Negative pressure generation circuit, charging device, and vehicle
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- BYD CO LTD
- Filing Date
- 2025-06-30
- Publication Date
- 2026-08-07
AI Technical Summary
而现有技术中的负压产生方案需要使用较多的电子器件，导致体积大且成本高
[0032]本申请中的负压产生电路通过开关模块分别与第一电容、第一二极管、第二电容和第二二极管交替构成第一回路和第二回路，从而通过第二电容输出负压，仅需使用少量器件，降低了体积和成本。
Smart Images
Figure CN224610716U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of automotive charging technology, and in particular to a negative pressure generating circuit, a charging device, and a vehicle. Background Technology
[0002] The CP (Charge Point) signal is a crucial communication signal used in electric vehicle charging. It is typically provided by charging stations and monitored by the vehicle's onboard charging system to detect charging status, facilitate handshake communication, and negotiate charging parameters. The CP signal communicates using PWM (Pulse Width Modulation), where the duty cycle of the PWM signal represents the maximum charging current the charging station can provide, and the amplitude of the PWM signal corresponds to different states of the charging gun. Specifically, the CP signal is typically required to be a ±12V PWM signal.
[0003] The CP signal is generated by a corresponding signal generation circuit. Since the CP signal has a negative voltage, a corresponding negative voltage power supply signal needs to be provided to the signal generation circuit. However, existing negative voltage generation schemes require the use of many electronic components, resulting in large size and high cost. Utility Model Content
[0004] This application provides a negative pressure generating circuit, a charging device, and a vehicle. By using a switching module to alternately form a first circuit and a second circuit with a first capacitor, a first diode, a second capacitor, and a second diode, a negative pressure is output through the second capacitor, thereby at least partially solving the above-mentioned technical problems.
[0005] To achieve the above objectives, according to a first aspect of this application, a negative voltage generating circuit is provided, comprising a switching module, a first capacitor, a first diode, a second capacitor, and a second diode;
[0006] The first terminal of the first capacitor is electrically connected to the first access terminal of the switching module. The second terminal of the first capacitor is electrically connected to the anode of the first diode and the cathode of the second diode. The cathode of the first diode is electrically connected to the second terminal of the second capacitor and the second access terminal of the switching module. The anode of the second diode is electrically connected to the first terminal of the second capacitor.
[0007] The switching module is used to alternately form a first circuit with the first capacitor and the first diode, and to form a second circuit with the first capacitor, the second diode, and the second capacitor, so as to output a negative voltage power signal through the second capacitor.
[0008] Optionally, the switching module includes a first switching transistor and a second switching transistor;
[0009] The input terminal of the first switching transistor is used to connect to a positive voltage power supply signal. The output terminal of the first switching transistor is electrically connected to the first terminal of the first capacitor and the input terminal of the second switching transistor. The output terminal of the second switching transistor is electrically connected to the cathode of the first diode and the second terminal of the second capacitor and is used to ground. The control terminals of the first and second switching transistors are used to connect to the target control signal.
[0010] The target control signal includes alternating first and second levels. The first level is used to drive the first switch to turn on and the second switch to turn off, and the second level is used to drive the first switch to turn off and the second switch to turn on.
[0011] Optionally, the first switching transistor includes an NPN transistor, the second switching transistor includes a PNP transistor, the first level is a high level, and the second level is a low level.
[0012] Optionally, the first switching transistor includes a PMOS transistor, the second switching transistor includes a first NMOS transistor, the first level is low, and the second level is high.
[0013] Optionally, the switch module may also include a first drive unit;
[0014] The gate of the PMOS transistor is used to access the target control signal through the first driving unit;
[0015] The first driving unit is used to control the PMOS transistor to turn on at a first speed when the target control signal is low and to control the PMOS transistor to turn off at a second speed when the target control signal is high, wherein the second speed is greater than the first speed.
[0016] Optionally, the first driving unit includes a third diode, a first resistor, and a second resistor;
[0017] The anode of the third diode is electrically connected to the first end of the second resistor and is used to input the target control signal. The cathode of the third diode is electrically connected to the first end of the first resistor. The second ends of the first resistor and the second ends of the second resistor are respectively electrically connected to the gate of the PMOS transistor.
[0018] Optionally, the resistance of the second resistor is greater than that of the first resistor.
