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
- 2026-06-19
Smart Images
Figure CN224385362U_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, the charging and discharging of the output energy storage circuit is controlled by controlling the on and off of the switching circuit, thereby generating negative voltage. If the negative voltage supply circuit is a negative voltage charge pump circuit (also known as a dual-inductor phase-inverting converter), the charging and discharging of the capacitor is controlled by the periodic on and off of the switching transistor in the negative voltage charge pump circuit, thereby accumulating and transferring charge and generating negative voltage.
[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 switch isolation 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 first terminal of the switch isolation module and the input terminal of the switch circuit.
[0008] The second terminal of the switch isolation module is connected to the output energy storage circuit; the conduction state of the switch isolation module is opposite to the conduction state of the switch circuit.
[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 switching isolation module includes a switching unit.
[0011] One end of the switching unit is connected to the input terminal of the first switching transistor, and the other end of the switching unit 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 conduction state of the switching unit is opposite to the conduction state of the first switching transistor.
[0012] Furthermore, the negative pressure supply circuit also includes a control chip; the switching unit includes a second switching transistor, a third switching transistor, and an inverter; the conduction level polarity of the second switching transistor is the same as that of the first switching transistor, and the conduction level polarity of the third switching transistor is low.
[0013] The signal output terminal of the control chip is connected to the conduction control terminal of the first switching transistor and the input terminal of the inverter;
[0014] The output terminal of the inverter is connected to the on-control terminal of the second switch, the input terminal of the second switch is connected to the on-control terminal of the third switch, and the output terminal of the second switch is grounded.
[0015] The input terminal of the third switch is connected to the input terminal of the first switch, and the output terminal of the third switch is connected to one end of the transfer capacitor.
[0016] Furthermore, the first switching transistor includes a first NMOS transistor, the second switching transistor includes a second NMOS transistor, and the third switching transistor includes a PMOS transistor;
[0017] The signal output terminal of the control chip is connected to the gate of the first NMOS transistor and the input terminal of the inverter.
[0018] The output terminal of the inverter is connected to the gate of the second NMOS transistor, the drain of the second NMOS transistor is connected to the gate of the PMOS transistor, and the source of the second NMOS transistor is grounded.
[0019] The source of the PMOS transistor is connected to the drain of the first NMOS transistor, and the drain of the PMOS transistor is connected to one end of the transfer capacitor.
[0020] Alternatively, the first switching transistor may include a first NPN bipolar junction transistor, the second switching transistor may include a second NPN bipolar junction transistor, and the third switching transistor may include a PNP bipolar junction transistor.
[0021] The signal output terminal of the control chip is connected to the base of the first NPN bipolar junction transistor and the input terminal of the inverter.
[0022] The output terminal of the inverter is connected to the base of the second NPN bipolar junction transistor, the collector of the second NPN bipolar junction transistor is connected to the base of the PNP bipolar junction transistor, and the emitter of the second NPN bipolar junction transistor is grounded.
[0023] The emitter of the PNP bipolar junction transistor is connected to the collector of the first NPN bipolar junction transistor, and the collector of the PNP bipolar junction transistor is connected to one end of the transfer capacitor.
[0024] Furthermore, the negative pressure supply circuit also includes a control circuit, which is connected to the switch circuit and the switch isolation module respectively. The control circuit controls the conduction state of the switch isolation module to be opposite to the conduction state of the switch circuit.
[0025] Furthermore, the negative pressure supply circuit also includes a control chip, and the switch isolation module also includes a fourth switch transistor;
[0026] The input terminal of the fourth switch is connected to the other end of the switch unit, and the output terminal of the fourth switch is grounded.
[0027] The control chip is connected to the conduction control terminal of the fourth switch transistor, and the control chip is used to control the conduction time of the fourth switch transistor to be the same as the conduction time of the first switch transistor.
[0028] Furthermore, the fourth switching transistor includes an NMOS transistor;
[0029] The drain of the NMOS transistor is connected to the other end of the switching unit, and the source of the NMOS transistor is grounded.
