Anti-power-off circuit and corresponding handheld device

Abstract

The present invention provides an anti-power-off circuit and a corresponding handheld device, wherein a main battery can output a first voltage, and a supercapacitor can output a second voltage. A voltage conversion module can perform a voltage conversion operation on the second voltage to generate a third voltage, and a voltage value of the third voltage is less than a voltage value of the first voltage. When the anti-power-off circuit works normally, the first voltage can supply power to the internal circuit of the handheld device. When the main battery has poor contact or the main battery is hot-plugged, the third voltage can supply power to the internal circuit of the handheld device. A voltage divider module can perform a voltage divider operation on the second voltage to generate a detection voltage. The device platform receives the detection voltage, and based on the detection voltage being less than a set value, the device platform outputs a control signal. The secondary battery charging module can perform a voltage stabilization operation on the power supply voltage output by the power supply based on the control signal to generate a charging voltage. Among them, the charging voltage can charge the supercapacitor.

Description

Technical Field

[0001] The present invention relates to the field of circuit technology, and in particular to an anti-power-off circuit and a corresponding handheld device. Background Art

[0002] In modern society, the main and auxiliary battery power supply circuits are often detected and controlled by software, so as to select the main battery or the auxiliary battery for power supply. When the main battery falls, the power supply circuit can be actively switched to be powered by the auxiliary battery. However, software detection and control require a certain amount of time. During this period of time, the device will be powered off for a short period of time, which may easily cause the loss of system data. Therefore, there is a technical problem that the existing main and auxiliary battery power supply circuits are prone to cause system data loss.

[0003] Therefore, it is necessary to provide an anti-power-off circuit and a corresponding handheld device to solve the above technical problems. Summary of the invention

[0004] The present invention provides a power-off prevention circuit and a corresponding handheld device, which effectively solves the technical problem that the existing main and auxiliary battery power supply circuits easily cause system data loss.

[0005] The present invention provides a power-off prevention circuit, which comprises:

[0006] A main battery, configured to output a first voltage;

[0007] A supercapacitor, configured to output a second voltage;

[0008] a voltage conversion module, connected to the supercapacitor, and configured to perform a voltage conversion operation on the second voltage to generate a third voltage, wherein a voltage value of the third voltage is smaller than a voltage value of the first voltage;

[0009] When the anti-power-off circuit works normally, the first voltage is used to power the internal circuit of the handheld device; when the main battery has poor contact or is hot-swapped, the third voltage is used to power the internal circuit of the handheld device;

[0010] a voltage dividing module, one end of which is connected to the supercapacitor and the other end of which is connected to the device platform, and the voltage dividing module is used to perform a voltage dividing operation on the second voltage to generate a detection voltage;

[0011] The device platform receives the detection voltage, and based on the detection voltage being less than a set value, the device platform outputs a control signal;

[0012] A secondary battery charging module, one end of which is connected to the device platform and the power supply, and the other end of which is connected to the supercapacitor, is used to stabilize the power voltage output by the power supply based on the control signal to generate a charging voltage, wherein the charging voltage is used to charge the supercapacitor.

[0013] In the anti-power-off circuit of the present invention, the voltage conversion module includes a voltage conversion chip, the voltage conversion chip includes a voltage conversion input pin and a voltage conversion output pin, the voltage conversion input pin is connected to the supercapacitor, the voltage conversion input pin is used to input the second voltage, the voltage conversion chip is used to perform a voltage conversion operation on the second voltage to generate a third voltage, the voltage conversion output pin is connected to the internal circuit of the handheld device, and the voltage conversion output pin is used to output the third voltage.

[0014] In the anti-power-off circuit of the present invention, the secondary battery charging module includes a charging chip, and the charging chip includes a charging input pin, a charging output pin and a charging control pin. The charging input pin is connected to the power supply, and the charging control pin is connected to the device platform. The charging input pin is used to receive the power supply voltage, and the charging control pin is used to receive the control signal. The charging chip is used to stabilize the power supply voltage output by the power supply based on the control signal to generate a charging voltage. The charging output pin is connected to the supercapacitor, and the charging output pin is used to output the charging voltage.

[0015] In the anti-power-off circuit of the present invention, the secondary battery charging module also includes a voltage limiting unit, one end of the voltage limiting unit is connected to the charging output pin, the other end of the voltage limiting unit is grounded, and the voltage limiting unit is used to limit the voltage value of the charging voltage.

[0016] In the anti-power-off circuit of the present invention, the secondary battery charging module also includes a current limiting unit, one end of the current limiting unit is connected to the charging output pin, and the other end of the current limiting unit is connected to the supercapacitor, and the current limiting unit is used to perform current limiting protection on the charging of the supercapacitor.

