Rearview mirror chip logic operation method and system with retry function

Abstract

The invention belongs to the technical field of vehicle rearview mirrors, and particularly relates to a rearview mirror chip logic operation method and system with a retry function. Through a designed current detection circuit, a threshold detection circuit and a current comparison circuit, special customization of a rearview mirror folding driving chip is realized, and a rearview mirror driving motor tries to recover when being in a stuck state, so that normal operation of folding work is facilitated; meanwhile, a soft start-off circuit is designed, so that current impact during starting can be reduced, mechanical stress during starting can be reduced, system instability can be prevented, the situations of voltage spike and current sudden change when the motor is turned off are reduced, the motor and a driving circuit are protected, the reliability of the system is improved, the service life of the system is prolonged, and noise and vibration situations are reduced; and the condition of reverse current in the turn-off process of the motor is prevented.

Description

Technical Field

[0001] The present invention belongs to the technical field of vehicle rearview mirrors, and in particular, relates to a rearview mirror chip logic operation method and system with a retry function. Background Art

[0002] With the development of the automobile industry, most cars support the rearview mirror folding function. And during vehicle use, the frequency of rearview mirror folding is high, so the stability requirements of rearview mirror folding technology have increased. The folding of rearview mirrors is mostly driven by DC motors. The current rearview mirror folding motor drive module adopts a discrete component solution or is driven by an ordinary DC motor driver chip. Although the discrete component solution can provide good performance and has experience in mass production, its disadvantages are a large PCB area and relatively expensive BOM component costs, and its accuracy is not high, and it does not support the various protection functions required by the on-board chip. The disadvantage of using an ordinary DC motor driver chip to drive the rearview mirror is that it is impossible to customize some specific functions according to the use background of the rearview mirror.

[0003] Based on this situation, a solution specifically for the rearview mirror folding drive motor has been designed in the prior art. Its feature is that the functional module is integrated into an IC, which greatly saves space and cost, and the chip monitors the current in real time to determine whether the rearview mirror is folded in place. Once the rearview mirror is folded in place, the motor stops rotating and reaches the stall state, and the motor current will increase significantly. This increased current will be detected by the chip, and after the detection, the chip will automatically shut down and reduce the motor current to zero. On the one hand, it reduces unnecessary power consumption, and on the other hand, it reduces the heating of the motor and eliminates the safety hazards caused by heating.

[0004] However, a new problem has arisen, that is, the onboard chip needs to meet the working requirements of motor vehicles in various harsh environments. In cold winter weather, the rearview mirror will be difficult to open or fold due to freezing. In addition, in deserts or areas with severe sand and dust, foreign objects often squeeze into the rearview mirror module. This will also cause the rearview mirror to get stuck when folding or opening. Summary of the invention

[0005] In view of the above-mentioned problems existing in the prior art, the purpose of the present invention is to provide a rearview mirror chip logic operation method and system with a retry function, which realizes the special customization of the rearview mirror folding drive chip, allowing the rearview mirror drive motor to try to recover when it is stuck, thereby facilitating the normal operation of the folding work.

[0006] In order to solve the above problems, the technical solution adopted by the present invention is as follows: The logic operation method of a rearview mirror chip with a retry function comprises the following steps: S1: Start the motor that drives the rearview mirror to generate a direction signal, and the chip recognizes the information that the drive starts; S2: After the current of the motor ends the starting ignoring time, sampling and detecting the current; S3: According to the current sampled and detected in step S2, an external set resistor is used to determine the threshold value for detecting the stall current. If the current sampled and detected exceeds the threshold value, that is, a STALL high level occurs, the chip recognizes that the motor is in a stall state, otherwise it recognizes that the motor is not in a stall state; S4: When the motor is identified as being in a stalled state, the chip will shut down and restart several times; During the process of the chip being continuously restarted in step S4 for several times, if the current sampled and detected does not exceed the threshold value in one of them, that is, the STALL high level does not occur, the chip recognizes that the motor is not in a stalled state, and enters the normal driving process; if during the last restart process, the chip still recognizes that the motor is in a stalled state, the chip is directly shut down and no longer retries.