[0030] The gate of the NMOS transistor is connected to the control chip.
[0031] Furthermore, the fourth switching transistor includes an NPN bipolar junction transistor;
[0032] The collector of the NPN bipolar junction transistor is connected to the other end of the switching unit, and the emitter of the NPN bipolar junction transistor is grounded.
[0033] The base of the NPN bipolar junction transistor is connected to the control chip.
[0034] Furthermore, the negative pressure supply circuit also includes a control chip; the current detection module includes one of a current sampling resistor, a current transformer, and a Hall effect sensor.
[0035] One end of the current sampling resistor, the current transformer, or the Hall effect sensor is connected to the output terminal of the first switching transistor and the sampling signal input terminal of the control chip.
[0036] The other end of the current sampling resistor, the current transformer, or the Hall effect sensor is grounded.
[0037] This application also provides an electronic device, including the negative pressure supply circuit described above.
[0038] As can be seen from the above technical solutions, this utility model has the following advantages:
[0039] In this invention, the negative voltage supply circuit includes: an input energy storage circuit, a switching circuit, an output energy storage circuit, a switch isolation 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 first terminal of the switch isolation module and the input terminal of the switching circuit; the second terminal of the switch isolation module is connected to the output energy storage circuit; the conduction state of the switch isolation module is opposite to the conduction state of the switch circuit; the input terminal of the switch circuit is connected to the current detection module, or the output terminal of the switch circuit is connected to the current detection module.
[0040] Understandably, the conduction state of the switch isolation module is opposite to that of the switch circuit. When the switch circuit is on, the switch isolation module is off to prevent the charging current of the output energy storage circuit from flowing into the switch circuit. At this time, only the charging current of the input energy storage circuit flows through the switch circuit. The charging current of the input energy storage circuit can be obtained by detecting the current flowing through the switch 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 there is an overcurrent. Attached Figure Description
[0041] 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.
[0042] Figure 1 This is a circuit block diagram of a negative pressure supply circuit disclosed in this utility model;
[0043] Figure 2 This is a circuit block diagram of another negative pressure supply circuit disclosed in this utility model;
[0044] Figure 3This is a schematic diagram of a current detection module disclosed in this utility model;
[0045] Figure 4 This is a circuit block diagram of a CUK circuit disclosed in this utility model;
[0046] Figure 5 This is a circuit block diagram of a negative pressure charge pump circuit disclosed in this utility model;
[0047] Figure 6 This is a circuit diagram of a conventional negative pressure charge pump circuit disclosed in this utility model;
[0048] Figure 7 This is a circuit block diagram of another negative pressure supply circuit disclosed in this utility model;
[0049] Figure 8 This is a circuit diagram of a switch isolation module disclosed in this utility model;
[0050] Figure 9 This is a circuit diagram of another switch isolation module disclosed in this utility model;
[0051] Figure 10 This is a connection diagram of a control chip disclosed in this utility model;
[0052] Figure 11 This is a circuit diagram of a negative pressure charge pump circuit disclosed in this utility model. Detailed Implementation
[0053] 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.
[0054] 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.
[0055] 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.
[0056] 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.
[0057] If the negative pressure supply circuit is a negative pressure charge pump circuit, then the negative pressure charge pump circuit is as follows: Figure 6 As 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 L, charging the energy storage inductor L. The charging current IL of the energy storage inductor L is the charging current of the power supply input, and this charging current IL of the energy storage inductor L 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 charges the output capacitor C2 through the isolation diode D1. 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 L 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 C2 is difficult to set and predict, which will make it difficult to accurately determine the charging current IL of the energy storage inductor L by detecting the current flowing through the switch S1, and make it difficult to provide overcurrent protection for the energy storage inductor L.
[0058] 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:
[0059] 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 switch isolation 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).