[0019] Optionally, the switch module may also include a second drive unit;
[0020] The gate of the first NMOS transistor is used to access the target control signal through the second driving unit;
[0021] The second driving unit is used to control the first NMOS transistor to turn off at a third speed when the target control signal is low and to control the first NMOS transistor to turn on at a fourth speed when the target control signal is high, wherein the third speed is greater than the fourth speed.
[0022] Optionally, the second driving unit includes a fourth diode, a third resistor, and a fourth resistor;
[0023] The cathode of the fourth diode is electrically connected to the first end of the fourth resistor and is used to input the target control signal. The anode of the fourth diode is electrically connected to the first end of the third resistor. The second ends of the third resistor and the second ends of the fourth resistor are respectively electrically connected to the gate of the first NMOS transistor.
[0024] Optionally, the resistance of the fourth resistor is greater than that of the third resistor.
[0025] Optionally, the switching module may also include a third switching transistor;
[0026] The input terminal of the third switch is electrically connected to the input terminal of the first switch, the control terminal of the first switch, and the control terminal of the second switch, respectively. The output terminal of the third switch is electrically connected to the output terminal of the second switch. The control terminal of the third switch is used to receive the initial control signal.
[0027] The initial control signal includes alternating third and fourth levels. The third level is used to drive the third switch to operate in a first state, outputting a first level to the first and second switches; the fourth level is used to drive the third switch to operate in a second state, outputting a second level to the first and second switches.
[0028] Optionally, the third switch may include a second NMOS transistor.
[0029] According to a second aspect of this application, a charging device is provided, including a signal generating circuit and a negative voltage generating circuit in any of the above embodiments.
[0030] The power supply terminal of the signal generation circuit is electrically connected to the negative voltage generation circuit, and is used to generate a CP signal based on the positive voltage power supply signal and the negative voltage power supply signal output by the negative voltage generation circuit.
[0031] According to a fourth aspect of this application, a vehicle is provided, including an on-board charging device, which is electrically connected to the output terminal of a signal generation circuit in any of the above embodiments to access a CP signal generated by the signal generation circuit.
[0032] The negative voltage generating circuit in this application uses a switching module to alternately form a first circuit and a second circuit with a first capacitor, a first diode, a second capacitor, and a second diode, thereby outputting negative voltage through the second capacitor. Only a few components are needed, reducing size and cost.
[0033] Other features and advantages of this application will be described in detail in the following detailed description section. Attached Figure Description
[0034] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0035] To gain a more complete understanding of this application and its beneficial effects, the following description will be provided in conjunction with the accompanying drawings, wherein the same reference numerals in the following description denote the same parts.
[0036] Figure 1 This is a schematic diagram of the negative pressure generating circuit provided in an exemplary embodiment of this application;
[0037] Figure 2 This is a schematic diagram of a switching module including a first switching transistor and a second switching transistor provided in an exemplary embodiment of this application;
[0038] Figure 3 This is a schematic diagram showing that the first and second switching transistors provided in the exemplary embodiments of this application are respectively adopted as transistors;
[0039] Figure 4 This is a schematic diagram showing that the first and second switching transistors provided in the exemplary embodiments of this application are respectively MOSFETs;
[0040] Figure 5 This is a schematic diagram of a specific circuit including a first driving unit and a second driving unit provided in an exemplary embodiment of this application;
[0041] Figure 6 This is a schematic diagram showing that the switching module provided in the exemplary embodiment of this application also includes a third switching transistor;
[0042] Figure 7 This is a schematic diagram showing that the first and second switching transistors are respectively transistors and the third switching transistor is a MOSFET in an exemplary embodiment of this application;
[0043] Figure 8 This is a schematic diagram showing that the first switch, second switch, and third switch provided in the exemplary embodiment of this application are respectively MOSFETs. Detailed Implementation
[0044] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the protection scope of this application.
[0045] According to the first aspect of this application, Figure 1 As shown, a negative voltage generating circuit is provided, including a switching module, a first capacitor C1, a first diode D1, a second capacitor C2, and a second diode D2.
[0046] The first terminal of the first capacitor C1 is electrically connected to the first access terminal of the switch module. The second terminal of the first capacitor C1 is electrically connected to the anode of the first diode D1 and the cathode of the second diode D2. The cathode of the first diode D1 is electrically connected to the second terminal of the second capacitor C2 and the second access terminal of the switch module. The anode of the second diode D2 is electrically connected to the first terminal of the second capacitor C2.
