Power supply circuit and electronic equipment

Abstract

The utility model discloses a power supply circuit and electronic equipment. The power supply circuit comprises a first isolation branch, an energy storage branch, a switch element, a second isolation branch and a voltage stabilization branch. The first isolation branch circuit is connected between the input power supply and the energy storage branch circuit, and the input power supply charges the energy storage branch circuit through the first isolation branch circuit, so that the energy storage branch circuit stores electric energy. The switch element, the input power supply and the second isolation branch circuit are connected to a first node, the switch element, the energy storage branch circuit and the first isolation branch circuit are connected to a second node, and the switch element, the voltage stabilization branch circuit and the second isolation branch circuit are connected to a third node. And the switch element is switched on when the difference value between the voltage of the first node and the voltage of the second node is smaller than or equal to a preset difference threshold value, so as to supply power to the third node based on the electric energy stored in the energy storage branch. And the voltage stabilization branch is also connected with a load, and outputs a power supply voltage based on the voltage of the third node to supply power to the load. In this way, normal operation of the load can be kept.

Description

Technical Field

[0001] Embodiments of the present application relate to the technical field of electronic circuits, and in particular, to a power supply circuit and an electronic device. Background Art

[0002] Currently, for loads in a circuit system, such as a controller, a voltage regulator device can be used for power supply. Specifically, after an input power supply is input to the voltage regulator device, the voltage regulator device outputs a relatively stable voltage to supply power to the load.

[0003] During the process of using a voltage regulator device for power supply, if the voltage of the input power supply fluctuates above the minimum input voltage required by the voltage regulator device, the voltage regulator device can still output a relatively stable voltage. However, if the voltage of the input power supply fluctuates below the minimum input voltage required by the voltage regulator device, the voltage regulator device cannot output a stable voltage. Furthermore, if the voltage output by the voltage regulator device is lower than the minimum voltage required for the normal operation of the load, the load cannot operate normally. Summary of the Utility Model

[0004] Embodiments of the present application provide a power supply circuit and an electronic device that can maintain the normal operation of a load.

[0005] In a first aspect, embodiments of the present application provide a power supply circuit, including:

[0006] A first isolation branch and an energy storage branch, the first isolation branch is connected between an input power supply and the energy storage branch, wherein the input power supply charges the energy storage branch through the first isolation branch so that the energy storage branch stores electrical energy;

[0007] A switching element, a second isolation branch, and a voltage regulation branch, the switching element is connected to the input power supply and the second isolation branch at a first node, the switching element is connected to the energy storage branch and the first isolation branch at a second node, and the switching element is connected to the voltage regulation branch and the second isolation branch at a third node;

[0008] The switching element is configured to conduct when the difference between the voltage at the first node and the voltage at the second node is less than or equal to a preset difference threshold, so as to supply power to the third node based on the electrical energy stored in the energy storage branch;

[0009] The voltage regulation branch is further connected to a load, and the voltage regulation branch is configured to output a supply voltage based on the voltage at the third node to supply power to the load.

[0010] In one or more embodiments, the first isolation branch includes a diode;

[0011] The anode of the diode is connected to the first node, and the cathode of the diode is connected to the second node.

[0012] In one or more embodiments, the second isolation branch includes a diode;

[0013] The anode of the diode is connected to the first node, and the cathode of the diode is connected to the third node.

[0014] In one or more embodiments, the diode is a Schottky diode.

[0015] In one or more embodiments, the energy storage branch includes a first capacitor;

[0016] The first capacitor is connected between the second node and ground.

[0017] In one or more embodiments, the switching element includes a first switching transistor;

[0018] The control terminal of the first switching transistor is connected to the first node, the first end of the non-control terminal of the first switching transistor is connected to the second node, and the second end of the non-control terminal of the first switching transistor is connected to the third node.

[0019] In one or more embodiments, the first switching transistor is a PMOS transistor;

[0020] The gate of the PMOS transistor is the control terminal of the first switching transistor, the source of the PMOS transistor is the first end of the non-control terminal of the first switching transistor, and the drain of the PMOS transistor is the second end of the non-control terminal of the first switching transistor.

[0021] In one or more embodiments, the power supply circuit further includes a first resistor;

[0022] The first resistor is connected between the control terminal of the first switching transistor and the first end of the non-control terminal of the first switching transistor.