[0060] The input energy storage circuit 300 has one end connected to the first end of the switch isolation module 100 and the input end of the switch circuit 400; the second end of the switch isolation module 100 is connected to the output energy storage circuit 500; the conduction state of the switch isolation module 100 is opposite to that of the switch circuit 400. That is, when the switch circuit 400 is on, the switch isolation module 100 is off, and when the switch circuit 400 is off, the switch isolation module 100 is on. The on and off states of the switch isolation module 100 refer to the on and off states of the first and second ends of the switch isolation module 100. The switch isolation module 100 includes a switching transistor, which can be a MOSFET or a transistor; the specific type is not limited here.
[0061] When the switching circuit 400 is turned on, the switch isolation module 100 is turned off, isolating the current flowing from the second terminal to the first terminal of the switch isolation module 100. In other words, the switch isolation module 100 prevents current from flowing back from the second terminal to the first terminal, ensuring that the switch isolation module 100 carries a unidirectional current, meaning the current flows only from the first terminal to the second terminal. By isolating the current flowing from the second terminal to the first terminal of the switch isolation 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 input energy storage circuit 300 flows through the switch circuit 400.
[0062] 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.
[0063] 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. The output current of the switching circuit 400 can be obtained by detecting the current in the secondary coil of the current transformer (CT) using an ammeter. Alternatively, the current detection module 200 may include a sampling resistor, with the corresponding current obtained by the voltage across the sampling resistor. Or, the current detection module 200 may include a Hall effect sensor, which detects magnetic field strength based on the Hall effect to indirectly measure the current. The positive power supply pin of the Hall effect sensor is connected to the output of the switching circuit 400, the negative power supply pin is grounded, and the signal output pin of the Hall effect sensor is connected to an ammeter, allowing the ammeter to detect the output current of the switching circuit 400.
[0064] 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. When the switching circuit 400 is turned on and the switch isolation module 100 is turned off, only the charging current of the input energy storage circuit 300 flows through the switching circuit 400. By detecting the current flowing through the switching circuit 400 through the current detection module 200, the accurate value of the charging current of the input energy storage circuit 300 can be obtained, thus achieving accurate acquisition of the charging current of the input energy storage circuit 300. Based on the charging current of the input energy storage circuit 300, overcurrent protection can be provided for the negative voltage supply circuit.
[0065] In this invention, the negative voltage supply circuit includes: an input energy storage circuit, a switching circuit, an output energy storage circuit, a switch isolation 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 first terminal of the switch isolation module and the input terminal of the switching circuit; the second terminal of the switch isolation module is connected to the output energy storage circuit; the conduction state of the switch isolation module is opposite to the conduction state of the switch circuit; the input terminal of the switch circuit is connected to the current detection module, or the output terminal of the switch circuit is connected to the current detection module.
[0066] Understandably, the conduction state of this switch isolation module is opposite to that of the switch circuit. When the switch circuit is on, the switch isolation module is off, preventing the charging current of the output energy storage circuit from flowing into the switch circuit. At this time, only the charging current of the input energy storage circuit flows through the switch circuit. The charging current of the input energy storage circuit can be obtained by detecting the current flowing through the switch circuit using the current detection module. Overcurrent protection is then performed based on the charging current of the input energy storage circuit, enabling the negative voltage supply circuit to have overcurrent protection functionality. This completes the overcurrent protection function of the negative voltage supply circuit, improving its reliability and preventing damage during 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.
[0067] Furthermore, in this invention, the negative pressure supply circuit can be a CUK circuit, such as... Figure 4 As 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. The capacitance stored in the transfer capacitor C1 can charge the output capacitor C2 through the inductor L2. In this invention, the negative voltage supply circuit can also be a negative voltage charge pump circuit, such as... Figure 5As 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.
