CN111756091A - Power switching circuit and smart door lock - Google Patents

Abstract

The embodiment of the application provides a power supply switching circuit and intelligent lock relates to the electronic equipment field, and this power supply switching circuit includes: the first wiring end of the DC-DC power supply circuit is connected with the to-be-supplied equipment, the inverting circuit is connected with the second wiring end of the LDO power supply circuit, the second wiring end of the inverting circuit is connected with the control circuit, and the second wiring end of the DC-DC power supply circuit is connected with the control circuit. The application utilizes the control circuit to realize the switching of the LDO power supply circuit and the DC-DC power supply circuit, and the service efficiency of the power supply can be improved to a certain extent.

Description

Power switching circuit and smart door lock

technical field

The present application relates to the technical field of electronic equipment, and in particular to a power switching circuit and an intelligent door lock.

Background technique

With the rapid development of science and technology, more and more electronic devices have entered people's lives. At present, most electronic devices, especially electronic devices with low power consumption, can usually be powered by multiple power sources, so as to facilitate the use of electronic devices by users. However, when multiple power sources are used to supply power to electronic devices, the power loss is often increased due to the different power supply voltages of the power sources.

SUMMARY OF THE INVENTION

The purpose of the present application is to provide a power switching circuit and an intelligent door lock. The power switching circuit can not only improve the use efficiency of the power supply, but also has a simple, flexible and easy to implement power switching circuit design.

In a first aspect, an embodiment of the present application provides a power supply switching circuit, the power supply switching circuit includes: an LDO power supply circuit, a first terminal of the LDO power supply circuit is connected to a device to be powered; a DC-DC power supply circuit, a DC-DC power supply circuit The first terminal of the circuit is connected with the equipment to be powered; the inversion circuit, the first terminal of the inversion circuit is connected with the second terminal of the LDO power supply circuit; the control circuit, the second terminal of the inversion circuit is connected with the control circuit , the second terminal of the DC-DC power supply circuit is connected to the control circuit. When the power supply device is in a dormant state, the control circuit sends a low-level signal to the inversion circuit, and uses the inversion circuit to switch the low-level signal to a high-level signal. level signal, so that the LDO power supply circuit supplies power to the device to be powered. When the device to be powered is in the wake-up state, the control circuit sends a high-level signal to the inversion circuit and the DC-DC power supply circuit respectively, and uses the inversion circuit to convert the high-level signal. Switching to a low level signal makes the LDO power supply circuit and the device to be powered off, and controls the DC-DC power supply circuit to supply power to the device to be powered.

Further, the LDO power supply circuit includes a first control unit, the first control unit is used to supply power to the device to be powered when the LDO power supply circuit is connected to the device to be powered, the DC-DC power supply circuit includes a second control unit, the second control unit It is used to supply power to the device to be powered when the DC-DC power supply circuit is connected to the device to be powered; the first terminal of the inversion circuit is connected to the enabling end of the first control unit, and the enabling end of the second control unit is connected to the control unit. circuit connection.

Further, the inversion circuit includes a triode, the collector of the triode is connected to the enabling terminal of the first control unit, the base of the triode is connected to the control circuit, and the emitter of the triode is grounded.

Further, the LDO power supply circuit further includes a first resistor, the first resistor is connected to the first power supply, and the second terminals of the first resistor are respectively connected to the enable terminal of the first control unit and the collector of the triode.

Further, the inversion circuit also includes a second resistor, the first terminal of the second resistor is respectively connected to the enable terminal of the first control unit and the second terminal of the first resistor, and the second terminal of the second resistor is connected to the The collector connection of the triode.

Further, the inversion circuit further includes a diode, the anode of the diode is respectively connected to the base of the triode and the control circuit, and the cathode of the diode is connected to the second power supply.

Further, the DC-DC power supply circuit is connected to the anti-backflow circuit, and the anti-backflow circuit is used to prevent backflow current between the first power supply and the third power supply.

Further, the anti-backflow circuit includes: a first MOS tube and a second MOS tube; the drain of the first MOS tube is connected to the LDO power supply circuit or the DC-DC power supply circuit, and the source of the first MOS tube is connected to the second MOS tube. The source is connected, the gate of the first MOS tube is grounded; the source of the second MOS tube is connected to the third power source, and the gate of the second MOS tube is grounded.

