CN114928152A

CN114928152A - Power supply management circuit with function of controlling voltage input of standby battery

Info

Publication number: CN114928152A
Application number: CN202210556567.1A
Authority: CN
Inventors: 徐宏宇; 后建京
Original assignee: Wuxi Yuning Intelligent Technology Co ltd
Current assignee: Wuxi Yuning Intelligent Technology Co ltd
Priority date: 2021-10-08
Filing date: 2021-10-08
Publication date: 2022-08-19
Also published as: CN114928151B; CN113904436A; CN114928151A; CN113904436B

Abstract

The invention provides a power supply management circuit with a function of controlling voltage input of a standby battery. The main battery outputs a first voltage, the standby battery outputs a second voltage, and the reference voltage module outputs a reference voltage. The voltage management module receives the first voltage, the second voltage and the reference voltage, the voltage management module outputs the working voltage to the load, and the voltage division unit converts the first voltage into a third voltage. When the first voltage and the second voltage are both invalid voltages, the working voltage is in a high impedance state. When the first voltage is an effective voltage and the second voltage is an invalid voltage, the working voltage is the first voltage. When the second voltage is an effective voltage and the first voltage is an invalid voltage, the working voltage is the second voltage. When the first voltage and the second voltage are both effective voltages, if the third voltage is greater than the reference voltage, the working voltage is the first voltage. If the third voltage is less than the reference voltage, the working voltage is the second voltage.

Description

Power supply management circuit with function of controlling voltage input of standby battery

The present application is a divisional application of a patent application having a patent application number "202111171501.2" filed on "10/08/2021" entitled "power management circuit".

Technical Field

The invention relates to the field of circuits, in particular to a power management circuit.

Background

Currently, the existing power management circuit can switch between a main battery and a backup battery. However, the main battery must have an in-place detection signal, and the main board generally detects the cover of the battery compartment. When the cover of the battery compartment is in place, the circuit is powered by the main battery. After the lid of battery compartment taken off, the lid transmission of battery compartment is not in position detected signal and is given the mainboard. At the moment, the main battery is still in the battery bin, and the software control circuit is switched to the standby battery for supplying power. The user takes off the main battery at first and changes the new battery, and the user closes the lid of battery compartment again. The cover of the battery compartment transmits an in-place detection signal to the mainboard, and the software control circuit is switched back to the main battery for power supply.

The existing power management circuit needs to provide an additional detection signal for a mainboard, and the existing power management circuit needs to control a main battery and a standby battery to switch power supply through a software algorithm, so that the technical problem that the existing power management circuit is complex exists.

Therefore, it is desirable to provide a power management circuit with a function of controlling the voltage input of the backup battery to solve the above-mentioned technical problems.

Disclosure of Invention

The invention provides a power management circuit with a function of controlling the voltage input of a standby battery, which effectively solves the technical problem that the conventional power management circuit is complex.

The invention provides a power management circuit, which is used for managing a power supply of a load, and comprises:

a main battery for outputting a first voltage;

a backup battery for outputting a second voltage;

a reference voltage module for outputting a reference voltage;

the voltage management module comprises a voltage division unit, the first voltage is converted into a third voltage through the voltage division unit, and the voltage management module comprises a TPS2121 chip of the voltage management module;

the TPS2121 chip comprises an IN1 pin, an IN2 pin, a CP2 pin, a PR1 pin and an OUT pin; the pin IN1 is connected with a main battery and used for receiving the first voltage, the pin IN2 is connected with the backup battery and used for receiving the second voltage, the pin CP2 is connected with a reference voltage module and used for receiving the reference voltage, the pin PR1 is connected with one end of the voltage dividing unit and used for receiving the third voltage, and the other end of the voltage dividing unit is connected with the main battery; the OUT pin is used for outputting working voltage;

the power management circuit further comprises a first control module, a second control module and a key signal output module, wherein the first control module outputs the first control signal, and based on the first control signal, whether the voltage management module receives the first voltage or not is judged; the power management circuit comprises a second control module, the second control module outputs the second control signal, and based on the second control signal, whether the voltage management module receives the second voltage or not is judged;

the power management circuit comprises a voltage path management module, the voltage path management module comprises a first input end and a first output end, the first input end is connected with a charging power supply, and the first output end is connected with the main battery and used for protecting the main battery during charging; the voltage path management module comprises a second input end and a second output end, the second input end is connected with the output end of the voltage management module, and the second output end is connected with the load and is used for stabilizing the working voltage and managing the paths of the working voltage and the output voltage of the charging power supply;

the power management circuit also comprises a key signal output module, the key signal output module outputs a key signal, and the low level of the key signal is effective;

based on the first control module receiving the reference voltage signal or the first control module receiving the charging voltage signal or the first control module receiving the key signal, the first control module outputs a first control signal to the voltage management module, and the voltage management module receives the first voltage;

the voltage path management module comprises an enabling end, the enabling end outputs an enabling signal, and the low level of the enabling signal is effective;

based on the second control module not receiving the reference voltage signal and the second control module not receiving the charging voltage signal and the second control module receiving the key signal, the second control module outputs a second control signal to the voltage management module, and the voltage management module receives the second voltage;

or based on that a second control module receives the reference voltage signal and the second control module does not receive the enable signal, the second control module outputs a second control signal to the voltage management module, and the voltage management module receives the second voltage;

the TPS2121 chip further comprises an OV1 pin and an OV2 pin, the key signal output module comprises a startup key, the first control module and the second control module respectively comprise a seventh MOS (metal oxide semiconductor) transistor, the first control module comprises a first MOS transistor, and the second control module comprises a second MOS transistor, a fifth MOS transistor and a sixth MOS transistor;

the OV1 pin is connected with a main battery and a drain electrode of the first MOS tube, a source electrode of the first MOS tube is grounded, a grid electrode of the first MOS tube receives the reference signal, the charging voltage signal and the key signal respectively, the grid electrode of the first MOS tube is also connected with a power supply and a drain electrode of the seventh MOS tube, a grid electrode of the seventh MOS tube is connected with the start-up key, and a source electrode of the seventh MOS tube is grounded;

the OV2 pin is connected with the drain electrode of the second MOS tube and the standby battery, the source electrode of the second MOS tube is grounded, the grid electrode of the second MOS tube is connected with the power supply and the drain electrode of the fifth MOS tube, the grid electrode of the fifth MOS tube receives the reference voltage signal, and the source electrode of the fifth MOS tube is grounded; the grid electrode of the second MOS tube also receives the enabling signal; the grid electrode of the second MOS tube is also connected with a power supply and the drain electrode of the sixth MOS tube, the grid electrode of the sixth MOS tube receives a charging voltage signal, and the source electrode of the sixth MOS tube is grounded; the grid electrode of the second MOS tube receives the key signal, the drain electrode of the seventh MOS tube is connected with a power supply and the grid electrode of the second MOS tube, the grid electrode of the seventh MOS tube is connected with the starting key, and the source electrode of the seventh MOS tube is grounded;