[0007] Further, in step S2, the circuit for sampling and detecting the current includes an M1 low-side power transistor and an M2 high-side power transistor in an H-bridge structure. The working logic of the circuit is that the M1 low-side power transistor and the M2 low-side power transistor are sampled by the mapping transistor M1A and the mapping transistor M2A respectively, and the sampled currents are converted into a low-side induced voltage LS_SENSE and a high-side induced voltage HS_SENSE through resistors R_SENSE1 and R_SENS2 respectively. The high-side induced voltage HS_SENSE is used to perform overcurrent protection on the internal circuit, and the low-side induced voltage LS_SENSE is used to detect the stall state.

[0008] Further, in step S3, the threshold circuit for detecting the stalled-rotor current includes a resistor R1, a resistor R2, an operational amplifier, and a power supply VP. The working logic of the circuit is that the voltage of the power supply VP is distributed by the resistors R1 and R2 so that the voltage at the input end of the operational amplifier is 1 / 8 of the power supply VP voltage. The output end of the operational amplifier is connected to RSET, and the value of RSET determines the value of the branch current. The branch current is copied through the current mirror to obtain an I_ST current that increases only with the increase of the power supply VP, that is, the threshold of the stalled-rotor current. The low-side inductive voltage LS_SENSE obtained in step S2 forms an I_SENSE current through a voltage-current converter. The I_SENSE current and the I_ST current are compared by a current comparator to generate a logic result. When the logic result is a high level, it represents that a STALL high level occurs and a stall state is established.

[0009] Furthermore, the method includes a soft start-stop circuit for controlling the motor to perform soft start-stop; The circuit for sampling and detecting the current includes an M1 low-side power transistor and an M2 high-side power transistor in an H-bridge structure, and the soft start-stop circuit includes an 8-bit DAC circuit connected to the gate of the M1 low-side power transistor, and the DAC circuit controls the VGS value of the M1 low-side power transistor.

[0010] The rearview mirror chip logic operation system with a retry function comprises a current detection module, a threshold detection module and a current comparison module; The current detection module is used to sample and detect the current, which is the current generated after the motor driving the rearview mirror to rotate generates a direction signal and the current generated by the motor ends the start ignoring time; The threshold detection module uses an external setting resistor to determine the threshold for detecting the locked-rotor current; The current comparison module compares the current value obtained by sampling and detecting the current detection module with the threshold value determined by the threshold detection module. If the current detected by sampling exceeds the threshold value, that is, the STALL high level occurs, the chip recognizes that the motor is in a stalled state, otherwise it is recognized that the motor is not in a stalled state; When the chip identifies that the motor is in a stalled state, the system controls the motor that drives the rearview mirror to restart several times, and during the continuous restarting process, if the current sampled and detected in one of them does not exceed the threshold, that is, the STALL high level does not occur, the chip identifies that the motor is not in a stalled state, and no restart is performed, and the normal driving process is directly entered; if after the last restart, the chip still identifies that the motor is in a stalled state, the chip is directly shut down and no further retries are made.

[0011] Furthermore, the current detection module includes a sampling detection circuit, which includes an M1 low-side power transistor and an M2 high-side power transistor in an H-bridge structure. The mapping transistor M1A and the mapping transistor M2A sample the M1 low-side power transistor and the M2 low-side power transistor respectively, and then convert the sampled currents through resistors R_SENSE1 and R_SENS2 to obtain a low-side induced voltage LS_SENSE and a high-side induced voltage HS_SENSE. The high-side induced voltage HS_SENSE is used to perform overcurrent protection on the internal circuit, and the low-side induced voltage LS_SENSE is used to detect the stall state.

