Three-state switching signal acquisition system

Abstract

The utility model discloses a three-state switching signal acquisition system, which realizes low static loss and instant wake-up capability of a controller. The system comprises a three-state switching signal acquisition circuit and a wake-up circuit, the power supply end of the acquisition circuit is connected with a first power supply; the first power supply is turned on when the controller works normally and turned off when the controller is dormant; the power end of the wake-up circuit is connected to a second power supply; the acquisition circuit is connected between the output end of the three-state switch and the first input end of the controller and is used for converting different logic states output by the three-state switch into signals with different voltage values under the power supply of the first power supply; the wake-up circuit is connected between the output end of the three-state switch and the second input end of the controller, and is used for switching the logic state of the output end of the three-state switch from a suspended state to a high level or a low level under the power supply of the second power supply after the first power supply is turned off, and converting the logic state into a preset wake-up signal; the wake-up signal is used for waking up the controller from the dormant state to the normal working state.

Description

Technical Field

[0001] This application relates to the field of electronic technology, and in particular, to a three-state switch signal acquisition system. Background Art

[0002] A three-state switch is a circuit element that can flexibly switch and output among three different logic states: high level, low level, and floating. The main task of a three-state switch signal acquisition circuit is to convert the different logic states output by the three-state switch into signals with different voltage values and output them to a controller. The controller can identify the current output logic state of the three-state switch based on the input voltage value.

[0003] When the controller does not receive any substantial operation or processing tasks sent from the three-state switch, sensor, or other hardware interfaces within a certain period of time, in order to reduce power consumption, the controller usually automatically enters the sleep state. In the sleep state, the power consumption of the controller will be significantly reduced, but it still needs to maintain a certain wake-up ability so that it can resume the normal working state when needed. However, existing wake-up schemes often have the disadvantages of relatively large static power loss of the controller (the current from the device to ground when the device is in the sleep state is called the static current, and the power consumption generated by the static current flowing through the circuit is called the static power loss) and slow wake-up response. Summary of the Utility Model

[0004] In view of the above problems, this application provides a three-state switch signal acquisition system to achieve low static power loss and instant wake-up ability of the controller. The specific solutions are as follows:

[0005] This application provides a three-state switch signal acquisition system, including: a three-state switch signal acquisition circuit and a wake-up circuit;

[0006] The power supply terminal of the three-state switch signal acquisition circuit is connected to a first power supply; the first power supply is turned on when the controller is working normally and turned off when the controller is in the sleep state; the power supply terminal of the wake-up circuit is connected to a second power supply;

[0007] The three-state switch signal acquisition circuit is connected between the output terminal of the three-state switch and the first input terminal of the controller, and is used to convert the different logic states output by the three-state switch into signals with different voltage values under the power supply of the first power supply;

[0008] The wake-up circuit is connected between the output terminal of the three-state switch and the second input terminal of the controller, and is used to switch the output terminal of the three-state switch from the floating state to the high-level or low-level logic state and convert it into a preset wake-up signal after the first power supply is turned off under the power supply of the second power supply; the wake-up signal is used to wake up the controller from the sleep state to the normal working state.

[0009] In a possible implementation, the wake-up circuit includes: operational amplifier U1, operational amplifier U2, resistor R5, resistor R6, resistor R7, resistor R8, resistor R9, resistor R10, resistor R11, resistor R12, resistor R13, resistor R14, diode D2, and an equivalent resistor;

[0010] The equivalent resistor refers to the equivalent resistance connected between the output terminal of the tri-state switch and the ground inside the tri-state switch signal acquisition circuit;

[0011] One end of resistor R7 and one end of resistor R10 are connected and then connected to the output terminal of the tri-state switch;

[0012] The other end of resistor R7 is connected to one end of resistor R8 and the non-inverting input terminal of operational amplifier U1; resistor R6 is connected between the non-inverting input terminal and the output terminal of operational amplifier U1;

[0013] One end of resistor R5 is connected to one end of resistor R9 and the inverting input terminal of operational amplifier U1;

[0014] The other end of resistor R10 is connected to the cathode of diode D2, the anode of diode D2 is connected to one end of resistor R11 and the inverting input terminal of operational amplifier U2; one end of resistor R12 is connected to one end of resistor R14 and the non-inverting input terminal of operational amplifier U2;

[0015] Resistor R13 is connected between the non-inverting input terminal and the output terminal of operational amplifier U2;

[0016] The other end of resistor R5, the other end of resistor R11, and the other end of resistor R12 are connected to the second power supply;

[0017] The other end of resistor R8, the other end of resistor R9, and the other end of resistor R14 are all grounded;

[0018] The second input terminal of the controller is a dual-channel input port, and the output terminals of operational amplifier U1 and operational amplifier U2 are connected to the dual-channel input port.

