Negative pressure supply circuit and electronic device
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SZ ZHUOYU TECH CO LTD
- Filing Date
- 2025-07-03
- Publication Date
- 2026-06-23
Smart Images
Figure CN224401401U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of negative pressure conversion technology, and in particular to a negative pressure supply circuit and electronic equipment. Background Technology
[0002] Negative voltage refers to a voltage value less than zero. It is often required in various electronic products. For example, in lidar, the receiving device of lidar, such as a single-photon avalanche diode (SPAD) or a silicon photomultiplier tube (SiPM), needs to be provided with a negative reverse bias voltage to operate in Geiger mode.
[0003] In existing negative voltage supply circuits, negative voltage is generated by controlling the charging and discharging of the output energy storage circuit through the control of the switching circuit's conduction and cutoff. If the negative voltage supply circuit is a CUK circuit (also known as a dual-inductor inverting converter), the CUK circuit uses components such as dual inductors and coupling capacitors to control the inductor's energy storage and release by switching transistors. This allows the input positive voltage to be converted into a negative voltage for output. The output voltage can be increased or decreased, and the output ripple is small, making it suitable for applications with high requirements for output voltage ripple.
[0004] However, in existing negative voltage supply circuits, both the charging current of the power input and the charging current of the output energy storage circuit pass through the switching circuit. It is difficult to accurately determine the charging current of the power input by detecting the current flowing through the switching circuit, which makes it difficult to perform overcurrent protection. The lack of overcurrent protection function in the negative voltage supply circuit can easily lead to damage when the negative voltage supply circuit is overcurrent. Utility Model Content
[0005] This invention provides a negative pressure supply circuit and an electronic device. The negative pressure supply circuit has an overcurrent protection function to prevent damage to the negative pressure supply circuit when there is an overcurrent.
[0006] This utility model provides a negative pressure supply circuit, including: an input energy storage circuit, a switching circuit, an output energy storage circuit, a unidirectional conduction module, and a current detection module;
[0007] One end of the input energy storage circuit is connected to the voltage input terminal of the negative voltage supply circuit, and the other end of the input energy storage circuit is connected to the current input terminal of the unidirectional conduction module and the input terminal of the switching circuit.
[0008] The current output terminal of the unidirectional conduction module is connected to the output energy storage circuit; the unidirectional conduction module is used to direct current from the current input terminal to the current output terminal in one direction.
[0009] The input terminal of the switching circuit is connected to the current detection module, or the output terminal of the switching circuit is connected to the current detection module.
[0010] Furthermore, the switching circuit includes a first switching transistor; the output energy storage circuit includes a transfer capacitor and an output capacitor; and the unidirectional conduction module includes a unidirectional conduction device.
[0011] The current input terminal of the unidirectional conducting device is connected to the input terminal of the first switching transistor, the current output terminal of the unidirectional conducting device is connected to one end of the transfer capacitor, and the other end of the transfer capacitor is connected to the output capacitor; wherein, the unidirectional conducting device is used to direct the current from the current output terminal to the current input terminal in one direction.
[0012] Furthermore, the unidirectional conducting device includes: an isolation diode;
[0013] The anode of the isolation diode is connected to the input terminal of the first switching transistor;
[0014] The cathode of the isolation diode is connected to one end of the transfer capacitor;
[0015] Alternatively, the unidirectional conducting device may include: a solid-state relay;
[0016] The input terminal of the solid-state relay is connected to a DC power supply;
[0017] The positive terminal of the solid-state relay is connected to the input terminal of the first switching transistor, and the negative terminal of the solid-state relay is connected to one end of the transfer capacitor.
[0018] Furthermore, the negative pressure supply circuit also includes a control circuit, which is connected to the switching circuit and the current detection module respectively. The control circuit is used to acquire the current signal detected by the current detection module and control the switching circuit to turn on or off.
[0019] Furthermore, the negative pressure supply circuit also includes a control chip, and the unidirectional conduction module also includes a second switching transistor;
[0020] The input terminal of the second switching transistor is connected to the current output terminal of the unidirectional conducting device, and the output terminal of the second switching transistor is grounded.
[0021] The control chip is connected to the conduction control terminal of the second switch transistor, and the control chip is used to control the conduction time of the second switch transistor to be the same as the conduction time of the first switch transistor.