Further, the DC-DC power supply circuit also includes an inductor and a first capacitor, the first terminal of the inductor is connected to the inductor current input terminal of the second control unit of the DC-DC power supply circuit, and the second terminal of the inductor is connected to the first MOS. Drain connection of the tube.

In a second aspect, an embodiment of the present application provides a smart door lock. The smart door lock system includes a smart door lock and the power switching circuit of the first aspect, and the smart door lock is electrically connected to the power switching circuit.

The power supply switching circuit and the smart door lock provided by the present application realize the switching of the LDO power supply circuit and the DC-DC power supply circuit by setting a control circuit and an inversion circuit. The first terminal of the LDO power supply circuit is connected to the equipment to be powered, the first terminal of the DC-DC power supply circuit is connected to the equipment to be powered, and the first terminal of the inversion circuit is connected to the second terminal of the LDO power supply circuit. , the second terminal of the inversion circuit is connected to the control circuit, and the second terminal of the DC-DC power supply circuit is connected to the control circuit. When the power supply device is in a dormant state, the control circuit sends a low-level signal to the inversion circuit, and The inversion circuit is used to switch the low-level signal to a high-level signal, so that the LDO power supply circuit supplies power to the device to be powered. When the device to be powered is in the wake-up state, the control circuit sends a high-level signal to the inversion circuit and DC-DC respectively. The power supply circuit is used to switch the high-level signal to a low-level signal by an inversion circuit, so that the LDO power supply circuit is cut off from the equipment to be powered, and the DC-DC power supply circuit is controlled to supply power to the equipment to be powered. In the present application, by introducing a control circuit, the switching of the LDO power supply circuit and the DC-DC power supply circuit can be realized more quickly and effectively, and the power waste can be reduced while improving the use efficiency of the power supply.

Description of drawings

In order to illustrate the technical solutions in the embodiments of the present application more clearly, the following briefly introduces the drawings that are used in the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application. For those skilled in the art, other drawings can also be obtained from these drawings without creative effort.

1 is a schematic block diagram of a power supply switching circuit provided by an embodiment of the present application;

2 is a schematic diagram of an LDO power supply circuit in a power supply switching circuit provided by an embodiment of the present application;

3 is a schematic diagram of a DC-DC power supply circuit in a power supply switching circuit provided by an embodiment of the present application;

4 is a schematic block diagram of a power supply switching circuit provided by another embodiment of the present application;

5 is a schematic diagram of a DC-DC power supply circuit in a power supply switching circuit provided by another embodiment of the present application;

FIG. 6 is a schematic structural diagram of a smart door lock system provided by an embodiment of the present application.

Detailed ways

In order to make the purposes, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments It is a part of the embodiments of the present application, but not all of the embodiments. The components of the embodiments of the present application generally described and illustrated in the drawings herein may be arranged and designed in a variety of different configurations.

Thus, the following detailed description of the embodiments of the application provided in the accompanying drawings is not intended to limit the scope of the application as claimed, but is merely representative of selected embodiments of the application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application.

It should be noted that like numerals and letters refer to like items in the following figures, so once an item is defined in one figure, it does not require further definition and explanation in subsequent figures.

In the description of the present application, it should be noted that the terms "first", "second", "third", etc. are only used to distinguish descriptions, and cannot be understood as indicating or implying relative importance.

In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "arrangement", "installation", "connection" and "connection" should be interpreted in a broad sense, for example, it may be a fixed connection, It can also be a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or the internal communication between the two components. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood in specific situations.

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application.

At present, in order to improve the power efficiency of low-power devices, a low-power LDO (Low Dropout Regulator) is generally used for power supply. When sleeping, peripheral devices are in a disconnected state; when waking up, DC-DC is added. Powers peripheral devices. In the sleep state, the current consumed by the LDO is at the level of uA. Although the efficiency is low, the energy consumption is low due to the small current. However, in the wake-up state, the current consumed by the LDO is at the level of mA, and the energy consumption is relatively large at this time. , especially when the input and output voltage difference is relatively large, the loss will further increase.