[0023] In one or more embodiments, the voltage regulation branch includes a low dropout linear regulator;

[0024] The input terminal of the low dropout linear regulator is connected to the third node, the ground terminal of the low dropout linear regulator is grounded, and the output terminal of the low dropout linear regulator is connected to the load.

[0025] In a second aspect, an embodiment of the present application provides an electronic device, including a load and the power supply circuit as described above;

[0026] The power supply circuit is connected between the input power supply and the load.

[0027] The beneficial effects of the present application are as follows: The power supply circuit of the embodiment of the present application includes a first isolation branch, an energy storage branch, a switching element, a second isolation branch, and a voltage stabilization branch. Among them, the input power supply charges the energy storage branch through the first isolation branch so that the energy storage branch stores electrical energy. When the voltage of the input power supply fluctuates to make the difference between the voltage of the first node and the voltage of the second node less than or equal to a preset difference threshold, the switching element conducts, and the electrical energy stored in the energy storage branch supplies power to the third node through the switching element, so that the voltage stabilization branch outputs a power supply voltage for supplying power to the load. It can be seen that by configuring the voltage of the input power supply to fluctuate to make the voltage of the third node lower than the minimum input voltage required by the voltage stabilization branch, and making the difference between the voltage of the first node and the voltage of the second node less than or equal to the preset difference threshold, the switching element can be turned on to supply power to the third node based on the electrical energy stored in the energy storage branch, maintaining a stable power supply voltage output by the voltage stabilization branch to keep the load running normally. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] One or more embodiments are exemplarily illustrated by pictures in the corresponding drawings. These exemplary illustrations are not intended to limit the embodiments. Elements with the same reference numerals in the drawings represent similar elements.

[0029] Figure 1 is a schematic diagram of the block diagram of the power supply circuit provided by the embodiment of the present application;

[0030] Figure 2 is related to Figure 1 the circuit structure corresponding to the shown block diagram Figure 1 ;

[0031] Figure 3 is a schematic diagram of each signal in the related art method and Figure 2 each signal in the shown circuit structure;

[0032] Figure 4 is related to Figure 1 the circuit structure corresponding to the shown block diagram Figure 2 . DETAILED DESCRIPTION OF THE EMBODIMENTS

[0033] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and detailedly described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some, but not all, of the embodiments of the present application. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0034] It should be noted that when an element is described as "connected" to another element, it can be directly connected to the other element, or there can be one or more intermediate elements therebetween.

[0035] In addition, the technical features involved in the various embodiments of the present application described below can be combined with each other as long as there is no conflict between them.

[0036] Please refer to Figure 1 , Figure 1 which is a schematic diagram of the block diagram of the power supply circuit provided by the embodiment of the present application. As Figure 1 shown, the power supply circuit 100 includes a first isolation branch 10, an energy storage branch 20, a switching element 30, a second isolation branch 40, and a voltage regulation branch 50.

[0037] Among them, the first isolation branch 10 is connected between the input power supply VIN and the energy storage branch 20. The switching element 30, the input power supply VIN, and the second isolation branch 40 are connected to the first node P1. The switching element 30, the energy storage branch 20, and the first isolation branch 10 are connected to the second node P2. The switching element 30, the voltage regulation branch 50, and the second isolation branch 40 are connected to the third node P3. The voltage regulation branch 50 is also connected to the load 200.

[0038] Specifically, the input power supply VIN charges the energy storage branch 20 through the first isolation branch 10 so that the energy storage branch 20 stores electrical energy. The switching element 30 is configured to conduct when the difference between the voltage at the first node P1 and the voltage at the second node P2 is less than a preset difference threshold, and supply power to the third node P3 based on the electrical energy stored in the energy storage branch 20. The voltage regulation branch 50 is configured to output a supply voltage based on the voltage at the third node P3 to supply power to the load 200. Among them, due to the presence of the first isolation branch 10 and the second isolation branch 40, it can be ensured that the charge can only flow from the input power supply VIN to the second node P2 or the third node P3, and cannot flow in the reverse direction, which is beneficial to protecting the input power supply VIN and maintaining the stable and reliable operation of the input power supply VIN.

