Voltage acquisition circuit and power supply circuit

Abstract

The invention provides a voltage acquisition circuit and a power supply circuit, the power supply circuit comprises a power supply output end and a plurality of power supply input circuits, and each power supply input circuit is provided with a power supply access end for accessing external voltage and a diode. The voltage acquisition circuit comprises a voltage division circuit and a leakage current discharge circuit. A first end of the voltage division circuit is electrically connected with a power supply access end of the power supply input circuit, and the voltage division circuit is used for dividing an external voltage accessed by the power supply access end and then outputting a first voltage signal; the first end of the leakage current leakage circuit is electrically connected with a path between the first end of the voltage division circuit and the anode of the diode, and the second end of the leakage current leakage circuit is grounded; the leakage current discharging circuit is used for discharging the leakage current generated by the diode. According to the invention, the leakage current generated by the diode is discharged to the grounding end through the leakage current discharge circuit, so that the problem of voltage error measurement of the voltage acquisition circuit is solved, and the adverse effect caused by the leakage current is reduced to the greatest extent while multiple paths of voltage signals are obtained.

Description

Technical Field

[0001] The present invention relates to the technical field of voltage acquisition, and in particular to a voltage acquisition circuit and a power supply circuit. Background Art

[0002] The battery power acquisition of existing battery-powered products, when used in scenarios where accuracy requirements are not high, mostly adopts ADC voltage acquisition to convert the collected voltage into battery power. In the case of multiple battery power supplies (such as dry batteries and lithium batteries), in order to ensure the compatibility of the two power supply methods, a diode solution is usually used to seamlessly switch between the power supplies, and the output is sent to the processor for ADC voltage detection through a voltage divider resistor. However, when using ADC voltage acquisition to achieve acquisition in the case of multiple battery power supplies, the diode has leakage current, which will flow in the circuit, affecting the normal voltage acquisition and causing voltage mismeasurement problems. Summary of the invention

[0003] The main purpose of the present invention is to provide a voltage acquisition circuit and a power supply circuit, aiming to solve the problem of voltage mismeasurement.

[0004] To this end, the present invention proposes a voltage acquisition circuit, which is applied to a power supply circuit, wherein the power supply circuit includes a power supply output end and multiple power supply input circuits, and the output ends of the multiple power supply input circuits are respectively connected to the power supply output end; the power supply input circuit has a power supply access end and a diode for accessing an external voltage, and the power supply access end is connected to the power supply output end via a diode, the anode of the diode is connected to the power supply access end, and the cathode of the diode is connected to the power supply output end, and the output end of the power supply input circuit includes the cathode of the diode, and the voltage acquisition circuit includes: a voltage divider circuit, a first end of the voltage divider circuit is electrically connected to the power supply access end of the power supply input circuit, and the voltage divider circuit is used to divide the external voltage accessed by the power supply access end and then output a first voltage signal; a leakage current discharge circuit, a first end of the leakage current discharge circuit is electrically connected to the path between the first end of the voltage divider circuit and the anode of the diode, and a second end of the leakage current discharge circuit is grounded; the leakage current discharge circuit is used to discharge the leakage current generated by the diode.

[0005] In one embodiment, the leakage current discharge circuit includes a discharge resistor, a first end of the discharge resistor is the first end of the leakage current discharge circuit, and a second end of the discharge resistor is the second end of the leakage current discharge circuit.

[0006] In one embodiment, the voltage acquisition circuit further includes a filter circuit, and the filter circuit is connected in parallel with the discharge resistor; the filter circuit is used to filter the power input circuit.

[0007] In one embodiment, the voltage divider circuit includes: a first voltage divider resistor and a second voltage divider resistor; the first end of the two voltage divider resistors is the first end of the voltage divider circuit, the second end of the second voltage divider resistor is connected to the first end of the first voltage divider resistor, and the second end of the first voltage divider resistor is grounded.