the voltage path management module comprises an ETA6956Q4Y chip, the ETA6956Q4Y chip comprises a VAC pin, a VBUS pin, a BAT pin and a SYS pin, the VAC pin and the VBUS pin are both connected with the charging power supply, and the BAT pin is connected with the main battery; the BAT pin is also connected with the OUT pin, and the SYS pin is connected with the load; the OUT pin is connected with the BAT pin, the VAC pin and the VBUS pin are both connected with the charging power supply, the BAT pin is further connected with the main battery, and the SYS pin is connected with the load;

the voltage path management module comprises a main battery charging control unit, the main battery charging control unit is connected between the voltage path management module and the main battery, and the main battery charging control unit is used for controlling the charging power supply to charge the main battery; the second control module comprises a conducting signal output unit, the conducting signal output unit is connected with the main battery charging control unit, and based on the fact that the second control module does not output the second control signal, the conducting signal output unit receives the reference voltage signal or the charging voltage signal, the conducting signal output unit outputs a conducting signal, and the conducting signal is used for matching with the charging voltage signal or the reference voltage signal to control the on-off of the main battery charging control unit circuit;

the main battery charging control unit comprises a third MOS tube and a fourth MOS tube which are connected in parallel, a source electrode of the third MOS tube and a source electrode of the fourth MOS tube are both connected with the BAT pin, a drain electrode of the third MOS tube and a drain electrode of the fourth MOS tube are both connected with the main battery, a grid electrode of the third MOS tube receives the charging voltage signal and the reference voltage signal respectively, and a grid electrode of the fourth MOS tube receives the charging voltage signal and the reference voltage signal respectively;

the conduction signal output unit comprises an eighth MOS tube, the grid electrode of the eighth MOS tube is connected with the grid electrode of the second MOS tube, the source electrode of the eighth MOS tube is grounded, and the drain electrode of the eighth MOS tube outputs the conduction signal to the grid electrodes of the third MOS tube and the fourth MOS tube;

when the first voltage and the second voltage are both invalid voltages, the working voltage is in a high impedance state, when the first voltage is an effective voltage and the second voltage is an invalid voltage, the working voltage is the first voltage, and when the second voltage is an effective voltage and the first voltage is an invalid voltage, the working voltage is the second voltage;

when the first voltage and the second voltage are both effective voltages, the working voltage is the first voltage based on the third voltage being greater than the reference voltage, and the working voltage is the second voltage based on the third voltage being less than the reference voltage;

the voltage management module comprises a voltage adjustment unit, the TPS2121 chip further comprises an ST pin, one end of the voltage adjustment unit is connected to the voltage dividing unit, the other end of the voltage adjustment unit is connected to the ST pin, and the voltage adjustment unit is controlled by the ST pin to pull down the third voltage when the third voltage is lower than the reference voltage, so as to prevent the circuit from oscillating.

In the power management circuit of the present invention, the power management circuit includes:

a main battery for outputting a first voltage;

a backup battery for outputting a second voltage;

a reference voltage module for outputting a reference voltage;

the voltage management module receives a first voltage, a second voltage and a reference voltage and outputs a working voltage to the load; the voltage management module comprises a voltage division unit, and the first voltage is converted into a third voltage through the voltage division unit;

when the first voltage and the second voltage are both the invalid voltage, the working voltage is in a high impedance state, when the first voltage is the effective voltage and the second voltage is the invalid voltage, the working voltage is the first voltage, and when the second voltage is the effective voltage and the first voltage is the invalid voltage, the working voltage is the second voltage;

when the first voltage and the second voltage are both the effective voltages, if the third voltage is greater than the reference voltage, the working voltage is the first voltage, and if the third voltage is less than the reference voltage, the working voltage is the second voltage.

In the power management circuit of the present invention, the power management circuit includes a first control module, the first control module outputs a first control signal, the voltage management module receives the first control signal, and based on the first control signal, the voltage management module determines whether to receive the first voltage;

the power management circuit comprises a second control module, the second control module outputs a second control signal, the voltage management module receives the second control signal, and based on the second control signal, the voltage management module determines whether to receive the second voltage.

In the power management circuit of the present invention, the power management circuit includes a voltage path management module, the voltage path management module includes a first input end and a first output end, the first input end is connected to a charging power supply, and the first output end is connected to the main battery and is used for protecting the main battery when charging;

the voltage path management module comprises a second input end and a second output end, the second input end is connected with the output end of the voltage management module, and the second output end is connected with the load and used for stabilizing the working voltage and managing the path of the working voltage and the output voltage of the charging power supply.

In the power management circuit of the invention, the reference voltage module outputs a reference voltage signal, the power management circuit further comprises a charging power supply, the charging power supply outputs a charging voltage signal, the power management circuit further comprises a key signal output module, the key signal output module outputs a key signal, and the low level of the key signal is effective;

based on the first control module receiving the reference voltage signal or the first control module receiving the charging voltage signal or the first control module receiving the key signal, the first control module outputs a first control signal to a voltage management module, and the voltage management module receives the first voltage;

based on the second control module not receiving the reference voltage signal and the second control module not receiving the charging voltage signal and the second control module not receiving the key signal, the second control module outputs a second control signal to the voltage management module, and the voltage management module receives the second voltage;

or based on that the second control module receives the reference voltage signal and the second control module does not receive the enable signal, the second control module outputs a second control signal to the voltage management module, and the voltage management module receives the second voltage.

IN the power management circuit, the voltage management module comprises a TPS2121 chip, the TPS2121 chip comprises an IN1 pin, an IN2 pin, a CP2 pin, a PR1 pin and an OUT pin, the IN1 pin is connected with the main battery, the IN1 pin is used for inputting the first voltage, the IN2 pin is connected with the standby battery, and the IN2 pin is used for inputting the second voltage;

the pin CP2 is connected to the reference voltage module, the pin CP2 is used for inputting the reference voltage, the pin PR1 is connected to one end of the voltage dividing unit, the other end of the voltage dividing unit is connected to the main battery, the pin PR1 is used for inputting the third voltage, the pin OUT is connected to the load, and the pin OUT is used for outputting the working voltage.

In the power management circuit of the present invention, the TPS2121 chip further includes an OV1 pin and an OV2 pin, the key signal output module includes a power-on key, the first control module and the second control module each include a seventh MOS transistor, the first control module includes a first MOS transistor, a drain of the first MOS transistor is connected to the main battery and the OV1 pin, a source of the first MOS transistor is grounded, a gate of the first MOS transistor receives the charging voltage signal, the reference voltage signal, and the key signal, a gate of the first MOS transistor is connected to a power supply and a drain of the seventh MOS transistor, a gate of the seventh MOS transistor is connected to the power-on key, and a source of the seventh MOS transistor is grounded;

the second control module comprises a second MOS tube, a fifth MOS tube and a sixth MOS tube, wherein the drain electrode of the second MOS tube is respectively connected with the standby battery and the OV2 pin, the source electrode of the second MOS tube is grounded, the grid electrode of the second MOS tube is connected with a power supply and the drain electrode of the fifth MOS tube, the grid electrode of the fifth MOS tube receives the reference signal, and the source electrode of the fifth MOS tube is grounded; the grid electrode of the second MOS tube also receives the enabling signal; the grid electrode of the second MOS tube is also connected with a power supply and the drain electrode of the sixth MOS tube, the grid electrode of the sixth MOS tube receives the charging signal, and the source electrode of the sixth MOS tube is grounded; the grid electrode of the second MOS tube also receives the key signal, the drain electrode of the seventh MOS tube is connected with the grid electrode of the second MOS tube and the power supply, the grid electrode of the seventh MOS tube is connected with the start-up key, and the source electrode of the seventh MOS tube is grounded.