[0047] The switching module is used to alternately form a first circuit with the first capacitor C1 and the first diode D1, and to form a second circuit with the first capacitor C1, the second diode D2 and the second capacitor C2, so as to output a negative voltage power supply signal VCC- through the second capacitor C2.
[0048] As can be understood, the first and second loops are used to realize the flow of current, thus requiring energy input; that is, the switching module is also used to connect to the positive voltage power supply signal VCC+. Similarly, in a circuit, the formation of a loop usually requires a path between the power supply and ground, therefore grounding is also required; that is, the second input terminal of the switching module is also used for grounding. Furthermore, the switching module is used to change its own state to achieve the alternation of the first and second loops; therefore, the switching module needs to be subject to relevant control, meaning the switching module is also used to connect to the control signal CTRL.
[0049] Specifically, when the switching module is in the first state under the control of the control signal CTRL, it forms a first circuit with the first capacitor C1 and the first diode D1. Based on the positive voltage power supply signal VCC+, due to the unidirectional conduction characteristic of the first diode D1, the current flows out from the first input terminal of the switching module, passes through the first capacitor C1 and the first diode D1, and flows into the ground. At this time, the first capacitor C1 is charged, and the first capacitor C1 accumulates positive charge near the plate of the switching module. When the switching module is in its second state under the control of the control signal CTRL, it forms a second circuit with the first capacitor C1, the second diode D2, and the second capacitor C2. Based on the charge accumulation in the first capacitor C1, and due to the unidirectional conduction characteristic of the second diode D2, current flows out of the first capacitor C1, through the first and second input terminals of the switching module, the second capacitor C2, and the second diode D2, before returning to the first capacitor C1. At this point, because the plate of the first capacitor C1 closest to the switching module is pulled to ground, its voltage becomes zero. Based on the characteristic that the voltage across a capacitor cannot change abruptly, the voltage between the plates of the first capacitor C1 closest to the first diode D1 and the second diode D2 drops to a negative voltage. The first capacitor C1 charges the second capacitor C2 through the switching module and the second diode D2, causing a negative voltage to accumulate on the plate of the second capacitor closest to the second diode D2, ultimately forming a negative voltage across the second capacitor C2. As the switching module continuously switches between the first and second states, a negative voltage meeting the amplitude requirements is eventually formed across the second capacitor C2, enabling the output of the negative voltage power signal VCC-.
[0050] It should be noted that since the main function of the first capacitor C1 and the second capacitor C2 is energy storage, the capacitance requirement is relatively large. In one example, the capacitance values of the first capacitor C1 and the second capacitor C2 are both above 100μF. Since the main function of the first diode D1 and the second diode D2 is switching, thus forming different circuits, the forward conduction speed requirement is relatively large. In one example, the first diode D1 and the second diode D2 are Schottky diodes.
[0051] As a supplement, the control signal CTRL connected to the switching module needs to control the switching module to continuously switch between the first state and the second state. Therefore, the control signal CTRL also needs to be a constantly changing signal. In one example, the control signal CTRL can be a PWM signal.
[0052] The negative voltage generating circuit in this application uses a switching module to alternately form a first circuit and a second circuit with a first capacitor, a first diode, a second capacitor, and a second diode, thereby outputting negative voltage through the second capacitor. Only a few components are needed, reducing size and cost.
[0053] like Figure 2As shown, optionally, the switching module includes a first switching transistor and a second switching transistor.
[0054] The input of the first switching transistor is used to connect to the positive voltage power supply signal VCC+. The output of the first switching transistor is electrically connected to the first terminal of the first capacitor C1 and the input of the second switching transistor. The output of the second switching transistor is electrically connected to the cathode of the first diode D1 and the second terminal of the second capacitor C2 and is used for grounding. The control terminals of the first and second switching transistors are used to connect to the target control signal CTRL1.
[0055] The target control signal CTRL1 includes alternating first and second levels. The first level is used to drive the first switch to turn on and the second switch to turn off, and the second level is used to drive the first switch to turn off and the second switch to turn on.
[0056] Specifically, when the target control signal CTRL1 is at the first level, the first switch is turned on and the second switch is turned off. The positive voltage power supply signal VCC+ passes through the first switch, the first capacitor C1, and the first diode D1 to form a first loop to ground. When the target control signal CTRL1 is at the second level, the first switch is turned off and the second switch is turned on. The first capacitor C1 passes through the second switch, the second capacitor C2, and the second diode D2 to form a second loop back to the first capacitor C1.