[0008] In one embodiment, the resistance of the voltage divider circuit is greater than 100 kilo-ohms.

[0009] In one embodiment, the voltage acquisition circuit includes: a switching circuit, the input end of the switching circuit is connected to the second end of the leakage current discharge circuit, and the output end of the switching circuit is used to connect to the ground end; the switching circuit is used to turn on / off the path between the leakage current discharge circuit and the ground end.

[0010] In one embodiment, the voltage acquisition circuit further includes: a main control circuit, which is connected to the controlled end of the switch circuit; and the main control circuit is used to control the switch circuit to turn on / off the path between the leakage current discharge circuit and the ground end.

[0011] In one embodiment, the main control circuit is connected to the output end of the voltage divider circuit; the main control circuit is used to control the switch circuit to turn on the path between the leakage current discharge circuit and the ground terminal when determining the voltage value of the external voltage according to the first voltage signal.

[0012] The present invention provides a power supply circuit, which comprises a power supply output terminal, a plurality of power supply input circuits and at least one voltage acquisition circuit.

[0013] In one embodiment, there are multiple voltage acquisition circuits, and the multiple voltage acquisition circuits are electrically connected to the multiple power input circuits in a one-to-one correspondence.

[0014] The present invention proposes a voltage acquisition circuit and a power supply circuit, wherein the power supply circuit includes a power supply output terminal and a plurality of power supply input circuits, wherein the power supply input circuit has a power supply access terminal and a diode for accessing an external voltage. The voltage acquisition circuit includes: a voltage divider circuit and a leakage current discharge circuit. The first end of the voltage divider circuit is electrically connected to the power supply access terminal of the power supply input circuit, and the voltage divider circuit is used to divide the external voltage accessed by the power supply access terminal and output a first voltage signal; the first end of the leakage current discharge circuit is electrically connected to the path between the first end of the voltage divider circuit and the anode of the diode, and the second end of the leakage current discharge circuit is grounded; the leakage current discharge circuit is used to discharge the leakage current generated by the diode. The present invention is provided with a leakage current discharge circuit to discharge the leakage current generated by the diode to the ground terminal, thereby solving the voltage mismeasurement problem of the voltage acquisition circuit, and minimizing the adverse effects caused by the leakage current while acquiring multiple voltage signals. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0016] Figure 1 A circuit flow chart of a voltage acquisition circuit and a power supply circuit of the present invention; Figure 2 It is a two-way voltage collection circuit diagram described in the specification of the present invention; Figure 3 A circuit structure diagram of an embodiment of a voltage acquisition circuit and a power supply circuit of the present invention; Figure 4 A circuit structure diagram of another embodiment of a voltage acquisition circuit and a power supply circuit of the present invention; Figure 5 A circuit structure diagram of another embodiment of a voltage acquisition circuit and a power supply circuit of the present invention; Figure 6 A circuit structure diagram of another embodiment of a voltage acquisition circuit and a power supply circuit of the present invention; Figure 7 The circuit structure diagram of another embodiment of a voltage acquisition circuit and a power supply circuit of the present invention.

[0017] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0018] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0019] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0020] In the present invention, unless otherwise clearly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, 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, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0021] In addition, in the present invention, descriptions such as "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0022] It is understandable that the battery power acquisition of existing battery-powered products, when applied in scenarios where the accuracy requirements are not high, mostly adopts the ADC voltage acquisition method to convert the collected voltage into battery power. In the case of multiple battery power supply (such as dry batteries and lithium batteries), in order to ensure the compatibility of the two power supply methods, a diode solution is usually used to seamlessly switch between the power supplies, and output to the processor through a voltage divider resistor for ADC voltage detection. However, when the ADC voltage acquisition method is used to achieve acquisition in the case of multiple battery power supply, there is a leakage current phenomenon in the diode. For example, when one of the battery access terminals is disconnected, the other battery access terminals still have actual voltage due to the leakage current transmitted from the diode, and the voltages of multiple battery access terminals tend to be the same. Due to the existence of leakage current, the collected voltage signal will be blurred, and it is impossible to confirm whether the power supply exists through the collected voltage signal, so it is impossible to detect whether the battery is plugged in or out.