Therefore, in view of the above problems, the inventor proposes the power switching circuit and the smart door lock in the embodiments of the present application, and each embodiment of the present application will be described in detail below with reference to the accompanying drawings.

Referring to FIG. 1 , FIG. 1 shows a schematic block diagram of a power supply switching circuit provided by an embodiment of the present application. The power supply switching circuit may include an LDO power supply circuit 110 , a DC-DC power supply circuit 120 , a control circuit 140 and a device to be powered 150 . The first terminal of the LDO power supply circuit 110 is connected to the device to be powered 150 , the second terminal of the LDO power supply circuit 110 is connected to the control circuit 140 , and the first terminal of the DC-DC power supply circuit 120 is connected to the device to be powered 150 , the second terminal of the DC-DC power supply circuit 120 is connected to the control circuit 140 .

In one way, the first terminal of the inversion circuit 130 is connected to the second terminal of the LDO power supply circuit 110 , and the second terminal of the inversion circuit 130 is connected to the control circuit 140 . In the embodiment of the present application, the control circuit 140 is connected to the inversion circuit 130 and the DC-DC power supply circuit 120 respectively. When the power supply device 150 is in a dormant state, the control circuit 140 sends a low-level signal to the inversion circuit 130, and uses all the The inversion circuit 130 switches the low-level signal to a high-level signal, so that the LDO power supply circuit 110 supplies power to the device 150 to be powered.

In one way, when the device to be powered 150 is in the wake-up state, the control circuit 140 sends a high-level signal to the inversion circuit 130 and the DC-DC power supply circuit 120 respectively, and uses the inversion circuit 130 to convert the high-level signal. The signal is switched to a low level signal, so that the LDO power supply circuit 110 and the device to be powered 150 are turned off, and the control circuit 140 can also control the DC-DC power supply circuit 120 to supply power to the device to be powered 150, wherein, The model of the LDO can be SGM2202, and the DC-DC can be SY8120. Optionally, the device 150 to be powered can be represented by a high level "0" in a dormant state, and the device to be powered 150 in a wake-up state can be represented by a low level "1", the states obtained by the control circuit 140 are different, Then the circuit for supplying power to the device 150 to be powered is also different.

As a method, the device 150 to be powered may include at least one sub-device, each of which is configured with a voltage terminal, and the control circuit 140 may detect whether the voltage of the voltage terminal on each sub-device is less than a voltage threshold, if the sub-device is If the voltage of the upper voltage terminal is less than the voltage threshold, it indicates that the sub-devices of the device to be powered 150 are in a dormant state, and the control circuit 140 can then determine that the device to be powered 150 is in a dormant state. And when the voltage of the sub-device voltage terminal of the device to be powered 150 is greater than the voltage threshold, it means that the device to be powered 150 is in a state of wake-up.

As a method, the sub-device of the device to be powered 150 may be configured with an enable terminal. When the voltage of the enable terminal is low, it indicates that the sub-device of the device to be powered 150 is in a dormant state, that is, the device to be powered 150 is in a dormant state , and when the voltage of the enable terminal is a high voltage, it indicates that the sub-devices of the device to be powered 150 are in the wake-up state, that is, the device to be powered 150 is in the wake-up state of the whole machine.

As a method, the control circuit 140 can also determine its state according to the device parameters sent by the device to be powered 150, that is, when the device parameter sent by the device to be powered 150 is the first parameter, the device to be powered 150 is in a dormant state, and when the device to be powered 150 is sent When the device parameter sent by the device 150 is the second parameter, the device 150 to be powered is in a state of wake-up. The first parameter and the second parameter may be parameters of the sub-devices of the device to be powered 150 in different states. For example, when the computer's screen is in the sleep state, its parameter is the first parameter, and when the computer's screen is in the wake-up state, its parameter is the second parameter. Because the voltage of the computer is different when the computer is in the sleep state and the wake-up state, the first parameter and the first parameter are in the wake-up state. The two parameters are different. Therefore, the control circuit 140 can determine the state of the device to be powered 150 according to the first parameter and the second parameter sent by the device to be powered, wherein the first parameter and the second parameter can be obtained by configuring electronic devices such as voltage or resistance.