[0068] The following explanation uses a CUK circuit or a negative voltage charge pump circuit as an example. The switch isolation module 100 includes a switching unit; it can be understood that this switching unit may contain a MOSFET, a transistor, or a field-effect transistor, and no specific limitation is made here. One end of the switching unit is connected to the input terminal of the first switching transistor S1, and the other end of the switching unit is connected to one end of the transfer capacitor C1. The other end of the transfer capacitor C1 is connected to the output capacitor C2. The conduction state of the switching unit is opposite to the conduction state of the first switching transistor S1, that is, when the first switching transistor S1 is on, the switching unit is off, and when the first switching transistor S1 is off, the switching unit is on. The on and off states of the first switching transistor S1 refer to the on and off states between the input and output terminals of the first switching transistor S1; the on and off states of the switching unit refer to the on and off states between one end of the switching unit and the other end.
[0069] Understandably, when it is necessary to charge the transfer capacitor C1, the first switch S1 is turned off (cut off), the switching unit is turned on, and the current of the energy storage inductor L charges the transfer capacitor C1. When it is necessary to charge the energy storage inductor L, the first switch S1 is turned on, the switching unit is turned off, and the charging current of the energy storage inductor L flows through the first switch S1. However, since the switching unit is turned off, the charging current of the transfer capacitor C1 to the output capacitor C2 cannot flow through the switching unit to the first switch S1, so as to prevent the charging current of the transfer capacitor C1 to the output capacitor C2 from flowing into the first switch S1, so that the first switch S1 only has the charging current of the energy storage inductor L1 flowing through it.
[0070] Furthermore, such as Figure 7 As shown, in this utility model, the negative pressure supply circuit further includes a control circuit 600, which is connected to the switch circuit 400 and the switch isolation module 100. The control circuit 600 controls the switch isolation module 100 to be in the opposite state to the switch circuit 400. That is, when the control circuit 600 controls the switch circuit 400 to be on, it controls the switch isolation module 100 to be off. At this time, the current flowing through the switch circuit 400 is the charging current of the input energy storage current 300. By detecting the current flowing through the switch current 400 through the current detection module 300, the charging current of the input energy storage circuit 300 can be obtained. Overcurrent protection is then performed based on the charging current of the input energy storage circuit 300 to achieve overcurrent protection of the negative pressure supply circuit.
[0071] Furthermore, such as Figure 8As shown, the negative pressure supply circuit also includes a control chip, i.e., the control circuit 600 includes a control chip. The switch unit 101 in the switch isolation module 100 includes a second switch S2, a third switch S3, and an inverter K1; wherein the conduction level polarity of the second switch S2 is the same as that of the first switch S1, and the conduction level polarity of the third switch S3 is low. It can be understood that the conduction level polarity of the switch is used to control the conduction level polarity of the switch. For example, if the conduction level polarity of the switch is high, a high level input to the conduction control terminal of the switch will turn the switch on; a low level input to the conduction control terminal of the switch will turn the switch off.
[0072] The signal output terminal of the control chip is connected to the conduction control terminal of the first switch S1 and the input terminal of the inverter K1; the output terminal of the inverter K1 is connected to the conduction control terminal of the second switch S2, the input terminal of the second switch S2 is connected to the conduction control terminal of the third switch S3, and the output terminal of the second switch S2 is grounded; the input terminal of the third switch S3 is connected to the input terminal of the first switch S1, and the output terminal of the third switch S3 is connected to one end of the transfer capacitor C1.
[0073] Understandably, when it is necessary to charge the transfer capacitor C1, the polarity of the control signal output from the signal output terminal of the control chip is opposite to the polarity of the conduction level of the first switch S1. The first switch S1 is turned off, the polarity of the control signal is inverted by the inverter K1, the second switch S2 is turned on, pulling down the level of the conduction control terminal of the third switch S3. When the third switch S3 is turned on, the current of the energy storage inductor L charges the transfer capacitor C1. When the energy storage inductor L needs to be charged, the polarity of the control signal output from the signal output terminal of the control chip is the same as the polarity of the conduction level of the first switch S1. The first switch S1 is turned on, and the polarity of the control signal is inverted by the inverter K1. The second switch S2 is turned off, and the third switch S3 is turned off. At this time, the charging current IL of the energy storage inductor L flows through the first switch S1. However, since the third switch S3 is turned off, the charging current IC of the transfer capacitor C1 to the output capacitor C2 cannot flow to the first switch S1 through the third switch S3, so as to avoid the charging current IC of the transfer capacitor C1 to the output capacitor C2 flowing into the first switch S1, so that the first switch S1 only has the charging current IL of the energy storage inductor L1 flowing through it.