[0023] In order to solve the problem of voltage mismeasurement, the present invention proposes a voltage acquisition circuit, which is applied to a power supply circuit, wherein the power supply circuit includes a power supply output terminal VSYS and a plurality of power supply input circuits 10, wherein the output terminals of the plurality of power supply input circuits 10 are respectively connected to the power supply output terminal VSYS; the power supply input circuit 10 has a power supply access terminal and a diode for accessing an external voltage, wherein the power supply access terminals are connected to the power supply output terminal VSYS via the diode, the anode of the diode is connected to the power supply access terminal, the cathode of the diode is connected to the power supply output terminal VSYS, and the output terminal of the power supply input circuit 10 includes the cathode of the diode, Figure 1 , the voltage acquisition circuit comprises: A voltage divider circuit 20, wherein a first end of the voltage divider circuit 20 is electrically connected to a power supply access end of the power supply input circuit 10, and the voltage divider circuit 20 is used to divide an external voltage connected to the power supply access end and then output a first voltage signal; A leakage current discharge circuit 30, wherein a first end of the leakage current discharge circuit 30 is electrically connected to a path between a first end of the voltage divider circuit 20 and an anode of the diode, and a second end of the leakage current discharge circuit 30 is grounded; the leakage current discharge circuit 30 is used to discharge the leakage current generated by the diode.

[0024] It is understandable that when the diode generates leakage current, it will affect the acquisition accuracy of the voltage acquisition circuit. Figure 2The two-way voltage acquisition circuit is realized by using ADC voltage acquisition to collect the voltage of two different types of batteries by connecting the dry battery at the VBAT1 end and the lithium battery at the VBAT2 end, and outputting the voltage signal ADC1 after dividing the voltage of the dry battery at the VBAT1 end through two voltage-dividing resistors; and outputting the voltage signal ADC2 after dividing the voltage of the lithium battery at the VBAT2 end through two voltage-dividing resistors, thereby realizing the acquisition of the voltage of two different types of batteries. However, when the diode is in a reverse biased state, a reverse current, i.e., a leakage current, is generated due to the presence of minority carriers. Since the diode has leakage current, when the dry battery is disconnected from the VBAT1 end, the leakage current will still flow in the circuit. There is leakage current transmitted from the diode at the VBAT2 end, resulting in the actual voltage at the VBAT1 end, and the voltage at the VBAT2 end tends to be the same as the voltage at the VBAT1 end. As the voltage tends to be balanced, voltage confusion will occur, making the collected voltage signal ADC1 and voltage signal ADC2 blurred, and it is impossible to distinguish whether the dry battery, lithium battery, or both are supplying power based on this mixed voltage, so it is difficult to confirm whether the power supply exists. That is, it is impossible to confirm whether the power supply exists through the collected voltage signal, and it is impossible to detect whether the battery is plugged in or out when it is uncertain whether the power supply exists. Therefore, in order to reduce the influence of leakage current on the voltage collection circuit, the present invention is provided with a leakage current discharge circuit 30 to discharge the leakage current generated by the diode to the ground terminal, solve the voltage mismeasurement problem of the voltage collection circuit, and minimize the adverse effects caused by leakage current while obtaining multiple voltage signals.