[0039] When the voltage of the input power supply VIN is maintained such that the difference between the voltage of the first node P1 and the voltage of the second node P2 is greater than a preset difference threshold, the switching element 30 remains off. The connection between the energy storage branch 20 and the third node P3 is disconnected. The input power supply VIN supplies power to the third node P3 through the second isolation branch 40. At this time, as long as the voltage of the input power supply VIN is configured to enable the voltage of the third node P3 to be maintained higher than the minimum input voltage of the voltage stabilizing branch 50, the voltage stabilizing branch 50 can output a stable power supply, and the load 200 can operate normally. It can be seen that when the voltage of the input power supply VIN enables the voltage of the third node P3 to be maintained higher than the minimum input voltage of the voltage stabilizing branch 50, the difference between the voltage of the first node P1 and the voltage of the second node P2 is greater than or equal to the preset difference threshold. Among them, the preset difference threshold is a threshold set in advance, which can be set based on the actual application scenario. The embodiments of the present application do not make specific limitations on this. For example, in some embodiments, the preset difference threshold can be set to the maximum voltage value for driving the switching element 30 to conduct.

[0040] When the voltage of the input power supply VIN fluctuates to make the difference between the voltage of the first node P1 and the voltage of the second node P2 less than or equal to the preset difference threshold, the switching element 30 conducts. The connection between the energy storage branch 20 and the third node P3 is established. The electric energy stored in the energy storage branch 20 supplies power to the third node P3 through the switching element 30. At this time, even if the voltage of the input power supply VIN fluctuates to make the voltage of the third node P3 lower than the minimum input voltage required by the voltage stabilizing branch, since the energy storage branch 20 can supply power to the third node P3, the voltage stabilizing branch 50 can also output a stable supply voltage to supply power to the load 200. It can be seen that when the voltage of the input power supply VIN fluctuates to make the voltage of the third node P3 lower than the minimum input voltage required by the voltage stabilizing branch 50, the difference between the voltage of the first node P1 and the voltage of the second node P2 can be made less than the preset difference threshold, so as to ensure that even if the voltage of the input power supply VIN fluctuates to make the voltage of the third node P3 lower than the minimum input voltage required by the voltage stabilizing branch, the energy storage branch 20 can supply power to the third node P3 by turning on the switching element 30, and the voltage stabilizing branch 50 can output a stable supply voltage to supply power to the load 200 to keep the load 200 operating normally.

[0041] In summary, when the voltage of the input power supply VIN fluctuates greatly, the voltage stabilizing branch 50 can also output a stable supply voltage to supply power to the load 200 to keep the load 200 operating normally, which is beneficial to improving the reliability and stability of the operation of the power supply circuit 100 and the load 200.

[0042] Please refer to Figure 2 , Figure 2 which exemplarily shows the relationship with Figure 1A circuit structure corresponding to the shown composition block diagram. As Figure 2 shown, the first isolation branch 10 includes a diode D1.

[0043] Among them, the anode of the diode D1 is connected to the first node P1, and the cathode of the diode D1 is connected to the second node P2.

[0044] In this embodiment, the second isolation branch 40 includes a diode D2.

[0045] Among them, the anode of the diode D2 is connected to the first node P1, and the cathode of the diode D2 is connected to the third node P3.

[0046] In this embodiment, the energy storage branch 20 includes a first capacitor C1.

[0047] Among them, the first capacitor C1 is connected between the second node P2 and the ground GND.

[0048] In this embodiment, the switching element 30 includes a first switching transistor Q1.

[0049] Among them, the control end of the first switching transistor Q1 is connected to the first node P1, the first end of the non-control end of the first switching transistor Q1 is connected to the second node P2, and the second end of the non-control end of the first switching transistor Q1 is connected to the third node P3.

[0050] Among them, in this embodiment, taking the first switching transistor Q1 as a PMOS transistor as an example. The gate (i.e., G pole) of the PMOS transistor is the first end of the first switching transistor Q1, the source (i.e., S pole) of the PMOS transistor is the second end of the first switching transistor Q1, and the drain (i.e., D pole) of the PMOS transistor is the third end of the first switching transistor Q1.

[0051] In addition, the first switching transistor Q1 can be any controllable switch, for example, an insulated gate bipolar transistor (IGBT) device, an integrated gate-commutated thyristor (IGCT) device, a gate turn-off thyristor (GTO) device, a silicon controlled rectifier (SCR) device, a junction gate field effect transistor (JFET) device, a MOS controlled thyristor (MCT) device, etc.

[0052] In this embodiment, the power supply circuit 100 further includes a first resistor R1.

[0053] Among them, the first resistor R1 is connected between the control end of the first switching transistor Q1 and the first end of the non-control end of the first switching transistor Q1. By setting the first resistor R1, it can be ensured that when the voltage of the input power supply VIN drops, the first switch Q1 is in the on state.