[0017] In the anti-power-off circuit of the present invention, the secondary battery charging module also includes a filtering unit, one end of the filtering unit is connected to the power supply and the charging input pin, and the other end of the filtering unit is grounded, and the filtering unit is used to filter the power supply voltage.

[0018] In the anti-power-off circuit of the present invention, the voltage conversion module includes a diode, the positive electrode of the diode is connected to the voltage conversion output pin, and the negative electrode of the diode is connected to the internal circuit of the handheld device. The diode is used to prevent the first voltage output by the main battery from reversely charging the voltage conversion chip and the supercapacitor.

[0019] In the anti-power-off circuit of the present invention, the model of the voltage conversion chip is SGM6623YN6G / TR, and the model of the charging chip is SGM2036-ADJYN5G / TR.

[0020] A power-off prevention circuit, comprising:

[0021] A main battery, configured to output a first voltage;

[0022] A supercapacitor, configured to output a second voltage, wherein a voltage value of the second voltage is less than a voltage value of the first voltage;

[0023] A voltage dividing module, connected to the main battery, for performing a voltage dividing operation on the first voltage to generate a measurement voltage;

[0024] The device platform is used to output an enable signal, wherein the enable signal is used to enable the TPS2121 chip;

[0025] The TPS2121 chip includes an IN1 pin, an IN2 pin, a CP2 pin, a PR1 pin and an OUT pin, wherein the IN1 pin is connected to a main battery, the IN1 pin is used to input a first voltage, the IN2 pin is connected to the supercapacitor, the IN2 pin is used to input a second voltage, the PR1 pin is connected to the voltage divider module, the CP2 pin is connected to the device platform, the CP2 pin is used to receive the enable signal, the PR1 pin is used to input the measured voltage, the TPS2121 chip is used to select the first voltage or the second voltage based on a comparison result between the measured voltage and a set voltage, the OUT pin is used to output the first voltage or the second voltage, and the first voltage or the second voltage is used to power an internal circuit of a handheld device;

[0026] Among them, when the measured voltage is greater than the set voltage, the TPS2121 chip selects the first voltage, so that the OUT pin outputs the first voltage; or when the measured voltage is less than the set voltage, the TPS2121 chip selects the second voltage, so that the OUT pin outputs the second voltage.

[0027] A handheld device, comprising any of the above-mentioned anti-power-off circuits, the handheld device also comprising a first circuit board and a second circuit board, the anti-power-off circuit being arranged on the first circuit board and the second circuit board, the main battery and the device platform being arranged on the first circuit board, the second circuit board being electrically connected to the first circuit board, and the supercapacitor, the voltage conversion module, the voltage divider module and the secondary battery charging module being arranged on the second circuit board.

[0028] Compared with the prior art, the present invention has the following beneficial effects: the present invention provides an anti-power-off circuit, which is provided with a main battery, a super capacitor, a voltage conversion module, a voltage dividing module, a device platform and a secondary battery charging module. The main battery is used to output a first voltage, and the super capacitor is used to output a second voltage. The voltage conversion module can perform a voltage conversion operation on the second voltage, and the voltage conversion module can generate a third voltage. The voltage value of the third voltage is less than the voltage value of the first voltage, and the third voltage and the first voltage can simultaneously power the internal circuit of the handheld device. Therefore, when the anti-power-off circuit works normally, the first voltage is used to power the internal circuit of the handheld device. When the main battery has poor contact or the main battery is hot-plugged, the third voltage can power the internal circuit of the handheld device in time. Therefore, the device can remain in a standby state for a long time. Furthermore, the device will not be powered off in a short time, thereby causing the loss of system data. The technical problem that the existing main and secondary battery power supply circuits are prone to cause system data loss is effectively solved.

[0029] The voltage divider module is used to divide the second voltage, and the voltage divider module can generate a detection voltage. The device platform receives the detection voltage, and based on the detection voltage being less than a set value, the device platform outputs a control signal. The secondary battery charging module can stabilize the power voltage output by the power supply based on the control signal, and the secondary battery charging module can generate a charging voltage, and the charging voltage is used to charge the supercapacitor. The setting of the secondary battery charging module can enable the supercapacitor to maintain sufficient power for a long time. When the main battery has poor contact or the main battery is hot-swapped, the supercapacitor can instantly power the internal circuit of the handheld device. Therefore, the handheld device can maintain a stable working state for a long time without sudden power outages. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. The drawings described below are only drawings corresponding to some embodiments of the present invention.

[0031] Figure 1 FIG. 4 is a block diagram of a first embodiment of a power-off protection circuit according to the present invention.

[0032] Figure 2 FIG. 1 is a circuit diagram of the first embodiment of the anti-power-off circuit of the present invention.

