Power supply circuits and electronic equipment

Abstract

The present application relates to the field of electronic circuit technology, and discloses a power supply circuit and an electronic device, the power supply circuit comprising: a main battery, a backup battery, a conversion module and a hysteresis switching module; the conversion module is used to convert the output voltage of the main battery output into a power supply voltage, and transmit the power supply voltage to the load to be powered for power supply; the hysteresis switching module is used to collect the output voltage and the power supply voltage, and when the output voltage is not within a first preset voltage interval, and / or the power supply voltage is not within a second preset voltage interval, disconnect the circuit between the main power supply and the load to be powered, and conduct the circuit between the backup power supply and the load to be powered for power supply. Compared with the existing ones, the present application compares the output voltage and the power supply voltage with the corresponding preset voltage intervals respectively, so that when the output voltage fluctuates outside the normal range, it switches to the backup battery for power supply, reduces the switching back and forth of the backup battery, and improves the service life.

Description

Technical Field

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

[0002] At present, whether it is a new energy vehicle or a traditional gasoline vehicle, in order to be able to know some control status of the vehicle in time, a small vehicle-mounted wireless communication module will be pre-installed in the vehicle. Common vehicle-mounted wireless communication modules include telematics boxes (T-BOX) or car emergency rescue call systems (Emergency Call, e-call), etc. These vehicle-mounted wireless communication modules are mainly used for abnormal vehicle failures or emergency rescue. The existing vehicle-mounted wireless communication module is generally powered by the main battery of the vehicle, and a backup battery is also set up. After the main battery fails (for example, disconnection after a collision), the backup battery is used as an independent power source to power the vehicle-mounted wireless communication module.

[0003] However, when switching from the main battery to the backup battery, the current method generally compares the output voltage of the main battery, that is, when the output voltage is lower than a certain threshold, the backup battery is immediately switched to supply power. The actual main battery power supply may fluctuate within a normal range, but it does not mean that there is a fault. The current method still switches, that is, when the output voltage drops below a preset threshold, the backup battery is switched to supply power, and when it recovers to the preset threshold, the main battery is switched back to supply power, which results in the backup battery switching back and forth, and a shorter service life. Summary of the invention

[0004] The main purpose of the present application is to provide a power supply circuit and an electronic device, which aims to solve the technical problem that when the output voltage fluctuates within the normal range through the existing threshold comparison method, it will still switch to the backup battery to power the vehicle-mounted wireless communication module, resulting in the backup battery switching back and forth and a short service life.

[0005] To achieve the above object, the present application provides a power supply circuit, the circuit comprising: a main battery, a backup battery, a conversion module and a hysteresis switching module;

[0006] The conversion module is respectively connected to the load to be powered, the main battery and the hysteresis switching module, and the hysteresis switching module is also connected to the main battery, the backup battery and the load to be powered;

[0007] The conversion module is used to convert the output voltage of the main battery into a supply voltage, and transmit the supply voltage to the load to be powered for power supply;

[0008] The hysteresis switching module is used to collect the output voltage and the supply voltage, and when the output voltage is not within a first preset voltage range and / or the supply voltage is not within a second preset voltage range, disconnect the loop between the main power supply and the load to be powered, and connect the loop between the backup power supply and the load to be powered to supply power.

[0009] In one embodiment, the hysteresis switching module includes: a first comparison unit, a second comparison unit and a switching unit;

[0010] The first comparison unit is respectively connected to the main battery, the conversion module, the switching unit and the second comparison unit, the second comparison unit is respectively connected to the conversion module and the switching unit, and the switching unit is respectively connected to the backup battery and the load to be powered;

[0011] The first comparison unit is used to collect the output voltage, and when the output voltage is not within the first preset voltage interval, stop outputting the first switching signal to the switching unit, and stop outputting the main power supply signal to the conversion module;

[0012] The second comparing unit is used to collect the supply voltage, and stop outputting the second switching signal to the switching unit when the supply voltage is not within a second preset voltage range;

[0013] The conversion module is used to disconnect the circuit between the main battery and the load to be powered and stop converting the output voltage into the supply voltage when the main power supply signal is not received;

[0014] The switching unit is used to switch on the circuit between the backup battery and the load to be powered to supply power when the first switching signal and / or the second switching signal is not received.

[0015] In one embodiment, the switching unit includes: a conversion subunit and a switching subunit;

[0016] The conversion subunit is respectively connected to the first comparison unit, the second comparison unit and the switching subunit, and the switching subunit is respectively connected to the backup battery and the load to be powered;

[0017] The conversion subunit is configured to output a conversion signal to the switching subunit when the first switching signal is not received and / or the second switching signal is not received;

[0018] The switching subunit is used to conduct the circuit between the backup battery and the load to be powered to supply power when receiving the conversion signal.

[0019] In one embodiment, the second comparison unit is also connected to the backup battery and the switching subunit respectively;

[0020] The second comparison unit is further used to collect the backup voltage output by the backup battery, and output a backup power supply signal to the switching subunit when the backup voltage is within a third preset voltage range;

[0021] The switching subunit is further used to conduct the circuit between the backup battery and the load to be powered to supply power when receiving the conversion signal and the backup power supply signal.

[0022] In one embodiment, the first comparison unit is also connected to the backup battery and the switching subunit;

[0023] The first comparison unit is also used to collect the backup voltage and, when the backup voltage reaches a preset backup voltage threshold, output the main power supply signal to the conversion module, so that the conversion module switches on the circuit between the main battery and the load to be powered for power supply when receiving the main power supply signal.

[0024] In one embodiment, the second comparison unit is further configured to stop outputting the second switching signal to the conversion subunit when the backup voltage reaches the preset backup voltage threshold and the output voltage is within a fourth preset voltage interval, so that the conversion subunit outputs the conversion signal to the switching subunit;

[0025] The switching subunit is further configured to disconnect the circuit between the backup battery and the load to be powered when the switching signal is received but the backup power supply signal is not received.

[0026] In one embodiment, the circuit further comprises: a charging module;

[0027] The charging module is respectively connected to the first comparison unit, the main battery and the backup battery;

[0028] The first comparison unit is further configured to output a charging signal to the charging module when the output voltage is within the first preset voltage interval;

[0029] The charging module is used to transmit the output voltage to the backup battery for charging when receiving the charging signal.

[0030] In one embodiment, the charging module includes: a first protection unit, a charging unit, and a second protection unit;

[0031] The first protection unit is connected to the first comparison unit, the main battery and the charging unit respectively, and the second protection unit is connected to the first comparison unit, the backup battery and the charging unit respectively;

[0032] The first comparison unit is used to output a first charging signal to the first protection unit and output a second charging signal to the second protection unit when the output voltage is within the first preset voltage interval;

[0033] The first protection unit is configured to transmit the output voltage to the charging unit upon receiving the first charging signal;

[0034] The charging unit is used to convert the output voltage into a charging voltage, and transmit the charging voltage to the second protection unit;

[0035] The second protection unit is used to transmit the charging voltage to the backup battery for charging when receiving the second charging signal.

[0036] In one embodiment, the charging unit includes: a voltage stabilizing subunit and a constant current subunit;

[0037] The voltage stabilizing subunit is connected to the first protection unit and the constant current subunit respectively, and the constant current subunit is connected to the second protection unit;

[0038] The voltage stabilizing subunit is used to stabilize the output voltage and transmit the stabilized output voltage to the constant current subunit;

[0039] The constant current subunit is used to perform constant current on the stabilized output voltage and transmit the obtained charging voltage to the second protection unit.

[0040] In addition, to achieve the above objectives, the present application also provides an electronic device, which includes the power supply circuit as described above.

[0041] The present application provides a power supply circuit and an electronic device, the power supply circuit comprising: a main battery, a backup battery, a conversion module and a hysteresis switching module; the conversion module is respectively connected to the load to be powered, the main battery and the hysteresis switching module, and the hysteresis switching module is also connected to the main battery, the backup battery and the load to be powered; the conversion module is used to convert the output voltage of the main battery output into a power supply voltage, and transmit the power supply voltage to the load to be powered for power supply; the hysteresis switching module is used to collect the output voltage and the power supply voltage, and when the output voltage is not within a first preset voltage range and / or the power supply voltage is not within a second preset voltage range, disconnect the circuit between the main power supply and the load to be powered, and connect the circuit between the backup power supply and the load to be powered for power supply. Since the present application may be provided with a conversion module and a hysteresis switching module, the conversion module may convert the output voltage output by the main battery into a power supply voltage and then supply power to the load to be supplied, and the hysteresis switching module may respectively collect the output voltage and the power supply voltage, and only when the output voltage is not within the first preset voltage range and / or the power supply voltage is not within the second preset voltage range, switch to the backup battery to supply power to the load to be supplied. Compared with the existing method of comparing by threshold values, the present application compares the output voltage and the power supply voltage with the corresponding preset voltage ranges respectively, so that when the output voltage fluctuates outside the normal range, switch to the backup battery for power supply, reduce the switching back and forth of the backup battery, and improve the service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0043] In order to more clearly illustrate the embodiments of the present application 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, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0044] Figure 1 This is a schematic diagram of the structure of the first embodiment of the power supply circuit of the present application;

[0045] Figure 2 A partial circuit schematic diagram of the second embodiment of the power supply circuit of the present application;

[0046] Figure 3 This is a circuit schematic diagram of a first comparison unit in a second embodiment of a power supply circuit of the present application;

[0047] Figure 4 This is a logic level state diagram of the second embodiment of the power supply circuit of the present application;

[0048] Figure 5 This is a circuit schematic diagram of a second comparison unit in a second embodiment of the power supply circuit of the present application;

[0049] Figure 6 This is a schematic diagram of hardware and software switching in the second embodiment of the power supply circuit of the present application;

[0050] Figure 7 This is a schematic diagram of the structure of the third embodiment of the power supply circuit of the present application;

[0051] Figure 8 A partial circuit schematic diagram of a fourth embodiment of the power supply circuit of the present application;

[0052] Fig. 9 A circuit schematic diagram of a second comparison unit in a fourth embodiment of a power supply circuit of the present application;

[0053] Fig.10 This is a circuit schematic diagram of a first comparison unit in a fourth embodiment of a power supply circuit of the present application;

[0054] Fig.11 This is a schematic diagram of the structure of the fifth embodiment of the power supply circuit of the present application;

[0055] Fig.12 This is a circuit schematic diagram of a charging module in a sixth embodiment of the power supply circuit of the present application;

[0056] Fig.13 This is a circuit schematic diagram of the first comparison unit in the sixth embodiment of the power supply circuit of the present application.