[0019] In a possible implementation, the wake-up circuit further includes: a first filtering circuit and a second filtering circuit;

[0020] The first filtering circuit is connected between the output terminal of operational amplifier U1 and the ground;

[0021] The second filtering circuit is connected between the output terminal of operational amplifier U2 and the ground.

[0022] In a possible implementation, both the first filtering circuit and the second filtering circuit are filtering capacitors.

[0023] In a possible implementation, the wake-up circuit further includes: a diode D1; the anode of the diode D1 is connected to the output terminal of the tri-state switch through a resistor R7, and the cathode of the diode D1 is connected to the non-inverting input terminal of the operational amplifier U1.

[0024] In a possible implementation, the second power supply is turned off when the controller is operating normally, and is turned on when the controller is in a sleep state.

[0025] In a possible implementation, the second power supply is a constant power supply.

[0026] In a possible implementation, the tri-state switch signal acquisition circuit includes: a resistor R1, a resistor R3, and a resistor R4;

[0027] Wherein, one end of the resistor R1 is connected to one end of the resistor R3 and then connected to the output terminal of the tri-state switch;

[0028] The other end of the resistor R1 is the power supply terminal of the tri-state switch signal acquisition circuit;

[0029] One end of the resistor R4 is grounded;

[0030] The other end of the resistor R3 is connected to the other end of the resistor R4 and then connected to the first input terminal of the controller.

[0031] In a possible implementation, the tri-state switch signal acquisition circuit further includes: a resistor R2; the resistor R2 is connected between the output terminal of the tri-state switch and the ground.

[0032] In a possible implementation, the controller is a vehicle-mounted controller.

[0033] By means of the above technical solution, the tri-state switch signal acquisition system provided by the present application is mainly obtained by adding a wake-up circuit on the basis of the existing tri-state switch signal acquisition circuit, wherein: the power supply of the tri-state switch signal acquisition circuit is only turned on when the controller is operating normally, and is turned off after the controller goes to sleep, so as to avoid the power supply forming a static current path through the controller and increasing the static loss of the controller; after the controller goes to sleep, the output terminal of the tri-state switch does not need to input a valid logic signal (high-level or low-level signal) and is placed in a floating state; the wake-up circuit is designed to switch the logic state of the output terminal of the tri-state switch from floating to high-level or low-level after the controller goes to sleep, and convert it into a preset wake-up signal to wake up the controller. Since the output terminal of the tri-state switch is in a floating state before the switch, there is no fixed level, so this switch will not be restricted or affected by the level state before the switch, and can be completed quickly and accurately, ensuring the immediacy of the controller wake-up. Description of the Drawings

[0034] In conjunction with the accompanying drawings and with reference to the following specific embodiments, the above and other features, advantages, and aspects of the various embodiments of the present disclosure will become more apparent. Throughout the drawings, the same or similar reference numerals denote the same or similar elements. It should be understood that the drawings are schematic, and the original components and elements are not necessarily drawn to scale.

[0035] Figure 1 Schematic diagram of a three-state switch signal acquisition system provided by this application;

[0036] Figure 2 Circuit schematic diagram of a three-state switch signal acquisition system provided by this application;

[0037] Figure 3 Another circuit schematic diagram of a three-state switch signal acquisition system provided by this application. Specific embodiments

[0038] Three-state switches and their signal acquisition circuits play an important role in electronic systems (such as automotive electronic control systems). By providing flexible logic state switching and precise signal processing functions, they provide strong support for the stable operation and high performance of electronic systems. The three-state switch and its signal acquisition circuit are introduced below:

[0039] A three-state switch is a circuit element that can flexibly switch and output between three different logic states: high level, low level, and floating. This flexible switching ability enables the three-state switch to undertake more complex and precise signal processing tasks in electronic systems.