[0022] Furthermore, the second switching transistor includes an NMOS transistor;
[0023] The drain of the NMOS transistor is connected to the current output terminal of the unidirectional conducting device, and the source of the NMOS transistor is grounded.
[0024] The gate of the NMOS transistor is connected to the control chip.
[0025] Furthermore, the second switching transistor includes an NPN bipolar junction transistor;
[0026] The collector of the NPN bipolar junction transistor is connected to the current output terminal of the unidirectional conducting device, and the emitter of the NPN bipolar junction transistor is grounded.
[0027] The base of the NPN bipolar junction transistor is connected to the control chip.
[0028] Furthermore, the negative pressure supply circuit also includes a control chip; the current detection module includes a current sampling resistor;
[0029] One end of the current sampling resistor is connected to the output terminal of the first switching transistor and the sampling signal input terminal of the control chip;
[0030] The other end of the current sampling resistor is grounded.
[0031] Furthermore, the negative pressure supply circuit also includes: a control chip; the output terminal of the control chip is connected to the conduction control terminal of the first switching transistor;
[0032] The control chip is used to perform overcurrent detection on the current of the input energy storage circuit based on the voltage signal of the current sampling resistor, and to control the first switch to turn off when the current of the input energy storage circuit is greater than a preset overcurrent threshold.
[0033] This invention also provides an electronic device, including the negative pressure supply circuit described above.
[0034] As can be seen from the above technical solutions, this utility model has the following advantages:
[0035] In this invention, the negative voltage supply circuit includes: an input energy storage circuit, a switching circuit, an output energy storage circuit, a unidirectional conduction module, and a current detection module; one end of the input energy storage circuit is connected to the voltage input terminal of the negative voltage supply circuit, and the other end of the input energy storage circuit is connected to the current input terminal of the unidirectional conduction module and the input terminal of the switching circuit; the current output terminal of the unidirectional conduction module is connected to the output energy storage circuit; the unidirectional conduction module is used to direct current from the current input terminal to the current output terminal; the input terminal of the switching circuit is connected to the current detection module, or the output terminal of the switching circuit is connected to the current detection module.
[0036] The unidirectional conduction module directs the current from the current input terminal to the current output terminal, preventing the charging current of the output energy storage circuit from flowing into the switching circuit. At this time, only the charging current of the input energy storage circuit flows through the switching circuit. The charging current of the input energy storage circuit can be obtained by detecting the current flowing through the switching circuit through the current detection module. Overcurrent protection is then performed based on the charging current of the input energy storage circuit, giving the negative voltage supply circuit an overcurrent protection function and preventing damage to the negative voltage supply circuit when overcurrent occurs. Attached Figure Description
[0037] To more clearly illustrate the technical solutions in this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings.
[0038] Figure 1 This is a circuit block diagram of a negative pressure supply circuit disclosed in this utility model;
[0039] Figure 2 This is a circuit block diagram of another negative pressure supply circuit disclosed in this utility model;
[0040] Figure 3 This is a schematic diagram of a current transformer for detecting current, as disclosed in this utility model.
[0041] Figure 4 This is a schematic diagram of a Hall effect sensor for detecting current disclosed in this utility model;
[0042] Figure 5 This is a circuit block diagram of a negative pressure charge pump circuit disclosed in this utility model;
[0043] Figure 6 This is a circuit block diagram of a CUK circuit disclosed in this utility model;
[0044] Figure 7 This is a circuit structure diagram of a conventional CUK circuit disclosed in this utility model;
[0045] Figure 8 This is a circuit block diagram of another negative pressure supply circuit disclosed in this utility model;
[0046] Figure 9 This is a current structure diagram of a unidirectional conduction module disclosed in this utility model;
[0047] Figure 10 This is a circuit diagram of another unidirectional conduction module disclosed in this utility model;
[0048] Figure 11This is a connection structure diagram of a control chip and a switching transistor disclosed in this utility model;
[0049] Figure 12 This is a connection structure diagram of another control chip and switching transistor disclosed in this utility model;
[0050] Figure 13 This is a circuit structure diagram of a CUK circuit disclosed in this utility model. Detailed Implementation
[0051] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings. These embodiments are merely illustrative of the present invention and should not be construed as limiting the scope of protection of the present invention.
[0052] In the description of this utility model, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.
[0053] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.