[0025] In this embodiment, refer to Figure 1, the power supply circuit includes a power supply output terminal VSYS and a plurality of power supply input circuits 10, the output terminals of the plurality of power supply input circuits 10 are interconnected, and the interconnection points thereof are connected to the power supply output terminal VSYS. Each power supply input circuit 10 includes a power supply access terminal and a diode, and the power supply access terminal is used to connect different types of batteries, for example, dry batteries or lithium batteries. In practical applications, when the voltage acquisition circuit realizes voltage acquisition, the power supply access terminal in each power supply input circuit 10 accesses the battery voltage connected thereto, and transmits the battery voltage to the voltage divider circuit 20, and at the same time transmits it to the diode. The voltage divider circuit 20 divides the battery voltage and outputs it to the voltage detection circuit or other processing circuit in the form of a voltage signal ADC, thereby realizing the function of multi-channel battery voltage acquisition. The diode has unidirectional conductivity, and is used to transmit the battery voltage to the power supply output terminal VSYS, and output it to the load through the power supply output terminal VSYS to power the load. When the diode is in a reverse biased state, leakage current will be generated due to the presence of minority carriers. The leakage current flows from the cathode of the diode to the anode of the diode. The leakage current discharge circuit 30 is arranged at the anode of the diode, and is used to access the leakage current generated by the diode and discharge the leakage current of the diode to the ground terminal. Such arrangement can prevent the leakage current from being output to the voltage divider circuit 20, so that the voltage signal output by the voltage divider circuit 20 is inaccurate, solve the voltage mismeasurement problem of the voltage acquisition circuit, and minimize the adverse effects caused by the leakage current while obtaining multiple voltage signals.

[0026] The present invention proposes a voltage acquisition circuit, which is applied to a power supply circuit. The power supply circuit includes a power supply output terminal VSYS and multiple power supply input circuits 10. The output terminals of the multiple power supply input circuits 10 are respectively connected to the power supply output terminal VSYS; the power supply input circuit 10 has a power supply access terminal and a diode for accessing an external voltage. The power supply access terminals are connected to the power supply output terminal VSYS through the diode. The anode of the diode is connected to the power supply access terminal, and the cathode of the diode is connected to the power supply output terminal VSYS. The output terminal of the power supply input circuit 10 includes the cathode of the diode. The voltage acquisition circuit includes: a voltage divider circuit 20 and a leakage current discharge circuit 30. In practical applications, the first end of the voltage divider circuit 20 is electrically connected to the power supply access terminal of the power supply input circuit 10, and the voltage divider circuit 20 is used to divide the external voltage accessed by the power supply access terminal and output a first voltage signal; the first end of the leakage current discharge circuit 30 is electrically connected to the path between the first end of the voltage divider circuit 20 and the anode of the diode, and the second end of the leakage current discharge circuit 30 is grounded; the leakage current discharge circuit 30 is used to discharge the leakage current generated by the diode. The present invention is provided with a leakage current discharge circuit 30 to discharge the leakage current generated by the diode to the ground terminal, thereby solving the voltage mismeasurement problem of the voltage acquisition circuit and minimizing the adverse effects caused by the leakage current while acquiring multiple voltage signals.

[0027] In one embodiment, the leakage current discharge circuit 30 includes a discharge resistor R5 , a first end of the discharge resistor R5 is a first end of the leakage current discharge circuit 30 , and a second end of the discharge resistor R5 is a second end of the leakage current discharge circuit 30 .

[0028] It can be understood that in this embodiment, according to Ohm's law I=V / R, the leakage current will form a loop through the bleeder resistor R5. Since the potential of the ground terminal is 0V, a voltage drop will be generated across the bleeder resistor R5, so that the leakage current can continue to flow from the diode through the resistor and finally discharge to the ground, thereby achieving the effect of leakage current discharge. Among them, the resistance value of the bleeder resistor R5 is selected according to the specific application scenario, and can be tens of kilo-ohms or tens of kilo-ohms, which is not limited here.

[0029] In one embodiment, the voltage acquisition circuit further includes a filter circuit, and the filter circuit is connected in parallel with the discharge resistor R5 ; the filter circuit is used to filter the power input circuit 10 .