[0040] Among them, when the output terminal of the three-state switch is in the high-level state, it means that the three-state switch outputs a relatively high voltage signal, generally reaching or approaching the power supply voltage. When the output terminal of the three-state switch is in the low-level state, it means that the three-state switch outputs a relatively low voltage signal, generally reaching or approaching the ground level. When the output terminal of the three-state switch is in the floating state (also known as the high-impedance state), it means that the output terminal of the three-state switch is neither connected to the high level nor connected to the low level, but is in an indeterminate level state, and the output terminal of the three-state switch exhibits an extremely high impedance and is almost electrically disconnected from the other parts of the circuit (this "disconnection" does not refer to a physical disconnection, but from the perspective of electrical characteristics, the influence of the output terminal of the three-state switch on the circuit on the output side of the three-state switch is very small and can almost be ignored).

[0041] The main task of the three-state switch signal acquisition circuit is to convert the different logical states of the three-state switch output into signals of different voltage values and output them to the controller. The controller can then identify the current output logic state of the three-state switch based on the input voltage value. The importance of the three-state switch signal acquisition circuit lies in its ability to ensure that the output signal of the three-state switch is accurately and reliably transmitted to the controller. This is crucial for electronic systems that require high-precision and complex signal processing, as any signal distortion or misinterpretation can lead to performance degradation or even failure of the electronic system.

[0042] Controller design should consider energy conservation. Specifically, if a controller does not receive any substantive operations or processing tasks from a tri-state switch, sensor, or other hardware interface within a certain period of time, it will typically automatically enter a sleep state to reduce power consumption. In sleep mode, the controller shuts down or reduces the power supply to non-essential internal circuits, significantly reducing power consumption. However, to ensure flexibility and responsiveness, the controller must maintain instant wake-up capabilities so that it can quickly resume normal operation when needed.

[0043] Moreover, the controller should maintain a low static loss as much as possible in the sleep state (the current from the device to the ground when the device is in the sleep state is called the static current. The power consumption generated by the static current flowing through the circuit is called the static loss. Its magnitude is small, but it persists during the entire circuit operation process. Accumulating it over a long period of time will also lead to significant energy waste), especially in occasions such as automotive electronic control systems where the static loss requirements are extremely stringent.

[0044] To ensure that the controller can respond to a wake-up signal immediately, quickly recover from sleep mode to normal working state, and ensure low static loss of the controller, an embodiment of the present application provides a three-state switch signal acquisition system. The three-state switch signal acquisition system is mainly obtained by adding a wake-up circuit on the basis of an existing three-state switch signal acquisition circuit, wherein: the power supply of the three-state switch signal acquisition circuit is only turned on when the controller is operating normally, and is turned off after the controller is in sleep mode, so as to avoid the power supply forming a static current path through the controller and increasing the static loss of the controller; after the controller is in sleep mode, the output end of the three-state switch does not need to be input with a valid logic signal (high level signal or low level signal) and is placed in a floating state; the wake-up circuit is designed to switch the output end of the three-state switch from a floating state to a high level or a low level logic state after the controller is in sleep mode, converting it into a preset wake-up signal to wake up the controller. Since the output end of the three-state switch is in a floating state before the switching and has no fixed level, the switching is not limited or affected by the level state before the switching, and can be completed quickly and accurately, ensuring the immediacy of the controller wake-up.

[0045] The following will elaborate on a three-state switch signal acquisition system provided by an embodiment of the present application in conjunction with the accompanying drawings. As is known to those of ordinary skill in the art, with the development of technology and the emergence of new scenarios, the technical solutions provided by the embodiments of the present application are equally applicable to similar technical problems.

[0046] The terms "first", "second", etc. in the specification, claims and the above-mentioned accompanying drawings of the present application are used to distinguish similar objects, and do not necessarily have to be used to describe a specific order or sequence. It should be understood that such terms can be interchanged under appropriate circumstances, which is only a way of distinguishing when describing objects with the same attributes in the embodiments of the present application. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion, so that a process, method, system, product or device comprising a series of units does not have to be limited to those units, but may include other units that are not clearly listed or are inherent to these processes, methods, products or devices.