[0054] Negative voltage is frequently required in various electronic products. For example, in lidar, the receiving devices—single-photon avalanche diodes (SPADs) or silicon photomultiplier tubes (SiPMs)—require a negative reverse bias voltage to operate in Geiger mode. Existing negative voltage supply circuits generate this negative voltage by controlling the on / off state of a switching circuit to regulate the charging and discharging of the output energy storage circuit. However, in these circuits, both the charging current from the power input and the charging current from the output energy storage circuit pass through the switching circuit, making it difficult to accurately determine the power input charging current by detecting the current flowing through the switching circuit.
[0055] If the negative voltage supply circuit is a CUK circuit, then... Figure 7As shown in the figure, when the control chip controls the switch S1 to conduct, the input voltage Vin is applied across the energy storage inductor L1, charging the energy storage inductor L1. The charging current IL of the energy storage inductor L1 is the charging current of the power supply input, and this charging current IL of the energy storage inductor L1 passes through the switch S1. At the same time, the transfer capacitor C1 discharges through the switch S1, and the capacitance stored in the transfer capacitor C1 will charge the output capacitor C2 through the inductor L2. The isolation diode D2 is reverse biased and cut off, and the charging current IC of the output capacitor C2 passes through the switch S1. At this time, the charging current IL of the energy storage inductor L1 and the charging current IC of the output capacitor both pass through the switch S1. However, the magnitude of the charging current IC of the output capacitor is difficult to set and predict, which will make it difficult to accurately determine the charging current IL of the energy storage inductor L1 by detecting the current flowing through the switch S1, and it will be difficult to provide overcurrent protection for the energy storage inductor L1.
[0056] At this time, the negative pressure supply circuit lacks overcurrent protection, making it prone to damage when overcurrent occurs. For example, if an overcurrent or short circuit occurs in the load, the circuit will burn out, and in severe cases, it can cause the product to catch fire, posing a high safety risk. Therefore, this utility model provides a negative pressure supply circuit with overcurrent protection to prevent damage when overcurrent occurs; the negative pressure supply circuit... Figure 1 As shown, the details are as follows:
[0057] In this invention, the negative voltage supply circuit includes: an input energy storage circuit 300, a switching circuit 400, an output energy storage circuit 500, a unidirectional conduction module 100, and a current detection module 200. The negative voltage supply circuit generates negative voltage and can be a negative voltage charge pump circuit, a CUK circuit, or other circuits that generate negative voltage; specific details are not limited here. One end of the input energy storage circuit 300 is connected to the voltage input terminal Vin of the negative voltage supply circuit. The input energy storage circuit 300 is located at the voltage input terminal of the negative voltage supply circuit and is used to store and regulate the input voltage. The output energy storage circuit 500 is located at the voltage output terminal Vout of the negative voltage supply circuit and is used to regulate the output voltage to ensure its stability. The input energy storage circuit 300 and the output energy storage circuit 500 can be energy storage circuits composed of inductors, capacitors, or other energy storage elements. The specific number of inductors, capacitors, and other energy storage elements in the energy storage circuit is not limited here. The switching circuit 400 may include one or more switching transistors, which are not specifically limited here. The switching transistors may be MOSFETs or transistors, which are not specifically limited here. The switching transistors are used to turn the switching circuit 400 on or off (i.e., the input terminal of the switching circuit 400 is connected to the output terminal, or the input terminal is disconnected from the output terminal).
[0058] The other end of the input energy storage circuit 300 is connected to the current input terminal of the unidirectional conduction module 100 and the input terminal of the switching circuit 400; the current output terminal of the unidirectional conduction module 100 is connected to the output energy storage circuit 500; the unidirectional conduction module 100 is used to unidirectionally direct current from the current input terminal to the current output terminal. Current in the unidirectional conduction module 100 can only flow unidirectionally from the current input terminal to the current output terminal, isolating current flowing from the current output terminal to the current input terminal of the unidirectional conduction module 100. In other words, the unidirectional conduction module 100 is used to prevent current from flowing back from the current output terminal to the current input terminal of the unidirectional conduction module 100, so that the unidirectional conduction module 100 carries unidirectional current, meaning that current only flows from the current input terminal to the current output terminal of the unidirectional conduction module 100.