[0074] Furthermore, in this invention, the first switching transistor S1 includes a first NMOS transistor, the second switching transistor S2 includes a second NMOS transistor, and the third switching transistor S3 includes a PMOS transistor. The signal output terminal of the control chip is connected to the gate of the first NMOS transistor S1 and the input terminal of the inverter K1; the output terminal of the inverter K1 is connected to the gate of the second NMOS transistor S2, the drain of the second NMOS transistor S2 is connected to the gate of the PMOS transistor S3, and the source of the second NMOS transistor S2 is grounded; the source of the PMOS transistor S3 is connected to the drain of the first NMOS transistor S1, and the drain-source terminal of the PMOS transistor S3 is connected to one end of the transfer capacitor C1.
[0075] Understandably, when charging the transfer capacitor C1 is required, the control chip outputs a low-level control signal, the first NMOS transistor S1 is turned off, and after the control signal is inverted by inverter K1, the second NMOS transistor S2 is turned on, pulling down the gate level of the PMOS transistor S3. The PMOS transistor S3 then turns on, and the current from the energy storage inductor L charges the transfer capacitor C1. When charging the energy storage inductor L is required, the control chip outputs a high-level control signal, the first NMOS transistor S1 is turned on, and after the control signal is inverted by inverter K1, the second NMOS transistor S2 is turned off, and the PMOS transistor S3 is turned off. At this time, the charging current of the energy storage inductor L flows through the first NMOS transistor S1; however, because the PMOS transistor S3 is turned off, the charging current from the transfer capacitor C1 to the output capacitor C2 cannot flow through the switching unit to the first NMOS transistor S1, thus preventing the charging current from the transfer capacitor C1 to the output capacitor C2 from flowing into the first NMOS transistor S1, ensuring that only the charging current of the energy storage inductor L1 flows through the first NMOS transistor S1.
[0076] Among them, the PMOS transistor P3 can be used as a voltage buffer. When the transfer capacitor C1 is charged, the PMOS transistor P3 is turned on. The source voltage of the PMOS transistor P3 is approximately equal to the drain voltage of the PMOS transistor P3. There is no additional conduction loss, which can improve the charging efficiency of the transfer capacitor C1.
[0077] Furthermore, such as Figure 9As shown, in this invention, the first switching transistor S1 includes a first NPN bipolar junction transistor (BJT), the second switching transistor S2 includes a second NPN bipolar junction transistor, and the third switching transistor S3 includes a PNP bipolar junction transistor. The signal output terminal of the control chip is connected to the base of the first NPN bipolar junction transistor S1 and the input terminal of the inverter K1; the output terminal of the inverter K1 is connected to the base of the second NPN bipolar junction transistor S2, the collector of the second NPN bipolar junction transistor S2 is connected to the base of the PNP bipolar junction transistor S3, and the emitter of the second NPN bipolar junction transistor S2 is grounded; the emitter of the PNP bipolar junction transistor S3 is connected to the collector of the first NPN bipolar junction transistor S1, and the collector of the PNP bipolar junction transistor S3 is connected to one end of the transfer capacitor C1.