In some embodiments, as shown in FIG. 2 , the LDO power supply circuit 110 may include a first control unit U1, the input terminal of the first control unit U1 is connected to a first power supply V1, wherein the first power supply V1 may be VCC_BAT , the first control unit is mainly used for supplying power to the device 150 to be powered when the LDO power supply circuit 110 is connected to the device 150 to be powered. The enabling terminal of the first control unit U1 can be connected to the inversion circuit 130, and the zero-potential terminal of the first control unit U1 is grounded. In this application, the LDO power supply circuit 110 can be connected to the device to be powered 150 through the test point TP1. As shown in FIG. 3 , the DC-DC power supply circuit 120 may include a second control unit U2, the input end of the second control unit U2 is connected to the first power supply V1, and the enabling end of the second control unit U2 may be connected to the control circuit 140 is connected, and the zero-potential end of the second control unit U2 is grounded. The second control unit U2 is used to supply power to the device to be powered 150 when the DC-DC power supply circuit 120 is connected to the device to be powered 150. This application The middle DC-DC power supply circuit 120 can be connected to the device to be powered 150 through the test point TP2.

In some embodiments, the level state of the enable terminal of the first control unit U1 and the level state of the enable terminal of the second control unit U2 may be the same or different, that is, the enable terminal of the first control unit U1 may be It is an enable terminal with active high level, and the enable terminal of the first control unit U1 may also be an enable terminal with active low level. Similarly, the enable terminal of the second control unit U2 may be an enable terminal that is active at a high level, and the enable terminal of the second control unit U1 may also be an enable terminal that is active at a low level.

In the embodiment of the present application, when the level states of the enable terminals of the first control unit U1 and the second control unit U2 are the same, the power switching circuit 100 may include an inversion circuit 130. At this time, the enable terminal of the first control unit U1 The enable terminal is a high-level active enable terminal, and the enable terminal of the second control unit U2 is also a high-level active enable terminal; or, the enable terminal of the first control unit U1 is a low-level active enable terminal. The enable terminal of the second control unit U2 is also an enable terminal with active low level, that is, the enable terminal of the first control unit U1 is connected to the first terminal of the inversion circuit 130 .

As a way, the first control unit U1 may be a low dropout linear regulator LDO, and the second control unit U2 may be DC-DC, the level state of the enable terminal of the first control unit U1 and the second control unit U2 enable When the level states of the energy terminals are the same, the first control unit U1 may be connected to the inversion circuit 130 . The inversion circuit 130 may include a triode Q1, the collector of the triode Q1 is connected to the enable terminal of the first control unit U1, the base of the triode Q1 may be connected to the control circuit 140, and the The emitter is grounded.

As an example, the LDO power supply circuit 110 may further include a first resistor R1, the first resistor R1 is connected to the first power supply V1, and the second terminals of the first resistor R1 are respectively connected to the first control unit U1 The enable terminal is connected to the collector of the transistor Q1. In addition, the inversion circuit 130 further includes a second resistor R2, and the first terminal of the second resistor R2 is connected to the enable terminal of the first control unit U1 and the second terminal of the first resistor R1 respectively. , the second terminal of the second resistor R2 is connected to the collector of the transistor Q1.

In one way, the inversion circuit 130 further includes a diode D1, the anode of the diode D1 is connected to the base of the transistor Q1 and the control circuit 140, respectively, and the cathode of the diode D1 is connected to the second power supply V2, wherein, The second power supply V2 may be VCC_3V3_DISCONTINUE.

It should be noted that, when the level state of the enable terminal of the first control unit U1 is different from the level state of the enable terminal of the second control unit U2, the enable terminal of the first control unit U1 is connected to the control circuit 140, and the second control unit U1 is connected to the control circuit 140. The enable terminal of the unit U2 is also connected to the control circuit 140 . Specifically, when the enable terminal of the first control unit U1 is a high-level enable terminal, and the enable terminal of the second control unit U2 is a low-level enable terminal, the high-level enable terminal of the first control unit U1 The energy terminal is connected to the control circuit 140, and the low-level enable terminal of the second control unit U2 is connected to the control circuit 140; when the enable terminal of the first control unit U1 is a low-level enable terminal, the second control unit U2 When the enable terminal of the first control unit U1 is a high-level enable terminal, the low-level enable terminal of the first control unit U1 is connected to the control circuit 140 , and the high-level enable terminal of the second control unit U2 is connected to the control circuit 140 .

