot feed the dog normally, and the enable terminal 2, i.e., the EN pin level state, of the main control chip 101 MCU is out of control, then the system needs to cut off the influence of the MCU output state on other components. Therefore, in this embodiment, the WD_OUT level of the watchdog chip is set to the highest priority, that is, when the MCU cannot feed the dog normally, WD_OUT outputs a low level, that is, the watchdog chip WD_OUT outputs a low level, then the system does not need to determine the MCU_EN state, and its corresponding on-board chip 106, i.e., the input terminal 14 pin EFUSE_HWLO of the EFUSE chip is high, and the EFUSE register is prohibited from writing.

[0109] At this time, since the MCU is abnormal and cannot output a PWM signal to the watchdog chip, the watchdog chip monitors the input signal IN as a non-PWM signal, and the corresponding OUT pin outputs a low level (similarly, when the subsequent stage of the logic control circuit including three switching elements provided in this embodiment requires a low level, and the output level of the watchdog model of the watchdog chip is a high level, it is necessary to flip the level of the signal, such as adding a NOT gate). At this time, regardless of whether the main control chip 101, i.e., the MCU, outputs a high level to turn on Q2 or not, since Q3 cannot be turned on, i.e., the HWLO pin cannot be pulled low, the EFUSE register must be in a write-prohibited state.

[0110] Specifically, such as Figure 3 As shown, Figure 3 This is a circuit diagram of an embodiment of the control circuit of the vehicle-mounted high-side driver chip provided by the utility model. Figure 3As shown in the figure, the detection signal output end 4 of the signal detection chip 102 is Figure 3 As shown in the figure, the enable end 2 of the master control chip 101 is Figure 3 As shown in the figure MCU_EFUSE1_EN, the first triode Q1 is Q2303, the second triode Q2 is Figure 3 As shown in the figure Q2301, the third triode Q3 is Figure 3 As shown in the figure Q2304, the first input resistor is Figure 3 As shown in the figure R2302, the first resistor is Figure 2 As shown in the figure R2321, the second resistor is Figure 2 As shown in the figure R2309.

[0111] In addition, ​ As shown in the figure, the first switching element 103 in the control circuit further comprises a capacitor C2040, the resistor R2318 is further electrically connected between the base of the first triode Q2303 and the collector of the second triode Q2301, the resistor R2301 is electrically connected between the second triode Q2301 and the enable end 2 of the master control chip 101, the resistor R2303 is electrically connected between the base and the emitter of the second triode Q2301, the resistor R2319 is electrically connected between the collector of the first triode Q2303 and the base of the third triode Q2304, and the resistor R2320 is electrically connected between the base and the emitter of the third triode Q2303. The first input resistor R2302, the second input resistor R2303 and the third input resistor R2320 in the above-mentioned resistors are input resistors, which can also be called internal resistors, and the function is to limit the leakage current.

[0112] In order to better illustrate the working principle and step flow of the control circuit and the chip protection device of the vehicle-mounted high-side drive chip, reference can be made to the related records in the above, but not limited thereto.

[0113] Correspondingly, reference can be made to ​ The utility model provides a kind of structure schematic diagram of the chip protection device of the vehicle-mounted high-side drive chip of the utility model, as shown in ​ The utility model embodiment further provides a kind of chip protection device of automobile distribution system, including the control circuit of any one of the vehicle-mounted high-side drive chip described above, signal switching module 107, current sampling resistance 108 and load interface 109;Wherein:

[0114] The input end of the signal switching module 107 is electrically connected with the output end 15 of the vehicle-mounted chip 106;

[0115] The sixth output end 17 of the signal switching module 107 is electrically connected with constant voltage source by the current sampling resistance 108;

[0116] The seventh output end 18 of the signal switching module 107 is grounded through the load interface 109.

[0117] In order to further ensure the safety of the rear load of the vehicle chip 106, the utility model discloses that signal switching module 107 is also electrically connected between vehicle chip 106 and the rear load, and signal switching module 107 is electrically connected with external voltage source through current sampling resistance 108, so as to ensure the safety and stability of the current output by vehicle chip 106, improve the reliability and stability of the chip protection device, and also ensure the safety and stability of the load electrically connected with signal switching module 107.

[0118] Through vehicle chip 106 and control circuit, primary power distribution protection is realized on the rear power distribution load of vehicle chip 106, and signal switching module 107 and current sampling resistance 108 cooperate to carry out secondary current protection on the load, which avoids power distribution anomaly and also avoids the adverse effects caused by current anomaly.

[0119] Through the chip protection device provided by the utility model, even if MCU flies abnormally resets, the drive output of vehicle chip 106 is still effective, and the original drive data of vehicle chip 106 is also ensured not to be tampered with, the unexpected failure of the important load of vehicle chip 106 is avoided, the functional safety level of the system is improved, and reliable safety protection is provided for the driver and passenger.

