Current output circuit, interface circuit and carrying tool
By introducing output detection and protection modules into the current output circuit, the problem of easy damage to the transistor switch control circuit is solved, and effective protection of load and circuit is achieved.
Patent Information
- Application Number
- CN202510430666.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-07
- Publication Date
- 2025-07-25
AI Technical Summary
The existing transistor switch control circuit lacks output detection and circuit protection functions, resulting in the load-side transistor being easily damaged or burned due to excessive current.
A current output circuit is designed, including an output detection module and a protection module, and the circuit protection is achieved by detecting the output voltage of the circuit and feeding it back to the protection module to control the circuit output interrupt.
When the load is abnormal, the circuit output is cut off in time to prevent load and circuit damage and achieve effective protection.
Smart Images
Figure CN120371069A_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to the field of circuit technologies, and particularly to a current output circuit, an interface circuit, and a vehicle carrier. Background Art
[0002] Currently, for vehicle carriers such as vehicles, many vehicle manufacturers have requirements for small current digital output at the instrument end. In view of this, during vehicle development, suppliers generally design a switch control circuit for realizing small current output. Since the circuit cost of a triode is relatively low, the triode switch control circuit is widely used in occasions with relatively small currents.
[0003] In related technologies, a triode switch control circuit includes a single-chip microcomputer output port and two triodes connected in sequence, and each triode is respectively equipped with two voltage dividing resistors. Based on the voltage division of the voltage dividing resistors, the two triodes are turned on so that current flows through the load end. However, this circuit is prone to damage. Summary of the Invention
[0004] In order to solve the above technical problems or at least partially solve the above technical problems, the present disclosure provides a current output circuit, an interface circuit, and a vehicle carrier.
[0005] In a first aspect, the present disclosure provides a current output circuit, including:
[0006] a circuit output module, an output detection module, and a first protection module;
[0007] The circuit output module includes a control end, a first end, and a second end. The output detection module includes an input end and an output end. The first protection module includes at least a first connection end and a second connection end. The first end of the circuit output module is connected to a first power supply. The second end of the circuit output module is connected to a load and the input end of the output detection module. The control end of the circuit output module is connected to the first connection end of the first protection module. The output end of the output detection module is connected to the second connection end of the first protection module;
[0008] wherein, the output detection module is configured to detect the output voltage of the circuit output module and feed it back to the first protection module; the first protection module is configured to control the output interruption of the circuit output module based on the output voltage being less than a first threshold value
[0009] In a second aspect, the present disclosure further provides an interface circuit, including any one of the above current output circuits.
[0010] In a third aspect, the present disclosure further provides a vehicle carrier, including any one of the above interface circuits.
[0011] The technical solution provided by the embodiments of the present disclosure has the following advantages compared with the prior art:
[0012] In the current output circuit provided by the present disclosure, the first end of the circuit output module is connected to the first power supply, the second end of the circuit output module is connected to the load and the input end of the output detection module, the control end of the circuit output module is connected to the first connection end of the first protection module, and the output end of the output detection module is connected to the second connection end of the first protection module. On this basis, the output detection module is used to detect the output voltage of the circuit output module and feedback it to the first protection module, so that the first protection module controls the output interruption of the circuit output module based on the output voltage being less than the first threshold. In this way, when a short circuit occurs, the circuit enters the protection mode, and the circuit output voltage can be maintained at 0V, and the output current of the output circuit is 0mA, thereby realizing circuit protection. BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The drawings herein are incorporated into the specification and form a part of the specification, showing embodiments consistent with the present disclosure, and are used together with the specification to explain the principles of the present disclosure.
[0014] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, for those of ordinary skill in the art, other drawings can also be obtained based on these drawings without creative efforts.
[0015] Figure 1 FIG. 15 is a schematic structural diagram of a triode switch control circuit provided by the related art;
[0016] Figure 2 FIG. 19 is a schematic structural diagram of a current output circuit provided by an embodiment of the present disclosure;
[0017] Figure 3 FIG. 23 is a schematic structural diagram of another current output circuit provided by an embodiment of the present disclosure;
[0018] Figure 4 FIG. 27 is a schematic structural diagram of yet another current output circuit provided by an embodiment of the present disclosure;
[0019] Figure 5 FIG. 31 is a schematic diagram of a simulation curve for a third resistor provided by an embodiment of the present disclosure;
[0020] Figure 6 FIG. 35 is a schematic diagram of another simulation curve for a third resistor provided by an embodiment of the present disclosure;
[0021] Figure 7 FIG. 39 is a schematic structural diagram of a hysteresis comparator circuit provided by an embodiment of the present disclosure;
[0022] Figure 8 Schematic diagram of another hysteresis comparator circuit provided by an embodiment of the present disclosure;
[0023] Figure 9 Logic diagram of a protection mechanism for a current output circuit provided by an embodiment of the present disclosure;
[0024] Figure 10 Schematic diagram of another transistor switch control circuit provided by the related art;
[0025] Figure 11 For the related art, a Figure 10 simulation curve schematic diagram;
[0026] Figure 12 Schematic diagram of yet another current output circuit provided by an embodiment of the present disclosure;
[0027] Figure 13 For an embodiment of the present disclosure, a Figure 12 simulation curve schematic diagram. Detailed implementation manners
[0028] In order to more clearly understand the above objects, features, and advantages of the present disclosure, the solutions of the present disclosure will be further described below. It should be noted that, without conflict, the embodiments of the present disclosure and the features in the embodiments may be combined with each other.
[0029] Many specific details are set forth in the following description to facilitate a thorough understanding of the present disclosure, but the present disclosure may be implemented in other ways different from those described herein; obviously, the embodiments in the specification are only a part of the embodiments of the present disclosure, rather than all of the embodiments.
[0030] Regarding the technical problems described in the background art, the applicant has found through research that due to the lack of output detection and circuit protection functions in the related transistor switch control circuit, when two transistors are in the amplification state and the current amplification factor is too large, it is very easy for the transistor connected to the load terminal to burn out due to its own excessive power consumption; or, when the load is abnormal, the circuit cannot limit the output current, resulting in a large body current flowing through the transistor connected to the load terminal, and then burning out. Specifically, with reference to Figure 1 the circuit in the related art is exemplarily described.
[0031] Exemplarily, Figure 1 Schematic diagram of a transistor switch control circuit provided by the related art. Refer to Figure 1, the triode switch control circuit includes a single-chip microcomputer output port 01, a first triode Q1, a second triode Q2, a first voltage-dividing resistor 02, a second voltage-dividing resistor 03, a third voltage-dividing resistor 04, a fourth voltage-dividing resistor 05, a capacitor 06, a power supply terminal 07, and a load 08. Specifically, one end of the single-chip microcomputer output port 01 is connected to the base of the first triode Q1 through the third voltage-dividing resistor 04, and the other end is connected to the emitter of the first triode Q1. One end of the fourth voltage-dividing resistor 05 is connected between the third voltage-dividing resistor 04 and the base of the first triode Q1, and the other end is grounded. The collector of the first triode Q1 is sequentially connected to the power supply terminal 07 through the second voltage-dividing resistor 03 and the first voltage-dividing resistor 02. The power supply terminal 07 is connected to one end of the load 08 through the second triode Q2, the other end of the load 08 is grounded, the base of the second triode Q2 is connected between the second voltage-dividing resistor 03 and the first voltage-dividing resistor 02, and the capacitor 06 is connected in parallel with the first voltage-dividing resistor 02.