[0047] See Figure 1 , a three-state switch signal acquisition system provided by an embodiment of the present application includes: a three-state switch signal acquisition circuit 1 and a wake-up circuit 2;

[0048] The three-state switch signal acquisition circuit 1 is connected between the output terminal of the three-state switch 3 and the first input terminal of the controller 4; the power supply terminal of the three-state switch signal acquisition circuit 1 is connected to the first power supply U power1 ; the first power supply U power1 is a controllable power supply, which is turned on when the controller 4 is working normally and turned off when the controller 4 is in a sleep state;

[0049] The wake-up circuit 2 is connected between the output terminal of the three-state switch 3 and the second input terminal of the controller 4; the power supply terminal of the wake-up circuit 2 is connected to the second power supply U power2 ;

[0050] The three-state switch signal acquisition circuit 1 is used to convert different logic states output by the three-state switch 3 into signals of different voltage values under the power supply of the first power supply U power1 ;

[0051] The wake-up circuit 2 is used to switch the output terminal of the three-state switch 3 from a floating state to a high-level or low-level logic state and convert it into a preset wake-up signal after the first power supply U power1 is turned off and under the power supply of the second power supply U power2 ; the wake-up signal is used to wake up the controller 4 from the sleep state to the normal working state.

[0052] The following will elaborate on Figure 1 the working principle of the shown solution:

[0053] The power supply of the tri-state switch signal acquisition circuit 1, which is also the first power supply U power1 (Controllable power supply) is only turned on when the controller 4 is working properly, and turned off when the controller 4 is in sleep mode (the on and off of the controllable power supply can be controlled by software), so as to avoid the first power supply U power1 forming a static current path through the controller 4 and increasing the static loss of the controller 4, while avoiding interference with the normal operation of the wake-up circuit 2. The main task of the tri-state switch signal acquisition circuit 1 is to output signals with different voltage values according to different logical states output by the tri-state switch 3. The controller 4 can identify whether the output terminal of the tri-state switch 3 is currently in a high-level state, a low-level state or a floating state according to the voltage range of the voltage value.

[0054] After the controller 4 enters the sleep mode, no effective logic signal input (high-level or low-level signal) is required at the output terminal of the tri-state switch 3, and it remains in the floating state. Moreover, the floating of the output terminal of the tri-state switch 3 can effectively "cut off" the electrical connection between the controller 4 and the input-side circuit of the tri-state switch 3, avoiding unnecessary energy flow between the controller 4 and the input-side circuit of the tri-state switch 3, thereby further reducing the static loss of the controller 4. Furthermore, when the controller 4 is in the sleep mode, its internal state may become unstable. If the input-side circuit of the tri-state switch 3 is still connected to the controller 4 through the tri-state switch 3, these unstable signals may be transmitted to the input-side circuit of the tri-state switch 3 through the tri-state switch 3, causing unnecessary interference or malfunction. By floating the output terminal of the tri-state switch 3, the signal transmission between the two can be isolated, reducing the possibility of such interference.

[0055] The wake-up circuit 2, after the first power supply U power1 is turned off, can not only convert the logical state transition of the output terminal of the tri-state switch 3 from floating to high level into a wake-up signal capable of waking up the controller 4 from the sleep mode to the normal working mode, but also convert the logical state transition of the output terminal of the tri-state switch 3 from floating to low level into a wake-up signal capable of waking up the controller 4 from the sleep mode to the normal working mode. Thus, when the controller 4 needs to be woken up, the controller 4 can be woken up by performing a logical state transition of the output of the tri-state switch 3. Since the output terminal of the tri-state switch 3 is in the floating state before the logical state transition and there is no fixed level, this transition will not be restricted or affected by the previous level state and can be completed quickly and accurately, ensuring the instantaneity and reliability of waking up the controller 4.

[0056] The embodiment of the present application can be applied to an automotive electronic control system. At this time, the controller 4 is an in-vehicle controller. Before the vehicle enters the ignition operation, the in-vehicle controller can be woken up by switching the output logical state of the tri-state switch 3.

[0057] In any of the above-disclosed embodiments, the second power supply U power2A controllable power supply can also be adopted. The controllable power supply is turned off when the controller 4 is operating normally and turned on when the controller 4 is in the sleep state to reduce energy consumption. Alternatively, to simplify the control complexity, a second power supply U can also be designed. power2 is a constant power supply, which refers to a power supply that can maintain a continuous power supply state.