[0033] Figure 3 This is the second circuit diagram of the first embodiment of the anti-power-off circuit of the present invention.

[0034] Figure 4 FIG. 2 is a schematic diagram of the circuit structure of the second embodiment of the power-off protection circuit of the present invention.

[0035] In the figure, 10, anti-power-off circuit; 11, main battery; 12, super capacitor; 13, voltage conversion module; 14, voltage divider module; 15, device platform; 16, auxiliary battery charging module; 161, voltage limiting unit; 162, current limiting unit; 163, filtering unit; 17, first circuit board; 171, first pin; 172, second pin; 173, third pin; 174, first power supply pin; 175, first interrupt pin; 18, second circuit board; 181, first pin; 182, second pin; 183, third pin; 184, second power supply pin; 185, second interrupt pin; 19, internal circuit of handheld device; 20, anti-power-off circuit; 21, main battery; 22, super capacitor; 23, voltage divider module; 24, device platform; 25, internal circuit of handheld device. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0037] The directional terms mentioned in the present invention, such as "up", "down", "front", "back", "left", "right", "inside", "outside", "side", "top" and "bottom", are only for reference to the orientation of the drawings. The directional terms used are used to illustrate and understand the present invention, but not to limit the present invention.

[0038] The terms "first", "second", etc. in the present invention are used for descriptive purposes only and should not be understood as indicating or implying relative importance, and should not be used as a limitation on the order of precedence.

[0039] In the figures, structurally similar elements are denoted by the same reference numerals.

[0040] Please refer to Figure 1 , Figure 2 and Figure 3 The following is a detailed description of the first embodiment of the anti-power-off circuit 10 of the present invention:

[0041] The present invention provides an anti-power-off circuit 10, which includes a main battery 11, a super capacitor 12, a voltage conversion module 13, a voltage dividing module 14, a device platform 15 and a secondary battery charging module 16. The main battery is connected to the internal circuit 19 of the handheld device, the main battery 11 is used to output a first voltage, and the super capacitor 12 is used to output a second voltage. The super capacitor 12 replaces the battery as the secondary battery, and a large capacitor with a common 2.7V and a capacitance of more than 10 farads on the market can be selected. The super capacitor 12 is sufficient to support the device to standby for several minutes in the screen-off state. The voltage conversion module 13 is connected to the super capacitor 12, and the voltage conversion module 13 is used to perform a voltage conversion operation on the second voltage, and the voltage conversion module 13 can generate a third voltage. In addition, the voltage value of the third voltage is less than the voltage value of the first voltage. When the anti-power-off circuit 10 works normally, the first voltage is used to power the internal circuit 19 of the handheld device. When the main battery 11 has poor contact or the main battery 11 is hot-swapped, the third voltage is used to power the internal circuit 19 of the handheld device.

[0042] Please refer to Figure 1 , Figure 2 and Figure 3 , one end of the voltage divider module 14 is connected to the supercapacitor 12, and the other end of the voltage divider module 14 is connected to the device platform 15. The voltage divider module 14 can perform a voltage divider operation on the second voltage, and the voltage divider module 14 can generate a detection voltage. The device platform 15 receives the detection voltage, and based on the detection voltage being less than the set value, the device platform 15 can output a control signal. One end of the secondary battery charging module 16 is connected to the device platform and the power supply VBAT, and the other end of the secondary battery charging module 16 is connected to the supercapacitor 12. The secondary battery charging module 16 can perform a voltage stabilization operation on the power supply voltage output by the power supply VBAT based on the control signal, so that the secondary battery charging module 16 can generate a charging voltage. Among them, the charging voltage is used to charge the supercapacitor 12.

[0043] In the prior art, the main and auxiliary batteries are directly connected in parallel. Thus, when the main battery is disconnected, the auxiliary battery can be directly powered. However, such direct parallel connection will cause the two batteries to consume power at the same time. When the auxiliary battery is low in power, the power of the auxiliary battery may not be able to support the operation of the system. Secondly, when the device is charging, it is equivalent to charging the main and auxiliary batteries at the same time. The current charged to the auxiliary battery cannot be controlled, which has certain safety hazards. In this solution, the voltage value of the third voltage is less than the voltage value of the first voltage. Therefore, when the main battery 11 has poor contact or the main battery 11 is hot-plugged, the supercapacitor 12 will power the internal circuit 19 of the handheld device. It can effectively avoid the situation where the two batteries consume power at the same time, and it can also effectively avoid the situation where the auxiliary battery is low in power. The user can hot-plug the main battery 11 to charge the main battery 11. Based on the detection voltage being less than the set value, the device platform 15 outputs a control signal to control the auxiliary battery, effectively avoiding the situation where the main and auxiliary batteries are charged at the same time.