As an example, as shown in FIG. 2, the LDO power supply circuit 110 may further include a second capacitor C2 and a third capacitor C3, wherein the first terminals of the second capacitor C2 and the third capacitor C3 are respectively connected to the first terminals of the second capacitor C2 and the third capacitor C3. A power supply V1 is connected, and the second terminals of the second capacitor C2 and the third capacitor C3 are respectively connected to the output terminal of the first control unit. In addition, the LDO power supply circuit 110 may further include a fourth capacitor C4, a fifth capacitor C5 and a sixth capacitor C6, wherein the first terminal of the fourth capacitor C4 is connected to the bypass terminal of the first control unit U1, so The second terminal of the fourth capacitor C4 is connected to the output terminal of the first control unit, and the first terminal of the fifth capacitor C5 and the first terminal of the sixth capacitor C6 are respectively connected to the output of the first control unit U1. The first terminal of the sixth capacitor C6 is connected to the fourth power supply V4. Wherein, the fourth power supply V4 may be VCC_3V3_SGM2202.

In one way, the inversion circuit 130 may further include a third resistor R3, a fourth resistor R4 and a fifth resistor R5, the first terminal of the third resistor R3 is connected to the base of the transistor Q1, and the first terminal of the third resistor R3 is connected to the base of the transistor Q1. The second terminal of the third resistor R3 is connected to the first terminal of the fifth resistor R5, the second terminal of the fifth resistor R5 is connected to the control circuit 140, and the first connection of the fifth resistor R5 The terminal is also connected to the first terminal of the diode D1. The first terminal of the fourth resistor R4 is respectively connected to the base of the transistor Q1 and the first terminal of the third resistor R3, and the second terminal of the fourth resistor R4 is grounded. In addition, the inversion circuit 130 may further include a sixth capacitor C6, the first terminal of the sixth capacitor C6 is respectively connected to the base of the transistor Q1 and the first terminal of the third resistor R3, and the sixth capacitor C6 The second terminal is grounded, and the first terminal of the sixth capacitor C6 is also connected to the first terminal of the third resistor R3.

In the power switching circuit provided by the application embodiment, the switching of the LDO power supply circuit and the DC-DC power supply circuit is realized by setting the control circuit. The first terminal of the LDO power supply circuit is connected to the equipment to be powered, the first terminal of the DC-DC power supply circuit is connected to the equipment to be powered, and the first terminal of the inversion circuit is connected to the second terminal of the LDO power supply circuit. , the second terminal of the inversion circuit is connected to the control circuit, and the second terminal of the DC-DC power supply circuit is connected to the control circuit. When the power supply device is in a dormant state, the control circuit sends a low-level signal to the inversion circuit, and The inversion circuit is used to switch the low-level signal to a high-level signal, so that the LDO power supply circuit supplies power to the device to be powered. When the device to be powered is in the wake-up state, the control circuit sends a high-level signal to the inversion circuit and DC-DC respectively. The power supply circuit is used to switch the high-level signal to a low-level signal by an inversion circuit, so that the LDO power supply circuit and the device to be powered are cut off, and the DC-DC power supply circuit is controlled to supply power to the device to be powered. In the present application, by introducing a control circuit, the switching of the LDO power supply circuit and the DC-DC power supply circuit can be realized more quickly and effectively, and the power waste can be reduced while improving the power use efficiency. In addition, the introduction of transistors, diodes, resistors and other devices in the present application makes the power switching more convenient and effective, and can improve the stability of the power switching circuit to a certain extent.

Referring to FIG. 4, FIG. 4 shows a schematic block diagram of a power supply switching circuit provided by another embodiment of the present application. It can be seen from FIG. 4 that the power supply switching circuit 100 may include an anti-backflow circuit 160, a DC-DC power supply circuit 120 and a The backflow circuit 160 is connected, and the anti-backflow circuit 160 is mainly used to prevent backflow current between the first power supply V1 and the third power supply V3.