[0057] Description of Figure Numbers:

[0058]

[0059] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0060] It should be understood that the specific embodiments described herein are only used to explain the technical solutions of the present application and are not used to limit the present application.

[0061] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0062] It should be noted that all directional indications in the embodiments of the present application (such as up, down, left, right, front, back, etc.) 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.

[0063] In addition, the descriptions of "first", "second", etc. in this application are only 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 this field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0064] It is understandable that, at present, whether it is a new energy vehicle or a traditional gasoline vehicle, in order to be able to know some control states of the vehicle in time, a small vehicle-mounted wireless communication module will be pre-installed in the vehicle. Common vehicle-mounted wireless communication modules include telematics boxes (T-BOX) or car emergency rescue call systems (Emergency Call, e-call), etc. These vehicle-mounted wireless communication modules are mainly used for abnormal vehicle failures or emergency rescue. The existing vehicle-mounted wireless communication module is generally powered by the main battery of the vehicle, and a backup battery is also set. After the main battery fails (for example, disconnection after a collision), the backup battery is used as an independent power source to power the vehicle-mounted wireless communication module, maintain emergency communication for a period of time, upload some important vehicle failure information to the cloud, and call out rescue calls, etc.

[0065] However, when switching from the main battery to the backup battery, the existing method is generally to compare the output voltage of the main battery, that is, when the output voltage is lower than a certain threshold, it is immediately switched to the backup battery for power supply. The actual power supply of the main battery may fluctuate within the normal range, but it does not mean that there is a fault. For example, at the moment of starting the car, the output voltage may drop instantly and then recover; during the driving process of the car, each central control and entertainment system module will increase the load of the output voltage, and the output voltage may also drop instantly and then recover; when the main battery is low in power, the power battery of new energy or the power generation system of traditional oil vehicles will charge the main battery, and the output voltage may be instantly high at the moment of charging; the output voltage change in the above process cannot be regarded as an abnormality of the main control power supply, and the existing method will still switch, that is, when the output voltage drops to below the preset threshold, it will switch to the backup battery for power supply, and when it recovers to the preset threshold, it will switch back to the main battery for power supply, resulting in the backup battery switching back and forth, and a low service life.

[0066] Therefore, in order to solve the above defects, this embodiment provides a power supply circuit, which can be provided with a conversion module and a hysteresis switching module. The conversion module can convert the output voltage output by the main battery into a power supply voltage and then supply power to the load to be powered. The hysteresis switching module can respectively collect the output voltage and the power supply voltage, and only switch to the backup battery to supply power to the load to be powered when the output voltage is not within the first preset voltage range and / or the power supply voltage is not within the second preset voltage range. Compared with the existing method of comparing the threshold value, this embodiment compares the output voltage and the power supply voltage with the corresponding preset voltage range respectively, so that when the output voltage fluctuates outside the normal range, it switches to the backup battery for power supply, reducing the switching back and forth of the backup battery and improving the service life.

[0067] For ease of understanding, the following combination Figures 1 to 13 The power supply circuit provided in the embodiment of the present application is described in detail.

[0068] Reference Figure 1 , Figure 1 Schematic diagram of the structure of the first embodiment of the power supply circuit of the present application, the first embodiment of the power supply circuit of the present application is proposed, such as Figure 1 As shown, in this embodiment, the power supply circuit includes: a main battery, a backup battery, a conversion module and a hysteresis switching module;

[0069] The conversion module is respectively connected to the load to be powered, the main battery and the hysteresis switching module, and the hysteresis switching module is also connected to the main battery, the backup battery and the load to be powered.

[0070] It is understandable that the power supply circuit provided in this embodiment can be a circuit for supplying power to any load to be powered, for example, it can be a circuit for supplying power to a vehicle-mounted wireless communication module (such as T-BOX, e-call, etc.), and of course, it can also be a circuit for supplying power to other loads to be powered, and this embodiment does not limit this. For the convenience of subsequent description, this embodiment uses the power supply of the vehicle-mounted wireless communication module for description, and the above-mentioned load to be powered can be the vehicle-mounted wireless communication module.

[0071] It should be understood that the main battery can be any battery that can be used to supply power to the load to be powered. Since the present embodiment is used to supply power to the on-board wireless communication module of the vehicle, the main battery can be the main battery of the vehicle. Of course, it can also be other batteries, which is not limited in the present embodiment. The backup battery can be another battery that can be used to supply power to the load to be powered. In the present embodiment, the backup battery can be another battery in the vehicle other than the main battery.

[0072] In consideration of the availability of backup batteries, this embodiment may use nickel-hydrogen batteries with higher safety as the backup batteries. Of course, other batteries may also be used as backup batteries, and this embodiment does not impose any restrictions on this.

[0073] The conversion module is used to convert the output voltage of the main battery into a supply voltage, and transmit the supply voltage to the load to be powered for power supply;

[0074] The hysteresis switching module is used to collect the output voltage and the supply voltage, and when the output voltage is not within a first preset voltage range and / or the supply voltage is not within a second preset voltage range, disconnect the loop between the main power supply and the load to be powered, and connect the loop between the backup power supply and the load to be powered to supply power.

[0075] It should be noted that the above-mentioned conversion module may be a module with a voltage conversion function, the above-mentioned output voltage may be the voltage output by the main battery, and the above-mentioned supply voltage may be the voltage required for the load to be powered to work. Since the voltage value of the output voltage provided by the main battery may not be compatible with the voltage value required for the load to be powered to work, the above-mentioned conversion module may be set in this embodiment to convert the output voltage of the main battery to obtain a supply voltage adapted to the load to be powered, and transmit the supply voltage to the load to be powered for power supply.

[0076] It should also be noted that the above-mentioned hysteresis switching module can be a module with a judgment function and a switching function. The above-mentioned first preset voltage interval can be a voltage interval for judging whether the output voltage is normal, that is, judging whether the output voltage of the main battery is a normal fluctuation, and the above-mentioned second preset voltage interval can be a voltage interval for judging whether the power supply voltage is normal, that is, judging whether the converted output voltage is a normal fluctuation. The above-mentioned first preset voltage interval and the above-mentioned second preset voltage interval can be set according to actual conditions. In this embodiment, the output voltage of the main battery is recorded as B+, and the power supply voltage output by the conversion module is recorded as VDD_5. The output voltage of the main battery is 12V under nominal conditions, and the working voltage of the load to be powered is 5V. The first preset voltage interval is 9V≤B+≤16V, and the second preset voltage interval is 4.99V≤VDD_5≤5.26V for explanation, that is, when the output voltage is within 9V≤B+≤16V, it can be judged as normal fluctuation, and when the power supply voltage is within 4.99V≤VDD_5≤5.26V, it can also be judged as normal fluctuation.

[0077] In actual use, when the main battery is supplying power, the conversion module can convert the output voltage output by the main battery into a supply voltage, and transmit the supply voltage to the load to be powered for power supply; at the same time, the hysteresis switching module can collect the output voltage and compare it with the first preset voltage interval, and collect the supply voltage and compare it with the second preset voltage interval; when the output voltage is in the first preset voltage interval, and the supply voltage is in the second preset voltage interval, it can be determined that the main battery is in a normal state, that is, no switching is performed, and the main battery continues to supply power; when the output voltage is not in the first preset voltage interval, and / or the supply voltage is not in the second preset voltage interval, it can be determined that the fluctuation of the main battery at this time is an abnormal fluctuation, then the circuit between the main battery and the load to be powered is disconnected, and the circuit between the backup battery and the load to be powered is connected, and the load to be powered is powered by the backup battery. Compared with the existing method of comparing by threshold values, this embodiment compares the output voltage and the supply voltage with the corresponding preset voltage intervals respectively, so that when the output voltage fluctuates in an abnormal range, it switches to the backup battery for power supply, reducing the switching back and forth of the backup battery and improving the service life.

[0078] At the same time, since this embodiment not only compares the output voltage with the first preset voltage range, but also compares the supply voltage with the second preset voltage range, a dual monitoring method is adopted to improve the accuracy of judgment and make the switching more stable and reliable.

[0079] Further, in order to achieve the above dual monitoring, continue as follows Figure 1 As shown, in this embodiment, the hysteresis switching module includes: a first comparison unit, a second comparison unit and a switching unit;

[0080] The first comparison unit is respectively connected to the main battery, the conversion module, the switching unit and the second comparison unit, the second comparison unit is respectively connected to the conversion module and the switching unit, and the switching unit is respectively connected to the backup battery and the load to be powered;

[0081] The first comparison unit is used to collect the output voltage, and when the output voltage is not within the first preset voltage interval, stop outputting the first switching signal to the switching unit, and stop outputting the main power supply signal to the conversion module;

[0082] The second comparing unit is used to collect the supply voltage, and stop outputting the second switching signal to the switching unit when the supply voltage is not within a second preset voltage range;

[0083] The conversion module is used to disconnect the circuit between the main battery and the load to be powered and stop converting the output voltage into the supply voltage when the main power supply signal is not received;

[0084] The switching unit is used to switch on the circuit between the backup battery and the load to be powered to supply power when the first switching signal and / or the second switching signal is not received.

[0085] It is understandable that the first comparison unit may be a module for judging whether the output voltage fluctuates abnormally, and the second comparison unit may be a module for judging whether the supply voltage fluctuates abnormally. In this embodiment, the first comparison unit may adopt a software judgment method when making a judgment, that is, a device with a program running function such as a microcontroller unit (MCU) may be used to run a judgment program, and the judgment program may realize the function realized by the first comparison unit when it is run by the MCU. Then, in actual use, the MCU may obtain the output voltage and judge whether the output voltage is in the first preset voltage range.