[0058] In any of the above-disclosed embodiments, the schematic diagram of the tri-state switch signal acquisition circuit 1 is, for example, Figure 2 shown, including: resistor R1, resistor R2, resistor R3, and resistor R4; one end of resistor R1, one end of resistor R2, and one end of resistor R3 are connected together and used as the input end of the tri-state switch signal acquisition circuit 1; the other end of resistor R1 is the power supply end of the tri-state switch signal acquisition circuit 1 and is connected to the first power supply U power1 ; the other end of resistor R2 and one end of resistor R4 are grounded; the other end of resistor R3 and the other end of resistor R4 are connected together and used as the output end of the tri-state switch signal acquisition circuit 1. According to the functions of each component in the tri-state switch signal acquisition circuit 1, the first power supply U power1 , resistor R1, resistor R2, resistor R3, and resistor R4 can be successively referred to as the pull-up source, pull-up resistor, pull-down resistor, current-limiting resistor, and voltage-dividing resistor. Resistor R2 mainly plays a role in stabilizing the voltage at the output end of the tri-state switch 3. In some cases where the requirement for the voltage stability at the output end of the tri-state switch 3 is not very strict, resistor R2 can also be omitted to save costs.

[0059] The working principle of the tri-state switch signal acquisition circuit 1 is as follows: According to the principle of series resistor voltage division, when the output end of the tri-state switch 3 is in the high-level state, the signal output by the tri-state switch signal acquisition circuit 1 (hereinafter simply referred to as signal A1) is a relatively high voltage value V1; when the output end of the tri-state switch 3 is in the low-level state, signal A1 is the ground level; when the output end of the tri-state switch 3 is in the floating state, signal A1 is a voltage value between the voltage value V1 and the ground level. It can be seen that the tri-state switch signal acquisition circuit 1 can output signals with different voltage values according to different logic states output by the tri-state switch 3. The controller 4 can identify the current logic state of the output end of the tri-state switch 3 according to the voltage range in which the voltage value of signal A1 is located. For example: Two thresholds Vth1 and Vth2 are preset in the controller 4. When the controller 4 detects that the voltage value of signal A1 is greater than the threshold Vth1, it is determined that the output end of the tri-state switch 3 is in the high-level state; when the controller 4 detects that the voltage value of signal A1 is less than the threshold Vth2, it is determined that the output end of the tri-state switch 3 is in the low-level state; when the controller 4 detects that the voltage value of signal A1 is greater than the threshold Vth2 and less than the threshold Vth1, it is determined that the output end of the tri-state switch 3 is in the floating state.

[0060] The circuit design of the wake-up circuit 2 allows for a certain offset effect on the output voltage value of the three-state switch signal acquisition circuit 1, but it is necessary to ensure that the offset voltage value will not cause the controller 4 to misjudge the output logic state of the three-state switch 3. That is, it is necessary to ensure that after the wake-up circuit 2 is introduced, when the output terminal of the three-state switch 3 is in the high-level state, the voltage value of signal A1 is greater than the threshold Vth1; when the output terminal of the three-state switch 3 is in the low-level state, the voltage value of signal A1 is less than the threshold Vth2; when the output terminal of the three-state switch 3 is in the floating state, the voltage value of signal A1 is greater than the threshold Vth2 and less than the threshold Vth1.

[0061] Based on any of the above-disclosed embodiments, still referring to Figure 2 , the wake-up circuit 2 may include: operational amplifier U1, operational amplifier U2, resistor R5, resistor R6, resistor R7, resistor R8, resistor R9, resistor R10, resistor R11, resistor R12, resistor R13, resistor R14, diode D2, and an equivalent resistor;

[0062] The equivalent resistor refers to the equivalent resistance connected between the input terminal of the three-state switch signal acquisition circuit 1 and the ground inside the three-state switch signal acquisition circuit 1 (taking the three-state switch signal acquisition circuit 1 shown in Figure 2 as an example, the equivalent resistance includes resistor R2, resistor R3, and resistor R4. At this time, resistor R2, resistor R3, and resistor R4 in the three-state switch signal acquisition circuit 1 are reused by the wake-up circuit 2);