In the power management circuit of the invention, the voltage path management module includes an ETA6956Q4Y chip, the ETA6956Q4Y chip includes the VAC pin, the VBUS pin, the BAT pin, and the SYS pin, both the VAC pin and the VBUS pin are connected to the charging power supply, and the BAT pin is connected to the main battery; the BAT pin is also connected with the OUT pin, and the SYS pin is connected with the load;

in the power management circuit of the present invention, the voltage path management module includes a main battery charging control unit, the main battery charging control unit is connected between the voltage path management module and the main battery, and the main battery charging control unit is configured to control the charging power supply to charge the main battery; the second control module comprises the conducting signal output unit, the conducting signal output unit is connected with the main battery charging control unit, and based on the fact that the second control module does not output the second control signal, the conducting signal output unit receives the reference voltage signal or the charging voltage signal, the conducting signal output unit outputs the conducting signal, and the conducting signal is used for matching with the charging voltage signal or the reference voltage signal to control the on-off of the main battery charging control unit circuit;

the main battery charging control unit comprises a third MOS tube and a fourth MOS tube which are connected in parallel, the source electrode of the third MOS tube and the source electrode of the fourth MOS tube are both connected with the BAT pin, and the drain electrode of the third MOS tube and the drain electrode of the fourth MOS tube are both connected with the main battery; the grid electrode of the third MOS tube receives the charging voltage signal and the reference voltage signal respectively; the grid electrode of the fourth MOS tube receives the charging voltage signal and the reference voltage signal respectively;

the conduction signal output unit comprises an eighth MOS tube, the grid electrode of the eighth MOS tube is connected with the grid electrode of the second MOS tube, the source electrode of the eighth MOS tube is grounded, and the drain electrode of the eighth MOS tube outputs the conduction signal to the grid electrodes of the third MOS tube and the fourth MOS tube.

In the power management circuit of the present invention, the voltage management module includes a voltage adjustment unit, the TPS2121 chip further includes an ST pin, one end of the voltage adjustment unit is connected to the voltage division unit, and the other end of the voltage adjustment unit is connected to the ST pin, and is configured to switch the first voltage to the second voltage and pull down the third voltage by controlling the ST pin when the third voltage is smaller than the reference voltage, so as to prevent the circuit from oscillating, and switch the second voltage to the first voltage and pull up the third voltage by controlling the ST pin when the third voltage is larger than the reference voltage, so as to prevent the circuit from oscillating.

Compared with the prior art, the invention has the beneficial effects that: the invention provides a power management circuit which comprises a main battery, a standby battery, a reference voltage module and a voltage management module. The voltage management module receives the first voltage, the second voltage and the reference voltage, and outputs the working voltage to the load. The voltage management module receives the first voltage, the second voltage and the reference voltage, and outputs the working voltage to the load. The voltage management module comprises a voltage division unit, and the first voltage is converted into a third voltage through the voltage division unit.

When the first voltage and the second voltage are both invalid voltages, the working voltage output by the voltage management module is in a high impedance state. When the first voltage is an effective voltage and the second voltage is an invalid voltage, the working voltage output by the voltage management module is the first voltage. When the second voltage is an effective voltage and the first voltage is an invalid voltage, the working voltage is the second voltage. When the first voltage and the second voltage are both effective voltages, the working voltage output by the voltage management module is the first voltage based on the third voltage being greater than the reference voltage. When the first voltage and the second voltage are both effective voltages, the working voltage output by the voltage management module is the second voltage based on the third voltage being less than the reference voltage. Therefore, the voltage management circuit can switch the voltages output by the main battery and the backup battery. The voltage management circuit does not need to detect an in-place detection signal of the cover of the battery compartment, and directly uses the third voltage as a detection signal to switch the power supply on the premise that the first voltage and the second voltage are both effective voltages. The power supply switching process is completed only by a hardware circuit, and software is not needed to participate in judgment and control. Therefore, the circuit structure of the power management circuit is simple, and the technical problem that the existing power management circuit is complex is effectively solved.

Drawings

FIG. 1 is a block diagram of an embodiment of a power management circuit according to the invention.

FIG. 2 is a circuit diagram of a power management circuit according to an embodiment of the present invention.

FIG. 3 is a circuit diagram of a voltage path management module of the power management circuit of the present invention.

Fig. 4 is a circuit diagram of a backup battery charging management module of the power management circuit of the present invention.

In the figure, 10, a power management circuit; 11. a main battery; 12. a backup battery; 13. a reference voltage module; 14. a voltage management module; 141. a voltage dividing unit; 142. a voltage adjustment unit; 15. a first control module; 16. a second control module; 161. a conduction signal output unit; 17. a key signal output module; 171. starting up a key; 18. a voltage path management module; 181. a main battery charging control unit; 19. a standby battery charging management module; 20. a charging power supply; 21. and a power supply.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the present invention, directional terms such as "up", "down", "front", "back", "left", "right", "inner", "outer", "side", "top" and "bottom" are used only with reference to the orientation of the drawings, and the directional terms are used for illustration and understanding of the present invention, and are not intended to limit the present invention.

The terms "first," "second," and the like in the terms of the invention are used for descriptive purposes only and not for purposes of indication or implication relative importance, nor as a limitation on the order of precedence.

Referring to fig. 1 to 4, fig. 1 is a block diagram of a power management circuit according to an embodiment of the present invention; FIG. 2 is a circuit diagram of an embodiment of a power management circuit of the present invention; FIG. 3 is a circuit diagram of a voltage path management module according to an embodiment of the power management circuit of the invention; FIG. 4 is a circuit diagram of a backup battery charging management module of the power management circuit according to an embodiment of the invention.

In the drawings, elements having similar structures are denoted by the same reference numerals.

Referring to fig. 1, the present invention provides a power management circuit 10. The power management circuit 10 includes a main battery 11, a backup battery 12, a reference voltage module 13, a voltage management module 14, a first control module 15, a second control module 16, and a voltage path management module 18. The main battery 11 is used for outputting a first voltage, the backup battery 12 is used for outputting a second voltage, and the reference voltage module 13 outputs a reference voltage. The power management circuit 10 is applied to a handheld device.

Referring to fig. 1 to 2, the voltage management module 14 receives a first voltage, a second voltage, and a reference voltage, and an output terminal of the voltage management module 14 outputs a working voltage to a load. The voltage management module 14 includes a voltage dividing unit 141, and the voltage dividing unit 141 is connected to the main battery 11. The voltage dividing unit 141 includes a first resistor R1903, a second resistor R1904, and a third resistor R1905, the first resistor R1903, the second voltage R1904, and the third voltage R1905 are connected in parallel, and the first voltage is converted into the third voltage by the voltage dividing unit 141.

Referring to fig. 1 to 2, when the first voltage and the second voltage are both invalid voltages, the working voltage output by the output terminal of the voltage management module 14 is in a high impedance state. When the first voltage is an effective voltage and the second voltage is an ineffective voltage, the working voltage output by the output end of the voltage management module 14 is the first voltage. When the second voltage is an effective voltage and the first voltage is an invalid voltage, the working voltage output by the output terminal of the voltage management module 14 is the second voltage.