[0012] Furthermore, the threshold detection module includes a threshold detection circuit, which includes a resistor R1, a resistor R2, an operational amplifier and a power supply VP. The voltage of the power supply VP is distributed by the resistor R1 and the resistor R2 so that the voltage at the input end of the operational amplifier is 1 / 8 of the power supply VP voltage. The output end of the operational amplifier is connected to RSET, and the value of RSET determines the value of the branch current. The branch current is copied through a current mirror to obtain an I_ST current that increases only with the increase of the power supply VP, that is, the threshold of the locked-rotor current.

[0013] Furthermore, the current comparison module includes a current comparison circuit, which converts the low-side induced voltage LS_SENSE obtained by the sampling detection circuit into an I_SENSE current through a voltage-current converter. The current comparison circuit compares the LS_SENSE current and the I_SENSE current through a current comparator. When the logic result is a high level, it represents that a STALL high level occurs and a stall state is established.

[0014] Furthermore, the system also includes a soft start-stop circuit for controlling the motor to perform soft start-stop; The circuit for sampling and detecting the current includes an M1 low-side power transistor and an M2 high-side power transistor in an H-bridge structure, and the soft start-stop circuit includes an 8-bit DAC circuit connected to the gate of the M1 low-side power transistor, and the DAC circuit controls the VGS value of the M1 low-side power transistor.

[0015] Compared with the prior art, the present invention has the following beneficial effects: (1) The present invention provides a logic operation method and system for a rearview mirror chip with a retry function, which realizes the special customization of the rearview mirror folding drive chip, allowing the rearview mirror drive motor to try to recover when it is stuck, thereby facilitating the normal operation of the folding work; (2) The present invention designs a soft start-stop circuit structure based on the above-mentioned chip logic operation method and system operation, which can reduce the current impact at startup, reduce the mechanical stress at startup, prevent system instability, and at the same time reduce the voltage spike and current mutation when the motor is shut down, protect the motor and drive circuit, improve the reliability and service life of the system, reduce noise and vibration, and prevent the motor from having reverse current during the shutdown process. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A schematic diagram of the current of a driving motor changing with time in the prior art; Figure 2 A schematic diagram of the circuit structure of a product in the prior art; Figure 3 A flowchart of the steps of the logic operation method of the present invention; Figure 4 It is a structural diagram of a sampling detection circuit in the logic operation system of the present invention; Figure 5 A structural diagram of a threshold detection circuit in a logic operation system according to the present invention; Figure 6 A structural diagram of a current comparison circuit in a logic operation system according to the present invention; Figure 7 It is a structural diagram of the soft start-stop circuit of the present invention; Figure 8 This is a schematic diagram of the change of VGS value controlled by the DAC circuit over time during soft start; Fig. 9 A schematic diagram showing the change of the VGS value controlled by the DAC circuit over time during soft shutdown; Fig.10 It is a schematic diagram of the change of motor current over time after the soft start-stop circuit is adopted; Fig.11 It is a schematic diagram of the motor state change during the soft closing process and a schematic diagram of the DAC circuit structure; Fig.12 A schematic diagram of a complete timing setting of the logic operation method and system of the present invention; Fig.13 Schematic diagram of simulation waveform of the retry process in this embodiment. DETAILED DESCRIPTION

[0017] The present invention is further described below in conjunction with specific embodiments.

[0018] like Figure 1As shown in the figure, it shows an existing design scheme specifically for the rearview mirror folding drive motor. Its feature is that the functional module is integrated into the IC, which greatly saves space and cost. The chip has real-time current monitoring inside to determine whether the rearview mirror is folded in place. Once the rearview mirror is folded in place, the motor stops rotating and reaches the stalled (SATLL) state, and the motor current will increase significantly. This increased current will be detected by the chip, and after the detection, the chip will automatically shut down and reduce the motor current to zero. On the one hand, it reduces unnecessary power consumption, and on the other hand, it reduces the heating of the motor and eliminates the safety hazards caused by heating.