[0030] It is understandable that in the power supply circuit, due to the internal resistance of the power supply, when the load fluctuates, according to Ohm's law U=IR, the voltage drop generated on the internal resistance will change. For example, if the load current suddenly increases, the voltage drop on the internal resistance of the power supply will increase, causing the output voltage of the power supply to drop instantly, forming a downward voltage burr; conversely, if the load current decreases, the internal resistance voltage drop decreases, and the output voltage of the power supply will rise instantly, forming an upward voltage burr. The voltage burr formed will affect the first voltage signal output by the voltage divider circuit 20. In view of the above shortcomings, the present embodiment is provided with a filter circuit, and the filter circuit is implemented by a filter capacitor C1. The power input circuit 10 is filtered by the filter capacitor C1 to filter out the voltage burrs flowing through the power input circuit 10, thereby ensuring the accuracy of the first voltage signal collected.

[0031] In one embodiment, referring to Figure 3 The voltage divider circuit 20 includes: a first voltage divider resistor R1 and a second voltage divider resistor R2; the first end of the two voltage divider resistors is the first end of the voltage divider circuit 20, the second end of the second voltage divider resistor R2 is connected to the first end of the first voltage divider resistor R1, and the second end of the first voltage divider resistor R1 is grounded.

[0032] It can be understood that, in this embodiment, the connection point between the first voltage-dividing resistor R1 and the second voltage-dividing resistor R2 can be used to connect an analog-to-digital converter or other acquisition equipment to connect the voltage output end after voltage division to the input end of the acquisition equipment. In practical applications, when voltage acquisition is realized through the first voltage-dividing resistor R1 and the second voltage-dividing resistor R2, the voltage after voltage division is obtained at both ends of the first voltage-dividing resistor R1 or at both ends of the second voltage-dividing resistor R2. If a higher input voltage is to be collected, but the input voltage range of the acquisition equipment is limited, the voltage after voltage division can be selected by selecting a suitable sum so that the voltage after voltage division falls within the input voltage range of the acquisition equipment, so that the acquisition equipment can collect and subsequently process the voltage after voltage division, thereby realizing indirect collection of higher voltages without exceeding the input voltage range of the acquisition equipment.

[0033] In one embodiment, the resistance of the voltage divider circuit 20 is greater than 100 kilo-ohms. It is understandable that since the voltage divider circuit 20 is always connected in parallel to the path between the power access terminal and the diode. Therefore, the voltage divider circuit 20 is composed of at least two voltage divider resistors, such as the two resistors mentioned above. When the power access terminal is connected to an external voltage provided by an external battery, the external voltage will form a current in the voltage divider circuit, so that the voltage divider circuit is always consuming electrical energy, thereby increasing the power consumption of the entire device, especially the static power consumption. To this end, in this embodiment, by using a large resistance resistor, such as a resistor with a resistance greater than 100 kilo-ohms to form a voltage divider circuit, the current in the voltage divider circuit can be reduced as much as possible, thereby reducing the power consumption of the voltage divider circuit as much as possible, thereby reducing the power consumption of the entire device.

[0034] In one embodiment, referring to Figure 4 , the voltage acquisition circuit comprises: A switch circuit, wherein the input end of the switch circuit is connected to the second end of the leakage current discharge circuit 30, and the output end of the switch circuit is used to connect to the ground end; the switch circuit is used to turn on / off the path between the leakage current discharge circuit 30 and the ground end.