Referring to fig. 1 to 2, when the first voltage and the second voltage are both effective voltages, the working voltage output by the output terminal of the voltage management module 14 is the first voltage based on that the third voltage is greater than the reference voltage. When the first voltage and the second voltage are both effective voltages, based on the third voltage being less than the reference voltage, the working voltage output by the output terminal of the voltage management module 14 is the second voltage. Therefore, the voltage management circuit 10 can switch the voltages output by the main battery 11 and the backup battery 12, and the switching time is only 5 μ s, thereby basically realizing seamless switching. When the power management circuit 10 works normally, the main battery 11 is hot plugged, and the power management circuit 10 can switch to the backup battery 12 for supplying power, so that the handheld device with the power management circuit 10 is more convenient for users to use. The first voltage is between 2.6V and 6V, respectively, and can be determined as the effective voltage by the ETA6956Q4Y chip, and the second voltage is between 2.6V and 6V, respectively, and can be determined as the effective voltage by the ETA6956Q4Y chip.

Referring to fig. 1 to 2, the voltage management module 14 includes a voltage adjustment unit 142, the voltage adjustment unit 142 includes a fourth resistor R1994 and a fifth resistor R1995 connected in series, and the fourth resistor R1994 and the fifth resistor R1995 each have a resistance of 470k Ω. The TPS2121 chip further includes an ST pin, one end of the voltage adjusting unit 142 is connected to the voltage dividing unit 141, and the other end of the voltage adjusting unit 142 is connected to the ST pin. When the third voltage is less than the reference voltage, the first voltage is switched to the second voltage, and the voltage adjusting unit 142 pulls down the third voltage. When the third voltage is greater than the reference voltage, the second voltage is switched to the first voltage, and the voltage adjusting unit 142 pulls up the third voltage. Further, when the first voltage is less than 3V, the third voltage is less than the reference voltage 1.8V, the first voltage is switched to the second voltage, and the voltage adjustment unit 142 pulls down the third voltage, so that the third voltage is difficult to fluctuate to be more than the reference voltage 1.8V. When the first voltage is greater than 3.42V, the third voltage is greater than the reference voltage 1.8V, the second voltage is switched to the first voltage, and the voltage adjustment unit 142 pulls up the third voltage, so that the third voltage is difficult to fluctuate below the reference voltage 1.8V. Therefore, the first voltage has a hysteresis of 0.42V, and the voltage adjustment unit 142 is configured to prevent the first voltage and the second voltage from being repeatedly switched.

Referring to fig. 1 to 2, the voltage management module 14 includes a TPS2121 chip, and 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 11, and the IN1 pin is used for inputting a first voltage. The pin IN2 is connected with the backup battery 12, the pin IN2 is used for inputting the second voltage, and the pin IN2 is connected with a twenty-eighth capacitor C1909 IN parallel. The pin CP2 is connected to the reference voltage module 13, and the pin CP2 is used for inputting a reference voltage. The pin PR1 is connected to one end of the voltage dividing unit 141, the other end of the voltage dividing unit 142 is connected to the main battery 11, and the pin PR1 is used for inputting a third voltage. The OUT pin is connected with a load and is used for outputting working voltage.

Referring to fig. 1 to 2, the TPS2121 chip includes an OUT1 pin, an ILIM pin, and an SS pin, and the voltage management module 14 includes a sixth resistor R1912 and a first capacitor C1910. The sixth resistor R1912 has a resistance of 10k Ω and the first capacitor C1910 has a capacitive reactance of 100 nF. One end of the sixth resistor R1912 is connected to the ILIM pin, and the other end of the sixth resistor R1912 is grounded. One end of the first capacitor C1910 is connected to the SS pin, and the other end of the first capacitor C1910 is grounded. The voltage management module 14 includes a second capacitor C1901, a third capacitor C1902, a fourth capacitor C1903, a fifth capacitor C1904, and a sixth capacitor C1905. The capacitive reactance of the second capacitor C1901, the third capacitor C1902, the fourth capacitor C1903, the fifth capacitor C1904 and the sixth capacitor C1905 is 22 μ F, and the highest withstand voltage value of the second capacitor C1901, the third capacitor C1902, the fourth capacitor C1903, the fifth capacitor C1904 and the sixth capacitor C1905 is 10V. The second capacitor C1901, the third capacitor C1902, the fourth capacitor C1903, the fifth capacitor C1904, and the sixth capacitor C1905 are all connected in parallel to the OUT pin.

Referring to fig. 1 to 2, the voltage management module 14 includes a seventh capacitor C1948, an eighth capacitor C1958, a ninth capacitor C1932, a tenth capacitor C1957, an eleventh capacitor C1931, a twelfth capacitor C1956, a thirteenth capacitor C1930, a fourteenth capacitor C1955, a fifteenth capacitor C1929, a sixteenth capacitor C1954, a seventeenth capacitor C1928, an eighteenth capacitor C1953, a nineteenth capacitor C1927, a twentieth capacitor C1952, a twenty-first capacitor C1926, a twenty-second capacitor C1951, a twenty-third capacitor C1925, a twenty-fourth capacitor C1950, a twenty-fifth capacitor C1924 and a twenty-sixth capacitor C1949. A seventh capacitor C1948, an eighth capacitor C1958, a ninth capacitor C1932, a tenth capacitor C1957, an eleventh capacitor C1931, a twelfth capacitor C1956, a thirteenth capacitor C1930, a fourteenth capacitor C1955, a fifteenth capacitor C1929, a sixteenth capacitor C1954, a seventeenth capacitor C1928, an eighteenth capacitor C1953, a nineteenth capacitor C1927, a twentieth capacitor C1952, a twenty first capacitor C1926, a twenty second capacitor C1951, a twenty third capacitor C1925, a twenty fourth capacitor C1950, a twenty fifth capacitor C1924 and a twenty sixth capacitor C1949 are all connected in parallel to the OUT pin.

Referring to fig. 1 to fig. 2, the power management circuit 10 includes a first control module 15, and the first control module 15 outputs a first control signal. The voltage management module 14 receives the first control signal, and based on the high-low level of the first control signal, the voltage management module 14 determines whether to receive the first voltage. The power management circuit 10 includes a second control module 16, and the second control module 16 outputs a second control signal. The voltage management module 14 receives the second control signal, and based on the high-low level of the second control signal, the voltage management module 14 determines whether to receive the second voltage. The power management circuit 10 further includes a key signal output module 17, the key signal output module 17 is connected to the first control module 15 and the second control module 16, the key signal output module 17 is configured to output a key signal, and the key signal is active at a low level.