[0019] like Figure 1 As shown in the figure, it shows a schematic diagram of the current change of the motor in this case. When the motor starts, a peak current will be generated. This peak current is temporarily generated in the initial state of the motor start-up, and then the motor enters a stable working state. The chip does not monitor this peak current, and its interval is designed to be 300ms, which is called the start blanking time. After the rearview mirror is folded, the motor current increases. If this increased current continues for a period of time (stall holding time), the chip will recognize that the rearview mirror has been folded into place. The meaning of this stall holding time is that when the motor is in a stalled state, the current increases significantly to a relatively large value. At this time, the chip will recognize that the rearview mirror has been rotated into place, and then choose to shut down the chip.

[0020] The question here is why do we have to wait for a while before shutting down? The reasons are: 1) When the motor is running, a large current noise will occasionally appear. The peak value of this noise is very high, higher than the detection value of stall. At this time, if a time segment is not set to distinguish, the chip will only recognize the peak value of this noise and shut down. However, the rearview mirror has not completed the folding work at this time; 2) Another situation is that there is a foreign object stuck in the rearview mirror module, such as a small stone or relatively large gravel or dust. When there is a foreign object stuck, the current will be very high during the stuck period. At this time, if the chip thinks that it has been folded and rotated into place and directly shuts down, it is easy for the rearview mirror to not rotate into place.

[0021] like Figure 2 As shown, it shows the circuit structure diagram of a designed product TMP7326, in which IN1 and IN2 are directly connected to the car battery through a relay, and the folding / opening command is executed through the relay switch button.

[0022] Therefore, based on the problems described in the aforementioned background technology, the rearview mirror chip logic operation method and system with a retry function described in the present invention have designed a complete circuit logic operation method and operation system, aiming to enable the chip to have a function of automatically retrying and restarting when a fault occurs, so that the rearview mirror can recover from a stuck state and achieve normal operation.

[0023] In the present invention, the retry function will allow the chip to automatically try to drive the motor 4 times, each time with an interval of 25ms. Specifically, the retry detection starts within 100ms after the initial ignore time. During this period, if the current exceeds the detection value of the stall, the chip will shut down and try to drive again, for a total of 4 attempts. If one of the motors starts to rotate during the 4 attempts, the normal driving sequence will be entered. If it still cannot be driven normally, the chip will be completely shut down after 4 attempts, and no further attempts will be made. The driver and passengers will check the condition of the rearview mirror.

[0024] Specifically, Figure 3 As shown, the rearview mirror chip logic operation method with a retry function of the present invention is based on a rearview mirror chip logic operation system with a retry function, and the method comprises the following steps: S1: Start the motor that drives the rearview mirror to generate a direction signal, and the chip recognizes the information that the drive starts.

[0025] S2: After the motor current ends the initial ignoring time, the circuit is sampled and tested; Figure 4 As shown, the aforementioned logic operation system includes a current detection module, which includes a sampling detection circuit, which includes an M1 low-side power transistor and an M2 high-side power transistor in an H-bridge structure, that is, a low-side switch and a high-side switch, which are driven by low-side and high-side driving circuits respectively. Further, next to the M1 low-side power transistor and the M2 high-side power transistor, a smaller-sized mapping transistor M1A and a mapping transistor M2A are respectively provided for current sampling, and the sampling current is one-three thousandth of the current flowing through the M1 low-side power transistor and the M2 high-side power transistor, and then the sampled current is converted into a low-side induction voltage LS_SENSE and a high-side induction voltage HS_SENSE obtained by passing through a resistor R_SENSE1 and a resistor R_SENSE2 (500KΩ), respectively, wherein the high-side induction voltage HS_SNESE is used for overcurrent protection of the internal circuit, and the low-side induction voltage LS_SENSE is used for detection of the stall state.