[0057] like Figure 3 As shown, optionally, the first switching transistor includes an NPN transistor Q1, and the second switching transistor includes a PNP transistor Q2. The first level is high, and the second level is low.
[0058] When the target control signal CTRL1 is at the first level, since the first level is high, NPN transistor Q1 is turned on and PNP transistor Q2 is turned off. The positive voltage power supply signal VCC+ forms a first loop to ground after passing through NPN transistor Q1, first capacitor C1, and first diode D1. When the target control signal CTRL1 is at the second level, since the second level is low, NPN transistor Q1 is turned off and PNP transistor Q2 is turned on. The first capacitor C1 forms a second loop back to the first capacitor C1 after passing through PNP transistor Q2, second capacitor C2, and second diode D2.
[0059] like Figure 4 As shown, optionally, the first switching transistor includes a PMOS transistor Q3, the second switching transistor includes a first NMOS transistor Q4, the first level is low, and the second level is high.
[0060] When the target control signal CTRL1 is at the first level, since the first level is low, PMOS transistor Q3 is turned on and the first NMOS transistor Q4 is turned off. The positive voltage power supply signal VCC+ forms a first loop to ground after passing through PMOS transistor Q3, first capacitor C1, and first diode D1. When the target control signal CTRL1 is at the second level, since the second level is high, PMOS transistor Q3 is turned off and the first NMOS transistor Q4 is turned on. The first capacitor C1 forms a second loop back to the first capacitor C1 after passing through the first NMOS transistor Q4, second capacitor C2, and second diode D2.
[0061] like Figure 5 As shown, optionally, the switching module also includes a first driving unit, which includes a third diode D3, a resistor R2, and a resistor R3.
[0062] The anode of the third diode D3 is electrically connected to the first end of the resistor R3 and is used to input the target control signal CTRL1. The cathode of the third diode D3 is electrically connected to the first end of the resistor R2. The second ends of the resistor R2 and the second ends of the resistor R3 are respectively electrically connected to the gate of the PMOS transistor Q3.
[0063] When using MOSFETs, the switching characteristics of MOSFETs can easily cause PMOS transistor Q3 and the first NMOS transistor Q4 to conduct simultaneously, which will prevent the circuit from functioning. Therefore, a first driving unit needs to be added to make the turn-off speed of PMOS transistor Q3 greater than its turn-on speed.
[0064] Specifically, when the target control signal CTRL1 is at the first level, since the first level is low, PMOS transistor Q3 enters the conduction stage. The gate voltage of PMOS transistor Q3 decreases through resistor R3, and PMOS transistor Q3 turns on at the first speed. When the target control signal CTRL1 is at the second level, since the second level is high, PMOS transistor Q3 enters the off stage. The gate voltage of PMOS transistor Q3 increases simultaneously through resistors R2 and R3, and PMOS transistor Q3 turns off at the second speed. Since resistors R2 and R3 are connected in parallel, the resistance after parallel connection is less than the resistance of either resistor R2 or R3. Therefore, the current corresponding to the decrease of the gate voltage of PMOS transistor Q3 is smaller, and the current corresponding to the increase of the gate voltage of PMOS transistor Q3 is larger. That is, the second speed is greater than the first speed, thereby achieving the purpose of PMOS transistor Q3's off speed being greater than its conduction speed.
[0065] In one example, the resistance of resistor R3 is greater than the resistance of resistor R2.
[0066] As mentioned above, the gate voltage of PMOS transistor Q3 decreases through resistor R3 during the turn-on phase and increases simultaneously through resistors R2 and R3 during the turn-off phase. Regardless of the configuration of resistors R2 and R3, the resistance of R3 is always greater than the resistance of the two resistors connected in parallel, ultimately ensuring that the turn-off speed of PMOS transistor Q3 is greater than its turn-on speed. To further enhance the turn-off speed of PMOS transistor Q3, the resistance of resistor R3 can be set to be greater than that of resistor R2, thereby improving the speed control effect.
[0067] like Figure 5 As shown, optionally, the switching module also includes a second driving unit, which includes a fourth diode D4, a resistor R4, and a resistor R5.