Referring to fig. 1 to 2, the TPS2121 chip further includes an OV1 pin and an OV2 pin, and the key signal output module 17 includes a power-on key 171 and a ninth diode D1910. The first control module 15 and the second control module 16 both include a seventh MOS transistor, the first control module 15 includes a first MOS transistor Q1904, and a drain of the first MOS transistor Q1904 is connected to the main battery 11 and the OV1 pin, respectively. The reference voltage module 13 outputs a reference voltage signal based on whether the reference voltage module 13 outputs the reference voltage. The charging power supply 20 outputs a charging voltage signal based on whether the charging power supply 20 outputs a charging voltage. The key signal output module 17 outputs a high-low level key signal based on whether the power-on key 171 is grounded. The source of the first MOS transistor Q1904 is grounded, the gate of the first MOS transistor Q1904 is connected to the charging power supply 20 and the reference voltage module 13, and the gate of the first MOS transistor Q1904 receives the charging voltage signal, the reference voltage signal, and the key signal. The gate of the first MOS transistor Q1904 is further connected to a power supply and a drain of the seventh MOS transistor Q1907, and the power supply 21 may be the main battery 11, the backup battery 12, or the charging power supply 20. The gate of the seventh MOS transistor Q1907 is connected to the power-on button 171, and the source of the seventh MOS transistor Q1907 is grounded. The anode of the ninth diode D1910 is connected to the gate of the seventh MOS transistor Q1907, and the cathode of the ninth diode D1910 is connected to the power-on button 171.

Referring to fig. 1 to 2, the first control module 15 further includes a seventh resistor R1920, an eighth resistor R1969, and a twenty-seventh capacitor C1983, wherein the capacitive reactance of the twenty-seventh capacitor C1983 is 100 pF. One end of the seventh resistor R1920 is connected to the gate of the first MOS transistor Q1904, and the other end of the seventh resistor R1920 is connected to the eighth resistor R1969. The twenty-seventh capacitor C1983 is connected in parallel with the eighth resistor R1969, and one end of the eighth resistor R1969 is grounded. The first control module 15 includes a first diode D1928, a second diode D1927, and a third diode D1926, wherein an anode of the first diode D1928 is connected to the reference voltage module 13, and a cathode of the first diode D1928 is connected to the gate of the first MOS transistor Q1904. The anode of the second diode D1927 is connected to the charging power source 20, and the cathode of the second diode D1927 is connected to the gate of the first MOS transistor. The anode of the third diode D1926 is the drain of the seventh MOS transistor, and the cathode of the third diode D1926 is connected to the gate of the first MOS transistor. The first control module 15 further includes a ninth resistor R1906, a tenth resistor R1913, and an eleventh resistor R1914, where one end of the ninth resistor R1906 is connected to the first control module, and the other end of the ninth resistor R1906 is connected to the tenth resistor R1913. The tenth resistor R1913 is connected to the drain of the first MOS transistor Q1904, one end of the eleventh resistor R1914 is connected to the OV1 pin, and the other end of the eleventh resistor R1914 is grounded.

Referring to fig. 1 to 2, the second control module 16 includes a second MOS transistor Q1905, a fifth MOS transistor Q1908 and a sixth MOS transistor Q1919, and a drain of the second MOS transistor Q1905 is connected to the pins of the backup battery 12 and the OV2, respectively. The source of the second MOS transistor Q1905 is grounded, and the gate of the second MOS transistor Q1905 is connected to the power supply 21 and the drain of the fifth MOS transistor Q1908. The gate of the fifth MOS transistor Q1908 is connected to the reference voltage module 13, the gate of the fifth MOS transistor Q1908 receives the reference voltage signal, the source of the fifth MOS transistor is grounded, and the gate of the second MOS transistor Q1905 also receives the enable signal. The gate of the second MOS transistor Q1905 is further connected to the power supply 21 and the drain of the sixth MOS transistor Q1919, the gate of the sixth MOS transistor Q1919 is connected to the charging power supply 20, the gate of the sixth MOS transistor Q1919 receives the charging voltage signal, and the source of the sixth MOS transistor Q1919 is grounded. The gate of the second MOS transistor Q1905 receives the key signal, the gate of the second MOS transistor Q1905 is further connected to a power supply and the drain of the seventh MOS transistor Q1907, and the power supply 21 may be the main battery 11, the backup battery 12, or the charging power supply 20. The gate of the seventh MOS transistor Q1907 is connected to the power-on button 171, and the source of the seventh MOS transistor Q1907 is grounded. A twenty-third resistor R1926 is connected between the drain of the seventh MOS transistor Q1907 and the power supply 21, and a forty-fifth resistor R1929 is connected between the gate Q1907 of the seventh MOS transistor and the power supply 21.

Referring to fig. 1 to 2, the second control module 16 further includes a fourth diode D1922, a fifth diode D1908, a sixth diode D1909, a twelfth resistor R1910, a thirteenth resistor R1916, a fourteenth resistor R1911, a fifteenth resistor R1919, a sixteenth resistor R1965, a seventeenth resistor R1924, and a twenty-ninth capacitor C1935. The anode of the fourth diode D1922 is connected to the drain of the fifth MOS transistor Q1908, and the cathode of the fourth diode D1922 is connected to the gate of the second MOS transistor. The fifth diode D1908 is connected to a seventeenth resistor R1924, the anode of the sixth diode D1909 is connected to the drain of the seventh MOS transistor Q1907, and the cathode of the sixth diode D1909 is connected to the anode of the fourth diode D1922. The twelfth resistor R1910 is connected between the pin IN2 and the pin OV2, and the thirteenth resistor R1916 is connected between the pin OV2 and the drain of the second MOS transistor Q1905. One end of the fourteenth resistor R1911 is connected to the OV2 pin, and the other end of the fourteenth resistor R1911 is grounded. One end of the fifteenth resistor R1919 is connected to the gate of the second MOS transistor Q1905, and the other end of the fifteenth resistor R1919 is connected to the seventeenth resistor R1924. One end of the sixteenth resistor R1965 is connected between the fifteenth resistor R1919 and the seventeenth resistor R1924, the other end of the sixteenth resistor R1965 is grounded, and the twenty-ninth capacitor C1935 is connected in parallel with the sixteenth resistor R1965.

Referring to fig. 1 to fig. 2, the second control module 16 further includes an eighteenth resistor R1922, a nineteenth resistor R1925, a twentieth resistor R1970, a twenty-first resistor R1964, a twenty-second resistor R1955, a twenty-third resistor R1955, a twenty-fourth resistor R1930, a thirty-third capacitor C1932, and a thirty-first capacitor C1934. One end of the eighteenth resistor R1922 is connected to the reference voltage module 13, the other end of the eighteenth resistor R1922 is connected to the nineteenth resistor R1925, and the nineteenth resistor R1925 is connected to the fifth diode D1908. One end of the twentieth resistor R1970 is connected to the gate of the sixth MOS transistor Q1919, and the other end of the twentieth resistor R1970 is connected to the charging power supply 20. One end of the twenty-first resistor R1964 is connected with the gate of the sixth MOS transistor, and the other end of the twenty-first resistor R1964 is grounded. One end of the twenty-second resistor R1955 is connected to the gate of the fifth MOS transistor Q1908, and the other end of the twenty-second resistor R1955 is connected to the reference voltage module 13. One end of the thirtieth capacitor C1932 is connected to the gate of the fifth transistor Q1908 and the anode of the first diode D1928, and the other end of the thirtieth capacitor C1932 is grounded. One end of a twenty-fourth resistor R1930 is connected with the drain electrode of the fifth MOS transistor Q1908, the other end of the twenty-fourth resistor R1930 is grounded, and a thirty-first capacitor C1934 is connected with the twenty-fourth resistor R1930 in parallel.