[0086] However, considering that the vehicle is generally in an emergency when the on-board wireless communication module is working, in order to upload the vehicle fault to the cloud in time, the above-mentioned method of judgment by software has a slow judgment speed due to the time requirements of running the program. Therefore, the second comparison unit in this embodiment can adopt a hardware judgment method, that is, a device with a direct comparison function is used to implement the judgment, such as a comparator or a chip with a comparison function, etc. This embodiment does not limit this. Therefore, the response speed can be further improved through the dual judgment method of software judgment and hardware judgment.

[0087] It should be understood that the above-mentioned switching unit may be a unit that switches to a backup battery for power supply, and may include components such as a switch tube.

[0088] In actual use, the first comparison unit can collect the output voltage and determine whether the output voltage is within the first preset voltage range; if it is, it can be said that the output voltage is normal at this time, and then the first comparison unit can continuously output the first switching signal to the switching unit, and continuously output the main power supply signal to the conversion unit; if it is not, it can be said that the output voltage is abnormal at this time, and then the first comparison unit can stop outputting the first switching signal to the switching unit, and stop outputting the main power supply signal to the conversion unit;

[0089] The second comparison unit can collect the power supply voltage and determine whether the power supply voltage is in the second preset voltage range; if it is, it can be said that the power supply voltage is normal at this time, and then the second switching signal is continuously output to the switching unit; if it is not, it can be said that the power supply voltage is abnormal at this time, and then the second switching signal is stopped from being output to the switching unit;

[0090] The above-mentioned conversion module can receive the main power supply signal. When the conversion module receives the main power supply signal, it can be said that the main battery is normal, and then continue to keep conducting, that is, convert the output voltage of the main battery into the power supply voltage and transmit it to the load to be powered for power supply; when the conversion module does not receive the main power supply signal, it can be said that the main battery is abnormal, and then the loop between the main battery and the load to be powered is disconnected, and at the same time, the conversion of the output voltage of the main battery into the power supply voltage is stopped; and since there is no power supply voltage at this time (that is, VDD_5 is 0V), the above-mentioned second comparison unit can determine that the power supply voltage at this time is not in the second preset voltage interval, and the second comparison unit can stop outputting the second switching signal;

[0091] The above-mentioned switching unit can receive a first switching signal and a second switching signal. When the main battery is normal, the switching unit can receive the first switching signal output by the first comparison unit, and at the same time receive the second switching signal output by the second comparison unit. When both the first switching signal and the second switching signal are received, the switching unit can keep the circuit between the backup battery and the load to be powered disconnected, and continue to supply power through the main battery; when the main battery is abnormal, the switching unit may not receive the first switching signal, and / or the second switching signal. As long as one switching signal is not received, it can indicate that the main battery is abnormal, and then the switching unit can connect the circuit between the backup battery and the load to be powered, and supply power to the load to be powered through the backup battery.

[0092] Further, in order to supply power to the first comparison unit, the second comparison unit and the switching unit, continue as follows Figure 1 As shown, in this embodiment, the power supply circuit further includes: a power supply module;

[0093] The power supply module is respectively connected to the main battery, the backup battery, the first comparison unit, the second comparison unit and the switching unit;

[0094] The power supply module is used to convert the output voltage of the main battery into an operating voltage when the main battery is connected to the load to be powered, and transmit the operating voltage to the first comparison unit, the second comparison unit and the switching unit for power supply;

[0095] The power supply module is also used to convert the backup voltage output by the backup battery into the operating voltage when the backup battery is connected to the load to be powered, and transmit the operating voltage to the first comparison unit, the second comparison unit and the switching unit for power supply.

[0096] It should be noted that the power supply module can be any module that realizes voltage conversion. The backup voltage can be the voltage output by the backup battery. In this embodiment, the backup voltage of the backup battery is recorded as VBAT_CON, and the backup voltage is 3.8V in the nominal case and 4.2V when charging.

[0097] It is understandable that the above operating voltage can be the required voltage for the normal operation of the first comparison unit, the second comparison unit and the switching unit. Since the general operating voltage of devices such as MCU, comparator or chip with comparison function is 3.3V. Therefore, in this embodiment, when the main battery supplies power to the load to be powered, the power supply module can convert the output voltage of the main battery output into a 3.3V operating voltage, and transmit it to the first comparison unit, the second comparison unit and the switching unit for power supply; when the backup battery supplies power to the load to be powered, the power supply module can convert the backup voltage output by the backup battery into a 3.3V operating voltage, and transmit it to the first comparison unit, the second comparison unit and the switching unit for power supply.

[0098] This embodiment may be provided with a conversion module and a hysteresis switching module. The conversion module may convert the output voltage output by the main battery into a supply voltage and then supply power to the load to be supplied. The hysteresis switching module may respectively collect the output voltage and the supply voltage, and only switch to the backup battery to supply power to the load to be supplied when the output voltage is not within the first preset voltage range and / or the supply voltage is not within the second preset voltage range. Compared with the existing method of comparing the threshold value, this embodiment compares the output voltage and the supply voltage with the corresponding preset voltage range respectively, so that when the output voltage fluctuates outside the normal range, it switches to the backup battery for power supply, reducing the switching back and forth of the backup battery and improving the service life.

[0099] Reference Figure 2 , Figure 2This is a partial circuit schematic diagram of the second embodiment of the power supply circuit of the present application. Based on the above-mentioned first embodiment, the second embodiment of the power supply circuit of the present application is proposed.

[0100] like Figure 2 As shown, in this embodiment, the conversion module includes: a first chip U1, a first diode D1, and first to third capacitors C1 to C3;

[0101] The input end of the first chip U1 (i.e., the first pin of the first chip U1) is connected to the main battery and the first end of the first capacitor C1 respectively, the second end of the first capacitor C1 is grounded, and the output end of the first chip U1 (i.e., the second pin of the first chip U1) is connected to the second comparison unit (i.e., Figure 2 VDD_5V), the first end of the second capacitor C2 and the anode of the first diode D1 are connected, and the control end of the first chip U1 (ie, the third pin of the first chip U1) is connected to the first comparison unit (ie Figure 2 5V_EN), a second end of the second capacitor C2 is grounded, a cathode of the first diode D1 is respectively connected to the switching unit, the load to be powered and a first end of the third capacitor C3, and a second end of the third capacitor C3 is grounded.

[0102] It should be noted that the first chip U1 may be a DC-DC converter chip (ie Figure 2 In actual use, when the main battery is used for power supply, the output voltage B+ output by the main battery is converted by the first chip U1 to obtain a 5V power supply voltage (i.e. Figure 2 VDD_5V), and then filtered by the third capacitor C3, the filtered supply voltage (i.e. Figure 2 V_SYS) is transmitted to the load to be powered for power supply.

[0103] At the same time, the first diode D1 can prevent current backflow. The first diode D1 can be a diode with a small forward conduction voltage, a small reverse leakage current, and a large forward working current, such as a Schottky diode that can operate with a large current, etc. This embodiment does not limit this.

[0104] The first capacitor C1 to the third capacitor C3 can be selected from capacitors with larger capacitance values ​​to achieve voltage stabilization and current storage. It should be noted that the first capacitor C1 can be selected from capacitors with higher withstand voltage values. In addition, multiple capacitors can be connected in parallel at one end of the first capacitor C1 to the third capacitor C3 close to the first chip U1 to filter out high-frequency interference signals and improve the current storage capacity at both ends of the first chip U1.

[0105] Reference Figure 3 , Figure 3 This is a circuit schematic diagram of the first comparison unit in the second embodiment of the power supply circuit of the present application, such as Figure 2 and Figure 3 As shown, in this embodiment, the second comparison unit includes: an analog-to-digital converter and a second chip U2;

[0106] The input of the analog-to-digital converter is connected to the main battery, and the output of the analog-to-digital converter (i.e. Figure 2 The ADC1 in the middle is connected to the first input terminal of the second chip U2 (i.e., the third pin of the second chip U2), and the first output terminal of the second chip U2 (i.e., the first pin of the second chip U2) is connected to the control terminal of the first chip U1 (i.e., Figure 3 5V_EN), the second output terminal of the second chip U2 (ie, the second pin of the second chip U2) is connected to the switching unit (ie Figure 3 5V_SW), the power supply end of the second chip U2 (i.e. the fourth pin of the second chip U2) is connected to the power supply module (i.e. Figure 3 MCU_3V3) connection.

[0107] It is understandable that the second chip U2 may be an MCU chip, or other chips with similar functions, which is not limited in this embodiment.

[0108] If the main power supply signal is recorded as 5V_EN, it is at a high level when output, and the first switching signal is recorded as 5V_SW, it is at a high level when output. Figure 4 , Figure 4 This is a logic level state diagram of the second embodiment of the power supply circuit of the present application, as shown in FIG. Figure 4 As shown, in actual use, the analog-to-digital converter may first collect the output voltage B+ of the main battery and transmit it to the first input terminal of the second chip U2 in the form of a digital signal. After receiving the output voltage B+, the second chip U2 may compare it with the first preset voltage range;

[0109] When the output voltage B+ is in the first preset voltage range, that is, 9V≤B+≤16V (i.e. Figure 4 When B+ is normal), the first output terminal of the second chip U2 can output a high-level main power supply signal 5V_EN (i.e. Figure 4 When the first chip U1 receives the main power supply signal 5V_EN, it can work, that is, convert the output voltage B+ into the power supply voltage VDD_5, and the second output end of the second chip U2 can output the high-level first switching signal 5V_SW (that is, Figure 4 5V_SW is high level H) to the switching unit;

[0110] When the output voltage B+ is not in the first preset voltage range, that is, B+>16V (the main battery is over-voltage (i.e. Figure 4B+ overvoltage)) or 0V≤B+<9V (main battery undervoltage (i.e. Figure 4 B+ undervoltage) or fault (i.e. Figure 4 When the B+ fault occurs, the first output terminal of the second chip U2 stops outputting the high-level main power supply signal 5V_EN to the control terminal of the first chip U1, that is, the first output terminal of the second chip U2 is at a low level (i.e. Figure 4 5V_EN is low level L), the first chip U1 can stop working when it does not receive the main power supply signal 5V_EN, that is, stop converting the output voltage B+ into the power supply voltage VDD_5, and disconnect the loop between the main battery and the load to be powered. At the same time, the second output end of the second chip U2 can stop outputting the high-level first switching signal 5V_SW to the switching unit, that is, the second output end of the second chip U2 is low level (that is, Figure 4 5V_SW is low level L).