[0054] In this embodiment, the voltage regulation branch 50 includes a low dropout linear regulator U1.

[0055] Among them, the input terminal of the low-dropout linear regulator U1 is connected to the third node P3, the ground terminal of the low-dropout linear regulator U1 is grounded to GND, and the output terminal of the low-dropout linear regulator U1 is connected to the load 200.

[0056] The following combines Figure 3 to Figure 2 illustrate the principle of the circuit structure shown. Among them, in Figure 3 , the abscissa is time and the ordinate is voltage (unit: volt). Figure 3 Part (a1) in shows a schematic diagram of the input power supply VIN voltage (as shown by curve L11, taking about 3.7V when the input power supply VIN operates normally in this embodiment as an example) and the voltage output by the voltage regulator device (as shown by curve L12) when adopting the solution of the related technology; Figure 3 Part (a2) in shows a schematic diagram of the voltage of the input power supply VIN (as shown by curve L21, also taking about 3.7V when the input power supply VIN operates normally as an example), the voltage input to the low-dropout linear regulator U1 (as shown by curve L22), and the voltage output by the low-dropout linear regulator U1 (as shown by curve L23) when adopting the solution provided by the embodiment of the present application.

[0057] As Figure 3 shown in part (a1) of, in the related technology, before time T11, although the voltage of the input power supply VIN fluctuates, the voltage of the input power supply VIN remains greater than the minimum input voltage required by the voltage regulator device, so the output voltage of the voltage regulator device also remains fluctuating within a small range. Until time T11, the voltage of the input power supply VIN decreases rapidly due to an abnormality (such as a short-circuit abnormality) and decreases to about 2.1V at time T12. Subsequently, the output voltage of the voltage regulator device also decreases accordingly and rapidly decreases to about 2.3V. At this time, the output voltage of the voltage regulator device drops too much and may be lower than the minimum voltage required for the normal operation of the load, thereby causing the load to fail to operate normally.

[0058] As Figure 3 shown in part (a2) of, in the embodiment of the present application, before time T21, the voltage of the input power supply VIN can keep the voltage of the third node P3 greater than the minimum input voltage required by the low-dropout linear regulator U1. On the one hand, the diode D1 is forward-conducted, and the voltage of the input power supply VIN charges the first capacitor C1 through the diode D1. At the same time, the voltage of the first node P1 is greater than the voltage of the second node P2, so that the difference between the voltage of the first node P1 and the voltage of the second node P2 (corresponding to the voltage V GS ) between the gate and the source of the first switching transistor Q1 is greater than 0, that is, V GS >0>-V TH, the first switching transistor Q1 is turned off. Among them, -V TH is the threshold voltage of the first switching transistor Q1, which is configured as a preset difference threshold in this embodiment. On the other hand, the diode D2 is forward-conducted, and the voltage of the input power supply VIN acts on the third node P3 through the diode D2, that is, the voltage of the third node P3 is the difference between the voltage of the input power supply VIN and the forward conduction voltage drop of the diode D2. The voltage of the third node P3 remains greater than the minimum input voltage required by the low-dropout linear regulator U1, and the low-dropout linear regulator U1 can output a voltage of about 3.0V with less fluctuation.

[0059] Until time T21, the voltage of the input power supply VIN decreases rapidly due to an abnormality (such as a short-circuit abnormality) and decreases to about 2.1V at time T22. On the one hand, since the voltage of the input power supply VIN acts on the third node P3 through the diode D2, the decrease of the input power supply VIN will also cause the voltage on the third node P3 to decrease. On the other hand, the voltage of the first node P1 also decreases rapidly to about 2.1V. Since the first capacitor C1 stores electrical energy, the voltage of the second node P2 can be maintained at about 3.7V for a short time. The difference between the voltage of the first node P1 and the voltage of the second node P2 is less than 0 and less than the threshold voltage of the first switching transistor Q1, that is, less than the preset difference threshold, which is V GS <-V TH , the first switching transistor Q1 is turned on. The voltage on the first capacitor C1 acts on the third node P3 through the first switching transistor Q1 to increase the voltage of the third node P3. Combining the above two aspects, the voltage on the third node P3 can only decrease slightly, so the voltage output by the low-dropout linear regulator U1 can only decrease slightly, only decreasing to about 2.9V (much higher than 2.3V in the related art), so it can remain higher than the minimum voltage required for the normal operation of the load 200, and then maintain the normal operation of the load 200.