[0068] The cathode of the fourth diode D4 is electrically connected to the first end of the resistor R5 and is used to input the target control signal CTRL1. The anode of the fourth diode D4 is electrically connected to the first end of the resistor R4. The second ends of the resistor R4 and the second ends of the resistor R5 are respectively electrically connected to the gate of the first NMOS transistor Q4.
[0069] Similarly, a second driving unit needs to be added to make the turn-off speed of the first NMOS transistor Q4 greater than its turn-on speed.
[0070] Specifically, when the target control signal CTRL1 is at the first level, since the first level is low, the first NMOS transistor Q4 enters the off-state. The gate voltage of the first NMOS transistor Q4 decreases simultaneously through resistors R4 and R5, and the first NMOS transistor Q4 turns off at the third speed. When the target control signal CTRL1 is at the second level, since the second level is high, the first NMOS transistor Q4 enters the on-state. The gate voltage of the first NMOS transistor Q4 increases through resistor R5, and the first NMOS transistor Q4 turns on at the fourth speed. Since resistors R4 and R5 are connected in parallel, the resistance after parallel connection is less than the resistance of either resistor R4 or R5. Therefore, the current corresponding to the decrease of the gate voltage of the first NMOS transistor Q4 is larger, and the current corresponding to the increase of the gate voltage of the first NMOS transistor Q4 is smaller. That is, the third speed is greater than the fourth speed, thereby achieving the purpose of the first NMOS transistor Q4's off-state speed being greater than its on-state speed.
[0071] In one example, the resistance of resistor R5 is greater than the resistance of resistor R4.
[0072] As mentioned above, the gate voltage of the first NMOS transistor Q4 increases through resistor R5 during the conduction phase and decreases simultaneously through resistors R4 and R5 during the turn-off phase. Regardless of the configuration of resistors R4 and R5, the resistance of R5 is always greater than the resistance of the two resistors connected in parallel, ultimately ensuring that the turn-off speed of the first NMOS transistor Q4 is greater than its conduction speed. To further enhance the turn-off speed of the first NMOS transistor Q4, the resistance of resistor R5 can be set to be greater than that of resistor R4, thereby improving the speed control effect.
[0073] like Figure 6 As shown, optionally, the switching module also includes a third switching transistor.
[0074] The input terminal of the third switch is electrically connected to the input terminal of the first switch, the control terminal of the first switch, and the control terminal of the second switch, respectively, so as to output the target control signal CTRL1 to the first switch and the second switch respectively. The output terminal of the third switch is electrically connected to the output terminal of the second switch, and the control terminal of the third switch is used to receive the initial control signal CTRL2.
[0075] The initial control signal CTRL2 includes alternating third and fourth levels. The third level is used to drive the third switch to operate in a first state where it outputs the first level of the target control signal CTRL1 to the first and second switches. The fourth level is used to drive the third switch to operate in a second state where it outputs the second level of the target control signal CTRL1 to the first and second switches.
[0076] As can be seen, the third level of the initial control signal CTRL2 corresponds to the first level of the target control signal CTRL1, and the fourth level of the initial control signal CTRL2 corresponds to the second level of the target control signal CTRL1. By adding a third switch, when the first or second level of the output target control signal needs to be high, it can be directly converted to the input positive voltage power supply signal VCC+, thereby improving the driving capability.
[0077] like Figure 7 or Figure 8 As shown, optionally, the third switch includes the second NMOS transistor Q5.
[0078] Among them, reference Figure 7 When the first switching transistor and the second switching transistor are NPN transistor Q1 and PNP transistor Q2 respectively, the initial control signal CTRL2 connected to the second NMOS transistor Q5 includes a low level third level and a high level fourth level.
[0079] Specifically, if the input positive voltage power supply signal VCC+ is +12V, when the initial control signal CTRL2 is low, the second NMOS transistor Q5 is off, the target control signal CTRL1 is high, the NPN transistor Q1 is on, and the PNP transistor Q2 is off. The +12V positive voltage power supply signal VCC+ charges the first capacitor C1 through the NPN transistor Q1 and the first diode D1. The first terminal of the first capacitor C1 is positive and the second terminal is negative. When the initial control signal CTRL2 is high, the second NMOS transistor Q5 is on, the target control signal CTRL1 is low, the NPN transistor Q1 is off, and the PNP transistor Q2 is off. When transistor Q2 is turned on, the first terminal of capacitor C1 is pulled down to 0V, and the second terminal of capacitor C1 is at a negative voltage. Capacitor C1 charges capacitor C2 through transistor Q2 and diode D2. The second terminal of capacitor C2 is positive and the first terminal is negative, and the first terminal of capacitor C2 is at a negative voltage. After several alternating cycles, the first terminal of capacitor C1 is +12V and the first terminal of capacitor C2 is -12V. However, since transistors Q1, Q2, D1, and D2 all have forward voltage drops, the actual voltage at the first terminal of capacitor C2 is around -10V.