[0026] S3: According to the low-side induction voltage LS_SENSE obtained in step S2, an external setting resistor RSET is used to determine the threshold for detecting the stall current. Here, the threshold detection module in the logic operation system is first combined, and the module includes a threshold detection circuit, and its circuit structure is as follows Figure 5 As shown, it includes resistors R1, R2, an operational amplifier and a power supply VP. The voltage of the power supply VP is distributed by resistors R1 and R2 so that the voltage at the input end of the operational amplifier is 1 / 8 of the power supply VP voltage. The output end of the operational amplifier is connected to RSET. The value of RSET determines the value of the branch current. The branch current is copied through the current mirror to obtain an I_ST current that increases only with the increase of the power supply VP, that is, the threshold of the stall current. The increase of the power supply VP will increase both the running current and the stall current of the motor. At this time, the detection value of the stall current will also increase, thereby achieving accurate detection.

[0027] Furthermore, if Figure 6 As shown, it shows the current comparison circuit in the current comparison module in the present logic operation system, which converts the low-side sensing voltage LS_SENSE into the I_SENSE current through a voltage-current converter, and then compares the LS_SENSE current and the I_SENSE current through a current comparator. When the logic result is a high level, it indicates that the STALL high level occurs and the stall state is established.

[0028] During the 100ms period after the start ignore time, if the STALL high level occurs, the chip will shut down and restart. However, a problem will arise in this process. With the development and popularization of new energy vehicles, the environment inside the car is much quieter than that of fuel vehicles. This repeated retry function will cause the motor module to mechanically shake and emit noise such as "da, da, da" due to the high current change. Therefore, we introduced a soft start-stop circuit based on the retry, which can control the motor to soft start and stop, thereby eliminating such noise and vibration.

[0029] Specifically, Figure 7 As shown, the soft start-stop circuit includes an 8-bit DAC circuit connected to the gate of the M1 low-side power transistor. The DAC circuit controls the VGS value of the M1 bottom-side transistor, thereby making the on-resistance of the low-side switch change linearly to achieve soft start-stop.

[0030] like Figure 8 As shown in FIG. 1 , in this embodiment, during soft start, the value of VGS rises slowly from 0 to 5V, and the on-resistance also drops slowly from a high impedance state to a normal level (150mΩ). The soft shutdown process is just the opposite. Fig. 9As shown in the figure, the value of VGS slowly decreases from 5V to 0, and the on-resistance slowly increases from 150mΩ to the high-impedance state when it is turned off.

[0031] In this embodiment, the soft start and soft shutdown time are both 60ms. During this 60ms process, 8 bits of data enter the DAC as time changes, and the DAC generates a corresponding VGS value based on the 8 bytes of data. Fig.10 As shown in Figure 1, it shows how the motor current changes over time after the soft start-stop circuit is adopted.

[0032] like Fig.11 As shown in the figure, during the 60ms of soft shutdown, the chip current is linearly reduced through the DAC circuit control. In the following 20μs, the high and low side switches of the H-bridge are completely turned off, and it enters the high impedance state (HiZ). Then all the switches on the low side of the H-bridge are turned on, and it enters the braking state (BRAKE). The soft shutdown process is to gradually release the electromotive force energy of the inductance in the motor to avoid the instantaneous impact of the electromotive force caused by sudden shutdown.

[0033] Specifically, the functions of soft start include: 1) Reduce the impact of starting current: When the motor starts, it will generate a large starting current, which may cause impact on the power supply and circuit; the soft start function can effectively reduce the impact of the starting current and protect the power supply and drive circuit by gradually increasing the current; 2) Reduce mechanical stress: Sudden start-up will cause great stress on the mechanical parts of the motor, which may cause wear or damage to the mechanical parts; the soft start function can smoothly increase the speed of the motor, reduce mechanical stress, and extend the service life of the motor; 3) Prevent system instability: Sudden high current startup may cause power supply voltage fluctuations, thus affecting system stability; the soft start function can increase the current smoothly, reduce the impact on the power supply, and ensure system stability; 4) Reduce noise and vibration: Starting the motor suddenly may generate a lot of noise and vibration; the soft start function can reduce noise and vibration by smoothly increasing the speed, thereby improving the comfort and reliability of the system.