[0044] In the prior art, the battery and battery cover of the device are integrated. When the existing solution is used to hot-swap the main battery, the device will lose power. However, when the solution of the present invention is used, the handheld device can maintain a normal working state by hot-swapped main battery, so that the handheld device can ensure that system data is not lost. When the device falls from a low height, the system does not have time to detect the falling state, and the main battery has already had poor contact. When the existing main and auxiliary battery power supply solution is used, the device will lose power. However, when the solution of the present invention is used, when the device falls from a low height, the handheld device can maintain a normal working state, and the handheld device can also ensure that system data is not lost.

[0045] Please refer to Figure 1 , Figure 2 and Figure 3The handheld device further includes a first circuit board 17 and a second circuit board 18, and the anti-power-off circuit 10 is arranged on the first circuit board 17 and the second circuit board 18. Among them, the second circuit board 18 is electrically connected to the first circuit board 17. The first circuit board 17 is provided with a main battery 11 and a device platform 15, and the second circuit board 18 is provided with a supercapacitor 12, a voltage conversion module 13, a voltage dividing module 14 and a secondary battery charging module 16. In order to facilitate the maintenance of production materials, the circuit sets the relevant modules of the supercapacitor 12 on the second circuit board 18. When the relevant modules of the supercapacitor 12 are damaged, the user only needs to maintain the second circuit board 18. When the relevant modules of the main battery 11 are damaged, the user only needs to maintain the first circuit board 17, which can effectively save the time and cost of subsequent maintenance of the circuit board. Such a circuit arrangement does not require the production of a large area of ​​circuit boards, which can save the production cost of the circuit boards. In this way, the first circuit board 17 only needs to leave an interface, which can be compatible with two configurations with and without secondary batteries, thereby increasing the scope of use of the first circuit board 17. Moreover, the first circuit board 17 is compatible with two configurations without the need for material changes.

[0046] Please refer to Figure 1 , Figure 2 and Figure 3 The voltage conversion module 13 includes a voltage conversion chip U1, and the model of the voltage conversion chip U1 is SGM6623YN6G / TR. The voltage conversion chip U1 includes a voltage conversion input pin SW and a voltage conversion output pin VS, and the voltage conversion input pin SW is connected to the supercapacitor 12. The voltage conversion input pin SW is used to input the second voltage, and the voltage conversion chip U1 is used to perform a voltage conversion operation on the second voltage, and the voltage conversion chip U1 can generate a third voltage. The voltage conversion output pin VS is connected to the internal circuit of the handheld device and the positive electrode of the main battery 11, and the voltage conversion output pin VS is used to output the third voltage.

[0047] SGM6623YN6G / TR is a universal micro-boost DC switching regulator with high efficiency. The efficiency of the chip is as high as 90%. The input voltage range of the regulator is 0.8V-12V, and the output voltage range of the regulator is 3.3V-13V. In addition, the regulator also has a variety of built-in protection functions, such as cycle-by-cycle overcurrent limiting, soft start, thermal shutdown and open-loop overvoltage protection.

[0048] Please refer to Figure 1 , Figure 2 and Figure 3The voltage conversion module 13 includes a diode D1, the positive electrode of the diode D1 is connected to the voltage conversion output pin VS, the negative electrode of the diode D1 is connected to the internal circuit of the handheld device, and the diode D1 is used to prevent the first voltage output by the main battery 11 from reversely charging the voltage conversion chip U1 and the super capacitor 12. Therefore, the setting of the diode D1 effectively protects the voltage conversion chip U1 and the super capacitor 12. It can prevent the large voltage output by the main battery 11 from damaging the voltage conversion chip U1 and the super capacitor 12, which is beneficial to improve the service life of the voltage conversion chip U1 and the super capacitor 12.

[0049] Please refer to Figure 1 , Figure 2 and Figure 3 , the voltage conversion module 13 also includes a resistor R4 and a resistor R5, the resistance value of the resistor R4 is 10KΩ, and the resistance value of the resistor R5 is 20.5KΩ. The resistor R4 and the resistor R5 can control the output voltage of the voltage conversion chip U1 to about 3.7V, that is, the voltage value of the third voltage is about 3.7V. After the third voltage of 3.7V passes through the diode, there is a voltage drop of about 0.3V, and the third voltage can be changed to 3.4V. The voltage of 3.4V is just equal to the minimum startup voltage of the handheld device. Therefore, when the main battery 11 is disconnected, the supercapacitor 12 can quickly supply power to the internal circuit 19 of the handheld device. Moreover, because the voltage value of the third voltage is less than the voltage value of the first voltage, the anti-power-off circuit 10 will not have the safety hazard of two batteries being directly connected in parallel.