[0059] By isolating the current flowing from the current output terminal of the unidirectional conduction module 100 to the current input terminal of the unidirectional conduction module 100, the charging current of the output energy storage circuit 500 is prevented from flowing into the switching circuit 400. The charging current of the input energy storage circuit 300 is separated from the charging current of the output energy storage circuit 500. At this time, only the charging current of the output energy storage circuit 500 flows through the switching circuit 400.
[0060] Meanwhile, in the negative pressure supply circuit, the input terminal of the switching circuit 400 is connected to the current detection module 200, or the output terminal of the switching circuit 400 is connected to the current detection module 200. For example... Figure 1 As shown, the output terminal of the switching circuit 400 is connected to the current detection module 200. The current detection module 200 can detect the current at the output terminal of the switching circuit 400 to obtain the current flowing through the switching circuit 400; or, as shown... Figure 2 As shown, the input terminal of the switching circuit 400 is connected to the current detection module 200. The current detection module 200 can detect the current at the input terminal of the switching circuit 400 and obtain the current flowing through the switching circuit 400.
[0061] The current detection module 200 may include: a current transformer, which uses the principle of electromagnetic induction to detect changes in the main circuit current through a secondary coil; such as Figure 3 As shown, the main circuit (primary coil) of the current transformer CT is the output circuit of the switching circuit 400. By detecting the current in the secondary coil of the current transformer CT with an ammeter, the output current of the switching circuit 400 can be obtained. Alternatively, the current detection module 200 may include a Hall effect sensor, which detects the magnetic field strength based on the Hall effect to indirectly measure the current; such as Figure 4As shown, the positive power supply pin (pin 1) of the Hall effect sensor is connected to the output terminal of the switching circuit 400, the negative power supply pin (pin 2) of the Hall effect sensor is grounded, and the signal output pin (pin 3) of the Hall effect sensor is connected to the ammeter. The output current of the switching circuit 400 can be detected through the ammeter.
[0062] Understandably, the current detection module 200 is used to detect the current flowing through the switching circuit 400. The input current and output current of the switching circuit 400 are the same. The current flowing through the switching circuit 400 can be obtained by detecting either the input current or the output current. Since only the charging current of the input energy storage circuit 300 flows through the switching circuit 400, the accurate value of the charging current of the input energy storage circuit 300 can be obtained by detecting the current flowing through the switching circuit 400 using the current detection module 200. This allows for accurate acquisition of the charging current of the input energy storage circuit 300, and overcurrent protection is provided for the negative voltage supply circuit based on the charging current of the input energy storage circuit 300.
[0063] In this invention, the negative voltage supply circuit includes: an input energy storage circuit, a switching circuit, an output energy storage circuit, a unidirectional conduction module, and a current detection module; one end of the input energy storage circuit is connected to the voltage input terminal of the negative voltage supply circuit, and the other end of the input energy storage circuit is connected to the current input terminal of the unidirectional conduction module and the input terminal of the switching circuit; the current output terminal of the unidirectional conduction module is connected to the output energy storage circuit; the unidirectional conduction module is used to direct current from the current input terminal to the current output terminal; the input terminal of the switching circuit is connected to the current detection module, or the output terminal of the switching circuit is connected to the current detection module.
[0064] The unidirectional conduction module directs current from the input terminal to the output terminal, preventing the charging current of the output energy storage circuit from flowing into the switching circuit. At this time, only the charging current of the input energy storage circuit flows through the switching circuit. The charging current of the input energy storage circuit can be obtained by detecting the current flowing through the switching circuit using a current detection module. Overcurrent protection is then implemented based on this input charging current, giving the negative voltage supply circuit overcurrent protection functionality. This completes the overcurrent protection function of the negative voltage supply circuit, improving its reliability and preventing damage from overcurrent. This negative voltage supply circuit is suitable for applications that generate negative voltage and have high safety requirements, such as lidar, oscilloscopes, and other electronic devices.
[0065] Furthermore, in this invention, the negative pressure supply circuit can be a CUK circuit, such as... Figure 6As shown; the input energy storage circuit 300 includes an energy storage inductor L1, the switching circuit 400 includes a first switching transistor S1, and the output energy storage circuit 500 includes a transfer capacitor C1, an output capacitor C2, an inductor L2, and a diode D2. In this invention, the negative voltage supply circuit can also be a negative voltage charge pump circuit, such as... Figure 5 As shown; wherein, the input energy storage circuit 300 includes: energy storage inductor L, the switching circuit 400 includes: first switching transistor S1, and the output energy storage circuit 500 includes: transfer capacitor C1, output capacitor C2, isolation diode D1, and diode D2.