[0063] One end of resistor R7 and one end of resistor R10 are connected together and used as the input terminal of the wake-up circuit 2;

[0064] The other end of resistor R7 is connected to one end of resistor R8 and the non-inverting input terminal of operational amplifier U1; resistor R6 is connected between the non-inverting input terminal and the output terminal of operational amplifier U1;

[0065] One end of resistor R5 is connected to one end of resistor R9 and the inverting input terminal of operational amplifier U1;

[0066] The other end of resistor R10 is connected to the cathode of diode D2, and the anode of diode D2 is connected to one end of resistor R11 and the inverting input terminal of operational amplifier U2; one end of resistor R12 is connected to one end of resistor R14 and the non-inverting input terminal of operational amplifier U2;

[0067] Resistor R13 is connected between the non-inverting input terminal and the output terminal of operational amplifier U2;

[0068] The other end of resistor R5, the other end of resistor R11, and the other end of resistor R12 are connected to the second power supply U power2 ;

[0069] The other end of resistor R8, the other end of resistor R9, and the other end of resistor R14 are all grounded;

[0070] The second input terminal of controller 4 is a dual-channel input port, the wake-up circuit 2 is a dual-channel output circuit, and the output terminals of operational amplifier U1 and operational amplifier U2 form the dual-channel output terminals of the wake-up circuit 2 and are connected to the dual-channel input port.

[0071] Next, by analyzing three operating conditions of the wake-up circuit 2 when the controller 4 is in the sleep state (at this time the first power supply U power1 is turned off), the working principle of the Figure 2 shown wake-up circuit 2 will be described in detail:

[0072] Operating condition 1: The controller 4 is in the sleep state and the output terminal of the three-state switch 3 is in the floating state

[0073] After the controller 4 goes to sleep, the initial state of the output terminal of the three-state switch 3 is the floating state. At this time, according to the "virtual open" characteristic of the operational amplifier (that is, the input currents of the in-phase input terminal and the anti-phase input terminal of the operational amplifier are both zero), it can be known that:

[0074] The voltage U at the inverting input terminal of operational amplifier U1 1IN1 is:

[0075]

[0076] Without considering the diode voltage drop, the voltage U at the non-inverting input terminal of operational amplifier U1 1IN2 is:

[0077]

[0078] The voltage U at the inverting input terminal of operational amplifier U2 2IN1 is:

[0079]

[0080] Without considering the diode voltage drop, the voltage U at the non-inverting input terminal of operational amplifier U2 2IN2 is:

[0081]

[0082] Operating condition 2: The controller 4 is in the sleep state and the output terminal of the three-state switch 3 is switched from the floating state to the high-level state

[0083] After the controller 4 goes to sleep, when the three-state switch 3 is switched from the floating state to the high-level state, the voltage at the output terminal of the three-state switch 3 becomes U power2 , and at this time, according to the "virtual open" characteristic of the operational amplifier and the anti-reverse characteristic of diode D2, it can be known that:

[0084] The voltage U at the inverting input terminal of the operational amplifier U1 1IN1 is:

[0085]

[0086] Without considering the diode voltage drop, the voltage U at the non-inverting input terminal of the operational amplifier U1 1IN2 is:

[0087]

[0088] The voltage U at the inverting input terminal of the operational amplifier U2 2IN1 = U power2 ;

[0089] Without considering the diode voltage drop, the voltage U at the non-inverting input terminal of the operational amplifier U2 2IN2 is:

[0090]

[0091] Operating condition three: The controller 4 is in sleep mode and the output terminal of the three-state switch 3 switches from the floating state to the low-level state

[0092] After the controller 4 enters the sleep mode, when the three-state switch 3 switches from the floating state to the low-level state, the voltage at the output terminal of the three-state switch 3 becomes the ground level. At this time, according to the "virtual open" characteristic of the operational amplifier, it can be known that:

[0093] The voltage U at the inverting input terminal of the operational amplifier U1 1IN1 is:

[0094]

[0095] The voltage U at the non-inverting input terminal of the operational amplifier U1 1IN2 is 0V.