[0111] Specifically, in this embodiment, the second chip U2 can be made to determine that the main battery is over-voltage when the output voltage B+>16V is detected, determine that the main battery is under-voltage when the output voltage is 6V≤B+<9V, and determine that the main battery is faulty when the output voltage is 0V≤B+<6V. In these cases, the first output end of the second chip U2 stops outputting the main power supply signal 5V_EN, that is, 5V_EN is at a low level L, and the second output end of the second chip U2 stops outputting the first switching signal 5V_SW, that is, 5V_SW is at a level L.

[0112] Reference Figure 5 , Figure 5 This is a circuit schematic diagram of the second comparison unit in the second embodiment of the power supply circuit of the present application, such as Figure 5 As shown, in this embodiment, the second comparison unit includes: a third chip U3 and first to third resistors R1 to R3;

[0113] The power supply end of the third chip U3 (i.e. the first pin of the third chip U3) is respectively connected to the power supply module (i.e. Figure 5 MCU_3V3) and the second end of the first resistor R1 are connected, and the first end of the first resistor R1 is connected to the first output end of the third chip U3 (that is, the second pin of the third chip U3) and the switching unit (that is, Figure 5 The first input terminal of the third chip U3 (i.e., the fourth pin of the third chip U3) is connected to the first end of the second resistor R2 and the first end of the third resistor R3 respectively, and the second end of the second resistor R2 is connected to the output terminal of the first chip U1 (i.e., Figure 5 A second end of the third resistor R3 is grounded, and a grounding end of the third chip U3 (ie, a fifth pin of the third chip U3) is grounded.

[0114] It should be understood that the third chip U3 in this embodiment can be a chip with a voltage detection function, and in order to detect the range, the third chip U3 in this embodiment can have an optional hysteresis interval function. Specifically, a voltage detector with model TPS3780 can be used. Of course, other chips can also be used. This embodiment uses TPS3780 for illustration.

[0115] And because TPS3780 has dual-channel judgment capability, this embodiment can make the first channel (i.e. Figure 5 SENSE1) is used to determine the power supply voltage.

[0116] It should also be understood that, in this embodiment, the second preset voltage interval can be set by setting the resistance value of the second resistor R2 and the resistance value of the third resistor R3. If the forward trigger voltage of the first channel is recorded as V rise1 , the negative trigger voltage is denoted as V fall1 ,but Where R2 is the resistance value of the second resistor R2, R3 is the resistance value of the third resistor R3, V IT+ is the positive reference level, V IT- is the negative reference voltage, after calculation, we can get V rise1 and V fall1 , then the V rise1 As the upper limit of the second preset voltage interval, V fall1 As the lower limit value of the second preset voltage interval. rise1 Set to 5.26V, V fall1 Set to 4.99 V. This prevents frequent oscillation switching of the backup battery when the supply voltage VDD_5V fluctuates under high load.

[0117] If the second switching signal is recorded as HW_5V_SW, it is at a high level when output. In actual use, the first input terminal of the third chip U3 can collect the power supply voltage VDD_5V and determine whether the power supply voltage VDD_5V is in the second preset voltage range, that is, whether it is within 4.99V≤VDD_5≤5.26V;

[0118] If the condition is positive, the first output terminal of the third chip U3 outputs the second switching signal HW_5V_SW (ie Figure 4 If HW_5V_SW is high level H) to the switching unit; if not, the first output terminal of the third chip U3 stops outputting the second switching signal HW_5V_SW to the switching unit, that is, the first output terminal of the third chip U3 is low level (that is Figure 4 HW_5V_SW is low level L).

[0119] Continue to refer to Figure 2 As shown, in this embodiment, the switching unit can be respectively connected to the power supply module (ie Figure 2 MCU_3V3 in the middle), the second output terminal of the second chip U2 (ie Figure 2 5V_SW), the first output terminal of the third chip U3 (ie Figure 2 HW_5V_SW), backup battery, and load to be powered (i.e. Figure 2 V_SYS) connection.

[0120] It should be noted that, since the backup voltage of the backup battery in this embodiment can directly supply the load to be powered, the voltage conversion function may not be provided in the above switching unit, and the voltage of the backup battery can be directly transmitted to the load to be powered.

[0121] In actual use, the switching unit can be set to disconnect the circuit between the backup battery and the load to be powered when receiving the first switching signal and the second switching signal. At this time, the backup battery does not supply power, and the circuit relies on the main battery for power supply (i.e. Figure 4 When the first switching signal is received and / or the second switching signal is received, since the circuit between the main battery and the load to be powered is disconnected at this time, the switching unit can connect the circuit between the backup battery and the load to be powered, and the circuit relies on the backup battery for power supply (i.e. Figure 4 Software + hardware switch to backup battery).

[0122] Reference Figure 6 , Figure 6 This is a schematic diagram of hardware and software switching in the second embodiment of the power supply circuit of the present application. Figure 6 As shown, based on the above description, if the hardware switching is recorded as HW and the software switching is recorded as SW, when the main battery is normal, the software switching and the hardware switching work together (i.e. Figure 6 9V≤B+≤16VSW&HW), when the main battery is over-voltage, software switching and hardware switching work together (i.e. Figure 6 B+>16V SW&HW), when the main battery is undervoltage, software switching and hardware switching work together (i.e. Figure 6 6V≤B+<9V SW&HW), when the main battery fails, software switching and hardware switching work together (i.e. Figure 6 0V≤B+<6V SW&HW).

[0123] Further, continue to refer to Figure 2 In this embodiment, the power supply module may include: a fourth chip U4, a second diode D2, a third diode D3, a fourth capacitor C4 and a fifth capacitor C5;

[0124] The anode of the second diode D2 is connected to the main battery, the cathode of the second diode D2 is respectively connected to the cathode of the third diode D3, the first end of the fourth capacitor C4 and the input end of the fourth chip U4 (i.e., the first pin of the fourth chip U4), the anode of the third diode D3 is connected to the backup battery, the second end of the fourth capacitor C4 is grounded, the grounding end of the fourth chip U4 (i.e., the third pin of the fourth chip U4) is grounded, the output end of the fourth chip U4 (i.e., the second pin of the fourth chip U4) is respectively connected to the first end of the fifth capacitor C5, the power supply end of the second chip U2, the power supply end of the third chip U3 and the switching unit, and the second end of the fifth capacitor C5 is grounded.

[0125] It is understandable that the fourth chip U4 may be a chip with a static power consumption of uA level and a voltage stabilization function, such as a low voltage drop linear regulator (i.e. Figure 2 Medium LDO (3V3)), etc., this embodiment does not limit this.

[0126] If the operating voltage is recorded as MCU_3V3. In actual use, when the main battery is used for power supply, the input end of the fourth chip U4 can receive the output voltage of the main battery, and obtain the operating voltage MCU_3V3 after voltage stabilization, and transmit the operating voltage MCU_3V3 to the power supply end of the second chip U2 to power the second chip U2, to the power supply end of the third chip U3 to power the third chip U3, and to the switching unit to power the switching unit; similarly, when the backup battery is used for power supply, the input end of the fourth chip U4 receives the backup voltage output by the backup battery, and obtains the operating voltage MCU_3V3 after voltage stabilization, and transmits the operating voltage to the second chip U2, the third chip U3 and the switching unit for power supply.

[0127] It should be emphasized that the second diode D2 and the third diode D3 can prevent the current from flowing back between the output voltage of the main battery and the backup voltage of the backup battery. When selecting the second diode D2 and the third diode D3, a diode with a small forward conduction voltage, a small reverse leakage current, and a large forward working current can be selected, such as a Schottky diode that can work with a large current, etc., and this embodiment does not limit this.

[0128] It should also be emphasized that the fourth capacitor C4 and the fifth capacitor C5 can be selected as capacitors with larger capacitance to achieve voltage stabilization and current storage, and the fourth capacitor C4 also needs to be selected as a capacitor with a higher withstand voltage. In addition, multiple capacitors can be connected in parallel near the fourth capacitor C4 and the fifth capacitor C5 near the fourth chip U4 to filter out high-frequency interference signals and improve the current storage capacity at both ends of the fourth chip U4.

[0129] In this embodiment, since the first comparison unit of this embodiment can not only identify the main battery failure, but also the main battery overvoltage and undervoltage, the application scenario is improved and the identification is more comprehensive. At the same time, this embodiment also combines software switching and hardware switching to achieve seamless switching and ensure the normal and stable operation of the subsequent vehicle-mounted wireless communication module.

[0130] Reference Figure 7 , Figure 7 This is a structural schematic diagram of the third embodiment of the power supply circuit of the present application. Based on the above embodiments, the third embodiment of the power supply circuit of the present application is proposed.

[0131] like Figure 7 As shown, in this embodiment, the switching unit includes: a conversion subunit and a switching subunit;

[0132] The conversion subunit is respectively connected to the first comparison unit, the second comparison unit and the switching subunit, and the switching subunit is respectively connected to the backup battery and the load to be powered;

[0133] The conversion subunit is configured to output a conversion signal to the switching subunit when the first switching signal is not received and / or the second switching signal is not received;

[0134] The switching subunit is used to conduct the circuit between the backup battery and the load to be powered to supply power when receiving the conversion signal.

[0135] It should be noted that the above-mentioned conversion subunit may be a subunit for level conversion. The above-mentioned switching subunit may be a subunit for switching backup batteries.