[0032] During the operation of the circuit, the single-chip microcomputer output port 01 normally outputs a high-level voltage. Through the voltage division of the third voltage-dividing resistor 04 and the fourth voltage-dividing resistor 05, the base-emitter voltage (Vbe, abbreviated as the base voltage) of the first triode Q1 is forward-biased, causing the first triode Q1 to turn on. And based on the voltage division of the first voltage-dividing resistor 02 and the second voltage-dividing resistor 03, the Vbe of the second triode Q2 is reverse-biased, causing the second triode Q2 to turn on. Thus, the current flows from the power supply terminal 07 through the second triode Q2 to the load 08, realizing that there is current flowing through the load 08. Exemplarily, the power supply terminal 07 can be configured as a 12V power supply.
[0033] When the circuit is working properly, the triode switch control circuit needs to ensure that the first triode Q1 and the second triode Q2 are in the saturation state. If the two triodes are in the amplification state and the current amplification factor is too large, it is very easy to cause the second triode Q2 to burn out due to its own excessive power consumption. In addition, when the load is abnormal, the circuit cannot limit the output current, resulting in a relatively large body current flowing through the second triode Q2, and then burning out.
[0034] To address at least one of the above problems, an embodiment of the present disclosure provides a current output circuit, which can also be referred to as a switch circuit. The current output circuit has the functions of output detection and circuit protection. Specifically: an output detection module is used to detect the output voltage of the circuit output module and feedback it to the first protection module, so that the first protection module controls the output interruption of the circuit output module based on the output voltage being less than the first threshold to achieve circuit protection.
[0035] Next, the current output circuit, interface circuit, and carrier tool provided by the embodiments of the present disclosure will be described exemplarily with reference to the accompanying drawings.
[0036] Figure 2Schematic diagram of a current output circuit provided by an embodiment of the present disclosure. Refer to Figure 2 , the current output circuit includes: a circuit output module 110, an output detection module 120, and a first protection module 130; the circuit output module 110 includes a control end, a first end, and a second end, the output detection module 120 includes an input end and an output end, and the first protection module 130 includes at least a first connection end and a second connection end; the first end of the circuit output module 110 is connected to a first power supply 140, the second end of the circuit output module 110 is connected to a load 08 and the input end of the output detection module 120, the control end of the circuit output module 110 is connected to the first connection end of the first protection module 130, and the output end of the output detection module 120 is connected to the second connection end of the first protection module 130.
[0037] Among them, the output detection module 120 is configured to detect the output voltage of the circuit output module 110 and feedback it to the first protection module 130; the first protection module 130 is configured to control the output interruption of the circuit output module 110 based on the output voltage being less than a first threshold.
[0038] Specifically, the output detection module 120 detects the output voltage of the circuit output module 110 and feeds back the detected output voltage to the first protection module 130, thereby introducing a feedback mechanism for the output voltage. Among them, the first protection module 130 determines the working state of the load 08 based on the received output voltage, such as an abnormal working state (such as overcurrent, short circuit, etc.) or a normal working state, and takes corresponding measures for protection when the working state of the load 08 is in an abnormal working state.
[0039] Exemplarily, when the load 08 is in an abnormal working state, the load 08 may exhibit at least one of abnormal conditions such as overcurrent and short circuit, so that the output voltage of the circuit output module 110 will be abnormal, that is, the output voltage will usually be small. At this time, the output detection module 120 feeds back the output voltage to the first protection module 130, and the first protection module 130 controls the output interruption of the circuit output module 110 based on the output voltage being less than a set first threshold to improve the adverse effects generated when the load 08 is in an abnormal working state.
[0040] In this way, the current output circuit provided by the present disclosure completes the self-diagnosis of the circuit based on the corresponding feedback mechanism, and when the output voltage is less than the first threshold, the output of the circuit output module 110 is timely cut off by the first protection module 130 to prevent abnormal output (or large current) from damaging the load and even the entire circuit, realizing effective protection of the entire circuit.
[0041] The current output circuit provided by the embodiments of the present disclosure detects the output voltage of the circuit output module 110 by using the output detection module 120 and feeds it back to the first protection module 130, so that the first protection module 130 controls the output interruption of the circuit output module 110 based on the output voltage being less than the first threshold, achieving effective circuit protection.
[0042] In some embodiments, Figure 3 FIG. is a schematic structural diagram of another current output circuit provided by the embodiments of the present disclosure. On the basis of Figure 2 and with reference to Figure 3 , this current output circuit further includes an output control module 150 and a second protection module 160; the output control module 150 includes a control signal input terminal and a control signal output terminal, and the second protection module 160 includes a first end and a second end; the first end of the second protection module 160 is connected to the second end of the circuit output module 110, the second end of the second protection module 160 is connected to the control signal input terminal of the output control module 150, and the control signal output terminal of the output control module 150 is coupled to the control terminal of the circuit output module 110.
[0043] Among them, the second protection module 160 is configured to control the output control module 150 to turn off and interrupt the output of the circuit output module 110 based on the output voltage of the second end of the circuit output module 110 being less than the second threshold.
[0044] It should be noted that the control signal input terminal of the output control module 150 receives an external control signal, and the second protection module 160 is at least used to adjust the level of the control signal, so as to control the on / off state of the output control module 150 based on the level of the control signal. For example, after pulling down the control signal, the output control module 150 is controlled to turn off, so that the output of the circuit output module 110 is interrupted. On the contrary, if the control signal is at a high level, the output control module 150 is turned on, so that the circuit output module 110 can perform circuit output.
[0045] Specifically, when the load 08 is in an abnormal working state, including but not limited to overcurrent, short circuit, etc., the output voltage of the circuit output module 110 will be abnormal, that is, the output voltage is usually small. At this time, the second protection module 160 obtains the output voltage of the second end of the circuit output module 110, determines that the output voltage is less than the set second threshold, controls the output control module 150 to turn off, and then interrupts the output of the circuit output module 110 to avoid the adverse effects generated when the load 08 is in an abnormal working state.
[0046] Thus, when the output voltage of the current output circuit provided by the present disclosure is less than the second threshold, the second protection module 160 timely cuts off the output of the circuit output module 110 to prevent abnormal output (or large current) from damaging the load and even the entire circuit, thereby achieving effective protection for the entire circuit.
[0047] In some embodiments, based on Figure 2 and with continued reference to Figure 3 , the first protection module 130 further includes a third connection terminal, and the control signal output terminal of the output control module 150 is connected to the third connection terminal of the first protection module 130.