[0035] It can be understood that in this embodiment, the switch circuit is implemented by the first switch tube Q1. The first switch tube Q1 can be a triode, a MOS tube, a power tube, an IGBT tube, etc. When voltage acquisition is required, the first switch tube Q1 is controlled to conduct the path between the leakage current discharge circuit 30 and the ground terminal to discharge the leakage current generated by the diode to the ground terminal to avoid the leakage current affecting the accuracy of voltage acquisition; when voltage acquisition is not required, the first switch tube Q1 is controlled to disconnect the path between the leakage current discharge circuit 30 and the ground terminal. At this time, the leakage current discharge circuit 30 does not generate any power consumption. For example, an external terminal is provided in a device provided with the power supply circuit and the voltage acquisition circuit of the present application. The external terminal can output a corresponding signal according to the above process to control the state of the switch circuit according to the current demand for voltage detection, thereby realizing the on / off control of the path between the leakage current discharge circuit 30 and the ground terminal. Compared with other embodiments in which the first switch tube Q1 is not provided, the present embodiment realizes that the first switch tube Q1 is turned on only during a short period of voltage acquisition. Due to the short on time, the power consumption is also reduced accordingly. That is, compared with the case where the leakage current discharge circuit 30 is always connected to the ground terminal, the total power consumption of this embodiment is greatly reduced. During this short voltage acquisition time, the external voltage value can be obtained while minimizing the adverse effects of leakage current and power consumption.

[0036] Furthermore, in one embodiment, referring to Figure 5 , the voltage acquisition circuit also includes: The main control circuit 40 is connected to the controlled end of the switch circuit; the main control circuit 40 is used to control the switch circuit to turn on / off the path between the leakage current discharge circuit 30 and the ground end.

[0037] In this embodiment, the main control circuit 40 can be implemented by a main controller, such as MCU, DSP (Digital Signal Process), FPGA (Field Programmable Gate Array), PLC, SOC (System On Chip), etc. The main control circuit 40 controls the first switch tube Q1 to turn on / off the path between the leakage current discharge circuit 30 and the ground terminal according to the voltage acquisition situation. For example, the main control circuit 40 acts according to the control instruction given by the external terminal in the device. When the external terminal needs to collect voltage through the voltage acquisition circuit, the main control circuit 40 controls the first switch tube Q1 to turn on the path between the leakage current discharge circuit 30 and the ground terminal to discharge the leakage current generated by the diode in the leakage current discharge circuit 30 to the ground terminal; when the voltage acquisition circuit is not required, the main control circuit 40 controls the first switch tube Q1 to disconnect the path between the leakage current discharge circuit 30 and the ground terminal. At this time, the leakage current discharge circuit 30 does not generate any power consumption.

[0038] Furthermore, in one embodiment, referring to Figure 6 The main control circuit 40 is connected to the output end of the voltage divider circuit 20; the main control circuit 40 is used to control the switch circuit to turn on the path between the leakage current discharge circuit 30 and the ground terminal when the voltage value of the external voltage is determined according to the first voltage signal.

[0039] In this embodiment, the main control circuit 40 is connected to the output end of the voltage divider circuit 20. For example, referring to the above embodiments and Figure 6 , the main control circuit 40 is connected to the connection point between the first voltage-dividing resistor R1 and the second voltage-dividing resistor R2, and is also connected to the controlled end of the first switch tube Q1. When the voltage acquisition circuit needs to perform voltage acquisition, the main control circuit 40 receives the voltage between the first voltage-dividing resistor R1 and the second voltage-dividing resistor R2, that is, the first voltage signal, and determines the voltage value of the external voltage according to the first voltage signal to realize the function of voltage acquisition. At the same time, the first switch tube Q1 is controlled to conduct the path between the leakage current discharge circuit 30 and the ground terminal to discharge the leakage current generated by the diode to the ground terminal to realize the function of leakage current discharge. When the voltage acquisition circuit does not need to perform voltage acquisition, the main control circuit 40 controls the first switch tube Q1 to disconnect the path between the leakage current discharge circuit 30 and the ground terminal to reduce the power consumption generated by the leakage current discharge circuit 30 and realize the function of reducing power consumption. With such a configuration, in the process of the main control circuit 40 determining the voltage value of the external voltage through the voltage-dividing circuit 20, the above embodiment can minimize the influence of the leakage current generated by the diode on the accuracy of voltage detection, and at the same time, in the process of not needing voltage detection, reduce the power consumption generated by the leakage current discharge circuit.