Referring to fig. 1 and 3, the power management circuit 10 includes a voltage path management module 18, the voltage path management module 18 includes a first input terminal and a first output terminal, the first input terminal is connected to the charging power source 12, the first output terminal is connected to the main battery 11, and when the main battery 11 is being charged, the voltage path management module 18 can protect the main battery to prevent the main battery from being damaged by a large current. The voltage path management module 18 includes a second input terminal connected to the output terminal of the voltage management module 14 and a second output terminal connected to the load. The voltage path management module 18 may also stabilize the operating voltage, and since the operating voltage is output to the load through the voltage path management module 18 and the voltage output by the charging power supply 20 is output to the main battery 11 through the voltage path management module 18, the voltage path management module 18 may manage a path of the operating voltage and the voltage output by the charging power supply 20.

Referring to fig. 1 and 3, the voltage path management module 14 includes an ETA6956Q4Y chip, the ETA6956Q4Y chip includes a VAC pin, a VBUS pin, a BAT pin, an SYS pin, a VAC pin, and a VBUS pin, which are all connected to the charging power source 20, and the BAT pin is connected to the main battery. The BAT pin is also connected with the OUT pin, and the SYS pin is connected with a load. The ETA6956Q4Y chip further includes a PMID pin, an NCE pin, a PSEL pin, a NQON pin, a SW pin, a NINT pin, and an NPG pin, and the voltage path management module 18 further includes a thirtieth resistor R610, a thirty-first resistor R611, a thirty-second resistor R612, a thirty-third resistor R613, a thirty-fourth resistor R614, a thirty-fifth resistor R615, a thirty-third capacitor C607, and a thirty-fourth capacitor C608. A thirty-third capacitor C607 is connected in parallel with the VAC pin, one terminal of a thirty-fourth capacitor C608 is connected to the PMID pin, and the other terminal of the thirty-fourth capacitor C608 is grounded. The NINT pin and the NPG pin are both connected with the reference voltage module 13, the thirtieth resistor R610 is connected between the NINT pin and the reference voltage module 13, and the thirty-first resistor R611 is connected between the NPG pin and the reference voltage module 13. The NCE pin is connected to a nineteen resistor R1925, the NCE pin is an enable terminal of the voltage path management module 14, and the NCE pin outputs an enable signal based on whether the voltage path management module 14 receives the charging voltage, and the enable signal is active at a low level. The nqin pin is connected to one end of a thirty-fifth resistor R615, and the other end of the thirty-fifth resistor R615 is connected to the power-on button 171. The PSEL pin is connected to one end of a thirty-third resistor R613, the other end of the thirty-third resistor R613 is connected to the reference voltage block 13, and a thirty-fourth resistor R614 is connected in parallel to the PSEL pin.

Referring to fig. 1 and 3, the ETA6956Q4Y chip further includes BST pins, SW pins, STAT pins, VLDO pins, TS pins, NC pins, and GND pins. The voltage path management module 18 further includes a thirty-sixth resistor R620, a thirty-seventh resistor R621, a thirty-fifth capacitor C609, a thirty-sixth capacitor C612, a thirty-seventh capacitor C614, a thirty-eighth capacitor C615, a thirty-ninth capacitor C610, a forty-fourth capacitor C611, and an inductor L601. The thirty-fifth capacitor C609 is connected in series between the BST pin and the SW pin, and the SW pin is connected with the SYS pin. The inductor L601 is connected in series with the SW pin, and the thirty-sixth capacitor C612, the thirty-seventh capacitor C614, and the thirty-eighth capacitor C615 are all connected in parallel with the SW pin. A fortieth capacitor C611 is connected in parallel with the BAT pin, one end of a thirty ninth capacitor C610 is connected to the VLDO pin, and the other end of the thirty ninth capacitor C610 is grounded. One end of the thirty-seventh resistor R621 is connected to the TS pin, the other end of the thirty-seventh resistor R621 is grounded, and the thirty-sixth resistor R620 is connected between the VLDO pin and the TS pin. The STAT pin and the NC pin are both suspended, and the GND pin is grounded.

Referring to fig. 1 to 3, the voltage path management module 18 includes a main battery charging control unit 181, the main battery charging control unit 181 is connected between the voltage path management module 18 and the main battery 11, and the main battery charging control unit 181 can control the charging power source 20 to charge the main battery 11. The second control module 16 includes a turn-on signal output unit 161, and the turn-on signal output unit 161 is connected to the main battery charging control unit 181. Based on that the second control module does not output the second control signal, and the conducting signal output unit 161 receives the reference voltage signal or receives the charging voltage signal, the conducting signal output unit 161 outputs the conducting signal, and the conducting signal can be used to control the on/off of the circuit of the main battery charging control unit 181 in cooperation with the charging voltage signal or the reference voltage signal.

Referring to fig. 1 to 2, the main battery charging control unit 181 includes a third MOS transistor Q1901 and a fourth MOS transistor Q1902 connected in parallel, and a source of the third MOS transistor Q1901 and a source of the fourth MOS transistor Q1902 are both connected to the BAT pin. The drain of the third MOS transistor Q1901 and the drain of the fourth MOS transistor Q1902 are both connected to the main battery, the gate of the third MOS transistor Q1901 is respectively connected to the charging power supply 20 and the reference voltage module 13, and the gate of the third MOS transistor Q1901 receives the charging voltage signal and the reference voltage signal, respectively. The gates of the fourth MOS transistor Q1902 are connected to the charging power supply 20 and the reference voltage module 13, respectively, and the gates of the fourth MOS transistor Q1902 receive the charging voltage signal and the reference voltage signal, respectively. The turn-on signal output unit 161 includes an eighth MOS transistor Q1906, a gate of the eighth MOS transistor Q1906 is connected to a gate of the second MOS transistor, a source of the eighth MOS transistor Q1906 is grounded, a drain of the eighth MOS transistor Q1906 is connected to gates of the third MOS transistor Q1901 and the fourth MOS transistor Q1902, and a drain of the eighth MOS transistor Q1906 outputs a turn-on signal to gates of the third MOS transistor Q1901 and the fourth MOS transistor Q1902. The main battery charging control unit 181 includes a tenth MOS transistor Q1911 and an eleventh MOS transistor Q1912, a gate of the tenth MOS transistor Q1911 and a gate of the eleventh MOS transistor Q1912 are both connected to the gate of the third MOS transistor Q1901, and a drain of the tenth MOS transistor Q1911 and a drain of the fourth MOS transistor Q1912 are both connected to the BAT pin. The source of the tenth MOS transistor Q1911 is connected to the source of the third MOS transistor Q1901, and the source of the eleventh MOS transistor Q1912 is connected to the source of the fourth MOS transistor Q1902. The main battery charging control unit 181 further includes a twenty-sixth resistor R1901 and a thirty-second capacitor C1937, the twenty-sixth resistor R1901 is connected between the source and the gate of the eleventh MOS transistor Q1912, and the twenty-seventh capacitor C1937 is connected between the source and the gate of the tenth MOS transistor Q1911.