[0048] Specifically, based on the connection between the first protection module 130 and the circuit output module 110, by setting the control signal output terminal of the output control module 150 to be connected to the third connection terminal of the first protection module 130, it is possible to establish a connection between the output control module 150 and the circuit output module 110 via the first protection module 130, that is, the control signal output terminal of the output control module 150 is coupled to the control terminal of the circuit output module 110. Subsequently, the circuit output module 110, the first protection module 130, and the output control module 150 form an association in the connection relationship to cooperate in achieving circuit protection.
[0049] In some embodiments, Figure 4 is a schematic structural diagram of another current output circuit provided by an embodiment of the present disclosure. Based on Figure 3 and with reference to Figure 4 , the output control module 150 includes a first triode Q1 and a startup capacitor C1; the control terminal of the first triode Q1 is connected to the control signal input terminal of the output control module 150, the input terminal of the first triode Q1 is connected to the control signal output terminal of the output control module 150, and the output terminal of the first triode Q1 is grounded; the startup capacitor C1 is connected between the control terminal and the input terminal of the first triode Q1.
[0050] Among them, in the rising edge stage of the control signal, the current output circuit is used to start the circuit through the startup capacitor C1. Among them, the control signal can be provided by a control unit connected to the current output circuit, and the control unit can be a microcontroller unit (MCU), and the control signal can be a pulse width modulation (PWM) signal. When starting the current output circuit, the PWM signal changes from low level to high level and then remains to ensure that the current output circuit continuously outputs current until the control of the current output circuit stops outputting.
[0051] Specifically, during the circuit startup process, the control terminal of the first triode Q1 receives the control signal output by the second protection module 160. When the control signal is in the rising edge stage, the startup capacitor C1 is charged until the potentials at both ends of the startup capacitor C1 are approximately equal, and based on this, a certain voltage is provided for the first protection module 130 and the first triode Q1, so that the entire circuit can subsequently output a high level normally, ensuring the normal conduction of the circuit. The specific process of the circuit startup process will be described exemplarily later, and will not be elaborated here.
[0052] Exemplarily, the capacitance value of the startup capacitor C1 can be set to 500 nF (nanofarad), and the model of the first triode Q1 can be set to NHDTC114YT. In other embodiments, it can also be set to other values and models according to the specific requirements of the current output circuit, which will not be limited here.
[0053] In some embodiments, on the basis of Figure 3 referring to Figure 4 the output control module 150 further includes a first resistor R2 and a second resistor R3; the first resistor R2 is connected between the control terminal and the output terminal of the first triode Q1, and the second resistor R3 is connected between the control terminal of the first triode Q1 and the control signal input terminal of the output control module 150.
[0054] Exemplarily, the resistance value of the first resistor R2 can be set to 47 KΩ (kiloohm), and the resistance value of the second resistor R3 can be set to 2 KΩ, which can be set according to the specific requirements of the current output circuit and will not be limited here.
[0055] In some embodiments, on the basis of Figure 3 referring to Figure 4 the output detection module 120 includes a third resistor R6 and a fourth resistor R13; the first end of the third resistor R6 is connected to the input terminal of the output detection module 120, the second end of the third resistor R6 and the first end of the fourth resistor R13 are both connected to the output terminal of the output detection module 120, and the second end of the fourth resistor R13 is connected to the input terminal of the first triode Q1; wherein, the first threshold is set based on the ratio of the resistance values of the third resistor R6 and the fourth resistor R13.
[0056] Exemplarily, during the setting process of the first threshold, the third resistor R6 and the fourth resistor R13 can be used to divide the reference voltage Vbat to find the correlation between the voltage drop across the fourth resistor R13 and the corresponding voltage of the first protection module 130, and thus establish an equation relationship to determine the condition satisfied by the ratio of the resistance values of the third resistor R6 and the fourth resistor R13, so as to set the first threshold. The specific setting scenario will be described exemplarily later.
[0057] Thus, by adjusting the ratio of the resistance values of the third resistor R6 and the fourth resistor R13, a reasonable first threshold is set to adapt to different load conditions, further enhancing the circuit protection function. Exemplarily, the resistance value of the third resistor R6 can be set to 27 KΩ, and the resistance value of the fourth resistor R13 can be 1.7 KΩ.
[0058] In some embodiments, based on Figure 3 and with reference to Figure 4 , a current threshold is set based on the ratio of the resistance values of the third resistor R6 and the fourth resistor R13.
[0059] Among them, the current threshold is used to represent the upper limit of the current of the entire circuit to limit the output current of the circuit. Specifically, by adjusting the ratio of the resistance values of the third resistor R6 and the fourth resistor R13, a matching current threshold can be obtained, so that no matter what value the load is, the output current of the circuit will not exceed the current threshold. It can be understood that since both the current threshold and the first threshold are set based on the ratio of the resistance values of the third resistor R6 and the fourth resistor R13, the setting principle of the current threshold can be understood by referring to the setting process of the first threshold, which will not be elaborated here.
[0060] In some embodiments, based on Figure 3 and with reference to Figure 4 , the circuit output module 110 includes a second triode Q2, and the load 08 includes a fifth resistor R5; the control end of the second triode Q2 is connected to the control end of the circuit output module 110, the input end of the second triode Q2 is connected to the input end of the circuit output module 110, and the output end of the second triode Q2 is connected to the output end of the circuit output module 110; the resistance value R50 of the fifth resistor R5 and the resistance value R30 of the third resistor R6 satisfy:
[0061] R30 > 7 × R50.
[0062] It should be noted that if the load 08 is in an abnormal working state such as a short circuit, assuming the reference voltage Vbat = 18 V and the maximum current demand is 200 mA, the resistance value R50 of the fifth resistor R5 should satisfy the following relationship:
[0063] R50 = 18 V / 200 mA = 90 ohm.
[0064] According to general experience, the resistance value R30 of the third resistor R6 being 7 - 10 times the resistance value R50 of the fifth resistor R5 is sufficient. Here, taking R30 being 7 times R50 as an example, the resistance value R30 of the third resistor R6 and the resistance value R50 of the fifth resistor R5 should at least have the following relationship:
[0065] R30 > 7 × R50 = 630 hm.
[0066] Thus, by setting R30 > 7 × R50, R30 is made much larger than R50 (R30 >> R50) to prevent mutual influence and interference between modules in the circuit and ensure good electrical isolation.
[0067] In some embodiments, based on Figure 3 , with reference to Figure 4 , the first protection module 130 includes at least a third triode Q3; the control terminal of the third triode Q3 is connected to the second connection terminal of the first protection module 130, the input terminal of the third triode Q3 is connected to the first connection terminal of the first protection module 130, and the output terminal of the third triode Q3 is connected to the third connection terminal of the first protection module 130.
[0068] Among them, the third triode Q3 is at least used to implement circuit startup, normal circuit operation, and circuit protection against abnormal circuit operation. The working principle of the third triode Q3 will be elaborated below.