[0034] The effects of soft closing include: 1) Reduce voltage spikes and current mutations: When the power is suddenly cut off, the motor may generate voltage spikes and current mutations, which may cause damage to the motor drive circuit and other electronic components. The soft-off function can smoothly reduce the current, thereby reducing spikes and mutations; 2) Protect the motor and drive circuit: Sudden power outages may cause mechanical and electrical stress to the motor and drive circuit. The soft-off function can gradually reduce the motor current to protect the motor and drive circuit from damage; 3) Improve system reliability and life: By reducing electrical and mechanical stress, the soft shutdown function can improve the overall reliability and service life of the motor and drive system; 4) Reduce noise and vibration: Sudden current interruption may cause noise and vibration in the motor. The soft-off function can smoothly reduce motor speed and power, thereby reducing noise and vibration; 5) Prevent reverse current of the motor: When the motor is suddenly powered off, the inertia of the motor may generate reverse current, which may affect the power supply and other electronic components. The soft shutdown function can gradually reduce the current to prevent the generation of reverse current.

[0035] like Fig.12 As shown in the figure, it shows the complete timing setting diagram of the method and the retry system. When the direction signal (CW / CCW) is generated, the chip recognizes it as the start of driving (ST). The 500ms from this time belongs to the retry period. If the retry conditions are met, the retry operation will be performed during this period. This 500ms includes the 300ms of the start blanking time. In fact, the judgment of whether to retry occurs during the 100ms period after the start blanking time. If the current is greater than the value of the stall state during this 100ms, the chip determines that a retry is required. Fig.13 The figure shows the simulation waveform diagram of the retry in this embodiment.

Claims

1. A logic operation method of a rearview mirror chip with a retry function, characterized in that: The method comprises the following steps: S1: Start the motor that drives the rearview mirror to generate a direction signal, and the chip recognizes the information that the drive starts; S2: After the current of the motor ends the starting ignoring time, sampling and detecting the current; S3: According to the current sampled and detected in step S2, an external set resistor is used to determine the threshold value for detecting the stall current. If the current sampled and detected exceeds the threshold value, that is, a STALL high level occurs, the chip recognizes that the motor is in a stall state, otherwise it recognizes that the motor is not in a stall state; S4: When the motor is identified as being in a stalled state, the chip will shut down the motor and restart it several times; During the process of the chip being continuously restarted in step S4 for several times, if the current sampled and detected does not exceed the threshold value in one of them, that is, the STALL high level does not occur, the chip recognizes that the motor is not in a stalled state, and enters the normal driving process; if during the last restart process, the chip still recognizes that the motor is in a stalled state, the chip is directly shut down and no longer retries.

2. The logic operation method according to claim 1, characterized in that: In step S2, the circuit for sampling and detecting the current includes an M1 low-side power transistor and an M2 high-side power transistor in an H-bridge structure. The working logic of the circuit is that the M1 low-side power transistor and the M2 low-side power transistor are sampled by the mapping transistor M1A and the mapping transistor M2A respectively, and then the sampled currents are converted into a low-side induced voltage LS_SENSE and a high-side induced voltage HS_SENSE through resistors R_SENSE1 and R_SENS2 respectively. The high-side induced voltage HS_SENSE is used to perform overcurrent protection on the internal circuit, and the low-side induced voltage LS_SENSE is used to detect the stall state.

3. The logic operation method according to claim 2, characterized in that: In step S3, the threshold circuit for detecting the stalled-rotor current includes a resistor R1, a resistor R2, an operational amplifier, and a power supply VP. The working logic of the circuit is that the voltage of the power supply VP is distributed by the resistors R1 and R2 so that the voltage at the input end of the operational amplifier is 1 / 8 of the power supply VP voltage. The output end of the operational amplifier is connected to RSET, and the value of RSET determines the value of the branch current. The branch current is copied through the current mirror to obtain an I_ST current that increases only with the increase of the power supply VP, that is, the threshold of the stalled-rotor current. The low-side inductive voltage LS_SENSE obtained in step S2 forms an I_SENSE current through a voltage-current converter. The I_SENSE current and the I_ST current are compared by a current comparator to generate a logic result. When the logic result is a high level, it represents that a STALL high level occurs and a stall state is established.