[0066] The following description uses a CUK circuit and / or a negative voltage charge pump circuit as an example. The unidirectional conduction module 100 includes: a unidirectional conduction device; wherein, the current input terminal of the unidirectional conduction device is connected to the input terminal of the first switching transistor S1; the current output terminal of the unidirectional conduction device is connected to one end of the transfer capacitor C1, and the other end of the transfer capacitor C1 is connected to the output capacitor C2. The unidirectional conduction device is used to direct the current from the current input terminal to the current output terminal in one direction. That is, the current flows unidirectionally through the unidirectional conduction device, only from the current input terminal to the current output terminal, so as to prevent the charging current of the transfer capacitor C1 to the output capacitor C2 from flowing into the first switching transistor S1, so that the first switching transistor S1 only has the charging current of the energy storage inductor L1 flowing through it.
[0067] Furthermore, such as Figure 9 (Current detection module 200 not shown) As shown, in this invention, the unidirectional conducting device includes: a solid-state relay (SSR); the input terminal of the SSR is connected to a DC power supply V; the positive terminal of the SSR's output is connected to the input terminal of the first switching transistor S1, and the negative terminal of the SSR's output is connected to one end of the transfer capacitor C1. It can be understood that the DC voltage provided by the DC power supply V turns on the SSR. At this time, the current in the SSR can only flow from the positive terminal of the SSR's output to the negative terminal of the SSR's output; the reverse current is blocked to prevent the charging current of the transfer capacitor C1 to the output capacitor C2 from flowing into the first switching transistor S1.
[0068] Furthermore, such as Figure 10 (Current detection module 200 not shown) As shown, the unidirectional conduction device includes: an isolation diode D1; the anode of the isolation diode D1 is connected to the input terminal of the first switching transistor S1; the cathode of the isolation diode D1 is connected to one end of the transfer capacitor C1. For the isolation diode D1, current flows only from the anode to the cathode of the isolation diode D1 to prevent the charging current of the transfer capacitor C1 to the output capacitor C2 from flowing into the first switching transistor S1.
[0069] Furthermore, such as Figure 8 As shown, in this invention, the negative pressure supply circuit also includes a control circuit 600, which is connected to the switching circuit 400 and the current detection module 200. The control circuit 600 acquires the current signal detected by the current detection module 200 and controls the switching circuit 400 to turn on or off. It can be understood that when the output energy storage circuit 500 needs to be charged, the control circuit 600 controls the switching circuit 400 to turn on. At this time, the current signal detected by the current detection module 200 is the current flowing through the switching circuit 400, which is the charging current of the output energy storage circuit 500. When the current signal detected by the current detection module 200 is greater than a preset overcurrent threshold, i.e., the charging current of the output energy storage circuit 500 is greater than the preset overcurrent threshold, the switch circuit 400 is controlled to turn off, thereby achieving overcurrent protection for the negative pressure supply circuit.
[0070] Furthermore, in this invention, the negative pressure supply circuit also includes a control chip, that is, the control circuit 600 includes a control chip. The control chip can be a boost control chip (boost control IC) or an inverting DC-DC chip, which is not limited here; the unidirectional conduction module 100 also includes a second switching transistor S2; the second switching transistor S2 can be a MOSFET, a transistor or a field-effect transistor, which is not limited here. The input terminal of the second switch S2 is connected to the current output terminal of the unidirectional conduction device, and the output terminal of the second switch S2 is grounded. The control chip is connected to the conduction control terminal of the second switch S2. The control chip is used to control the conduction time of the second switch S2 to be the same as the conduction time of the first switch S1. That is, the second switch S2 and the first switch S1 are turned on at the same time. At this time, the charging current IC of the transfer capacitor C1 to the output capacitor C2 flows out of the second switch S2, and the charging current IL of the energy storage inductor S1 flows out of the first switch S1. The charging current IL of the energy storage inductor S1 and the charging current IC of the output capacitor C2 follow different current paths to avoid the charging current of the transfer capacitor C1 to the output capacitor C2 flowing into the first switch S1.