[0136] If the above conversion signal is recorded as COM_OUT, it is high level when output. Figure 4 In actual use, when the main battery is normal, the conversion sub-unit can receive the first switching signal 5V_SW (ie Figure 4 5V_SW is at high level H), and at the same time receives the second switching signal HW_5V_SW (i.e. Figure 4 HW_5V_SW is at high level H), the conversion subunit may stop outputting the conversion signal COM_OUT (ie, Figure 4 COM_OUT is low level L) to the switching subunit. When the switching subunit does not receive the conversion signal, the circuit between the backup battery and the load to be powered can be disconnected, and the main battery is still used for power supply;

[0137] When the main battery is abnormal, the conversion sub-unit does not receive the first switching signal 5V_SW (ie Figure 4 5V_SW is at low level L), and / or the second switching signal HW_5V_SW is not received (i.e. Figure 4 In the example, HW_5V_SW is at a low level L), the conversion subunit may output a conversion signal COM_OUT (i.e., Figure 4 When the switching subunit receives the conversion signal, it knows that the main battery is abnormal, and then turns on the loop between the backup battery and the load to be powered, and uses the backup battery for power supply.

[0138] Furthermore, considering that when a backup battery is needed to supply power, in order to ensure smooth power supply, it is possible to first determine whether the backup voltage of the backup battery meets the requirements of the load to be powered, and then supply power when it meets the requirements. Figure 7 As shown, in this embodiment, the second comparison unit is also connected to the backup battery and the switching subunit respectively;

[0139] The second comparison unit is further used to collect the backup voltage output by the backup battery, and output a backup power supply signal to the switching subunit when the backup voltage is within a third preset voltage range;

[0140] The switching subunit is further used to conduct the circuit between the backup battery and the load to be powered to supply power when receiving the conversion signal and the backup power supply signal.

[0141] It is understandable that, since the third chip U3 has dual-channel judgment capability, the present embodiment can use the third chip U3 to realize the judgment of the backup voltage. The third preset voltage interval can be an interval for judging that the backup voltage meets the power supply requirement. The present embodiment can be described by using 4V≤VBAT_CON≤4.21V.

[0142] It should be understood that in this embodiment, the backup power supply signal can be recorded as HW_VBAT_CON, which is at a high level when output. Figure 4 In this embodiment, the second comparison unit can also collect the backup voltage VBAT_CON output by the backup battery, and compare the backup voltage VBAT_CON with the third preset voltage interval; when it is in the third preset voltage interval, that is, 4V≤VBAT_CON≤4.21V, the second comparison unit can output the backup power supply signal HW_VBAT_CON (that is, Figure 4When the switching subunit receives the backup power supply signal HW_VBAT_CON, it knows that the backup battery is normal. When the switching subunit receives the conversion signal COM_OUT, it means that it is necessary to switch to the backup battery at this time. Then, the switching subunit can connect the loop between the backup battery and the load to be powered, and transmit the backup voltage of the backup battery to the load to be powered for power supply.

[0143] Furthermore, considering that when the backup battery fails, that is, the backup voltage VBAT_CON is 0V, in order to ensure that the vehicle-mounted wireless communication module can be powered in time, in this embodiment, continue as follows Figure 7 As shown, the first comparison unit is also connected to the backup battery and the switching subunit;

[0144] The first comparison unit is also used to collect the backup voltage and, when the backup voltage reaches a preset backup voltage threshold, output the main power supply signal to the conversion module, so that the conversion module switches on the circuit between the main battery and the load to be powered for power supply when receiving the main power supply signal.

[0145] It should be noted that the above-mentioned preset backup voltage threshold can be a voltage threshold used to determine whether the backup battery is faulty. In this embodiment, the above-mentioned preset backup voltage threshold can be lower than the above-mentioned third preset voltage range, and can be specifically described as 0V, but this is not limited to it.

[0146] Continue to combine Figure 4 In actual use, the first comparison unit can collect the backup voltage VBAT_CON output by the backup battery and determine whether the backup voltage VBAT_CON reaches 0V; when it does not reach 0V, it can be said that the backup battery is normal, and then the first comparison unit can stop outputting the main power supply signal 5V_EN, and the conversion module disconnects the circuit between the main battery and the load to be powered; when it reaches 0V (i.e. Figure 4 If VBAT_CON=0V), it means the backup battery is faulty, and the first comparison unit can output the main power supply signal 5V_EN (i.e. Figure 4 5V_EN is at a high level (H) to the conversion module, and the conversion module continues to keep the main battery and the load to be powered connected, that is, the load to be powered continues to be powered by the main battery.

[0147] Furthermore, considering that when the backup battery fails and the main battery is in an overvoltage or undervoltage state, in order to ensure that the main battery can continue to supply power, the second comparison unit is further configured to stop outputting the second switching signal to the conversion subunit when the backup voltage reaches the preset backup voltage threshold and the output voltage is within a fourth preset voltage interval, so that the conversion subunit outputs the conversion signal to the switching subunit;

[0148] The switching subunit is further configured to disconnect the circuit between the backup battery and the load to be powered when the switching signal is received but the backup power supply signal is not received.

[0149] It is understandable that the fourth preset voltage interval may be a voltage interval in which the main battery is in overvoltage or undervoltage, that is, 6V≤B+<9V or B+>16V.

[0150] Continue to combine Figure 4 , if the backup power supply signal is recorded as HW_VBAT_CON, and is output at a high level. In this embodiment, when the second comparison unit detects that the backup voltage VBAT_CON reaches 0V and the output voltage 6V≤B+<9V or B+>16V, the second comparison unit stops outputting the second switching signal HW_5V_SW (i.e. Figure 4 HW_5V_SW is low level L) to the conversion sub-unit, it will stop outputting the backup power supply signal HW_VBAT_CON (i.e. Figure 4 HW_VBAT_CON is at a low level L) to the switching subunit. Since the conversion subunit does not receive the second switching signal HW_5V_SW, it will output a conversion signal COM_OUT (i.e. Figure 4 COM_OUT is high level H) to the switching subunit. Even if the switching subunit can receive the conversion signal COM_OUT, since it does not receive the backup power supply signal HW_VBAT_CON, the switching subunit will disconnect the circuit between the backup battery and the load to be powered, thereby continuing to use the main battery for power supply (i.e. Figure 4 Since the conversion sub-unit does not receive the second switching signal HW_5V_SW at this time, it will output the conversion signal COM_OUT. Therefore, the first comparison unit can be set to output the first switching signal 5V_SW (ie Figure 4 In this embodiment, when the backup battery fails, the second car unit adopts a hardware judgment method, so it will react quickly (i.e. Figure 6 VBAT_CON=0V HW).

[0151] Reference Figure 8 , Figure 8 This is a partial circuit schematic diagram of the fourth embodiment of the power supply circuit of the present application. Based on the above embodiments, the fourth embodiment of the power supply circuit of the present application is proposed.

[0152] like Figure 8 As shown, in this embodiment, the conversion subunit includes: a first transistor Q1, a fourth diode D4, and fourth to sixth resistors R4 to R6;

[0153] The collector of the first transistor Q1 is connected to the second end of the sixth resistor R6 and the switching subunit (ie Figure 8 The first end of the sixth resistor R6 is connected to the output end of the fourth chip U4 (ie Figure 8 The base of the first transistor Q1 is connected to the second end of the fourth resistor R4 and the first end of the fifth resistor R5, respectively. The first end of the fourth resistor R4 is connected to the first output end of the third chip U3 (i.e. Figure 8 The cathode of the fourth diode D4 is connected to the second output terminal (ie, the second output terminal of the second chip U2) of the second chip U2. Figure 8 5V_SW), the second end of the fifth resistor R5 is also connected to the emitter of the first transistor Q1, and the emitter of the first switch tube is also grounded.

[0154] It should be noted that the power supply network of the first transistor Q1 may be the operating voltage MCU_3V3 output by the fourth chip U4. In this embodiment, the first transistor Q1 may be an NPN transistor.

[0155] In actual use, when the main battery is normal, the base of the first transistor Q1 can receive the first switching signal 5V_SW and the second switching signal HW_5V_SW. At this time, the first transistor Q1 is turned on, and because the emitter of the first transistor Q1 is grounded, the collector of the first transistor Q1 is at a low level, that is, the collector of the first transistor Q1 stops outputting the conversion signal COM_OUT to the switching sub-unit, and the switching sub-unit keeps the loop between the backup battery and the load to be powered disconnected;

[0156] When the main battery is abnormal, the base of the first transistor Q1 stops receiving the first switching signal 5V_SW and / or the second switching signal HW_5V_SW. At this time, the first transistor Q1 is disconnected. Since the collector of the first transistor Q1 receives the operating voltage MCU_3V3, the collector of the first transistor Q1 is at a high level, that is, the collector of the first transistor Q1 outputs the conversion signal COM_OUT to the switching sub-unit. The switching sub-unit connects the loop between the backup battery and the load to be powered, and supplies power through the backup battery.

[0157] Further, continue as Figure 8 In the present embodiment, the switching subunit includes: a second triode Q2, a first MOS transistor MOS1, a second MOS transistor MOS2, a seventh resistor R7 to a ninth resistor R9, a sixth capacitor C6, a fifth diode D5 and a sixth diode D6;

[0158] The base of the second transistor Q2 is connected to the second end of the seventh resistor R7 and the first end of the eighth resistor R8 respectively, the emitter of the second transistor Q2 is grounded, the emitter of the second transistor Q2 is also connected to the second end of the eighth resistor R8, the first end of the seventh resistor R7 is connected to the collector of the first transistor Q1 (i.e. Figure 8 COM_OUT) is connected to the anode of the fifth diode D5, and the cathode of the fifth diode D5 is connected to the second comparison unit (ie Figure 8 The collector of the second transistor Q2 is connected to the second end of the ninth resistor R9, the first end of the ninth resistor R9 is respectively connected to the second end of the tenth resistor R10, the gate of the first MOS transistor MOS1 and the gate of the second MOS transistor MOS2, the drain of the first MOS transistor MOS1 is connected to the backup battery, the source of the first MOS transistor MOS1 is respectively connected to the first end of the tenth resistor R10 and the source of the second MOS transistor MOS2, the drain of the second MOS transistor MOS2 is respectively connected to the first end of the sixth capacitor C6, the cathode of the sixth diode D6 and the backup battery (i.e. Figure 8 A second end of the sixth capacitor C6 is connected to an anode of a sixth diode D6, and an anode of the sixth diode D6 is also grounded.