Referring to fig. 1 to 2, the voltage path management module 18 includes a ninth MOS transistor Q1903, a twenty-seventh resistor R1967, a thirty-second capacitor C1936, a twenty-eighth resistor R1902, a twenty-ninth resistor R1999, a seventh diode D1924, and an eighth diode D1925. The drain of the ninth MOS transistor Q1903 is connected to the gate of the fourth MOS transistor, the source of the ninth MOS transistor Q1903 is grounded, and the drain of the ninth MOS transistor Q1903 is connected to the reference voltage module 13, the on-signal output unit 161, and the charging power supply 12, respectively. A twenty-seventh resistor R1967 and a thirty-second capacitor C1936 are connected between the source and the gate of the ninth MOS transistor Q1903. The anode of the seventh diode D1924 is connected to the reference voltage module 13, and the cathode of the seventh diode D1924 is connected to the gate of the ninth MOS transistor Q1903. The positive electrode of the eighth diode D1925 is connected to the charging power source 20, and the negative electrode of the eighth diode D1925 is connected to the gate of the ninth MOS transistor Q1903. The twenty-eighth resistor R1902 is connected between the gate of the ninth MOS transistor Q1903 and the cathode of the seventh diode D1924. The twenty-ninth resistor R1999 is connected between the anode of the eighth diode D1925 and the charging power source 20.

Referring to fig. 1 and fig. 4, the power management circuit 10 further includes a backup battery charging management module 19, one end of the backup battery charging management module 19 is connected to the charging power source 20, the other end of the backup battery charging management module 19 is connected to the backup battery 12, and the backup battery charging management module 19 can be used to protect the backup battery 12. The backup battery charging management module 19 can protect the backup battery 12 from a large current to damage the backup battery 12 when the backup battery 12 is charged. The backup battery charging management module 19 includes a BQ24040 chip, and the BQ24040 chip includes an IN pin, an ISET pin, a VSS pin, a pretm pin, a PG pin, an OUT pin, a TS pin, a CHG pin, an ISET2 pin, an NC pin, and a GND pin. The IN pin is connected to the charging power supply 20, and the OUT pin is connected to the backup battery 12. The backup battery charging management module 19 further includes a zener diode V1912, a forty-first capacitor C1918, a forty-second capacitor C1919, a thirty-eighth resistor R1934, a thirty-ninth resistor R1938, a forty-fourth resistor R1939, and a forty-first resistor R1941. A forty-first capacitor C1918 and a forty-second capacitor C1919 are both connected IN parallel with the IN pin, one end of a thirty-eighth resistor R1934 is connected to the ISET pin, and the other end of the thirty-eighth resistor R1934 is grounded. One end of the thirty-ninth resistor R1938 is connected to the PRETERM pin, the other end of the thirty-ninth resistor R1938 is grounded, and the VSS pin is grounded. The PG pin is connected with a forty-first resistor R1939, one end of the forty-first resistor R1941 is connected with the forty-first resistor R1939, and the other end of the forty-first resistor R1941 is grounded.

Referring to fig. 1 and 4, the backup battery charging management module 19 further includes a forty-third capacitor C1920, a forty-fourth capacitor C1921, a forty-second resistor R1935, a forty-third resistor R1936, and a forty-fourth resistor R1940. A forty-third capacitor C1920 and a forty-fourth capacitor C1921 are both connected in parallel with the OUT pin. One end of a forty-second resistor R1935 is connected with the TS pin, and the other end of the forty-second resistor R1935 is grounded. One end of a forty-third resistor R1936 is connected with the CHG pin, and the other end of the forty-third resistor R1936 is connected with a forty-fourth resistor R1940 and a forty-fourth resistor R1940 which are grounded. The ISET2 pin and the GND pin are both grounded, and the NC pin is floating.

The working principle of the power management circuit 10 of the present invention is as follows: when the power management circuit 10 operates normally, the main battery 11 outputs a first voltage. The first voltage is converted into a third voltage by the voltage dividing unit 141, the reference voltage module 13 outputs the reference voltage, and the voltage management module 14 inputs the third voltage and the reference voltage. When the circuit is operating normally, the reference voltage module 14 outputs a reference voltage signal based on which the first control module 15 receives. The anode of the first diode D1928 receives the reference voltage signal, the first diode D1928 is turned on, the gate of the first MOS transistor Q1904 receives the reference voltage signal, the first MOS transistor Q1904 is turned on, and the first control module 15 outputs the first control signal. The voltage management module 14 receives the first control signal, so the voltage management module 14 inputs the first voltage.

Or when the charging power supply 20 charges the main battery 11 or the backup battery 12, the charging power supply 20 outputs a charging voltage. Based on the charging voltage output by the charging power supply 20, the charging power supply outputs a charging voltage signal. The first control module 15 receives the charging voltage signal, the anode of the second diode D1927 receives the charging voltage signal, the gate of the first MOS transistor Q1904 receives the charging voltage signal, so that the first MOS transistor Q1904 is turned on, and the first control module 15 outputs a first control signal. The voltage management module receives the first control signal, so the voltage management module 14 inputs the first voltage.

Or when the user presses the power-on button 171, the button signal input module 17 outputs a button signal based on the grounding of the power-on button 171, and the first control module 15 receives the button signal. Since the power-on key 171 is grounded, the ninth diode D1910 receives the key signal of low level, and the ninth diode D1910 is not turned on. Since the gate of the seventh MOS transistor Q1907 is connected to the power-on key 171 through the ninth diode D1910, the gate of the seventh MOS transistor Q1907 receives the low-level key signal, and the seventh MOS transistor Q1907 is not turned on. Since the drain of the seventh MOS transistor Q1907 is connected to the power supply, the drain of the seventh MOS transistor Q1907 outputs a high-level power supply signal. The anode of the third diode D1926 receives the high-level power signal, and the third diode D1926 is turned on. Therefore, the gate of the first MOS transistor Q1904 receives the high-level power signal, so that the first MOS transistor Q1904 is turned on, and the first control module 15 outputs the first control signal. The voltage management module 14 receives the first control signal so that the voltage management module 14 inputs the first voltage. That is, the power management circuit 10 works normally, or the charging power supply 20 charges the main battery 11 or the backup battery 12, or the first control module receives a key signal, the first control module 15 outputs a low-level first control signal, and the first voltage input by the main battery 11 can be input by the TPS2121 chip. Otherwise, the first control module 15 outputs the first control signal with a high level, and the first voltage output by the main battery 11 is difficult to be input by the TPS2121 chip.

When the power management circuit 10 is operating normally, the backup battery 12 outputs the second voltage. When the charging power supply 20 does not charge the main battery 11 through the voltage path management module 18, the NCE pin does not output the enable signal, and the enable signal is active low. Therefore, the signal output from the NCE pin is high. The NCE pin of the ETA6956Q4Y chip outputs a high-level signal to the second control module 16, and since the anode of the fifth diode D1908 is connected to the NCE pin through R1925, the anode of the fifth diode D1908 receives the high-level signal, and the fifth diode D1908 is turned on. The gate of the second MOS transistor Q1905 receives a high-level signal, and the second MOS transistor Q1905 is turned on. The NCE pin of the ETA6956Q4Y chip does not output an enable signal, and the power management circuit 10 is in a normal operating state. Therefore, the reference voltage module 13 outputs the reference voltage signal, and the second control module 14 receives the reference voltage signal. The second control module 16 outputs a second control signal based on the second control module receiving the reference voltage signal and the second control module not receiving the enable signal. The voltage management module 14 receives the second control signal so that the voltage management module 14 inputs the second voltage.