[0096] The voltage U at the inverting input terminal of the operational amplifier U2 2IN1 is:

[0097]

[0098] The voltage U at the non-inverting input terminal of the operational amplifier U2 2IN2 is:

[0099]

[0100] In summary, by reasonably setting the resistance values of each resistor, it can be achieved that:

[0101] Under operating condition 1, the voltage at the inverting input terminal of operational amplifier U1 > the voltage at the non-inverting input terminal of operational amplifier U1, and the voltage at the inverting input terminal of operational amplifier U2 > the voltage at the non-inverting input terminal of operational amplifier U2. At this time, the operational amplifier U1 outputs a low level (resistor R6 and operational amplifier U1 form a hysteresis comparator, which has the characteristic that "when the voltage at the inverting input terminal of U1 > the voltage at the non-inverting input terminal of U1, U1 outputs a low level; when the voltage at the inverting input terminal of U1 < the voltage at the non-inverting input terminal of U1, U1 outputs a high level"), and U2 also outputs a low level (resistor R13 and operational amplifier U2 form another hysteresis comparator), as shown in Table 1 ("1" represents a high level, "0" represents a low level); when the controller 4 detects the current output level states of operational amplifiers U1 and U2, it determines that the three-state switch 3 is in a floating state;

[0102] Under operating condition 2, the voltage at the inverting input terminal of operational amplifier U1 < the voltage at the non-inverting input terminal of operational amplifier U1, and the voltage at the inverting input terminal of operational amplifier U2 > the voltage at the non-inverting input terminal of operational amplifier U2. At this time, the output signal of operational amplifier U1 (hereinafter simply referred to as signal A2) outputs a high level, and the output signal of operational amplifier U2 (hereinafter simply referred to as signal A3) outputs a low level, as shown in Table 1; when the controller 4 detects that signal A2 changes from a low level to a high level, it determines that the three-state switch 3 has switched from a floating state to a high-level output logic state, waking up the controller 4.

[0103] Under operating condition 3, the voltage at the inverting input terminal of operational amplifier U1 > the voltage at the non-inverting input terminal of operational amplifier U1, and the voltage at the inverting input terminal of operational amplifier U2 < the voltage at the non-inverting input terminal of operational amplifier U2. At this time, signal A2 outputs a low level, and signal A3 outputs a high level, as shown in Table 1; when the controller 4 detects that signal A3 changes from a low level to a high level, it determines that the three-state switch 3 has switched from a floating state to a low-level output logic state, waking up the controller 4.

[0104] Table 1

[0105]

[0106] According to the functions of the components in the wake-up circuit 2, the second power supply U power2 can be called the pull-up source, the diode D2 can be called the anti-reverse diode, the resistors R7 and R10 can both be called current-limiting resistors, the resistors R5, R11, and R12 can all be called pull-up resistors, the resistors R8, R9, and R14 can all be called pull-down resistors, and the resistors R6 and R13 can both be called feedback resistors.

[0107] In a possible implementation, the wake-up circuit 2 may further include: a first filter circuit and a second filter circuit;

[0108] The first filter circuit is connected between the output terminal of the operational amplifier U1 and the ground;

[0109] The second filter circuit is connected between the output terminal of the operational amplifier U2 and the ground.

[0110] The first filter circuit filters the output signal of the operational amplifier U1, and the second filter circuit filters the output signal of the operational amplifier U2. The two work together to make the wake-up signal clearer.

[0111] In a possible implementation, referring to Figure 3 , the first filter circuit is a filter capacitor C1, and the second filter circuit is a filter capacitor C2.

[0112] Based on any of the above-disclosed embodiments, still referring to Figure 3 , the wake-up circuit 2 further includes: a diode D1; the anode of the diode D1 is connected to the output terminal of the tri-state switch 3 through a resistor R7, and the cathode of the diode D1 is connected to the non-inverting input terminal of the operational amplifier U1. Specifically, the diode D1 is an anti-reverse diode, which can prevent the leakage current generated between the non-inverting input terminal and the inverting input terminal of the operational amplifier U1 from raising the voltage at the output terminal of the tri-state switch 3, resulting in misjudgment by the controller 4.