[0040] The present invention also proposes a power supply circuit, which includes a power supply output terminal, multiple power supply input circuits and at least one voltage acquisition circuit. The number of voltage acquisition circuits can be set according to the needs of the user. In the multi-channel voltage acquisition application scenario, the voltage acquisition circuit can be set to multiple, and the multiple voltage acquisition circuits are respectively electrically connected to the power supply input circuit to collect the voltage of the corresponding path through the power supply input circuit, thereby achieving the acquisition of multiple voltage signals while minimizing the adverse effects caused by leakage current. It should be understood that when the number of voltage acquisition circuits is multiple, the main control circuit is correspondingly integrated in the same main control chip.

[0041] In one embodiment, there are multiple voltage acquisition circuits, and the multiple voltage acquisition circuits are electrically connected to the multiple power input circuits in a one-to-one correspondence.

[0042] It is understandable that in this embodiment, the voltage acquisition circuit includes a first voltage acquisition circuit 100 and a second voltage acquisition circuit 200 as an example for explanation. Figure 7 , the first voltage-dividing circuit 20 in the first voltage acquisition circuit 100 includes a first voltage-dividing resistor R1 and a second voltage-dividing resistor R2, the first leakage current discharge circuit 30 in the first voltage acquisition circuit 100 includes a first switch tube Q1, a fifth resistor R5 and a first capacitor C1; the second voltage-dividing circuit 50 in the second voltage acquisition circuit 200 includes a third voltage-dividing resistor R3 and a fourth voltage-dividing resistor R4, and the second leakage current discharge circuit 60 in the second voltage acquisition circuit 200 includes a second switch tube Q2, a sixth resistor R6 and a second capacitor C2. Among them, the power supply circuit includes a first power supply access terminal VBAT1, a second power supply access terminal VBAT2 and a power supply output terminal VSYS. The first power supply access terminal VBAT1 is connected to a dry battery, the second power supply access terminal VBAT2 is connected to a lithium battery, and the power supply output terminal VSYS is connected to a load.

[0043] In practical applications, when the voltage of the dry cell battery needs to be collected, the first voltage-dividing resistor R1 and the second voltage-dividing resistor R2 detect the voltage of the first power access terminal VBAT1 and output it in the form of a first voltage signal ADC1. The first power access terminal VBAT1 outputs the voltage of the dry cell battery to the power output terminal VSYS after passing through a diode to achieve the effect of dry cell battery power supply. At the same time, the first switch tube Q1 receives a first control signal given by the main control circuit or other external terminal to conduct the path between the diode and the ground terminal, so as to output the leakage current generated by the diode to the ground terminal after passing through the fifth resistor R5. When the voltage of the dry cell battery does not need to be collected, or the dry cell battery is disconnected from the first power access terminal VBAT1, the first switch tube Q1 receives a second control signal given by the main control circuit or other external terminal to disconnect the path between the diode and the ground terminal, so that the diode cannot form a path with the ground.

[0044] When it is necessary to collect the voltage of the lithium battery, the third voltage-dividing resistor R3 and the fourth voltage-dividing resistor R4 are used to detect the voltage of the second power access terminal VBAT2, and output it in the form of a second voltage signal ADC2. The second power access terminal VBAT2 outputs the voltage of the lithium battery to the power output terminal VSYS after passing through a diode to achieve the effect of lithium battery power supply. At the same time, the second switch tube Q2 receives the third control signal given by the main control circuit or other external terminals to turn on the path between the diode and the ground terminal, so as to output the leakage current generated by the diode to the ground terminal after passing through the sixth resistor R6. When it is not necessary to collect the voltage of the lithium battery, or when the lithium battery is disconnected from the second power access terminal VBAT2, the second switch tube Q2 receives the fourth control signal given by the main control circuit or other external terminals to disconnect the path between the diode and the ground terminal, so that the diode cannot form a path with the ground.