[0050] Please refer to Figure 1 , Figure 2 and Figure 3 , the secondary battery charging module 16 includes a charging chip U2, and the model of the charging chip U2 is SGM2036-ADJYN5G / TR. The charging chip U2 includes a charging input pin IN, a charging output pin OUT, and a charging control pin EN. The charging input pin IN is connected to the power supply VBAT. The charging control pin EN is connected to the device platform 15, the charging input pin IN is used to receive the power supply voltage, and the charging control pin EN is used to receive the control signal. The charging chip U1 is used to stabilize the power supply voltage output by the power supply VBAT based on the control signal. The charging chip U1 can generate a charging voltage. The charging output pin OUT is connected to the supercapacitor 12, and the charging output pin OUT is used to output the charging voltage.

[0051] The SGM2036-ADJYN5G / TR chip is a low-noise, low-voltage, high-precision, low-dropout linear regulator. The chip is capable of providing 300mA of output current with a typical dropout voltage of only 165mV. The chip has an input voltage range of 1.6V to 5.5V, and an output voltage range of 0.8V to 5.0V. The chip also has functions such as logic-controlled shutdown mode, short-circuit current limiting, and thermal shutdown protection.

[0052] Please refer to Figure 1 , Figure 2 and Figure 3 , the auxiliary battery charging module 16 also includes a voltage limiting unit 161. One end of the voltage limiting unit 161 is connected to the charging output pin OUT, and the other end of the voltage limiting unit 161 is grounded. The voltage limiting unit 161 is used to limit the voltage value of the charging voltage. The voltage limiting unit 161 includes a resistor R1 and a resistor R2. The resistance value of the resistor R1 is 30KΩ, and the resistance value of the resistor R2 is 71.5KΩ. The setting of the resistor R1 and the resistor R2 can control the output of the charging chip to about 2.7V, that is, the charging voltage is about 2.7V. Since the supercapacitor 12 is a 2.7V capacitor, the voltage limiting unit 161 is equivalent to setting a charging cut-off voltage for the supercapacitor 12.

[0053] Please refer to Figure 1 , Figure 2 and Figure 3 , the auxiliary battery charging module 16 also includes a current limiting unit 162. One end of the current limiting unit 162 is connected to the charging output pin OUT, and the other end of the current limiting unit 162 is connected to the supercapacitor 12. The current limiting unit 162 is used to perform current limiting protection on the charging of the supercapacitor 12. The current limiting unit 162 includes a current limiting resistor R110, and the resistance of the current limiting resistor R110 is 10Ω. Therefore, the auxiliary battery charging module 16 can charge the supercapacitor 12 with a small current. Thereby, large current charging and damage to the supercapacitor 12 can be avoided, and the setting of the current limiting resistor R110 can effectively extend the service life of the supercapacitor 12.

[0054] Please refer to Figure 1 , Figure 2 and Figure 3The auxiliary battery charging module 16 also includes a filter unit 163, one end of which is connected to the power supply VBAT and the charging input pin IN, and the other end of the filter unit 163 is grounded. The filter unit 163 is used to filter the power supply voltage. The filter unit 163 includes a filter capacitor C3, the capacitive reactance of the filter capacitor C3 is 22μF, and the withstand voltage value of the filter capacitor C3 is 16V. The filter capacitor C3 can filter out the interference signal in the power supply voltage, thereby removing the noise in the power supply voltage and improving the quality of the power supply voltage. Furthermore, the power supply voltage can be stably input into the charging chip for a long time. Therefore, the auxiliary battery charging module 16 can charge the supercapacitor 12 stably for a long time.

[0055] Please refer to Figure 1 , Figure 2 and Figure 3 , the first circuit board 17 also includes a first interface J605, and the first interface J605 includes a first pin 171, a second pin 172 and a third pin 173. The charging chip U2 and the voltage conversion chip U1 are both arranged on the second circuit board 18, and the second circuit board 18 also includes a second interface J1, and the second interface J1 includes a fourth pin 181, a fifth pin 182 and a sixth pin 183. In addition, the second interface J1 is electrically connected to the first interface J605. One end of the first pin 171 is connected to the internal circuit of the handheld device, and the other end of the first pin 171 is connected to the fourth pin 181. Thus, the third voltage output by the voltage conversion chip U1 can be transmitted to the internal circuit of the handheld device through the fourth pin 181 and the first pin 171, and the third voltage can power the internal circuit of the handheld device.