[0159] It is understandable that the second transistor Q2 can be an NPN transistor, and the sixth diode D6 can be a voltage regulator. The first MOS transistor MOS1 and the second MOS transistor MOS2 can both be P-channel MOS transistors with small on-resistance and large overcurrent energy, and both are controlled to be turned on and off by the second transistor Q2.

[0160] In actual use, when the main battery is normal, since the base of the second transistor Q2 does not receive the conversion signal COM_OUT, the base of the second transistor Q2 is at a low level, and the collector and the emitter of the second transistor Q2 remain disconnected, the first MOS transistor MOS1 and the second MOS transistor MOS2 are disconnected, and the loop between the backup battery and the load to be powered remains disconnected;

[0161] When the main battery is abnormal, since the base of the second transistor Q2 receives the conversion signal COM_OUT, the base of the second transistor Q2 is at a high level, and then the collector and the emitter of the second transistor Q2 are connected to ground, the first MOS transistor MOS1 and the second MOS transistor MOS2 are turned on, and then the loop between the backup battery and the load to be powered is turned on, and power is supplied by the backup battery.

[0162] Furthermore, since the cathode of the fifth diode D5 in the switching subunit is connected to the second comparison unit, referring to Fig. 9 , Fig. 9 This is a circuit schematic diagram of the second comparison unit in the fourth embodiment of the power supply circuit of the present application, such as Fig. 9 As shown, in this embodiment, the second comparison unit further includes: an eleventh resistor R11 to a thirteenth resistor R13;

[0163] The second input terminal of the third chip U3 (i.e., the sixth pin of the third chip U3) is connected to the first end of the twelfth resistor R12 and the first end of the thirteenth resistor R13 respectively. The second end of the twelfth resistor R12 is also grounded. The second end of the thirteenth resistor R13 is connected to the backup battery (i.e., Fig. 9 The second output terminal of the third chip U3 (i.e., the third pin of the third chip U3) is connected to the cathode of the fifth diode D5 (i.e., Fig. 9 The second end of the eleventh resistor R11 is connected to the output end of the fourth chip U4 (ie, Fig. 9 MCU_3V3) connection.

[0164] It should be understood that, in this embodiment, the third preset voltage interval can be set by setting the resistance of the twelfth resistor R12 and the resistance of the thirteenth resistor R13. If the forward trigger voltage of the second channel is recorded as V rise2 , the negative trigger voltage is denoted as V fall2 ,but Wherein R12 is the resistance value of the twelfth resistor R12, R13 is the resistance value of the thirteenth resistor R13, V IT+ is the positive reference level, V IT- is the negative reference voltage, after calculation, we can get V rise2 and V fall2 , then the V rise2 As the upper limit of the third preset voltage interval, V fall2 As the lower limit value of the third preset voltage interval. In this embodiment, V rise2 Set to 4.21V, V fall2 Set to 4V. This can detect whether the backup voltage VBAT_CON is normal.

[0165] In actual use, the second input terminal of the third chip U3 can collect the backup voltage VBAT_CON and determine whether the backup voltage VBAT_CON is in the third preset voltage range, that is, whether it is within 4V≤VBAT_CON≤4.21V;

[0166] If the condition is positive, the second output terminal of the third chip U3 outputs a backup power supply signal HW_VBAT_CON (i.e. Figure 4 If HW_VBAT_CON is high level H) to the switching subunit; if not, the second output end of the third chip U3 stops outputting the backup power supply signal HW_VBAT_CON to the switching subunit, that is, the second output end of the third chip U3 is low level (that is Figure 4 HW_VBAT_CON is low level L).

[0167] Then, continue as Figure 8 As shown, when the main battery is normal and the backup battery is normal, the base of the second transistor Q2 does not receive the conversion signal COM_OUT, but receives the backup power supply signal HW_VBAT_CON, so the base of the second transistor Q2 is at a low level, the second transistor Q2 remains disconnected, and the loop between the backup battery and the load to be powered remains disconnected;

[0168] When the main battery is abnormal and the backup battery is normal, the base of the second transistor Q2 receives the conversion signal COM_OUT and the backup power supply signal HW_VBAT_CON, so the base of the second transistor Q2 is at a high level, the second transistor Q2 is turned on, the loop between the backup battery and the load to be powered is turned on, and the backup battery supplies power;

[0169] When the main battery and the backup battery are abnormal, the base of the second transistor Q2 receives the conversion signal COM_OUT but does not receive the backup power supply signal HW_VBAT_CON. Therefore, the base of the second transistor Q2 is at a low level, the second transistor Q2 remains disconnected, and the loop between the backup battery and the load to be powered remains disconnected.

[0170] Reference Fig.10 , Fig.10 This is a circuit schematic diagram of the first comparison unit in the fourth embodiment of the power supply circuit of the present application, such as Figure 8 and Fig.10 As shown, in order to enable the second chip U2 to collect the backup voltage, Figure 8 In the case of a backup battery, an analog-to-digital converter (i.e. Figure 8 The backup voltage is collected by the ADC and transmitted to the second chip U2 (i.e. Figure 8 In ADC2), Fig.10In the embodiment, the second input terminal of the second chip U2 (ie, the sixth pin of the second chip U2) can be connected to the analog-to-digital converter, so that the second chip U2 can collect the backup voltage VBAT_CON.

[0171] In actual use, when the second chip U2 determines that the backup voltage VBAT_CON=0V, and the output voltage 6V≤B+<9V or B+>16V, it means that it is necessary to force the main battery to supply power at this time, and then the first output end of the second chip U2 outputs the main power supply signal 5V_EN to the control end of the first chip U1, the main battery and the load to be powered are turned on to supply power, and the second output end of the second chip U2 outputs the first switching signal 5V_SW to the cathode of the fourth diode D4, and the first output end of the third chip U3 stops outputting the second switching signal HW_5V_SW, the first transistor Q1 is disconnected, the collector of the first transistor Q1 outputs the conversion signal COM_OUT to the first end of the seventh resistor R7, and the second output end of the third chip U3 stops outputting the backup power supply signal HW_VBAT_CON, and the cathode of the fifth diode D5 does not receive the backup power supply signal HW_VBAT_CON, the base of the second transistor Q2 remains at a low level, the second transistor Q2 is disconnected, the first MOS tube MOS1 and the second MOS tube MOS2 are disconnected, and the backup battery is not connected to the load to be powered.

[0172] Further, continue as Figure 8 and Fig.10 As shown, considering that the power supply voltage VDD_5V may have a momentary large load, which may trigger the first output end of the third chip U3 to stop outputting the second switching signal HW_5V_SW, thereby triggering the second transistor Q2 to turn on, but at this time, the backup battery is not needed to supply power. Therefore, in order to improve the reliability of the circuit, in this embodiment, the switching subunit further includes: a seventh diode D7;

[0173] An anode of the seventh diode D7 is connected to the first end of the seventh resistor R7 , and a cathode of the seventh diode D7 is connected to the third output end of the second chip U2 (ie, the fifth pin of the third chip U3 ).

[0174] It should be understood that the signal outputted by the third output terminal of the second chip U2 can be a backup switching signal, recorded as VBAT_CON / OFF_SW, which is at a high level when outputted. Furthermore, in actual use, the first comparison unit is also used to stop outputting the backup switching signal to the switching subunit when the output voltage is in the first preset voltage interval or the backup voltage reaches the preset backup voltage threshold;

[0175] The switching subunit is further used to disconnect the circuit between the backup battery and the load to be powered when the backup switching signal is not received.

[0176] Continue as Figure 4 As shown, when the second chip U2 determines that the output voltage is not within 9V≤B+≤16V and the backup voltage VBAT_CON is not 0V, the third pin of the second chip U2 outputs the backup switching signal VBAT_CON / OFF_SW to the switching subunit (i.e. Figure 4 VBAT_CON / OFF_SW is high level H), the collector and emitter of the second transistor Q2 are turned on, and the backup battery is powered;

[0177] When the second chip U2 determines that the output voltage is 9V≤B+≤16V, or the backup voltage VBAT_CON=0V, the third pin of the second chip U2 stops outputting the backup switching signal VBAT_CON / OFF_SW to the switching subunit (ie Figure 4 In the example, VBAT_CON / OFF_SW is at a low level L), since the base of the second transistor Q2 of the switching subunit does not receive the backup switching signal VBAT_CON / OFF_SW, the base of the second transistor Q2 is at a low level, and then the collector and emitter of the second transistor Q2 are disconnected, and the loop between the backup battery and the load to be powered is disconnected, thereby realizing power supply by the main battery, further improving reliability.

[0178] Reference Fig.11 , Fig.11 This is a structural schematic diagram of the fifth embodiment of the power supply circuit of the present application. Based on the above embodiments, the fifth embodiment of the power supply circuit of the present application is proposed.

[0179] In order to improve the reliability of the backup battery, the present embodiment can charge the backup battery so that the backup battery can be reused. Fig.11 As shown, in this embodiment, the circuit further includes: a charging module;

[0180] The charging module is respectively connected to the first comparison unit, the main battery and the backup battery;

[0181] The first comparison unit is further configured to output a charging signal to the charging module when the output voltage is within the first preset voltage interval;

[0182] The charging module is used to transmit the output voltage to the backup battery for charging when receiving the charging signal.

[0183] It should be noted that the charging module can be a module for charging the backup battery. In this embodiment, the first comparison unit can also determine whether the output voltage B+ of the main battery is normal, that is, whether it is in the range of 9V≤B+≤16V; when it is not in the range of 9V≤B+≤16V, it indicates that the main battery is abnormal, and the first comparison unit does not output a charging signal to the charging module. When the charging module does not receive the charging signal, it does not charge the backup battery; when it is in the range of 9V≤B+≤16V, it indicates that the main battery is normal, and the first comparison unit outputs a charging signal to the charging module. After receiving the charging signal, the charging module starts to charge the backup battery.