[0078] Understandably, when it is necessary to charge the transfer capacitor C1, the control chip outputs a low-level control signal, the first NPN bipolar junction transistor S1 is turned off, and after the control signal is inverted by the inverter K1, the second NPN bipolar junction transistor S2 is turned on, pulling down the base level of the PNP bipolar junction transistor S3. The PNP bipolar junction transistor S3 is turned on, and the current of the energy storage inductor L charges the transfer capacitor C1. When the energy storage inductor L needs to be charged, the control chip outputs a high-level control signal, turning on the first NPN bipolar junction transistor S1. After the control signal is inverted by the inverter K1, the second NPN bipolar junction transistor S2 turns off, and the PNP bipolar junction transistor S3 turns off. At this time, the charging current of the energy storage inductor L flows through the first NPN bipolar junction transistor S1. However, since the PNP bipolar junction transistor S3 is off, the charging current of the transfer capacitor C1 to the output capacitor C2 cannot flow through the switching unit to the first NPN bipolar junction transistor S1, so as to prevent the charging current of the transfer capacitor C1 to the output capacitor C2 from flowing into the first NPN bipolar junction transistor S1, so that the first NPN bipolar junction transistor S1 only carries the charging current of the energy storage inductor L1.
[0079] Furthermore, in this invention, the negative voltage supply circuit also includes: a control chip, which can be a boost control chip (boost control IC) or a negative voltage LDO (low dropout linear regulator) chip, or other chips, without specific limitations here; the switch isolation module 100 also includes: a fourth switch S4; the fourth switch S4 can be a MOSFET, a transistor, or a field-effect transistor, without specific limitations here. The input terminal of the fourth switch S4 is connected to the other end of the switch unit 101, and the output terminal of the fourth switch S4 is grounded; the control chip is connected to the conduction control terminal of the fourth switch S4, and the control chip is used to control the conduction time of the fourth switch S4 to be the same as the conduction time of the first switch S1.
[0080] The conduction level polarity of the fourth switch S4 can be the same as that of the first switch S1, and the same pin of the control chip can be connected to both the conduction control terminal of the first switch S1 and the conduction control terminal of the fourth switch S4; alternatively, two pins of the control chip can be connected to the conduction control terminals of the first switch S1 and the fourth switch S4, respectively. Figure 10 As shown, when the control chip turns on the first switch S1, it simultaneously turns on the fourth switch S4. At this time, the charging current IC of the transfer capacitor C1 to the output capacitor C2 flows through the fourth switch S4, and the charging current IL of the energy storage inductor L flows through the first switch S1. The charging current IL of the energy storage inductor L and the charging current IC of the output capacitor C2 follow different current paths to prevent the charging current of the transfer capacitor C1 to the output capacitor C2 from flowing into the first switch S1.
[0081] As can be seen, the added switch isolation module in the negative voltage supply circuit only requires three switching transistors (second switch S2, third switch S3, and fourth switch S4), eliminating the need for complex active components. This allows the negative voltage supply circuit to provide overcurrent protection while effectively controlling costs. Furthermore, the negative voltage supply circuit uses only one control chip to control two switching transistors simultaneously, effectively saving I / O resources and reducing control costs. Of course, in other embodiments, two or more control chips can be used to control the switching transistors, with each transistor capable of individual control.
[0082] Furthermore, in this invention, the fourth switch S4 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 switch S1 and the NMOS transistor S4 are simultaneously turned on, the charging current IC of the transfer capacitor C1 to the output capacitor C2 flows away from the NMOS transistor S4.
[0083] Furthermore, the fourth switch S4 includes an NPN bipolar junction transistor (BJT); the collector of the NPN BJT is connected to the current output terminal of the 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 switch S1 and the NPN BJT S4 are simultaneously turned on, the charging current IC of the transfer capacitor C1 to the output capacitor C2 flows away from the NPN BJT S4.
[0084] Furthermore, such as Figure 11As shown, in this invention, 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.
[0085] 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.
[0086] 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.
[0087] 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 of the electronic device has overcurrent protection, effectively preventing excessive negative pressure from being applied to the electronic device and ensuring the normal operation of both the electronic device and the mobile platform on which it is mounted.
[0088] 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, switch isolation 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 first terminal of the switch isolation module and the input terminal of the switch circuit. The second terminal of the switch isolation module is connected to the output energy storage circuit; the conduction state of the switch isolation module is opposite to the conduction state of the switch circuit. 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 switching isolation module includes a switching unit. One end of the switching unit is connected to the input terminal of the first switching transistor, and the other end of the switching unit 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 conduction state of the switching unit is opposite to the conduction state of the first switching transistor.