[0056] Please refer to Figure 1 , Figure 2 and Figure 3 , the second pin 172 is connected to the fifth pin 182, and the second pin 172 is connected to the device platform 15. Therefore, the detection voltage output by the voltage divider module 14 can be transmitted to the second pin 172 of the first interface J605 through the fifth pin 182. Subsequently, the second pin 172 of the first interface J605 can transmit the detection voltage to the device platform 15. The third pin 173 is connected to the sixth pin 183, and the third pin 173 is connected to the device platform 15. Therefore, the control signal output by the device platform 15 can be transmitted from the third pin 173 to the first interface J605, and then the first interface J605 can be transmitted to the sixth pin 183 of the second interface J1. Furthermore, the charging control pin EN of the charging chip U2 can receive the control signal.

[0057] Please refer to Figure 1 , Figure 2 and Figure 3, the first interface J605 also includes a first power supply pin 174, and the second interface J1 includes a second power supply pin 184. The second circuit board 18 includes an AW86502DNR chip. The AW86502DNR chip includes a VDD pin and an OUTPUT pin. One end of the first power supply pin 174 is connected to a power supply VIO18_PMU, and the other end of the first power supply pin 174 is connected to a second power supply pin 184. The second power supply pin 184 is also connected to a VDD pin, and the power supply VIO18_PMU is used to power the AW86502DNR chip.

[0058] Please refer to Figure 1 , Figure 2 and Figure 3 , the first interface J605 also includes a first interrupt pin 175, and the second interface J1 includes a second interrupt pin 185. One end of the first interrupt pin 174 is connected to the device platform 15, and the other end of the first interrupt pin 174 is connected to the second interrupt pin 185, and the second interrupt pin 185 is also connected to the OUTPUT pin. The AW86502DNR chip is a Hall sensor switch chip. The AW86502DNR chip has a distance sensing function. The AW86502DNR chip can be used to detect the magnet on the main battery or the main battery cover, and then sense whether the main battery 11 is in place. If the AW86502DNR chip senses that the main battery 11 is not in place, that is, the main battery 11 is hot-swapped or the main battery 11 is in poor contact, the OUTPUT pin of the AW86502DNR chip outputs a first interrupt signal (such as a high-level signal). The interrupt signal is transmitted to the device platform 15 through the second interrupt pin 185 and the first interrupt pin 175, so that the device platform can switch the handheld device to a low power consumption mode. If the chip senses that the main battery 11 is in place, the OUTPUT pin of the AW86502DNR chip outputs a second interrupt signal (such as a low level signal). Thus, the device platform 15 receives the second interrupt signal and can switch the handheld device to a normal mode.

[0059] The working principle of the present invention is as follows: when the anti-power-off circuit 10 is working, the main battery 11 can output a first voltage, and the supercapacitor 12 can output a second voltage. The voltage conversion input pin SW of the voltage conversion chip U1 is used to input the second voltage, and the voltage conversion chip U1 can perform a voltage conversion operation on the second voltage. The voltage conversion chip U1 can generate a third voltage, and the voltage conversion output pin VS of the voltage conversion chip U1 can output the third voltage, and the voltage value of the third voltage is less than the voltage value of the first voltage. If the anti-power-off circuit is in a normal working state, the first voltage can supply power to the internal circuit 19 of the handheld device. If the main battery 11 has poor contact or the main battery 11 is hot-swapped, the third voltage can supply power to the internal circuit 19 of the handheld device. In order to prevent the first voltage from reversely charging the voltage conversion chip U1 and the supercapacitor 12, a diode D1 is provided at the position of the voltage conversion output pin VS.

[0060] When the supercapacitor 12 is insufficiently charged, the voltage divider module 14 performs a voltage divider operation on the second voltage, and the voltage divider module 14 can generate a detection voltage. The device platform 15 can receive the detection voltage, and based on the detection voltage being less than the set value, the device platform 15 can output a control signal. In addition, the charging input pin IN of the charging chip U2 can receive the power supply voltage output by the power supply, and the charging control pin EN of the charging chip U2 can receive a control signal. In order to filter the power supply voltage, a filtering unit 163 is provided at the position of the charging input pin IN. The charging chip U2 can stabilize the power supply voltage based on the control signal, and the charging chip U2 can generate a charging voltage. The charging output pin OUT of the charging chip U2 is used to output a charging voltage, which can charge the supercapacitor 12. In order to limit the voltage value of the charging voltage, a voltage limiting unit 161 is provided at the position of the charging output pin OUT. In order to perform current limiting protection for the charging of the supercapacitor, a current limiting unit 162 is provided at the position of the charging output pin OUT.

[0061] Please refer to Figure 4 The following is a detailed description of the second embodiment of the anti-power-off circuit 20 of the present invention:

[0062] The present invention provides an anti-power-off circuit 20, which includes a main battery 21, a supercapacitor 22, a voltage divider module 23, a device platform 24, and a TPS2121 chip. The main battery 21 is used to output a first voltage, and the supercapacitor 22 is used to output a second voltage. The voltage divider module 23 is connected to the main battery 21, and the voltage divider module 23 is used to perform a voltage divider operation on the first voltage, so that the voltage divider module 23 can generate a measurement voltage. The voltage divider module 23 includes a resistor R21 and a resistor R22, the resistance value of the resistor R21 is 10.2KΩ, and the resistance value of the resistor R22 is 5KΩ. The device platform 24 is used to output an enable signal, and the enable signal is used to enable the TPS2121 chip.