[0113] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present application. Various modifications to these embodiments will be apparent to those skilled in the art. The general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the embodiments of the present application. Therefore, the embodiments of the present application will not be limited to the embodiments shown herein, but will be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A three-state switch signal acquisition system, characterized in that Including: A tri-state switch signal acquisition circuit and a wake-up circuit; The power supply terminal of the tri-state switch signal acquisition circuit is connected to a first power supply; The first power supply is turned on when the controller is working normally and turned off when the controller is in sleep mode; the power supply terminal of the wake-up circuit is connected to a second power supply; The tri-state switch signal acquisition circuit is connected between the output terminal of the tri-state switch and the first input terminal of the controller, and is used to convert different logic states output by the tri-state switch into signals with different voltage values under the power supply of the first power supply; The wake-up circuit is connected between the output terminal of the tri-state switch and the second input terminal of the controller, and is used to switch the output terminal of the tri-state switch from a floating state to a high-level or low-level logic state and convert it into a preset wake-up signal after the first power supply is turned off under the power supply of the second power supply; the wake-up signal is used to wake up the controller from the sleep state to the normal working state.

2. The three-state switch signal acquisition system according to claim 1, wherein The wake-up circuit includes: operational amplifier U1, operational amplifier U2, resistor R5, resistor R6, resistor R7, resistor R8, resistor R9, resistor R10, resistor R11, resistor R12, resistor R13, resistor R14, diode D2, and an equivalent resistor; The equivalent resistor refers to the equivalent resistor connected between the output terminal of the tri-state switch and the ground inside the tri-state switch signal acquisition circuit; One end of resistor R7 and one end of resistor R10 are connected and then connected to the output terminal of the tri-state switch; The other end of resistor R7 is connected to one end of resistor R8 and the non-inverting input terminal of operational amplifier U1; resistor R6 is connected between the non-inverting input terminal and the output terminal of operational amplifier U1; One end of resistor R5 is connected to one end of resistor R9 and the inverting input terminal of operational amplifier U1; The other end of resistor R10 is connected to the cathode of diode D2, the anode of diode D2 is connected to one end of resistor R11 and the inverting input terminal of operational amplifier U2; one end of resistor R12 is connected to one end of resistor R14 and the non-inverting input terminal of operational amplifier U2; Resistor R13 is connected between the non-inverting input terminal and the output terminal of operational amplifier U2; The other ends of resistor R5, resistor R11, and resistor R12 are connected to the second power supply; The other ends of resistor R8, resistor R9, and resistor R14 are all grounded; The second input terminal of the controller is a dual-channel input port, and the output terminals of operational amplifier U1 and operational amplifier U2 are connected to the dual-channel input port.

3. The three-state switch signal acquisition system according to claim 2, wherein The wake-up circuit further includes: a first filtering circuit and a second filtering circuit; The first filtering circuit is connected between the output terminal of operational amplifier U1 and the ground; The second filtering circuit is connected between the output terminal of operational amplifier U2 and the ground.

4. The three-state switch signal acquisition system according to claim 3, wherein, Both the first filtering circuit and the second filtering circuit are filtering capacitors.

5. The three-state switch signal acquisition system according to any one of claims 2 to 4, characterized in that, The wake-up circuit further includes: diode D1; the anode of diode D1 is connected to the output terminal of the tri-state switch through resistor R7, and the cathode of diode D1 is connected to the non-inverting input terminal of operational amplifier U1.

6. The three-state switch signal acquisition system according to claim 1, wherein The second power supply is turned off when the controller is working normally and turned on when the controller is in sleep mode.

7. The three-state switch signal acquisition system according to claim 1, characterized in that, The second power supply is a constant power supply.

8. The three-state switch signal acquisition system according to claim 1, characterized in that, The three-state switch signal acquisition circuit includes: resistor R1, resistor R3, and resistor R4; One end of resistor R1 is connected to one end of resistor R3 and then connected to the output end of the three-state switch; The other end of resistor R1 is the power supply end of the three-state switch signal acquisition circuit; One end of resistor R4 is grounded; The other end of resistor R3 is connected to the other end of resistor R4 and then connected to the first input end of the controller.

9. The three-state switch signal acquisition system according to claim 8, characterized in that, The three-state switch signal acquisition circuit further includes: resistor R2; resistor R2 is connected between the output end of the three-state switch and the ground.

10. The tri-state switch signal acquisition system according to claim 1, wherein The controller is a vehicle-mounted controller.

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