3. The negative pressure supply circuit according to claim 2, characterized in that, The negative pressure supply circuit further includes a control chip; the switching unit includes a second switching transistor, a third switching transistor, and an inverter; the conduction level polarity of the second switching transistor is the same as that of the first switching transistor. The signal output terminal of the control chip is connected to the conduction control terminal of the first switching transistor and the input terminal of the inverter; The output terminal of the inverter is connected to the on-control terminal of the second switch, the input terminal of the second switch is connected to the on-control terminal of the third switch, and the output terminal of the second switch is grounded. The input terminal of the third switch is connected to the input terminal of the first switch, and the output terminal of the third switch is connected to one end of the transfer capacitor.
4. The negative pressure supply circuit according to claim 3, characterized in that, The first switching transistor includes a first NMOS transistor, the second switching transistor includes a second NMOS transistor, and the third switching transistor includes a PMOS transistor; The signal output terminal of the control chip is connected to the gate of the first NMOS transistor and the input terminal of the inverter. The output terminal of the inverter is connected to the gate of the second NMOS transistor, the drain of the second NMOS transistor is connected to the gate of the PMOS transistor, and the source of the second NMOS transistor is grounded. The source of the PMOS transistor is connected to the drain of the first NMOS transistor, and the drain of the PMOS transistor is connected to one end of the transfer capacitor. Alternatively, the first switching transistor may include a first NPN bipolar junction transistor, the second switching transistor may include a second NPN bipolar junction transistor, and the third switching transistor may include a PNP bipolar junction transistor. The signal output terminal of the control chip is connected to the base of the first NPN bipolar junction transistor and the input terminal of the inverter. The output terminal of the inverter is connected to the base of the second NPN bipolar junction transistor, the collector of the second NPN bipolar junction transistor is connected to the base of the PNP bipolar junction transistor, and the emitter of the second NPN bipolar junction transistor is grounded. The emitter of the PNP bipolar junction transistor is connected to the collector of the first NPN bipolar junction transistor, and the collector of the PNP bipolar junction transistor is connected to one end of the transfer capacitor.
5. The negative pressure supply circuit according to claim 1, characterized in that, The negative pressure supply circuit further includes a control circuit, which is connected to the switch circuit and the switch isolation module respectively. The control circuit controls the conduction state of the switch isolation module to be opposite to the conduction state of the switch circuit.
6. The negative pressure supply circuit according to claim 2, characterized in that, The negative pressure supply circuit also includes a control chip, and the switch isolation module also includes a fourth switch transistor; The input terminal of the fourth switch is connected to the other end of the switch unit, and the output terminal of the fourth switch is grounded. The control chip is connected to the conduction control terminal of the fourth switch transistor, and the control chip is used to control the conduction time of the fourth switch transistor to be the same as the conduction time of the first switch transistor.
7. The negative pressure supply circuit according to claim 6, characterized in that, The fourth switching transistor includes: an NMOS transistor; The drain of the NMOS transistor is connected to the other end of the switching unit, and the source of the NMOS transistor is grounded. The gate of the NMOS transistor is connected to the control chip.
8. The negative pressure supply circuit according to claim 6, characterized in that, The fourth switching transistor includes: an NPN bipolar junction transistor; The collector of the NPN bipolar junction transistor is connected to the other end of the switching unit, 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.
9. The negative pressure supply circuit according to claim 2, characterized in that, The negative pressure supply circuit also includes a control chip; the current detection module includes one of a current sampling resistor, a current transformer, and a Hall effect sensor. One end of the current sampling resistor, the current transformer, or the Hall effect sensor 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, the current transformer, or the Hall effect sensor is grounded.
10. An electronic device, characterized in that, Includes the negative pressure supply circuit described in any one of claims 1 to 9.