[0071] It is understood that in this invention, a single control chip can be used to control both the first switch S1 and the second switch S2 to conduct simultaneously, thus allowing simultaneous control of both switches using only one chip. Specifically, one output pin of this control chip can be connected to both the conduction control terminals of the first switch S1 and the second switch S2, as shown below. Figure 10 As shown, the first switch S1 and the second switch S2 can be simultaneously turned on by one output pin of the control chip; alternatively, the two output pins of the control chip can be connected to the on-control terminals of the first switch S1 and the second switch S2, respectively, as shown. Figure 11As shown, the first switch S1 and the second switch S2 are simultaneously turned on by the two output pins of the control chip. It can be understood that in this invention, two control chips can also be used to control the first switch S1 and the second switch S2 simultaneously, as shown below. Figure 12 As shown, the output pin of one control chip is connected to the conduction control terminal of the first switch S1, and the output pin of another control chip is connected to the conduction control terminal of the second switch S2. The two control chips control the first switch S1 and the second switch S2 to conduct simultaneously.
[0072] As can be seen, the unidirectional conduction module added to the negative voltage supply circuit only requires one unidirectional conduction device and a second switching transistor, eliminating the need for complex active components. This enables the negative voltage supply circuit to have overcurrent protection while effectively controlling costs. Furthermore, the negative voltage supply circuit uses only one control chip to control both switching transistors simultaneously, effectively saving I / O resources and reducing control costs.
[0073] Furthermore, in some embodiments of this utility model, the second switching transistor includes: an NMOS transistor; the drain of the NMOS transistor is connected to the current output terminal of the unidirectional conducting device, and the source of the NMOS transistor is grounded; the gate of the NMOS transistor is connected to the control chip. When the first switching transistor S1 and the NMOS transistor S2 are simultaneously turned on, the charging current IC of the transfer capacitor C1 to the output capacitor C2 flows away from the NMOS transistor S2.
[0074] Furthermore, in some embodiments of this invention, the second switching transistor includes an NPN bipolar junction transistor (BJT); the collector of the NPN BJT is connected to the current output terminal of a unidirectional conducting device, and the emitter of the NPN BJT is grounded; the base of the NPN BJT is connected to the control chip. When the first switching transistor S1 and the NPN BJT S2 are simultaneously turned on, the charging current IC of the transfer capacitor C1 to the output capacitor C2 flows away from the NPN BJT S2.
[0075] Furthermore, such as Figure 13 As shown, in some embodiments of this utility model, the current detection module 200 includes: a current sampling resistor Rsense; one end of the current sampling resistor Rsense is connected to the output terminal of the first switching transistor S1 and the sampling signal input terminal of the control chip; the other end of the current sampling resistor Rsense is grounded. It can be understood that the control chip can obtain the voltage signal of the current sampling resistor Rsense input to the sampling signal input terminal, and divide the voltage value of the voltage signal by the resistance value of the current sampling resistor Rsense to obtain the current flowing through the first switching transistor S1.
[0076] Furthermore, the output terminal of the control chip is connected to the conduction control terminal of the first switching transistor S1. The control chip is used to perform overcurrent detection on the current of the energy storage inductor L1 based on the voltage signal of the current sampling resistor Rsense, and control the first switching transistor S1 to turn off when the current of the energy storage inductor L1 exceeds a preset overcurrent threshold. That is, the control chip can obtain the current flowing through the first switching transistor S1, i.e., the current of the energy storage inductor L1, based on the voltage signal of the current sampling resistor Rsense. When the current of the energy storage inductor L1 exceeds the preset overcurrent threshold, it controls the first switching transistor S1 to turn off, thereby realizing overcurrent protection for the negative voltage supply circuit. The preset overcurrent threshold can be 1.5 times or 2 times the rated current value of the negative voltage supply circuit, and the specific value is not limited here.
[0077] This invention also provides an electronic device, including the aforementioned negative pressure supply circuit. This electronic device can be an RF transceiver, oscilloscope, or lidar, and is not specifically limited here; the negative pressure supply circuit provides negative pressure to the electronic device. This negative pressure supply circuit has overcurrent protection, effectively preventing excessive negative pressure from being applied to the electronic device and ensuring its normal operation.