[0069] Specifically, the first triode Q1, the second triode Q2, and the third triode Q3 are all initially in the cut-off state. During the startup process of the current output circuit, the startup capacitor C1 is charged to approximately equal potentials at both ends during the rising edge stage of the control signal, and then a current can be formed that flows from the startup capacitor C1 to the third resistor R6 and the fifth resistor R5 in sequence, providing a base voltage for the base (i.e., the control terminal) of the third triode Q3. During this stage, the control signal is divided by the first resistor R2 and the second resistor R3 to provide a conduction voltage Vq1 for the first triode Q1. The voltages at both ends of the startup capacitor C1 are approximately equal, and the base voltage of the third triode Q3 is also the voltage Vq1. At this time, the voltage Vq1 reaches the base conduction voltage of the first triode Q1, and the first triode Q1 conducts. However, due to the existence of the fourth resistor R13, there is a voltage Vq1 at the emitter of the third triode Q3, making the third triode Q3 unable to meet the conduction condition of GS, and the third triode Q3 is in the cut-off state. During this stage, the startup capacitor C1 provides a conduction voltage Vq1 for the base of the first triode Q1. Until the base voltage of the first triode Q1 reaches the critical state, the first triode Q1 conducts. The startup capacitor C1 is still in the charging process, and a loop current is formed that flows from the startup capacitor C1 to the fourth resistor R13, the first triode Q1, and then to the ground in sequence, which is equivalent to introducing a new charging path. As the rising edge of the control signal continues to rise, the startup capacitor C1 continues to charge. At this time, the third triode Q3 is still in the cut-off state until the circuit enters the normal working state, and a new path for providing the base voltage of the third triode Q3 is introduced, that is, the output voltage is divided by the third resistor R6 and the fourth resistor R13 to provide a base voltage for the third triode Q3. At this time, the startup capacitor C1 completes charging and is in a dynamic equilibrium state. Before the circuit enters the normal working state, after the first triode Q1 is in the critical state, as the base voltage of the first triode Q1 and the base voltage of the third triode Q3 continue to increase, the first triode Q1 is fully saturated and conducts, and its collector potential is 0V. The third triode Q3 and the second triode Q2 reach the conduction state at the same time, so that the circuit normally outputs a high level.
[0070] Among them, the base voltage of the second triode Q2 is provided by dividing the control signal through the first resistor R2 and the second resistor R3, and remains at a high level output after the rising edge of the control signal. When the control signal decreases, the first triode Q1 will be cut off and the current output circuit will be turned off. The base voltage of the third triode Q3 is provided by the startup capacitor C1 during the startup phase, that is, the rising edge phase of the control signal. In the following text, in the case of a short circuit in the circuit, there is no other path to provide the base voltage of the third triode Q3. As the control signal stabilizes, the base voltage of the third triode Q3 will gradually drop to 0V, and the third triode Q3 will be cut off, and the circuit will be in a protected state. In the case of no short circuit in the circuit, a new path for providing the base voltage of the third triode Q3 is introduced, that is, the output voltage is divided by the third resistor R6 and the fourth resistor R13 to provide the base voltage for the third triode Q3. At this time, it does not depend on the startup capacitor C1 to provide the base voltage for the third triode Q3. That is, when the circuit is stable, the control signal is always high, and the conduction voltage of the third triode Q3 is provided by the output voltage through the output detection module 120 to maintain the normal output of the circuit.
[0071] During the normal operation of the circuit, the resistance value of the fifth resistor R5 is usually less than the set load value. The first protection module 130 outputs a level in the conduction state of the third triode Q3. After this level is divided by the third resistor R6 and the fourth resistor R13 in the output detection module 120, the voltage drop reaches the full saturation conduction voltage of the third triode Q3, realizing the full saturation conduction of the third triode Q3, and at the same time making the second triode Q2 saturated and conducting, and the circuit enters the normal operation mode.
[0072] When the load, that is, the fifth resistor R5, is in an abnormal operating state, the output detection module detects the output voltage of the circuit output module, which is equivalent to detecting the load state of the circuit, and feeds it back to the base of the third triode Q3. Accordingly, the conduction and cutoff of the third triode Q3 are controlled. Since the third triode Q3 is placed at the base of the second triode Q2, the conduction and cutoff of the second triode Q2 can be further controlled to complete the circuit protection under short circuit and high load conditions.
[0073] For example: when the fifth resistor R5 is short-circuited, the resistance value of the fifth resistor R5 usually exceeds the set load value. The level output by the first protection module 130 in the conduction state of the third triode Q3 will be relatively low, and it cannot maintain the conduction voltage of the third triode Q3. As the base voltage of the third triode Q3 drops, the third triode Q3 will be in a cut-off state. At this time, even if the external control signal controls the first triode Q1 to be in a conduction state, since the third triode Q3 is cut off, a complete loop cannot be formed between the base of the second triode Q2, making the second triode Q2 also in a cut-off state, that is, the output of the control circuit output module 110 is interrupted.
[0074] Thus, when the fifth resistor R5 is short-circuited, the circuit protection mechanism is triggered to interrupt the circuit output in case of a short circuit (or high load), so that the circuit output voltage is 0V and the circuit output current is 0mA, achieving the purpose of protecting the circuit.
[0075] In some embodiments, based on Figure 3 , with reference to Figure 4 , the specific scenario of setting the first threshold based on the ratio of the resistance values of the third resistor R6 and the fourth resistor R13 is described.
[0076] Specifically, during the normal operation of the circuit, the base voltage Vbe of the third triode Q3 is forward-biased. Therefore, it can be obtained that the voltage drop across the fourth resistor R13 is greater than or equal to 0.7V. Subsequently, the reference voltage Vbat, the resistance value of the third resistor R6, the resistance value of the fourth resistor R13, and the base voltage Vbe of the third triode Q3 satisfy the following relational expression:
[0077] Vbat×R13 / (R6 + R13) = Vbe_Q3,
[0078] where Vbe_Q3 represents the base voltage Vbe of the third triode Q3;
[0079] Further calculation yields: R6 / R13 = Vbat / Vbe_Q3 - 1, and based on this, the ratio of the resistance values of the third resistor R6 and the fourth resistor R13 is adjusted to meet the setting requirements of the first threshold.
[0080] Exemplarily, according to theoretical calculation, when the second triode Q2 is in the critical amplification state and the circuit output current is 200mA, the threshold value of the fifth resistor R5 should be set to 90Ω, and the theoretical resistance value (unit: KΩ) of the third resistor R6 should satisfy the following relational expression:
[0081]
[0082] where R 理论 represents the theoretical resistance value of the third resistor R6, Vbat represents the reference voltage, V ce_Q2 represents the collector-emitter voltage of the second triode Q2, and V be_Q3 represents the base voltage of the third triode Q3. On this basis, the actual threshold resistance value needs to be adjusted downward according to the theoretical result, and the reasonable selection range of the actual resistance value of the third resistor R6 can be determined through simulation.