[0080] Among them, reference Figure 8 When the first switch and the second switch are PMOS transistor Q3 and the first NMOS transistor Q4 respectively, the initial control signal CTRL2 connected to the second NMOS transistor Q5 includes a high level third level and a low level fourth level.
[0081] Specifically, if the input positive voltage power supply signal VCC+ is +12V, when the initial control signal CTRL2 is high, the second NMOS transistor Q5 is turned on; when the target control signal CTRL1 is low, the PMOS transistor Q3 is turned on; and the first NMOS transistor Q4 is turned off. The +12V positive voltage power supply signal VCC+ charges the first capacitor C1 through the PMOS transistor Q3 and the first diode D1. The first terminal of the first capacitor C1 is positive and the second terminal is negative. When the initial control signal CTRL2 is low, the second NMOS transistor Q5 is turned off; when the target control signal CTRL1 is high, the PMOS transistor Q3 is turned off; and the first NMOS transistor Q4 is turned off. When the S-channel transistor Q4 is turned on, the first terminal of the first capacitor C1 is pulled down to 0V, and the second terminal of the first capacitor C1 is at a negative voltage. The first capacitor C1 charges the second capacitor C2 through the first NMOS transistor Q4 and the second diode D2. The second terminal of the second capacitor C2 is positive and the first terminal is negative, so the first terminal of the second capacitor C2 is at a negative voltage. After several alternating cycles, the first terminal of the first capacitor C1 is +12V and the first terminal of the second capacitor C2 is -12V. However, since the PMOS transistor Q3, the first NMOS transistor Q4, the first diode D1, and the second diode D2 all have forward voltage drops, the first terminal of the second capacitor C2 is actually around -11V.
[0082] According to a second aspect of this application, a charging device is provided, including a signal generating circuit and a negative voltage generating circuit in any of the above embodiments.
[0083] The power supply terminal of the signal generation circuit is electrically connected to the negative voltage generation circuit, and is used to generate a CP signal based on the positive voltage power supply signal and the negative voltage power supply signal output by the negative voltage generation circuit.
[0084] The negative voltage generating circuit included in the charging device of this application forms a first circuit and a second circuit by switching module, which alternately connect to a first capacitor, a first diode, a second capacitor, and a second diode, respectively. The negative voltage is output through the second capacitor, requiring only a small number of components, thus reducing size and cost.
[0085] According to a fourth aspect of this application, a vehicle is provided, including an on-board charging device, which is electrically connected to the output terminal of a signal generation circuit in any of the above embodiments to access a CP signal generated by the signal generation circuit.
[0086] The negative pressure generating circuit used in the vehicle of this application forms a first circuit and a second circuit by alternating the switching module with the first capacitor, the first diode, the second capacitor, and the second diode, respectively, thereby outputting negative pressure through the second capacitor. Only a few components are needed, which reduces the size and cost.
[0087] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.
[0088] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.
[0089] The embodiments, implementation methods, and related technical features of this application can be combined and substituted for each other without conflict.
[0090] The above are merely preferred embodiments of this application and are not intended to limit this application in any way. In the embodiments of this application, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant content of other embodiments. Any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of this application without departing from the content of the technical solution of this application shall still fall within the scope of the technical solution of this application.
Claims
1. A negative voltage generating circuit, characterized in that, Includes a switch module, a first capacitor, a first diode, a second capacitor, and a second diode; The first terminal of the first capacitor is electrically connected to the first access terminal of the switching module, the second terminal of the first capacitor is electrically connected to the anode of the first diode and the cathode of the second diode, the cathode of the first diode is electrically connected to the second terminal of the second capacitor and the second access terminal of the switching module, and the anode of the second diode is electrically connected to the first terminal of the second capacitor. The switching module is used to alternately form a first circuit with the first capacitor and the first diode, and to form a second circuit with the first capacitor, the second diode and the second capacitor, so as to output a negative voltage power signal through the second capacitor.