In one way, the DC-DC power supply circuit 120 is connected to an anti-backflow circuit 160, and the anti-backflow circuit 160 may include a first MOS transistor Q2 and a second MOS transistor Q3. The drain of the first MOS transistor Q2 is connected to the DC-DC power supply circuit 120, the source of the first MOS transistor Q2 is connected to the source of the second MOS transistor Q3, and the source of the second MOS transistor Q3 is connected to the third power supply V3 connect. Wherein, the third power supply V3 may be VCC_3V3_CONTINUE.

Referring to FIG. 5 , the drain of the first MOS transistor Q2 of the anti-backflow circuit 160 is connected to the inductor current input end of the second control unit U2 of the DC-DC power supply circuit 120 . In addition, the anti-backflow circuit 160 may further include a ninth resistor R9, a tenth resistor R10 and a triode Q4, wherein the first terminal of the ninth resistor R9 is connected to the source of the first MOS transistor Q2, and the ninth resistor The second terminal of R9 is connected to the gate of the first MOS transistor Q2 and the triode Q4 respectively; the first terminal of the tenth resistor R10 is connected to the gate of the second MOS transistor Q3, and the tenth resistor R10 The second terminal is respectively connected to the gate of the first MOS transistor Q2, the second terminal of the ninth resistor R9 and the transistor Q4; the emitter of the transistor Q4 is connected to the ground terminal of the second control unit U2, the three The collector of the stage transistor is respectively connected to the gate of the first MOS transistor Q1, the second terminal of the tenth resistor R10 and the second terminal of the ninth resistor R9.

In one way, the DC-DC power supply circuit 120 further includes an inductor L1 and a first capacitor C1, the first terminal of the inductor L1 is connected to the inductor current input terminal of the second control unit U2, and the second terminal of the inductor L1 is connected to the first terminal of the inductor L1. The drain of a MOS transistor Q2 is connected. The DC-DC power supply circuit 120 further includes a sixth resistor R6, a seventh resistor R7 and an eighth resistor R8, the first terminal of the sixth resistor R6 is respectively connected with the second terminal of the inductor L1 and the first MOS transistor The drain of Q2 is connected, the second terminal of the sixth resistor R6 is connected to the first terminal of the seventh resistor R7 and the feedback terminal of the second control unit U2, respectively, the seventh resistor R7 The first terminal is connected to the feedback terminal of the second control unit U2, the second terminal of the seventh resistor R7 is connected to the second terminal of the emitter of the transistor Q4, and the eighth resistor R8 is connected to the second terminal of the emitter of the transistor Q4. The first terminal is respectively connected to the enable terminal of the second control unit U2 and the control circuit 140, the second terminal of the eighth resistor R8 is respectively connected to the second terminal of the seventh resistor and the emitter of the transistor Q4 connect.

In one way, the DC-DC power supply circuit 120 further includes a seventh capacitor C7 and an eighth capacitor C8, wherein the first terminals of the seventh capacitor C7 and the eighth capacitor C8 are respectively connected to the first power supply V1 , the second terminal of the seventh capacitor C7 and the second terminal of the eighth capacitor C8 are respectively connected to the second terminal of the seventh resistor R7, the second terminal of the eighth resistor R8 and the emitter of the transistor Q4 .

In one way, the DC-DC power supply circuit 120 further includes a ninth capacitor C9, an eleventh resistor R11 and a twelfth resistor R12, wherein the first terminals of the ninth capacitor C9 and the eleventh resistor R11 are respectively It is connected to the second terminal of the inductor L1 and the drain of the first MOS transistor Q2, the first terminal of the eleventh resistor R11 is connected to the second power supply V2, and the first terminal of the eleventh resistor R11 is connected to the second power supply V2. The two terminals are respectively connected to the first terminal of the twelfth resistor R12 and the base of the transistor Q4. The second terminals of the ninth capacitor C9 and the twelfth resistor are respectively connected with the second terminal of the seventh capacitor C7, the second terminal of the eighth capacitor C8, the second terminal of the seventh resistor R7, and the eighth capacitor C7. The second terminal of the resistor R8 and the emitter of the transistor Q4 are connected, and the second terminal of the twelfth resistor R12 is grounded.

As an example, in this embodiment of the present application, the control circuit 140 may include a signal output terminal, through which the control circuit may output control signals to the LDO power supply circuit 110 and the DC-DC power supply circuit 120 respectively, wherein the control circuit 140 The signal output can be EC_3V3_DISCONTINUE. In other words, the control circuit 140 can be respectively connected with the LDO power supply circuit 110 and the DC-DC power supply circuit 120 through the signal output terminals.