[0045] This embodiment discharges the leakage current generated by the diode to the ground terminal through the leakage current discharge circuit, thereby solving the voltage mismeasurement problem of the voltage acquisition circuit, and minimizing the adverse effects of the leakage current while obtaining the voltage signals of the dry cell and the lithium battery.

[0046] The above descriptions are only optional embodiments of the present invention, and are not intended to limit the patent scope of the present invention. All equivalent structural changes made using the contents of the present invention's specification and drawings, or directly / indirectly applied in other related technical fields, are included in the patent protection scope of the present invention.

Claims

1. A voltage acquisition circuit, applied to a power supply circuit, the power supply circuit comprises a power supply output terminal and a plurality of power supply input circuits, the output terminals of the plurality of power supply input circuits are respectively connected to the power supply output terminal; the power supply input circuit comprises a power supply access terminal and a diode for accessing an external voltage, the power supply access terminals are connected to the power supply output terminal via the diode, the anode of the diode is connected to the power supply access terminal, the cathode of the diode is connected to the power supply output terminal, the output terminal of the power supply input circuit comprises the cathode of the diode, characterized in that: The voltage acquisition circuit comprises: A voltage divider circuit, wherein a first end of the voltage divider circuit is electrically connected to a power supply access end of the power supply input circuit, and the voltage divider circuit is used to divide an external voltage connected to the power supply access end and then output a first voltage signal; A leakage current discharge circuit, wherein a first end of the leakage current discharge circuit is electrically connected to a path between a first end of the voltage divider circuit and an anode of the diode, and a second end of the leakage current discharge circuit is grounded; the leakage current discharge circuit is used to discharge the leakage current generated by the diode.

2. The voltage acquisition circuit according to claim 1, characterized in that: The leakage current discharge circuit includes a discharge resistor, a first end of the discharge resistor is a first end of the leakage current discharge circuit, and a second end of the discharge resistor is a second end of the leakage current discharge circuit.

3. The voltage acquisition circuit according to claim 2, characterized in that: The voltage acquisition circuit also includes a filter circuit, which is connected in parallel with the discharge resistor; the filter circuit is used to filter the power input circuit.

4. The voltage acquisition circuit according to claim 1, characterized in that: The voltage divider circuit includes: a first voltage divider resistor and a second voltage divider resistor; the first end of the two voltage divider resistors is the first end of the voltage divider circuit, the second end of the second voltage divider resistor is connected to the first end of the first voltage divider resistor, and the second end of the first voltage divider resistor is grounded.

5. The voltage acquisition circuit according to claim 4, characterized in that: The resistance of the voltage divider circuit is greater than 100 kilo-ohms.

6. The voltage acquisition circuit according to any one of claims 1 to 5, characterized in that: The voltage acquisition circuit comprises: A switch circuit, wherein the input end of the switch circuit is connected to the second end of the leakage current discharge circuit, and the output end of the switch circuit is used to connect to the ground end; the switch circuit is used to turn on / off the path between the leakage current discharge circuit and the ground end.

7. The voltage acquisition circuit according to claim 6, characterized in that: The voltage acquisition circuit also includes: A main control circuit is connected to the controlled end of the switch circuit; the main control circuit is used to control the switch circuit to turn on / off the path between the leakage current discharge circuit and the ground end.

8. The voltage acquisition circuit according to claim 7, characterized in that: The main control circuit is connected to the output end of the voltage divider circuit; the main control circuit is used to control the switch circuit to conduct the path between the leakage current discharge circuit and the ground terminal when determining the voltage value of the external voltage according to the first voltage signal.

9. A power supply circuit, characterized in that: The power supply circuit includes a power supply output terminal, a plurality of power supply input circuits and at least one voltage collection circuit.

10. The power supply circuit according to claim 9, characterized in that: There are multiple voltage acquisition circuits, and the multiple voltage acquisition circuits are electrically connected to the multiple power input circuits in a one-to-one correspondence.

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