[0063] The TPS2121 chip includes an IN1 pin, an IN2 pin, a CP2 pin, a PR1 pin and an OUT pin. The IN1 pin is connected to the main battery 21, and the IN1 pin is used to input a first voltage. The IN2 pin is connected to the super capacitor 22, and the IN2 pin is used to input a second voltage, the voltage value of which is less than the voltage value of the first voltage. The PR1 pin is connected to the voltage divider module 23, and the CP2 pin is connected to the device platform 24. The CP2 pin is used to receive an enable signal, and the PR1 pin is used to input a measured voltage. Based on the comparison result between the measured voltage and the set voltage, the TPS2121 chip can select the first voltage or the second voltage. The OUT pin is used to output the first voltage or the second voltage, and the first voltage or the second voltage is used to power the internal circuit 25 of the handheld device. Among them, when the measured voltage is greater than the set voltage, the TPS2121 chip selects the first voltage, so that the OUT pin outputs the first voltage. Or when the measured voltage is less than the set voltage, the TPS2121 chip selects the second voltage, so that the OUT pin outputs the second voltage.

[0064] The TPS2121 chip is a power multiplexer, and the TPS2121 chip has relatively powerful functions. The TPS2121 chip can automatically assign the output to the highest input voltage or manually assign it to a lower voltage input to support resource selection operations. In addition, the TPS2121 chip can seamlessly switch between input sources. Even if the main battery 21 is disconnected, the TPS2121 chip can instantly switch to the supercapacitor 22 for power supply, thereby ensuring that the power-off protection will not cause power-off. Whether the main battery 21 is disconnected due to a fall, or the main battery 21 is actively removed, the anti-power-off circuit 20 will not cause the device to lose power. In addition, the TPS2121 chip also has features such as overvoltage, overcurrent protection, inrush current protection, soft start and thermal shutdown.

[0065] The present invention provides an anti-power-off circuit, which is provided with a main battery, a super capacitor, a voltage conversion module, a voltage dividing module, a device platform and a secondary battery charging module. The main battery is used to output a first voltage, and the super capacitor is used to output a second voltage. The voltage conversion module can perform a voltage conversion operation on the second voltage, and the voltage conversion module can generate a third voltage. The voltage value of the third voltage is less than the voltage value of the first voltage, and the third voltage and the first voltage can simultaneously power the internal circuit of the handheld device. Therefore, when the anti-power-off circuit works normally, the first voltage is used to power the internal circuit of the handheld device. When the main battery has poor contact or the main battery is hot-plugged, the third voltage can power the internal circuit of the handheld device in time. Therefore, the device can maintain a standby state for a long time. Furthermore, the device will not be powered off in a short time, thereby causing the loss of system data. The technical problem that the existing main and secondary battery power supply circuits are prone to cause system data loss is effectively solved.

[0066] The voltage divider module is used to divide the second voltage, and the voltage divider module can generate a detection voltage. The device platform receives the detection voltage, and based on the detection voltage being less than a set value, the device platform outputs a control signal. The secondary battery charging module can stabilize the power voltage output by the power supply based on the control signal, and the secondary battery charging module can generate a charging voltage, and the charging voltage is used to charge the supercapacitor. The setting of the secondary battery charging module can enable the supercapacitor to maintain sufficient power for a long time. When the main battery has poor contact or the main battery is hot-swapped, the supercapacitor can instantly power the internal circuit of the handheld device. Therefore, the handheld device can maintain a stable working state for a long time without sudden power outages.

[0067] In summary, although the present invention has been disclosed as above in terms of preferred embodiments, the above preferred embodiments are not intended to limit the present invention. A person skilled in the art may make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be based on the scope defined in the claims.

Claims

1. A power-off prevention circuit, characterized in that: These include, A main battery, configured to output a first voltage; A supercapacitor, configured to output a second voltage; a voltage conversion module, connected to the supercapacitor, and configured to perform a voltage conversion operation on the second voltage to generate a third voltage, wherein a voltage value of the third voltage is smaller than a voltage value of the first voltage; When the anti-power-off circuit works normally, the first voltage is used to power the internal circuit of the handheld device; when the main battery has poor contact or is hot-swapped, the third voltage is used to power the internal circuit of the handheld device; a voltage dividing module, one end of which is connected to the supercapacitor and the other end of which is connected to the device platform, and the voltage dividing module is used to perform a voltage dividing operation on the second voltage to generate a detection voltage; The device platform receives the detection voltage, and based on the detection voltage being less than a set value, the device platform outputs a control signal; A secondary battery charging module, one end of which is connected to the device platform and the power supply, and the other end of which is connected to the supercapacitor, is used to stabilize the power voltage output by the power supply based on the control signal to generate a charging voltage, wherein the charging voltage is used to charge the supercapacitor.