As an example, when the 3.3V output voltage of the second control unit U2 is established and stabilized, the state of VCC_3V3_DISCONTINUE is 1. Since EN_3V3_DISCONTINUE is also 1 in the wake-up state, the transistor Q1 can be driven to conduct, and the first control unit U1 can be enabled The terminal is set low to avoid current loss of the first control unit U1; when the 3.3V voltage output by the second control unit U2 is not stable, the VCC_3V3_DISCONTINUE state is 0, although EN_3V3_DISCONTINUE is also 1 in the wake-up state, but VCC_3V3_DISCONTINUE will be clamped The transistor Q1, at this time, the transistor Q1 is turned off, and the first control unit U1 supplies power normally to prevent the system from being powered down.

In the power switching circuit provided by the application embodiment, the switching of the LDO power supply circuit and the DC-DC power supply circuit is realized by setting the control circuit. The first terminal of the LDO power supply circuit is connected to the equipment to be powered, the first terminal of the DC-DC power supply circuit is connected to the equipment to be powered, the second terminal of the LDO power supply circuit is connected to the control circuit, and the DC-DC power supply circuit The second terminal of the LDO is connected to the control circuit. The control circuit is used to control the LDO power supply circuit to supply power to the equipment to be powered when the equipment to be powered is in a dormant state. Next, control the DC-DC power supply circuit to supply power to the device to be powered. In the present application, by introducing a control circuit, the switching of the LDO power supply circuit and the DC-DC power supply circuit can be realized more quickly and effectively, and the power waste can be reduced while improving the power use efficiency. In addition, the present application introduces an anti-backflow circuit, which can not only avoid current backflow due to different potentials of multiple power supplies, but also save energy consumption and ensure high-efficiency charging of the equipment. The action of the first control unit being completely turned off is completely triggered and enabled by the hardware circuit, which has higher stability than software control.

Referring to FIG. 6, FIG. 6 shows a schematic structural diagram of a smart door lock system provided by an embodiment of the present application. The smart door lock system includes a smart door lock and the above-mentioned power supply switching circuit, and the smart door lock and the power supply switch The circuit is electrically connected.

In the power switching circuit provided by the application embodiment, the switching of the LDO power supply circuit and the DC-DC power supply circuit is realized by setting the control circuit. The first terminal of the LDO power supply circuit is connected to the equipment to be powered, the first terminal of the DC-DC power supply circuit is connected to the equipment to be powered, and the first terminal of the inversion circuit is connected to the second terminal of the LDO power supply circuit. , the second terminal of the inversion circuit is connected to the control circuit, and the second terminal of the DC-DC power supply circuit is connected to the control circuit. When the power supply device is in a dormant state, the control circuit sends a low-level signal to the inversion circuit, and The inversion circuit is used to switch the low-level signal to a high-level signal, so that the LDO power supply circuit supplies power to the device to be powered. When the device to be powered is in the wake-up state, the control circuit sends a high-level signal to the inversion circuit and DC-DC respectively. The power supply circuit is used to switch the high-level signal to a low-level signal by an inversion circuit, so that the LDO power supply circuit and the device to be powered are cut off, and the DC-DC power supply circuit is controlled to supply power to the device to be powered. In this application, by introducing a control circuit, the switching of the LDO power supply circuit and the DC-DC power supply circuit can be realized more quickly and effectively, and the power waste can be reduced while improving the use efficiency of the power supply. At the same time, the circuit connection between these devices is simple and easy to implement. The power switching circuit proposed in the embodiments of the application is simple in design, flexible and low in cost.

The above descriptions are only preferred embodiments of the present application, and are not intended to limit the present application. For those skilled in the art, the present application may have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of this application shall be included within the protection scope of this application.