[0083] Exemplarily, Figure 5 FIG. is a schematic diagram of a simulation curve for the third resistor provided by an embodiment of the present disclosure. Figure 6Another schematic diagram of the simulation curve for the third resistor provided by the embodiments of the present disclosure. Wherein, both the horizontal axis X1 and the horizontal axis X2 represent time, with the unit of millisecond (ms), and both the vertical axis Y1 and the vertical axis Y2 represent the output current of the circuit, with the unit of milliampere (mA).
[0084] Specifically, Figure 5 The curve in represents the time-current curve corresponding to the third resistor R6 being 28 KΩ, indicating that when the third resistor R6 is 28 KΩ, the output current limit is 70 mA; Figure 6 The curve in represents the time-current curve corresponding to the third resistor R6 being 27 KΩ, indicating that when the third resistor R6 is 27 KΩ, the output current limit is 200 mA. Combining the simulation, it can be known that the resistance value of the third resistor R6 should be selected between 27 KΩ and 28 KΩ, and the simulation results are consistent with the theoretical analysis.
[0085] In this way, by changing the ratio of the resistance value of the third resistor R6 to the resistance value of the fourth resistor R13, it is possible to set at what value the load enters the circuit protection state, and the second triode Q2 is saturated and conducting under different load conditions, further realizing the functions of setting the first threshold and current limit. For example, it may include setting the current threshold when entering the circuit protection state under the same load conditions. It should be noted that the larger the ratio of the resistance value of the third resistor R6 to the resistance value of the fourth resistor R13, the easier it is to trigger the circuit protection mechanism, and the current limit will also be more stringent.
[0086] In some embodiments, on the basis of Figure 3 and continuing to refer to Figure 4 the first protection module 130 further includes a sixth resistor R4; the sixth resistor R4 is connected between the input end of the third triode Q3 and the first connection end of the first protection module 130.
[0087] Exemplarily, the resistance value of the sixth resistor R4 can be set to 4.7 KΩ, which can be set according to the actual requirements of the current output circuit and is not limited herein.
[0088] In some embodiments, on the basis of Figure 3 and continuing to refer to Figure 4 the second protection module 160 includes a hysteresis comparator circuit 170; the detection signal input end of the hysteresis comparator circuit 170 is connected to the first end of the second protection module 160, and the feedback signal output end of the hysteresis comparator circuit 170 is connected to the second end of the second protection module 160.
[0089] Specifically, when the load, i.e., the fifth resistor R5, is in an abnormal operating state, such as a short circuit of the fifth resistor R5, the resistance value of the fifth resistor R5 usually exceeds the set load value. The detection signal input terminal of the hysteresis comparator circuit 170 detects the output voltage at the second terminal of the detection circuit output module 110, and uses this output voltage as one input of the hysteresis comparator circuit 170. At the same time, a reference level, i.e., the second threshold, is set as the other input of the hysteresis comparator circuit 170. On this basis, when it is detected that the above output voltage is less than the second threshold, the hysteresis comparator circuit 170 outputs a low level, such as 0V, to control the output control module 150 to turn off, so that the output control module 150 stops working, thereby interrupting the output of the circuit output module 110.
[0090] In this way, based on the hysteresis characteristic of the hysteresis comparator circuit 170, the hysteresis comparator circuit 170 is used to monitor the circuit output to autonomously complete the short - circuit state judgment and circuit protection, which fully improves the anti - interference ability of the circuit.
[0091] In some embodiments, Figure 7 is a schematic structural diagram of a hysteresis comparator circuit provided by an embodiment of the present disclosure. Figure 8 is another schematic structural diagram of a hysteresis comparator circuit provided by an embodiment of the present disclosure. Combining Figure 7 and Figure 8 , the hysteresis comparator circuit at least includes a comparator unit 173, a detection signal processing unit 174, and a threshold signal setting unit 175; the detection signal processing unit 174 is connected between the detection signal input terminal of the hysteresis comparator circuit and the first input terminal of the comparator unit 173, the threshold signal setting unit 175 is connected to the second input terminal of the comparator unit 173, and the output terminal of the comparator unit 173 is connected to the feedback signal output terminal of the hysteresis comparator circuit.
[0092] Among them, the detection signal processing unit 174 is configured to detect the output voltage, and the threshold signal setting unit 175 is configured to set the second threshold.
[0093] Specifically, the detection signal processing unit 174 detects the output voltage and feeds it back to the first input terminal of the comparator unit 173. The comparator unit 173 compares the received output voltage with the second threshold set by the threshold signal setting unit 175 to obtain a comparison result, so as to take corresponding measures according to the comparison result. For example, if the output voltage is less than the second threshold, the output terminal of the comparator unit 173 can output 0V to control the cutting off of the output of the circuit output module 110.
[0094] In some embodiments, on the basis of Figure 7 , with reference to Figure 8, the comparator unit 173 includes an operational amplifier 1731. The first input terminal of the operational amplifier 1731 is connected to the first input terminal of the comparator unit 173, the second input terminal of the operational amplifier 1731 is connected to the second input terminal of the comparator unit 173, and the output terminal of the operational amplifier 1731 is connected to the output terminal of the comparator unit 173; the threshold signal setting unit 175 includes a seventh resistor R7 and an eighth resistor R8. The first end of the seventh resistor R7 is connected to the second power supply VCC1_BAR, the second end of the seventh resistor R7 is connected to the first end of the eighth resistor R8 and is connected to the second input terminal of the operational amplifier 1731, and the second end of the eighth resistor R8 is grounded; the detection signal processing unit 174 includes a ninth resistor R9 and a tenth resistor R10. The first end of the ninth resistor R9 is grounded, the second end of the ninth resistor R9 is connected to the first end of the tenth resistor R10 and is connected to the first input terminal of the operational amplifier 1731, and the second end of the tenth resistor R10 is coupled to the detection signal input terminal of the hysteresis comparator circuit.
[0095] Wherein, the second threshold is set based on the ratio of the resistance values of the seventh resistor R7 and the eighth resistor R8 and / or the ratio of the resistance values of the ninth resistor R9 and the tenth resistor R10.
[0096] Specifically, during the process of setting the second threshold, the second power supply VCC1_BAR can be divided by the seventh resistor R7 and the eighth resistor R8 to find the relationship between the voltage across the eighth resistor R8 and the corresponding voltage at the second input terminal of the operational amplifier 1731, and thus an equation relationship is established to determine the conditions satisfied by the ratio of the resistance values of the seventh resistor R7 and the eighth resistor R8. Similarly, the conditions satisfied by the resistance values of the ninth resistor R9 and the tenth resistor R10 can also be determined according to the voltage division principle of the ninth resistor R9 and the tenth resistor R10, so as to set the second threshold accordingly.