2. The negative pressure generating circuit according to claim 1, characterized in that, The switching module includes a first switching transistor and a second switching transistor; The input terminal of the first switching transistor is used to connect to a positive voltage power supply signal. The output terminal of the first switching transistor is electrically connected to the first terminal of the first capacitor and the input terminal of the second switching transistor. The output terminal of the second switching transistor is electrically connected to the cathode of the first diode and the second terminal of the second capacitor and is used to ground. The control terminals of the first and second switching transistors are used to connect to a target control signal. The target control signal includes alternating first and second levels. The first level is used to drive the first switch to turn on and the second switch to turn off, and the second level is used to drive the first switch to turn off and the second switch to turn on.
3. The negative pressure generating circuit according to claim 2, characterized in that, The first switching transistor includes an NPN transistor, the second switching transistor includes a PNP transistor, the first level is a high level, and the second level is a low level.
4. The negative pressure generating circuit according to claim 2, characterized in that, The first switching transistor includes a PMOS transistor, the second switching transistor includes a first NMOS transistor, the first level is a low level, and the second level is a high level.
5. The negative voltage generating circuit according to claim 4, characterized in that, The switching module further includes a first driving unit; The gate of the PMOS transistor is used to access the target control signal through the first driving unit; The first driving unit is configured to control the PMOS transistor to turn on at a first speed when the target control signal is low and to control the PMOS transistor to turn off at a second speed when the target control signal is high, wherein the second speed is greater than the first speed.
6. The negative pressure generating circuit according to claim 5, characterized in that, The first driving unit includes a third diode, a first resistor, and a second resistor; The anode of the third diode is electrically connected to the first end of the second resistor and is used to receive the target control signal. The cathode of the third diode is electrically connected to the first end of the first resistor. The second ends of the first resistor and the second resistor are respectively electrically connected to the gate of the PMOS transistor.
7. The negative pressure generating circuit according to claim 6, characterized in that, The resistance of the second resistor is greater than the resistance of the first resistor.
8. The negative pressure generating circuit according to claim 4, characterized in that, The switching module further includes a second drive unit; The gate of the first NMOS transistor is used to access the target control signal through the second driving unit; The second driving unit is used to control the first NMOS transistor to turn off at a third speed when the target control signal is low and to control the first NMOS transistor to turn on at a fourth speed when the target control signal is high, wherein the third speed is greater than the fourth speed.
9. The negative pressure generating circuit according to claim 8, characterized in that, The second driving unit includes a fourth diode, a third resistor, and a fourth resistor; The cathode of the fourth diode is electrically connected to the first end of the fourth resistor and is used to receive the target control signal. The anode of the fourth diode is electrically connected to the first end of the third resistor. The second ends of the third resistor and the second ends of the fourth resistor are respectively electrically connected to the gate of the first NMOS transistor.
10. The negative pressure generating circuit according to claim 9, characterized in that, The resistance value of the fourth resistor is greater than that of the third resistor.
11. The negative voltage generating circuit according to claim 2, characterized in that, The switching module also includes a third switching transistor; The input terminal of the third switch is electrically connected to the input terminal of the first switch, the control terminal of the first switch, and the control terminal of the second switch, respectively. The output terminal of the third switch is electrically connected to the output terminal of the second switch. The control terminal of the third switch is used to receive the initial control signal. The initial control signal includes alternating third and fourth levels, wherein the third level is used to drive the third switch to operate in a first state that outputs the first level to the first and second switches; The fourth level is used to drive the third switch to operate in a second state that outputs the second level to the first switch and the second switch.
12. The negative voltage generating circuit according to claim 11, characterized in that, The third switch includes a second NMOS transistor.
13. A charging device, characterized in that, Includes a signal generation circuit and a negative pressure generation circuit as described in any one of claims 1 to 12; The power supply terminal of the signal generation circuit is electrically connected to the negative pressure generation circuit, and is used to generate a CP signal based on the positive pressure power supply signal and the negative pressure power supply signal output by the negative pressure generation circuit.
14. A vehicle, characterized in that, The device includes an on-board charging unit, which is electrically connected to the output terminal of the signal generation circuit in the charging device of claim 13 to receive the CP signal generated by the signal generation circuit.