[0120] In summary, the utility model discloses a kind of control circuit and chip protection device of vehicle high-side driver chip, including main control chip and vehicle chip and signal detection chip, first switching element, second switching element and third switching element;The detection signal output end of signal detection chip is electrically connected with the input end of first switching element;The second output end of first switching element is electrically connected with the second input end of second switching element;The first output end of first switching element is electrically connected with the input end of third switching element;The fourth output end of third switching element is electrically connected with the input end of vehicle chip;The controlled end of signal detection chip is electrically connected with the control end of main control chip;The enable end of main control chip is electrically connected with the first input end of second switching element.Through signal detection chip, main control chip is monitored in real time, avoid main control chip abnormal data to influence vehicle chip rear load, improve the data security of vehicle chip and the stability of rear load power distribution.

[0121] The above-described specific embodiments have further detailed the purposes, technical solutions and beneficial effects of the present application, and it should be understood that the above-described is only a specific embodiment of the present application and is not used to limit the protection scope of the present application. It is particularly pointed out that, for those skilled in the art, any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A control circuit for an on-vehicle high-side driver chip, comprising a main control chip (101) and an on-vehicle chip (106), characterized in that: It also includes a signal detection chip (102), a first switch element (103), a second switch element (104) and a third switch element (105); wherein: The first switching element (103) has a third input terminal (5), a first output terminal (6) and a second output terminal (7); The second switching element (104) has a fifth output terminal (10), a first input terminal (8) and a second input terminal (9); The third switching element (105) has a fourth input terminal (11), a third output terminal (12) and a fourth output terminal (13); The detection signal output terminal (4) of the signal detection chip (102) is electrically connected to the third input terminal (5) of the first switch element (103); The second output terminal (7) of the first switching element (103) is electrically connected to the second input terminal (9) of the second switching element (104); The first output terminal (6) of the first switching element (103) is electrically connected to the fourth input terminal (11) of the third switching element (105); The fifth output terminal (10) of the second switching element (104) is grounded; The fourth output terminal (13) of the third switch element (105) is electrically connected to the input terminal (14) of the on-board chip (106); The third output terminal (12) of the third switching element (105) is grounded; The controlled end (3) of the signal detection chip (102) is electrically connected to the control end (1) of the main control chip (101); The enable terminal (2) of the main control chip (101) is electrically connected to the first input terminal (8) of the second switch element (104).

2. The control circuit of a vehicle-mounted high-side driver chip according to claim 1, characterized in that: The first switching element (103) is a triode or a MOS tube; The second switch element (104) is a triode or a MOS tube; The third switch element (105) is a triode or a MOS tube.

3. The control circuit of a vehicle-mounted high-side driver chip according to claim 2, characterized in that: The first switching element (103) is a PNP transistor, the second switching element (104) is an NPN transistor, and the third switching element (105) is an NPN transistor.

4. The control circuit of a vehicle-mounted high-side driver chip according to claim 1, wherein: Also included is a first input resistor; wherein: One end of the first input resistor is electrically connected to the third input end (5) of the first switch element (103), and the other end is electrically connected to the second output end (7) of the first switch element (103).

5. The control circuit of a vehicle-mounted high-side driver chip according to claim 1, characterized in that: Also included is a second input resistor; wherein: One end of the second input resistor is electrically connected to the fifth output end (10) of the second switch element (104), and the other end is electrically connected to the first input end (8) of the second switch element (104).

6. The control circuit of a vehicle-mounted high-side driver chip according to claim 1, characterized in that: Also included is a third input resistor; wherein: One end of the third input resistor is electrically connected to the third output end (12) of the third switch element (105), and the other end is electrically connected to the fourth input end (11) of the third switch element (105).

7. The control circuit of a vehicle-mounted high-side driver chip according to claim 1, characterized in that: Also includes a first resistor; wherein: One end of the first resistor is electrically connected to the fourth output end (13) of the third switch element (105), and the other end is electrically connected to a constant voltage source.

8. The control circuit of a vehicle-mounted high-side driver chip according to claim 1, characterized in that: Also includes a second resistor; wherein: One end of the second resistor is electrically connected to the fourth output end (13) of the third switch element (105), and the other end is electrically connected to the input end (14) of the on-board chip (106).

9. The control circuit of a vehicle-mounted high-side driver chip according to claim 1, characterized in that: The signal detection chip (102) is a watchdog chip.

10. A chip protection device for an automobile power distribution system, characterized in that: The invention comprises a control circuit of a vehicle-mounted high-side driver chip according to any one of claims 1 to 9, a signal switching module (107), a current sampling resistor (108) and a load interface (109); wherein: The signal switching module (107) has a sixth output terminal (17) and a seventh output terminal (18); The input end (16) of the signal switching module (107) is electrically connected to the output end (15) of the vehicle-mounted chip (106); The sixth output terminal (17) of the signal switching module (107) is electrically connected to a constant voltage source via the current sampling resistor (108); The seventh output terminal (18) of the signal switching module (107) is grounded via the load interface (109).

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