[0097] During the process of setting the second threshold based on the ratio of the resistance values of the seventh resistor R7 and the eighth resistor R8, first set the reference voltage Vref at the second input terminal of the operational amplifier 1731. According to the voltage division principle of the seventh resistor R7 and the eighth resistor R8, it can be known that the following relationship is satisfied among the resistance value of the seventh resistor R7, the resistance value of the eighth resistor R8, the second power supply VCC1_BAR, and the reference voltage Vref:
[0098] VCC1_BAR×R8 / (R7 + R8) = Vref,
[0099] Further calculation gives: R7 / R8 = VCC1_BAR / Vref - 1, and the ratio of the resistance value of the seventh resistor R7 to the resistance value of the eighth resistor R8 is adjusted accordingly to meet the setting requirements of the second threshold.
[0100] In the process of setting the second threshold based on the ratio of the resistance values of the ninth resistor R9 and the tenth resistor R10, first set the reference voltage Vref at the first input terminal of the operational amplifier 1731, and assume that the second triode Q2 is fully saturated and conducting, ignoring its Vce voltage drop. On this basis, refer to Figure 6 In the actual circuit design, the tenth resistor R10 can be connected to the collector of the second triode Q2 through the triode D1, and the emitter of the second triode Q2 is connected to the first power supply 140. Then, according to the voltage division principle of the ninth resistor R9 and the tenth resistor R10, it can be known that the following relationship is satisfied among the resistance value of the ninth resistor R9, the resistance value of the tenth resistor R10, and the reference voltage Vref:
[0101] (VCC_18V - Vd1)×R9 / (R10 + R9) = Vref,
[0102] where, VCC_18V represents the voltage value of the first power supply, and Vd1 represents the voltage value of the triode D1;
[0103] Further calculation gives: R9 / R10 = (VCC_18V - Vd1) / Vref - 1, and the ratio of the resistance values of the ninth resistor R9 and the tenth resistor R10 is adjusted accordingly to meet the setting requirements of the second threshold. In addition, the specific value of Vref can be set with reference to the chip manual matched during circuit design, which is not limited here.
[0104] In some embodiments, in combination with Figure 7 and Figure 8 , the hysteresis comparator circuit further includes a triode D1, an eleventh resistor R11, and a twelfth resistor R12; the anode of the triode D1 is connected to the detection signal input terminal of the hysteresis comparator circuit, and the cathode of the triode D1 is connected to the second end of the tenth resistor R10; the first end of the eleventh resistor R11 is connected to the second end of the ninth resistor R9, the first end of the tenth resistor R10, and the first input terminal of the operational amplifier 1731, and the second end of the eleventh resistor R11 and the first end of the twelfth resistor R12 are both connected to the third power supply VCC2_BAR, and the second end of the twelfth resistor R12 is connected to the output terminal of the operational amplifier 1731.
[0105] In some embodiments, Figure 9 is a logic schematic diagram of a protection mechanism for a current output circuit provided by an embodiment of the present disclosure. Refer to Figure 9 , the figure shows that the current output circuit provided by the embodiment of the present disclosure uses two independent protection measures for dual protection. One is the protection measure of the first protection module, and the other is the protection measure of the second protection module. While detecting the short circuit of the circuit, the protection function of the circuit is realized.
[0106] Specifically, for the first protection module, when an abnormal circuit output is detected, the first protection module activates protection, compares the output voltage with a set first threshold, and when the output voltage is less than the first threshold, controls the output of the circuit output module to be interrupted to protect the load. Correspondingly, for the second protection module, when an abnormal circuit output is detected, the second protection module activates protection, compares the output voltage with a set second threshold, and when the output voltage is less than the second threshold, pulls down the control signal to control the output control module to turn off, interrupting the output of the circuit output module to complete the protection.
[0107] It can be understood that the setting of the first threshold, the second threshold, the reference voltage, etc. in the embodiments of the present disclosure are all implemented based on the hardware structure (referring to the current output circuit) and are adaptively configured in combination with the actual situation of the circuit.
[0108] In some embodiments, Table 1 is a circuit truth table provided by the embodiments of the present disclosure. As shown in Table 1, the first row in the table sequentially shows parameters such as "R5", "Q2", "control signal", "Q1", "Q3", "i" out ", "V" out ", etc. The first column of the table sequentially shows parameters such as "first protection module", "second protection module", etc., and the corresponding parameter value conditions in a table are obtained through the intersection of rows and columns.
[0109] Table 1 Circuit Truth Table
[0110]
[0111] Among them, "R5" represents the operating condition of the fifth resistor R5, specifically including Normal, Critical, and Short. Normal means the load is normal, Critical means the load is critical, and Short means the load is short-circuited. "Q2" represents the operating condition of the second triode Q2, specifically including saturation conduction, critical conduction, and cut-off. "Control signal" represents the level condition of the control signal, which are high level (H) and low level (L) respectively. "Q1" represents the operating condition of the first triode Q1, specifically including saturation conduction and cut-off. "Q3" represents the operating condition of the third triode Q3, specifically including saturation conduction, critical conduction, and cut-off. "i" out " represents the current flowing through the fifth resistor R5, that is, the situation of the entire circuit output current, specifically including Normal (indicating normal current), 0 mA, and 200 mA. "V" out " represents the voltage across the fifth resistor R5, that is, the situation of the entire circuit output voltage, specifically including Normal (indicating normal voltage) and 0 V.
[0112] It can be understood that once the type of protection measure is determined, such as the type of protection measure being the "first protection module" or the "second protection module", the corresponding parameters such as "R5", "Q2", and "control signal" under this protection measure can be determined, forming a one-to-one correspondence relationship.
[0113] Specifically, referring to Table 1, when the resistance value of the fifth resistor R5 is within the normal range (e.g., greater than 90 ohm) and the load current demand is less than 200 mA, the entire circuit operates normally, manifested as the normal saturation conduction of the first triode Q1, the second triode Q2, and the third triode Q3, and i out and V out both output normally, where i out can be set according to the actual demand of the load, and V out satisfies the following relationship:
[0114] V out = VCC_18V - Vce_Q2,
[0115] where Vce_Q2 represents the collector-emitter voltage of the second triode Q2, and VCC_18V represents the voltage value of the first power supply.
[0116] When the fifth resistor R5 is in the critical condition, that is, the resistance value of the fifth resistor R5 is equal to 90 ohm, the entire circuit is in the critical output state. The first triode Q1 conducts normally in saturation, the second triode Q2 and the third triode Q3 conduct critically, and i out is 200 mA, and V out satisfies the following relationship:
[0117] V out = VCC_18V - Vce_Q2.
[0118] When the fifth resistor R5 is in the short-circuit condition, for example, the resistance value of the fifth resistor R5 is 0 ohm, the parameter situations of the two protection measures are different. Specifically, for the first protection module, when the external control signal is at a high level, the first triode Q1 will conduct accordingly. In this case, the current threshold is set by configuring the ratio of the resistance value of the third resistor R6 and the fourth resistor R13 in the output detection module to limit the circuit output current, and / or the ratio of the resistance value of the third resistor R6 and the fourth resistor R13 is adjusted to set the first threshold. Based on the output voltage being less than the first threshold, the output of the circuit output module is controlled to be interrupted. Therefore, both the second triode Q2 and the third triode Q3 are cut off, making the entire circuit output voltage 0V and output current 0 mA, achieving circuit protection.