[0060] In summary, when the voltage of the input power supply VIN fluctuates greatly, the low-dropout linear regulator U1 can also output a stable supply voltage to supply power to the load 200 to maintain the normal operation of the load 200, which is beneficial to improving the reliability and stability of the power supply circuit 100 and the load 200.

[0061] In particular, when the load 200 is a controller (such as a microcontroller unit (MCU)), it can also avoid the abnormal phenomenon of power-off reset of the controller caused by the unstable voltage of the input power supply VIN.

[0062] It should be noted that, as Figure 2The hardware structure of the power supply circuit 100 shown is merely an example, and the power supply circuit 100 may have more or fewer components than those shown in the figure, two or more components may be combined, or different component configurations may be provided. The various components shown in the figure may be implemented in hardware, software, or a combination of hardware and software including one or more signal processing and / or application specific integrated circuits.

[0063] For example, in some embodiments, as Figure 4 shown, both the diode D1 and the diode D2 in Figure 2 may be configured as Schottky diodes to minimize the power loss caused by the voltage drop when the diodes D1 and D2 are forward-conducting by taking advantage of the small voltage drop of the Schottky diodes.

[0064] The embodiments of the present application further provide an electronic device, which includes a load and the power supply circuit 100 in any one of the embodiments of the present application. Among them, the power supply circuit is connected between the input power supply and the load.

[0065] The above are only the embodiments of the present application, and do not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made by using the content of the specification and drawings of the present application, or directly or indirectly applied in other related technical fields, are equally included in the patent protection scope of the present application.

[0066] The above embodiments are only used to illustrate the technical solutions of the present application, and are not intended to limit them; under the idea of the present application, the technical features in the above embodiments or different embodiments may also be combined, and the steps may be implemented in any order. Those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A power supply circuit, characterized in that: include: A first isolation branch and an energy storage branch, wherein the first isolation branch is connected between an input power source and the energy storage branch, wherein the input power source charges the energy storage branch through the first isolation branch so that the energy storage branch stores electric energy; A switch element, a second isolation branch and a voltage stabilizing branch, wherein the switch element, the input power supply and the second isolation branch are connected at a first node, the switch element, the energy storage branch and the first isolation branch are connected at a second node, and the switch element, the voltage stabilizing branch and the second isolation branch are connected at a third node; The switch element is configured to be turned on when the difference between the voltage of the first node and the voltage of the second node is less than or equal to a preset difference threshold, so as to supply power to the third node based on the electric energy stored in the energy storage branch; The voltage stabilizing branch is also connected to a load, and is configured to output a supply voltage based on the voltage of the third node to supply power to the load.

2. The power supply circuit according to claim 1, characterized in that: The first isolation branch includes a diode; An anode of the diode is connected to the first node, and a cathode of the diode is connected to the second node.

3. The power supply circuit according to claim 1, characterized in that: The second isolation branch includes a diode; An anode of the diode is connected to the first node, and a cathode of the diode is connected to the third node.

4. The power supply circuit according to claim 2 or 3, characterized in that: The diode is a Schottky diode.

5. The power supply circuit according to claim 1, characterized in that: The energy storage branch includes a first capacitor; The first capacitor is connected between the second node and ground.

6. The power supply circuit according to claim 1, characterized in that: The switch element comprises a first switch tube; The control end of the first switch tube is connected to the first node, the first end of the non-control end of the first switch tube is connected to the second node, and the second end of the non-control end of the first switch tube is connected to the third node.

7. The power supply circuit according to claim 6, characterized in that: The first switch tube is a PMOS tube; The gate of the PMOS tube is the control end of the first switch tube, the source of the PMOS tube is the first non-control end of the first switch tube, and the drain of the PMOS tube is the second non-control end of the first switch tube.

8. The power supply circuit according to claim 6 or 7, characterized in that: The power supply circuit also includes a first resistor; The first resistor is connected between the control end of the first switch tube and a first end of the non-control end of the first switch tube.

9. The power supply circuit according to claim 1, characterized in that: The voltage stabilization branch includes a low voltage drop linear regulator; The input end of the low voltage dropout linear regulator is connected to the third node, the ground end of the low voltage dropout linear regulator is grounded, and the output end of the low voltage dropout linear regulator is connected to the load.

10. An electronic device, characterized in that: A load and a power supply circuit as claimed in any one of claims 1 to 9; The power supply circuit is connected between an input power source and the load.

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