[0184] It should be emphasized that when determining whether the backup battery needs to be charged, a periodic charging method can be adopted, that is, after the first comparison unit determines that the output voltage is in the above-mentioned first preset voltage range, it can output a charging signal to the charging module at a preset time interval, so that the charging module can charge the backup battery regularly.

[0185] As another implementation method, the first comparison unit can also determine whether the voltage value of the backup voltage reaches a preset charging threshold after determining that the output voltage is in the above-mentioned first preset voltage interval; if reached, it can indicate that the backup battery needs to be charged, that is, the first comparison unit outputs a charging signal to the charging module; if not reached, it can indicate that charging is not required at this time, that is, the first comparison unit does not output a charging signal to the charging module.

[0186] Furthermore, to improve safety, Fig.11 As shown, in this embodiment, the charging module includes: a first protection unit, a charging unit and a second protection unit;

[0187] The first protection unit is connected to the first comparison unit, the main battery and the charging unit respectively, and the second protection unit is connected to the first comparison unit, the backup battery and the charging unit respectively;

[0188] The first comparison unit is used to output a first charging signal to the first protection unit and output a second charging signal to the second protection unit when the output voltage is within the first preset voltage interval;

[0189] The first protection unit is configured to transmit the output voltage to the charging unit upon receiving the first charging signal;

[0190] The charging unit is used to convert the output voltage into a charging voltage, and transmit the charging voltage to the second protection unit;

[0191] The second protection unit is used to transmit the charging voltage to the backup battery for charging when receiving the second charging signal.

[0192] It is understandable that the first protection unit and the second protection unit may be provided with a switch. The charging unit may be a unit that converts the output voltage of the main battery into a charging voltage suitable for charging the backup battery.

[0193] In actual use, when the first comparison unit determines that the output voltage is not within the first preset voltage interval, no first charging signal and no second charging signal are output, and the first protection unit remains disconnected when the first charging signal is not received, and the second protection unit remains disconnected when the second charging signal is not received;

[0194] When the first comparison unit determines that the output voltage is within the first preset voltage range, it can output a first charging signal to the first protection unit and a second charging signal to the second protection unit. After receiving the first charging signal, the first protection unit turns on the circuit between the main battery and the charging unit. After receiving the second charging signal, the second protection unit turns on the circuit between the charging unit and the backup battery, thereby charging the backup battery.

[0195] Further, continue as Fig.11 As shown, in this embodiment, the charging unit includes: a voltage stabilizing subunit and a constant current subunit;

[0196] The voltage stabilizing subunit is connected to the first protection unit and the constant current subunit respectively, and the constant current subunit is connected to the second protection unit;

[0197] The voltage stabilizing subunit is used to stabilize the output voltage and transmit the stabilized output voltage to the constant current subunit;

[0198] The constant current subunit is used to perform constant current on the stabilized output voltage and transmit the obtained charging voltage to the second protection unit.

[0199] It should be understood that the voltage stabilizing subunit may be provided with a device for voltage stabilization, and the constant current subunit may be provided with a device for constant current.

[0200] In actual use, after the first protection unit transmits the output voltage to the voltage stabilizing subunit, the voltage stabilizing subunit can stabilize the output voltage and transmit the stabilized output voltage to the constant current subunit. The constant current subunit then performs constant current on the stabilized output current to obtain a charging voltage, and then transmits the charging voltage to the backup battery through the second protection unit for charging.

[0201] Reference Fig.12 , Fig.12 This is a circuit schematic diagram of a charging module in a sixth embodiment of a power supply circuit of the present application. Based on the above embodiments, a sixth embodiment of a power supply circuit of the present application is proposed.

[0202] like Fig.12 As shown, in this embodiment, the first protection subunit includes: a third transistor Q3, a third MOS transistor MOS3, a seventh capacitor C7, an eighth capacitor C8, an eighth diode D8, a ninth diode D9 and fourteenth resistors R14 to seventeenth resistors R17;

[0203] The first end of the seventh capacitor C7 is respectively connected to the main battery, the cathode of the eighth diode D8, the first end of the seventeenth resistor R17 and the source of the third MOS transistor MOS3, the second end of the seventh capacitor C7 is grounded, the anode of the eighth diode D8 is respectively connected to the second end of the seventeenth resistor R17, the first end of the sixteenth resistor R16 and the gate of the third MOS transistor MOS3, the second end of the sixteenth resistor R16 is connected to the collector of the third triode Q3, the base of the third triode Q3 is respectively connected to the second end of the fourteenth resistor R14 and the first end of the fifteenth resistor R15, the first end of the fourteenth resistor R14 is connected to the first comparison unit (i.e. Fig.11 The first end of the 15th resistor R15 is connected to the emitter of the third triode Q3, the emitter of the third triode Q3 is also grounded, and the drain of the third MOS tube MOS3 is respectively connected to the first end of the eighth capacitor C8, the cathode of the ninth diode D9 and the first comparison unit (i.e. Fig.11 A second end of the eighth capacitor C8 is connected to an anode of a ninth diode D9, and an anode of the ninth diode D9 is also grounded.

[0204] It should be noted that the eighth diode D8 and the ninth diode D9 can be voltage regulators to clamp the output voltage within a set safety range. The third MOS tube MOS3 can be a P-channel MOS tube.

[0205] It is understandable that if the first charging signal is recorded as CH_PWR_EN, it is at a high level when output. Figure 4 When the main battery is in the first preset voltage range, the main battery is normal, and the first comparison unit can output the first charging signal CH_PWR_EN according to whether charging is needed. When the first charging signal CH_PWR_EN is output, it can be a high level (i.e. Figure 4 When the first charging signal CH_PWR_EN is high level H), when the first charging signal CH_PWR_EN is not output, it can be low level (i.e. Figure 4 When the main battery is not in the first preset voltage range, the first charging signal CH_PWR_EN is not output.

[0206] When the first end of the fourteenth resistor R14 does not receive the first charging signal CH_PWR_EN, the collector and emitter of the third triode Q3 remain disconnected, the gate of the third MOS tube MOS3 remains at a high level, and the third MOS tube MOS3 remains disconnected; when the first end of the fourteenth resistor R14 receives the first charging signal CH_PWR_EN, the collector and emitter of the third triode Q3 are turned on, the gate of the third MOS tube MOS3 is grounded at a low level, and the third MOS tube MOS3 is turned on, thereby transmitting the output voltage B+ of the main battery to the voltage stabilizing sub-unit.

[0207] Furthermore, the voltage stabilizing subunit includes: a fifth chip U5, a ninth capacitor C9, a tenth capacitor C10, an eighteenth resistor R18 and a nineteenth resistor R19;

[0208] The first end of the ninth capacitor C9 is respectively connected to the drain of the third MOS tube MOS3 and the input end of the fifth chip U5 (i.e., the first pin of the fifth chip U5), the second end of the ninth capacitor C9 is grounded, the grounding end of the fifth chip U5 (i.e., the fourth pin of the fifth chip U5) is grounded, and the first output end of the fifth chip U5 (i.e., the second pin of the fifth chip U5) is respectively connected to the first end of the eighteenth resistor R18, the first end of the tenth capacitor C10, the first comparison unit (i.e., Fig.11 The second output terminal of the fifth chip U5 (i.e., the third pin of the fifth chip U5) is respectively connected to the second end of the eighteenth resistor R18 and the first end of the nineteenth resistor R19, the second end of the nineteenth resistor R19 is grounded, and the second end of the tenth capacitor C10 is grounded.

[0209] It should be understood that the fifth chip U5 may be a chip with a voltage stabilization function, and this embodiment may be described using a voltage stabilizer of model LP2951D. In addition, this embodiment may configure the output voltage through the resistance values ​​of the eighteenth resistor R18 and the nineteenth resistor R19.

[0210] In actual use, the drain of the third MOS tube MOS3 transmits the output voltage to the input end of the fifth chip U5. After being stabilized by the fifth chip U5, the stabilized output voltage is transmitted to the constant current sub-unit.

[0211] Furthermore, the above-mentioned constant current subunit includes: a sixth chip U6, a twentieth resistor R20, a tenth diode D10, an eleventh capacitor C11 and a twelfth capacitor C12;

[0212] The input end of the sixth chip U6 (i.e., the first pin of the sixth chip U6) is connected to the first output end of the fifth chip U5, the ground end of the sixth chip U6 (i.e., the fourth pin of the sixth chip U6) is grounded, the first output end of the sixth chip U6 is connected to the first end of the twentieth resistor R20, the second end of the twentieth resistor R20 is respectively connected to the second output end of the sixth chip U6 (i.e., the third pin of the sixth chip U6), the first end of the eleventh capacitor C11 and the anode of the tenth diode D10, the second end of the eleventh capacitor C11 is grounded, the cathode of the tenth diode D10 is respectively connected to the first comparison unit (i.e., Fig.11 V_CH_ON), ​​a first end of the twelfth capacitor C12 and the second protection unit are connected, and a second end of the twelfth capacitor C12 is grounded.

[0213] It should be noted that the sixth chip U6 may be a chip with a constant current function. In this embodiment, a voltage regulator of model LM317 may be used, and the constant current output by the sixth chip U6 may be set by the resistance value of the twentieth resistor R20. If the constant current for charging the backup battery is recorded as I ch ,but Where V ref is the fixed reference voltage value generated inside the sixth chip U6, R 20 is the resistance value of the twentieth resistor R20. In this embodiment, the fixed value V generated inside the sixth chip U6 can be used. ref , and within the maximum charging current range of the battery charging limit, R 20 Set to 24Ω, and then you can get I ch It is 52mA.

[0214] It should be emphasized that the twentieth resistor R20 can be a resistor with a relatively large power, or multiple resistors can be connected in parallel to have a resistance value equal to that of the twentieth resistor R20 to disperse the dissipated power of the resistor, which is not limited in this embodiment. In addition, this embodiment can achieve unidirectional isolation through the tenth diode D10 to prevent current backflow.