Claims (10)

1. A power switching circuit, comprising:

the LDO power supply circuit (110), a first terminal of the LDO power supply circuit (110) is connected with a device to be powered (150);

a DC-DC power supply circuit (120), a first terminal of the DC-DC power supply circuit (120) is connected with the equipment to be powered (150);

an inverting circuit (130), a first terminal of the inverting circuit (130) being connected to a second terminal of the LDO supply circuit (110);

a control circuit (140), a second terminal of the inverting circuit (130) is connected to the control circuit (140), a second terminal of the DC-DC power supply circuit (120) is connected to the control circuit (140), when the device to be powered (150) is in a sleep state, the control circuit (140) sends a low level signal to the inverting circuit (130), and switches the low level signal to a high level signal by using the inverting circuit (130), so that the LDO power supply circuit (110) supplies power to the device to be powered (150), when the device to be powered (150) is in an awake state, the control circuit (140) sends high level signals to the inverting circuit (130) and the DC-DC power supply circuit (120), and switches the high level signal to a low level signal by using the inverting circuit (130), the LDO power supply circuit (110) is cut off from the device to be powered (150), and the DC-DC power supply circuit (120) is controlled to supply power to the device to be powered (150).

2. The power switching circuit according to claim 1, wherein the LDO power supply circuit (110) comprises a first control unit (U1), the first control unit (U1) being configured to power the device to be powered (150) when the LDO power supply circuit (110) is conductive with the device to be powered (150), the DC-DC power supply circuit (120) comprising a second control unit (U2), the second control unit (U2) being configured to power the device to be powered (150) when the DC-DC power supply circuit (120) is conductive with the device to be powered (150);

the first terminal of the inverting circuit (130) is connected with the enabling terminal of the first control unit (U1), and the enabling terminal of the second control unit (U2) is connected with the control circuit (140).

3. The power switching circuit according to claim 2, wherein the inverting circuit (130) comprises a transistor (Q1), a collector of the transistor (Q1) is connected to the enable terminal of the first control unit (U1), a base of the transistor (Q1) is connected to the control circuit (140), and an emitter of the transistor (Q1) is grounded.

4. The power switching circuit of claim 3, wherein the LDO power supply circuit (110) further comprises a first resistor (R1), the first resistor (R1) is connected to a first power supply (V1), and a second terminal of the first resistor (R1) is connected to an enable terminal of the first control unit (U1) and a collector of a transistor (Q1), respectively.

5. The power switching circuit according to claim 4, wherein the inverting circuit (130) further comprises a second resistor (R2), a first terminal of the second resistor (R2) is connected to the enable terminal of the first control unit (U1) and a second terminal of the first resistor (R1), respectively, and a second terminal of the second resistor (R2) is connected to the collector of the transistor (Q1).

6. The power switching circuit according to claim 3, wherein the inverting circuit (130) further comprises a diode (D1), the anodes of the diode (D1) are respectively connected to the base of the transistor (Q1) and the control circuit (140), and the cathode of the diode (D1) is connected to the second power supply (V2).

7. The power switching circuit according to any one of claims 1 to 6, wherein the DC-DC power supply circuit (120) is connected to a reverse flow prevention circuit (160), and the reverse flow prevention circuit (160) is configured to prevent a reverse flow between the first power supply (V1) and the third power supply (V3).

8. The power switching circuit of claim 7, wherein the back-flow prevention circuit (160) comprises: a first MOS transistor (Q2) and a second MOS transistor (Q3);

the drain electrode of the first MOS tube (Q2) is connected with the LDO power supply circuit (110) or the DC-DC power supply circuit (120), the source electrode of the first MOS tube (Q2) is connected with the source electrode of the second MOS tube (Q3), and the gate electrode of the first MOS tube (Q2) is grounded;

the source electrode of the second MOS tube (Q3) is connected with a third power supply (V3), and the grid electrode of the second MOS tube (Q3) is grounded.

9. The power switching circuit according to claim 8, wherein the DC-DC power supply circuit (120) further comprises an inductor (L1) and a first capacitor (C1), a first terminal of the inductor (L1) is connected to an inductor current input terminal of a second control unit (U2) of the DC-DC power supply circuit (120), and a second terminal of the inductor (L1) is connected to the drain of the first MOS transistor (Q2).

10. An intelligent door lock system, characterized in that the intelligent door lock system (100) comprises an intelligent door lock (210) and the power switching circuit (100) according to any one of claims 1 to 9, wherein the intelligent door lock (210) is electrically connected with the power switching circuit (100).

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