4. A logic operation method according to any one of claims 1 to 3, characterized in that: The method includes a soft start-stop circuit for controlling the motor to perform soft start-stop; The circuit for sampling and detecting the current includes an M1 low-side power transistor and an M2 high-side power transistor in an H-bridge structure, and the soft start-stop circuit includes an 8-bit DAC circuit connected to the gate of the M1 low-side power transistor, and the DAC circuit controls the VGS value of the M1 low-side power transistor.

5. A rearview mirror chip logic operation system with a retry function, characterized in that: The system includes a current detection module, a threshold detection module and a current comparison module; The current detection module is used to sample and detect the current, which is the current generated after the motor driving the rearview mirror to rotate generates a direction signal and the current generated by the motor ends the start ignoring time; The threshold detection module uses an external setting resistor to determine the threshold for detecting the locked-rotor current; The current comparison module compares the current value obtained by sampling and detecting the current detection module with the threshold value determined by the threshold detection module. If the current detected by sampling exceeds the threshold value, that is, the STALL high level occurs, the chip recognizes that the motor is in a stalled state, otherwise it is recognized that the motor is not in a stalled state; When the chip identifies that the motor is in a stalled state, the system controls the motor that drives the rearview mirror to restart several times, and during the continuous restarting process, if the current sampled and detected in one of them does not exceed the threshold, that is, the STALL high level does not occur, the chip identifies that the motor is not in a stalled state, and no restart is performed, and the normal driving process is directly entered; if after the last restart, the chip still identifies that the motor is in a stalled state, the chip is directly shut down and no further retries are made.

6. The logic operation system according to claim 5, characterized in that: The current detection module includes a sampling detection circuit, which includes an M1 low-side power transistor and an M2 high-side power transistor in an H-bridge structure. The mapping transistor M1A and the mapping transistor M2A respectively sample the M1 low-side power transistor and the M2 low-side power transistor, and then convert the sampled currents through resistors R_SENSE1 and R_SENS2 to obtain a low-side induced voltage LS_SENSE and a high-side induced voltage HS_SENSE. The high-side induced voltage HS_SENSE is used to perform overcurrent protection on the internal circuit, and the low-side induced voltage LS_SENSE is used to detect the stall state.

7. The logic operation system according to claim 6, characterized in that: The threshold detection module includes a threshold detection circuit, which includes a resistor R1, a resistor R2, an operational amplifier and a power supply VP. The voltage of the power supply VP is distributed by the resistors R1 and R2 so that the voltage at the input end of the operational amplifier is 1 / 8 of the power supply VP voltage. The output end of the operational amplifier is connected to RSET, and the value of RSET determines the value of the branch current. The branch current is copied through a current mirror to obtain an I_ST current that increases only with the increase of the power supply VP, that is, the threshold of the stall current.

8. The logic operation system according to claim 7, characterized in that: The current comparison module includes a current comparison circuit, which converts the low-side induced voltage LS_SENSE obtained by the sampling detection circuit into an I_SENSE current through a voltage-current converter. The current comparison circuit compares the LS_SENSE current and the I_SENSE current through a current comparator. When the logic result is a high level, it represents that a STALL high level occurs and a stall state is established.

9. The logic operation system according to any one of claims 5 to 8, characterized in that: The system also includes a soft start-stop circuit for controlling the motor to perform soft start-stop; The circuit for sampling and detecting the current includes an M1 low-side power transistor and an M2 high-side power transistor in an H-bridge structure, and the soft start-stop circuit includes an 8-bit DAC circuit connected to the gate of the M1 low-side power transistor, and the DAC circuit controls the VGS value of the M1 low-side power transistor.

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