[0119] For the second protection module, when the control signal is at a low level, the first triode Q1, the second triode Q2, and the third triode Q3 are all forced into the short-circuit protection mode and thus cut off, making the output voltage of the entire circuit 0V and the output current 0mA, achieving circuit protection.
[0120] The advantages of the current output circuit provided by the embodiments of the present disclosure over the related art will be verified and described below.
[0121] Figure 10 FIG. is a schematic structural diagram of another triode switch control circuit provided by the related art. Referring to Figure 10 , for more conveniently describing the advantages of the current output circuit provided by the embodiments of the present disclosure over the related art in the following, some components in Figure 10 are represented by the same markings as those in the current output circuit of the present disclosure.
[0122] Among them, Figure 10 shows that the first power supply VCC_18V is grounded through the second triode Q2 and the fifth resistor R5 (i.e., the load) in sequence. The base of the second triode Q2 is connected to the collector of the first triode Q1 through the sixth resistor R4. The base of the first triode Q1 is grounded through the second resistor R3 and the starting capacitor C1 in sequence. The emitter of the first triode Q1 is grounded and connected to one end of the first resistor R2, and the other end of the first resistor R2 is connected to the base of the first triode Q1. In addition to the above components, Figure 10 also shows the remaining conventional components such as R52, R53, C51, and V2, which will not be elaborated here.
[0123] Exemplarily, Figure 11 FIG. is a schematic diagram of a simulation curve provided by the related art regarding Figure 10 , specifically a resistance-voltage-current curve. Among them, the horizontal axis X3 represents the resistance value of the fifth resistor R5, and the resistance value gradually increases from left to right, with the unit of kiloohm (KΩ). The left vertical axis Y3 represents the voltage output by the collector of the first triode Q1 (i.e., the circuit output voltage) under the load condition, with the unit of volt (V). The right vertical axis Y4 represents the current flowing through the second triode Q2 (i.e., the circuit output current) under the load condition, with the unit of milliampere (mA); L31 represents the resistance-voltage curve, and L32 represents the resistance-current curve, reflecting the circuit output changes under different load conditions based on the above curves.
[0124] In addition, L41 intersects L32 at a point A, whose coordinates are (90Ω, 20mA). Passing through this point indicates that the second triode Q2 is in the critical saturation conduction state; L42 intersects L32 at another point B. Passing through this point indicates that the output current of the second triode Q2 is the maximum value, which is limited to 100mA according to the specified value.
[0125] Specifically, at the initial position of the horizontal axis X3, the resistance of the fifth resistor R5 is 0KΩ, which physically indicates a load short-circuit state. In this case, the circuit output voltage corresponding to the left vertical axis Y3 is 0V, and the circuit output current corresponding to the right vertical axis Y4 is 420mA. At this time, the second transistor Q2 is in an amplification state, resulting in abnormal circuit output voltage and circuit output current exceeding the specified value, thereby causing circuit damage.
[0126] Afterwards, as the resistance of the fifth resistor R5 gradually increases, the magnitude of the fifth resistor R5 of the critical load is 90Ω, the circuit output voltage corresponding to the left vertical axis Y3 is 17.8V, and the circuit output current corresponding to the right vertical axis Y4 is 200mA. At this time, the second triode Q2 is in a critical saturation conduction state, its conduction voltage drop is small, and the output current is a critical specified value. On this basis, the resistance of the fifth resistor R5 continues to increase, the second triode Q2 is in a fully saturated conduction state, and the circuit completes normal output.
[0127] According to the above-mentioned actual circuit and its simulation results, the amplification factor of the second transistor Q2 is 50, the reference voltage Vbat is 18V, the resistance of the sixth resistor R4 is 4.7k, and the collector-emitter voltages of the first transistor Q1 and the second transistor Q2 are ignored. It can be calculated that when the second transistor Q2 is in the amplified state, the critical resistance R of the fifth resistor R5 is 临界 Satisfies the following relationship:
[0128]
[0129] Among them, V Q2b represents the base voltage of the second transistor Q2. At this time, the circuit output current i out Satisfies the following relationship:
[0130]
[0131] Based on this analysis, it is concluded that the first transistor Q1 in the circuit controls the second transistor Q2 by limiting the base. However, when the load is too large (i.e., the impedance is less than the critical value) or short-circuited, the first transistor Q1 will be in an amplified state, and the output current is not limited. At this time, the current flowing through the first transistor Q1 exceeds its specified value. It can be seen that the protection measures under load short-circuit or low load can easily cause circuit damage.
[0132] In some embodiments, Figure 12 A schematic diagram of a current output circuit according to another embodiment of the present disclosure is shown in FIG. Figure 12, where the connection relationships of the various modules and their components have been described in the foregoing embodiments and can be understood with reference to the corresponding drawings. In particular, the power supply V1 is shown in the figure. In the embodiments of the present disclosure, an external control signal can be generated through the power supply V1. For example, the amplitude of the control signal is 3.3V, the period is 300ms, and the duty cycle is 33.3%, so as to further control whether the first triode Q1 is turned on through the external control signal.
[0133] Exemplarily, Figure 13 A schematic diagram of a simulation curve provided by an embodiment of the present disclosure regarding Figure 12 is shown. It is a simulation diagram of the circuit in a short-circuit situation. Among them, the horizontal axis X4 represents time, with the unit of millisecond (ms), and the vertical axis Y5 represents the output current of the circuit, with the unit of milliampere (mA). The curve in the figure represents the time-current curve for the load.
[0134] Specifically, in combination with Figure 12 and Figure 13 , the fifth resistor R5 can be set to 0Ω or 0.001Ω to simulate the load short-circuit situation. It can be analyzed from the simulation diagram that when the load is short-circuited, the third triode Q3 is in an approximate cut-off state, and then the second triode Q2 is also cut off, thereby being able to limit the circuit output, making the circuit output voltage 0V and the circuit output current 0mA. Moreover, even if the external control signal controls the first triode Q1 to be turned on, the maximum value of the circuit output current is limited to 17mA. Thus, the short-circuit protection function of the circuit is well verified.
[0135] In this way, the current output circuit provided by the embodiments of the present disclosure realizes effective protection for the circuit and the load through self-diagnosis and logic control of the circuit output, including: when the load is short-circuited, such as when the load is 0Ω, and when the load is very small, such as when the load resistance is 1Ω - 100Ω, it can ensure that the circuit output voltage is 0V and the circuit output current is 0mA, completing small-current output and avoiding damage to the circuit caused by large currents generated when the load is abnormal.
[0136] In addition, when the circuit anomaly is eliminated, it can automatically resume the normal working state. Similarly, when the load is in the normal state, the first triode Q1, the second triode Q2, and the third triode Q3 are saturated and turned on, without affecting the normal output of the circuit.