[0078] In one feasible embodiment, the present invention also provides a mobile platform on which the aforementioned electronic device is mounted. This mobile platform can be a vehicle or a mobile robot, and the specific method is not limited here. The electronic device can be used while the mobile platform is in motion, thus broadening its application range. The negative pressure supply circuit on the electronic device has overcurrent protection, effectively preventing excessive negative pressure from being applied to the electronic device and ensuring its normal operation.
[0079] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model, and they should all be covered within the scope of the claims and specification of this utility model.
Claims
1. A negative voltage supply circuit, characterized in that, include: Input energy storage circuit, switching circuit, output energy storage circuit, unidirectional conduction module, and current detection module; One end of the input energy storage circuit is connected to the voltage input terminal of the negative voltage supply circuit, and the other end of the input energy storage circuit is connected to the current input terminal of the unidirectional conduction module and the input terminal of the switching circuit. The current output terminal of the unidirectional conduction module is connected to the output energy storage circuit; the unidirectional conduction module is used to direct current from the current input terminal to the current output terminal in one direction. The input terminal of the switching circuit is connected to the current detection module, or the output terminal of the switching circuit is connected to the current detection module.
2. The negative pressure supply circuit according to claim 1, characterized in that, The switching circuit includes a first switching transistor; the output energy storage circuit includes a transfer capacitor and an output capacitor; the unidirectional conduction module includes a unidirectional conduction device. The current input terminal of the unidirectional conducting device is connected to the input terminal of the first switching transistor, the current output terminal of the unidirectional conducting device is connected to one end of the transfer capacitor, and the other end of the transfer capacitor is connected to the output capacitor; wherein, the unidirectional conducting device is used to direct the current from the current output terminal to the current input terminal in one direction.
3. The negative pressure supply circuit according to claim 2, characterized in that, The unidirectional conduction device includes: an isolation diode; The anode of the isolation diode is connected to the input terminal of the first switching transistor; The cathode of the isolation diode is connected to one end of the transfer capacitor; Alternatively, the unidirectional conducting device may include: a solid-state relay; The input terminal of the solid-state relay is connected to a DC power supply; The positive terminal of the solid-state relay is connected to the input terminal of the first switching transistor, and the negative terminal of the solid-state relay is connected to one end of the transfer capacitor.
4. The negative pressure supply circuit according to claim 1, characterized in that, The negative pressure supply circuit also includes a control circuit, which is connected to the switching circuit and the current detection module. The control circuit is used to acquire the current signal detected by the current detection module and control the switching circuit to turn on or off.
5. The negative pressure supply circuit according to claim 2, characterized in that, The negative pressure supply circuit further includes a control chip, and the unidirectional conduction module further includes a second switching transistor; The input terminal of the second switching transistor is connected to the current output terminal of the unidirectional conducting device, and the output terminal of the second switching transistor is grounded. The control chip is connected to the conduction control terminal of the second switch transistor, and the control chip is used to control the conduction time of the second switch transistor to be the same as the conduction time of the first switch transistor.
6. The negative pressure supply circuit according to claim 5, characterized in that, The second switching transistor includes: an NMOS transistor; The drain of the NMOS transistor is connected to the current output terminal of the unidirectional conducting device, and the source of the NMOS transistor is grounded. The gate of the NMOS transistor is connected to the control chip.
7. The negative pressure supply circuit according to claim 5, characterized in that, The second switching transistor includes: an NPN bipolar junction transistor; The collector of the NPN bipolar junction transistor is connected to the current output terminal of the unidirectional conducting device, and the emitter of the NPN bipolar junction transistor is grounded. The base of the NPN bipolar junction transistor is connected to the control chip.
8. The negative pressure supply circuit according to claim 2, characterized in that, The negative pressure supply circuit further includes a control chip; the current detection module includes a current sampling resistor. One end of the current sampling resistor is connected to the output terminal of the first switching transistor and the sampling signal input terminal of the control chip; The other end of the current sampling resistor is grounded.
9. The negative pressure supply circuit according to claim 8, characterized in that, The negative pressure supply circuit further includes: a control chip; the output terminal of the control chip is connected to the conduction control terminal of the first switching transistor; The control chip is used to perform overcurrent detection on the current of the input energy storage circuit based on the voltage signal of the current sampling resistor, and to control the first switch to turn off when the current of the input energy storage circuit is greater than a preset overcurrent threshold.
10. An electronic device, characterized in that, Includes the negative pressure supply circuit described in any one of claims 1 to 9.