2. The anti-power-off circuit according to claim 1, characterized in that: The voltage conversion module includes a voltage conversion chip, which includes a voltage conversion input pin and a voltage conversion output pin. The voltage conversion input pin is connected to the supercapacitor, and the voltage conversion input pin is used to input the second voltage. The voltage conversion chip is used to perform a voltage conversion operation on the second voltage to generate a third voltage. The voltage conversion output pin is connected to the internal circuit of the handheld device, and the voltage conversion output pin is used to output the third voltage.

3. The anti-power-off circuit according to claim 2, characterized in that: The secondary battery charging module includes a charging chip, which includes a charging input pin, a charging output pin and a charging control pin. The charging input pin is connected to a power supply, the charging control pin is connected to the device platform, the charging input pin is used to receive the power supply voltage, the charging control pin is used to receive the control signal, the charging chip is used to stabilize the power supply voltage output by the power supply based on the control signal to generate a charging voltage, the charging output pin is connected to the supercapacitor, and the charging output pin is used to output the charging voltage.

4. The anti-power-off circuit according to claim 3, characterized in that: The secondary battery charging module further includes a voltage limiting unit, one end of which is connected to the charging output pin, and the other end of which is grounded, and the voltage limiting unit is used to limit the voltage value of the charging voltage.

5. The anti-power-off circuit according to claim 3, characterized in that: The secondary battery charging module also includes a current limiting unit, one end of which is connected to the charging output pin, and the other end of which is connected to a super capacitor, and the current limiting unit is used to perform current limiting protection on the charging of the super capacitor.

6. The anti-power-off circuit according to claim 3, characterized in that: The secondary battery charging module also includes a filter unit, one end of the filter unit is connected to the power supply and the charging input pin, the other end of the filter unit is grounded, and the filter unit is used to filter the power supply voltage.

7. The power-off prevention circuit according to claim 2, characterized in that: The voltage conversion module includes a diode, the positive electrode of the diode is connected to the voltage conversion output pin, the negative electrode of the diode is connected to the internal circuit of the handheld device, and the diode is used to prevent the first voltage output by the main battery from reversely charging the voltage conversion chip and the supercapacitor.

8. The power-off prevention circuit according to claim 3, characterized in that: The model of the voltage conversion chip is SGM6623YN6G / TR, and the model of the charging chip is SGM2036-ADJYN5G / TR.

9. A power-off prevention circuit, characterized in that: These include, A main battery, configured to output a first voltage; A supercapacitor, configured to output a second voltage, wherein a voltage value of the second voltage is less than a voltage value of the first voltage; A voltage dividing module, connected to the main battery, for performing a voltage dividing operation on the first voltage to generate a measurement voltage; The device platform is used to output an enable signal, wherein the enable signal is used to enable the TPS2121 chip; The TPS2121 chip includes an IN1 pin, an IN2 pin, a CP2 pin, a PR1 pin and an OUT pin, wherein the IN1 pin is connected to a main battery, the IN1 pin is used to input a first voltage, the IN2 pin is connected to the supercapacitor, the IN2 pin is used to input a second voltage, the PR1 pin is connected to the voltage divider module, the CP2 pin is connected to the device platform, the CP2 pin is used to receive the enable signal, the PR1 pin is used to input the measured voltage, the TPS2121 chip is used to select the first voltage or the second voltage based on a comparison result between the measured voltage and a set voltage, the OUT pin is used to output the first voltage or the second voltage, and the first voltage or the second voltage is used to power the internal circuit of the handheld device; Among them, when the measured voltage is greater than the set voltage, the TPS2121 chip selects the first voltage, so that the OUT pin outputs the first voltage; or when the measured voltage is less than the set voltage, the TPS2121 chip selects the second voltage, so that the OUT pin outputs the second voltage.

10. A handheld device, characterized in that: It includes the anti-power-off circuit described in any one of claims 1-8, and the handheld device also includes a first circuit board and a second circuit board, the anti-power-off circuit is arranged on the first circuit board and the second circuit board, the main battery and the device platform are arranged on the first circuit board, the second circuit board is electrically connected to the first circuit board, and the supercapacitor, the voltage conversion module, the voltage divider module and the secondary battery charging module are arranged on the second circuit board.

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