[0137] On the basis of the above embodiments, the embodiments of the present disclosure also provide an interface circuit, including any one of the current output circuits provided in the above embodiments, and having corresponding beneficial effects. To avoid repeated description, it will not be elaborated here.
[0138] The embodiments of the present disclosure also provide a carrier vehicle, including any one of the interface circuits provided in the above embodiments.
[0139] Exemplarily, the carrier includes, but is not limited to, vehicles, ships, aircraft and other carriers with circuit protection requirements, which will not be elaborated or limited herein.
[0140] It should be noted that in this text, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, such that a process, method, article or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the presence of additional identical elements in the process, method, article or device comprising the element.
[0141] The above are only specific embodiments of the present disclosure, enabling those skilled in the art to understand or implement the present disclosure. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present disclosure. Therefore, the present disclosure will not be limited to the embodiments described herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.
Claims
1. A current output circuit, characterized in that, Comprising: A circuit output module, an output detection module, and a first protection module; The circuit output module includes a control terminal, a first terminal, and a second terminal. The output detection module includes an input terminal and an output terminal. The first protection module includes at least a first connection terminal and a second connection terminal. The first terminal of the circuit output module is connected to a first power supply. The second terminal of the circuit output module is connected to a load and the input terminal of the output detection module. The control terminal of the circuit output module is connected to the first connection terminal of the first protection module. The output terminal of the output detection module is connected to the second connection terminal of the first protection module; Wherein, the output detection module is configured to detect the output voltage of the circuit output module and feedback it to the first protection module; The first protection module is configured to control the output interruption of the circuit output module based on the output voltage being less than a first threshold.
2. The current output circuit according to claim 1, wherein It further includes an output control module and a second protection module; The output control module includes a control signal input terminal and a control signal output terminal. The second protection module includes a first terminal and a second terminal. The first terminal of the second protection module is connected to the second terminal of the circuit output module. The second terminal of the second protection module is connected to the control signal input terminal of the output control module. The control signal output terminal of the output control module is coupled to the control terminal of the circuit output module; Wherein, the second protection module is configured to control the output control module to turn off and interrupt the output of the circuit output module based on the output voltage at the second terminal of the circuit output module being less than a second threshold.
3. The current output circuit according to claim 2, wherein The first protection module further includes a third connection terminal. The control signal output terminal of the output control module is connected to the third connection terminal of the first protection module.
4. The current output circuit according to claim 3, wherein The output control module includes a first triode and a startup capacitor; The control terminal of the first triode is connected to the control signal input terminal of the output control module. The input terminal of the first triode is connected to the control signal output terminal of the output control module. The output terminal of the first triode is grounded; The startup capacitor is connected between the control terminal and the input terminal of the first triode.
5. The current output circuit according to claim 4, characterized in that, The output control module further includes a first resistor and a second resistor; The first resistor is connected between the control terminal and the output terminal of the first triode. The second resistor is connected between the control terminal of the first triode and the control signal input terminal of the output control module.
6. The current output circuit according to claim 4, characterized in that, The output detection module includes a third resistor and a fourth resistor; The first terminal of the third resistor is connected to the input terminal of the output detection module. The second terminal of the third resistor and the first terminal of the fourth resistor are both connected to the output terminal of the output detection module. The second terminal of the fourth resistor is connected to the input terminal of the first triode; Wherein, the first threshold is set based on the ratio of the resistance values of the third resistor and the fourth resistor.
7. The current output circuit according to claim 6, wherein The circuit output module includes a second triode. The load includes a fifth resistor; The control terminal of the second triode is connected to the control terminal of the circuit output module. The input terminal of the second triode is connected to the input terminal of the circuit output module. The output terminal of the second triode is connected to the output terminal of the circuit output module; The resistance value R50 of the fifth resistor and the resistance value R30 of the third resistor satisfy: R30 > 7 × R50.
8. The current output circuit according to claim 3, characterized in that, The first protection module includes at least a third triode; The control terminal of the third triode is connected to the second connection terminal of the first protection module, the input terminal of the third triode is connected to the first connection terminal of the first protection module, and the output terminal of the third triode is connected to the third connection terminal of the first protection module.
9. The current output circuit according to claim 8, wherein, The first protection module further includes a sixth resistor; The sixth resistor is connected between the input terminal of the third triode and the first connection terminal of the first protection module.
10. The current output circuit according to claim 2, wherein The second protection module includes a hysteresis comparator circuit; The detection signal input terminal of the hysteresis comparator circuit is connected to the first terminal of the second protection module, and the feedback signal output terminal of the hysteresis comparator circuit is connected to the second terminal of the second protection module.
11. The current output circuit according to claim 10, wherein The hysteresis comparator circuit includes at least a comparator unit, a detection signal processing unit, and a threshold signal setting unit; The detection signal processing unit is connected between the detection signal input terminal of the hysteresis comparator circuit and the first input terminal of the comparator unit, the threshold signal setting unit is connected to the second input terminal of the comparator unit, and the output terminal of the comparator unit is connected to the feedback signal output terminal of the hysteresis comparator circuit; The detection signal processing unit is configured to detect the output voltage, and the threshold signal setting unit is configured to set the second threshold.
12. The current output circuit according to claim 11, characterized in that, The comparator unit includes an operational amplifier, the first input terminal of the operational amplifier is connected to the first input terminal of the comparator unit, the second input terminal of the operational amplifier is connected to the second input terminal of the comparator unit, and the output terminal of the operational amplifier is connected to the output terminal of the comparator unit; The threshold signal setting unit includes a seventh resistor and an eighth resistor. The first end of the seventh resistor is connected to the second power supply, the second end of the seventh resistor is connected to the first end of the eighth resistor and is connected to the second input terminal of the operational amplifier, and the second end of the eighth resistor is grounded; The detection signal processing unit includes a ninth resistor and a tenth resistor. The first end of the ninth resistor is grounded, the second end of the ninth resistor is connected to the first end of the tenth resistor and is connected to the first input terminal of the operational amplifier, and the second end of the tenth resistor is coupled to the detection signal input terminal of the hysteresis comparator circuit; Wherein, the second threshold is set based on the ratio of the resistance value of the seventh resistor to the resistance value of the eighth resistor and / or the ratio of the resistance value of the ninth resistor to the resistance value of the tenth resistor.
13. The current output circuit according to claim 12, wherein The hysteresis comparator circuit further includes a triode, an eleventh resistor, and a twelfth resistor; The anode of the triode is connected to the detection signal input terminal of the hysteresis comparator circuit, and the cathode of the triode is connected to the second end of the tenth resistor; The first end of the eleventh resistor is connected to the second end of the ninth resistor, the first end of the tenth resistor, and the first input terminal of the operational amplifier. The second end of the eleventh resistor and the first end of the twelfth resistor are both connected to the third power supply, and the second end of the twelfth resistor is connected to the output terminal of the operational amplifier.
14. An interface circuit, characterized in that, Comprising the current output circuit according to any one of claims 1-13.
15. A vehicle, characterized in that, Comprising the interface circuit according to claim 14.