[0215] Further, the second protection unit includes: a fourth transistor Q4, a fourth MOS transistor MOS4, a thirteenth capacitor C13, a fourteenth capacitor C14, an eleventh diode D11, a twelfth diode D12, and twenty-first resistors R21 to twenty-fourth resistors R24;

[0216] The first end of the thirteenth capacitor C13 is respectively connected to the cathode of the tenth diode D10, the cathode of the eleventh diode D11, the first end of the twenty-fourth resistor R24 ​​and the source of the fourth MOS transistor MOS4, the second end of the thirteenth capacitor C13 is grounded, the anode of the eleventh diode D11 is respectively connected to the second end of the twenty-fourth resistor R24, the first end of the twenty-third resistor R23 and the gate of the fourth MOS transistor MOS4, the second end of the twenty-third resistor R23 is connected to the collector of the fourth transistor Q4, the base of the fourth transistor Q4 is respectively connected to the second end of the twenty-first resistor R21 and the first end of the twenty-second resistor R22, the first end of the twenty-first resistor R21 is connected to the first comparing unit (i.e. Fig.11 The second end of the twenty-second resistor R22 is connected to the emitter of the fourth triode Q4, the emitter of the fourth triode Q4 is also grounded, and the drain of the fourth MOS tube MOS4 is respectively connected to the first end of the fourteenth capacitor C14, the cathode of the twelfth diode D12 and the first comparison unit (i.e. Fig.11 A second end of the fourteenth capacitor C14 is connected to an anode of the twelfth diode D12, and the anode of the twelfth diode D12 is also grounded.

[0217] It should be noted that the eleventh diode D11 and the twelfth diode D12 may be voltage regulators to clamp the output voltage within a set safety range. The fourth MOS transistor MOS4 may be a P-channel MOS transistor.

[0218] It is understandable that if the second charging signal is recorded as CH_EN, it is at a high level when output. Figure 4 When the main battery is in the first preset voltage range, the main battery is normal, and the first comparison unit can output the second charging signal CH_EN according to whether charging is needed. When the second charging signal CH_EN is output, it can be a high level (i.e. Figure 4 When the second charging signal CH_EN is not output, it can be a low level (i.e. Figure 4 When the main battery is not in the first preset voltage range, the second charging signal CH_EN is not output.

[0219] When the first end of the twenty-first resistor R21 does not receive the second charging signal CH_EN, the collector and emitter of the fourth transistor Q4 remain disconnected, the gate of the fourth MOS tube MOS4 remains at a high level, and the fourth MOS tube MOS4 remains disconnected; when the first end of the twenty-first resistor R21 receives the second charging signal CH_EN, the collector and emitter of the fourth transistor Q4 are turned on, the gate of the fourth MOS tube MOS4 is grounded at a low level, and the fourth MOS tube MOS4 is turned on, thereby transmitting the charging voltage to the backup battery for charging.

[0220] Reference Fig.13 , Fig.13 This is a circuit schematic diagram of the first comparison unit in the sixth embodiment of the power supply circuit of the present application, such as Fig.13 As shown, the fourth output terminal of the second chip U2 (ie, the seventh pin of the second chip U2) can be connected to the first end of the fourteenth resistor R14 (ie, Fig.13 The fifth output terminal of the second chip U2 (i.e., the ninth pin of the second chip U2) can be connected to the first end of the twenty-first resistor R21 (i.e., Fig.13 The third input terminal of the second chip U2 (i.e., the eighth pin of the second chip U2) can be connected to the drain of the third MOS tube MOS3 (i.e., Fig.13 The fourth input terminal of the second chip U2 (i.e., the tenth pin of the second chip U2) can be connected to the first output terminal of the fifth chip U5 (i.e., Fig.13 The fifth input terminal of the second chip U2 (ie, the eleventh pin of the second chip U2) can be connected to the cathode of the tenth diode D10 (ie, Fig.13 The sixth input terminal of the second chip U2 (i.e., the twelfth pin of the second chip U2) can be connected to the drain of the fourth MOS tube MOS4 (i.e., Fig.13 V_BAT_CON) connection.

[0221] In actual use, the second chip U2 may output the first charging signal CH_PWR_EN through the fourth output terminal of the second chip U2, and output the second charging signal CH_EN through the fifth output terminal of the second chip U2;

[0222] The second chip U2 can also collect the output voltage output by the first protection unit through the third input terminal of the second chip U2 to determine whether the output voltage is overloaded; the stabilized output voltage output by the voltage stabilizing subunit can be collected through the fourth input terminal of the second chip U2 to detect whether the voltage stabilizing subunit is normal; the charging voltage output by the constant current subunit can be collected through the fifth input terminal of the second chip U2 to detect whether the constant current subunit is normal; the charging voltage output by the second protection unit can be collected through the sixth input terminal of the second chip U2 to detect whether the output of the second protection unit is normal.

[0223] In addition, to achieve the above-mentioned purpose, an embodiment of the present application further provides an electronic device, which includes the power supply circuit as described above.

[0224] Other embodiments or specific implementation methods of the electronic device of the present application can refer to the embodiments of the above-mentioned power supply circuits, which will not be described in detail here.

[0225] The above are only preferred embodiments of the present application, and are not intended to limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A power supply circuit, characterized in that: The circuit comprises: a main battery, a backup battery, a conversion module and a hysteresis switching module; The conversion module is respectively connected to the load to be powered, the main battery and the hysteresis switching module, and the hysteresis switching module is also connected to the main battery, the backup battery and the load to be powered; The conversion module is used to convert the output voltage of the main battery into a supply voltage, and transmit the supply voltage to the load to be powered for power supply; The hysteresis switching module is used to collect the output voltage and the supply voltage, and when the output voltage is not within a first preset voltage range and / or the supply voltage is not within a second preset voltage range, disconnect the loop between the main power supply and the load to be powered, and connect the loop between the backup power supply and the load to be powered to supply power.

2. The power supply circuit according to claim 1, characterized in that: The hysteresis switching module includes: a first comparison unit, a second comparison unit and a switching unit; The first comparison unit is respectively connected to the main battery, the conversion module, the switching unit and the second comparison unit, the second comparison unit is respectively connected to the conversion module and the switching unit, and the switching unit is respectively connected to the backup battery and the load to be powered; The first comparison unit is used to collect the output voltage, and when the output voltage is not within the first preset voltage interval, stop outputting the first switching signal to the switching unit, and stop outputting the main power supply signal to the conversion module; The second comparing unit is used to collect the supply voltage, and stop outputting the second switching signal to the switching unit when the supply voltage is not within a second preset voltage range; The conversion module is used to disconnect the circuit between the main battery and the load to be powered and stop converting the output voltage into the supply voltage when the main power supply signal is not received; The switching unit is used to switch on the circuit between the backup battery and the load to be powered to supply power when the first switching signal and / or the second switching signal is not received.

3. The power supply circuit according to claim 2, characterized in that: The switching unit comprises: a conversion subunit and a switching subunit; The conversion subunit is respectively connected to the first comparison unit, the second comparison unit and the switching subunit, and the switching subunit is respectively connected to the backup battery and the load to be powered; The conversion subunit is configured to output a conversion signal to the switching subunit when the first switching signal is not received and / or the second switching signal is not received; The switching subunit is used to conduct the circuit between the backup battery and the load to be powered to supply power when receiving the conversion signal.

4. The power supply circuit according to claim 3, characterized in that: The second comparison unit is also connected to the backup battery and the switching subunit respectively; The second comparison unit is further used to collect the backup voltage output by the backup battery, and output a backup power supply signal to the switching subunit when the backup voltage is within a third preset voltage range; The switching subunit is further used to conduct the circuit between the backup battery and the load to be powered to supply power when receiving the conversion signal and the backup power supply signal.

5. The power supply circuit according to claim 4, characterized in that: The first comparison unit is also connected to the backup battery and the switching subunit; The first comparison unit is also used to collect the backup voltage and, when the backup voltage reaches a preset backup voltage threshold, output the main power supply signal to the conversion module, so that the conversion module switches on the circuit between the main battery and the load to be powered for power supply when receiving the main power supply signal.

6. The power supply circuit according to claim 5, characterized in that: The second comparison unit is further configured to stop outputting the second switching signal to the conversion subunit when the backup voltage reaches the preset backup voltage threshold and the output voltage is within a fourth preset voltage interval, so that the conversion subunit outputs the conversion signal to the switching subunit; The switching subunit is further configured to disconnect the circuit between the backup battery and the load to be powered when the switching signal is received but the backup power supply signal is not received.

7. The power supply circuit according to any one of claims 2 to 6, characterized in that: The circuit further comprises: a charging module; The charging module is respectively connected to the first comparison unit, the main battery and the backup battery; The first comparison unit is further configured to output a charging signal to the charging module when the output voltage is within the first preset voltage interval; The charging module is used to transmit the output voltage to the backup battery for charging when receiving the charging signal.

8. The power supply circuit according to claim 7, characterized in that: The charging module includes: a first protection unit, a charging unit and a second protection unit; The first protection unit is connected to the first comparison unit, the main battery and the charging unit respectively, and the second protection unit is connected to the first comparison unit, the backup battery and the charging unit respectively; The first comparison unit is used to output a first charging signal to the first protection unit and output a second charging signal to the second protection unit when the output voltage is within the first preset voltage interval; The first protection unit is configured to transmit the output voltage to the charging unit upon receiving the first charging signal; The charging unit is used to convert the output voltage into a charging voltage, and transmit the charging voltage to the second protection unit; The second protection unit is used to transmit the charging voltage to the backup battery for charging when receiving the second charging signal.

9. The power supply circuit according to claim 8, characterized in that: The charging unit comprises: a voltage stabilizing subunit and a constant current subunit; The voltage stabilizing subunit is connected to the first protection unit and the constant current subunit respectively, and the constant current subunit is connected to the second protection unit; The voltage stabilizing subunit is used to stabilize the output voltage and transmit the stabilized output voltage to the constant current subunit; The constant current subunit is used to perform constant current on the stabilized output voltage and transmit the obtained charging voltage to the second protection unit.

10. An electronic device, characterized in that: The electronic device comprises the power supply circuit according to any one of claims 1 to 9.

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