Or when the power management circuit 10 stops operating, the reference voltage module 13 does not output the reference voltage based on that the reference voltage module 13 does not output the reference voltage signal, and therefore, the gate of the fifth MOS transistor Q1908 does not receive the reference voltage signal, and the fifth MOS transistor Q1908 is not turned on. Since the drain of the fifth MOS transistor Q1908 is connected to the power supply, the drain of the fifth MOS transistor Q1908 receives the power supply signal with high level, the anode of the fourth diode D1922 is turned on, and the second MOS transistor Q1905 is turned on. And when the charging power supply 20 does not charge the main battery 11 or the backup battery 12, the charging power supply 20 does not output a charging voltage signal based on the charging power supply 20 not outputting the charging voltage, and the second control module 16 does not receive the charging voltage signal. Since the gate of the sixth MOS transistor Q1919 does not receive the charging voltage signal through the twentieth resistor R1970, the gate of the sixth MOS transistor Q1919 does not receive the charging voltage signal, and the sixth MOS transistor Q1919 is not turned on. Since the drain of the sixth MOS transistor Q1919 is connected to the power supply, the drain of the sixth MOS transistor Q1919 receives the power supply signal with high level, the anode of the fourth diode D1922 is turned on, and the second MOS transistor Q1905 is turned on.

And when the user presses the power-on key 171, the key signal input module 17 outputs a key signal based on the grounding of the power-on key 171, and the first control module 15 receives the key signal. Since the power-on key 171 is grounded, the ninth diode D1910 receives the key signal of low level, and the ninth diode D1910 is not turned on. Since the gate of the seventh MOS transistor Q1907 is connected to the power-on key 171 through the ninth diode D1910, the gate of the seventh MOS transistor Q1907 receives the low-level key signal, and the seventh MOS transistor Q1907 is not turned on. Since the drain of the seventh MOS transistor Q1907 is connected to the power supply, the drain of the seventh MOS transistor Q1907 outputs a high-level power supply signal, and the anode of the fourth diode D1922 receives the high-level power supply signal. Therefore, the fourth diode D1922 is turned on, and the second MOS transistor Q1905 is turned on. Based on that the second control module does not receive the reference voltage signal, the second control module does not receive the charging voltage signal, and the second control module receives the key signal, the fourth diode D1922 is turned on, the second MOS transistor Q1905 is turned on, and the second control module 16 outputs the second control signal of the low level. The voltage management module 14 receives the second control signal, and the voltage management module 14 inputs the second voltage based on the second control signal with a low level. That is, the charging power supply does not charge the main battery 11 through the voltage path management module 18 and the power management circuit 10 operates normally, or the power management circuit 10 stops operating and the charging power supply 20 does not charge the main battery 11 or the backup battery 12 and the user presses the power-on button 171, the second control module 16 outputs the second control signal with a low level, and the second voltage can be input by the TPS2121 chip. Otherwise, the second control module 16 outputs the second control signal with a high level, and the second voltage output by the backup battery 12 is difficult to be input by the TPS2121 chip.

After the voltage management module 14 inputs the first voltage and the second voltage, the voltage management module 14 may output the working voltage to the load. When the first voltage and the second voltage are both invalid voltages, the working voltage is in a high impedance state. When the first voltage is an effective voltage and the second voltage is an ineffective voltage, the working voltage is the first voltage. When the second voltage is an invalid voltage and the second voltage is an effective voltage, the working voltage is the second voltage. When the first voltage and the second voltage are both effective voltages, based on the third voltage being greater than the reference voltage, the working voltage output by the voltage management module 14 is the first voltage; based on the third voltage being less than the reference voltage, the operating voltage output by the voltage management module 14 is the second voltage.

When the charging power supply 20 charges the main battery 11 or the backup battery 12, the charging power supply 20 outputs a charging voltage signal based on the charging voltage output by the charging power supply 20, and therefore the anode of the seventh diode D1924 receives the charging voltage signal, and the seventh diode D1924 is turned on. When the second control module 16 does not output the second control signal, the second MOS transistor Q1905 is turned off, and the gate of the eighth MOS transistor Q1906 is connected to the gate of the second MOS transistor Q1905, so that the eighth MOS transistor Q1906 is turned off. The drain of the eighth MOS transistor Q1906 is connected to the charging power supply 20, and based on the charging voltage output by the charging power supply 20, the charging power supply 20 outputs a charging voltage signal, the drain of the eighth MOS transistor Q1906 receives the charging voltage signal, and the drain of the eighth MOS transistor Q1906 receives the charging voltage signal, so that the on-signal output unit 161 outputs an on-signal to the main battery charging control unit 181. At this time, the ninth MOS transistor Q1903 is turned on based on the charging voltage signal and the on signal, and the drain of the ninth MOS transistor Q1903 outputs a low-level signal. The gates of the third MOS transistor Q1901, the fourth MOS transistor Q1902, the tenth MOS transistor Q1911 and the eleventh MOS transistor Q1912 are all PMOS transistors, and the gates of the third MOS transistor Q1901, the fourth MOS transistor Q1902, the tenth MOS transistor Q1911 and the eleventh MOS transistor Q1912 all receive the low-level signal output by the drain of the transistor Q1903. Therefore, the third MOS transistor Q1901, the fourth MOS transistor Q1902, the tenth MOS transistor Q1911, and the eleventh MOS transistor Q1912 of the main battery charging control unit 181 are all turned on. Since the TPS2121 chip has a backflow prevention characteristic, the charging power supply 20 can charge the main battery 11 through the ETA6956Q4Y chip and the main battery charging control unit 181.

When the power management circuit 10 operates normally, the reference voltage module 13 outputs the reference voltage based on the reference voltage module 13, and thus the anode of the seventh diode D1924 outputs the reference voltage signal. When the second control module 16 does not output the second control signal, the second MOS transistor Q1905 is in an off state, and the gate of the eighth MOS transistor Q1906 is connected to the gate of the second MOS transistor Q1905, so that the eighth MOS transistor Q1906 is in an off state. Since the drain of the eighth MOS transistor Q1906 is connected to the reference voltage block, the reference voltage block 13 outputs the reference voltage signal based on the reference voltage block 13 outputting the reference voltage. The drain of the eighth MOS transistor Q1906 receives the reference voltage signal. The drain of the eighth MOS transistor Q1906 outputs a turn-on signal, so the turn-on signal output unit 161 outputs a turn-on signal to the main battery charging control unit 181. At this time, the ninth MOS transistor Q1903 is turned on based on the reference voltage signal and the on signal, and the drain of the ninth MOS transistor Q1903 outputs a low-level signal. The gates of the third MOS transistor Q1901, the fourth MOS transistor Q1902, the tenth MOS transistor Q1911 and the eleventh MOS transistor Q1912 all receive a low-level signal output by the drain of the transistor Q1903. Therefore, the third MOS transistor Q1901, the fourth MOS transistor Q1902, the tenth MOS transistor Q1911, and the eleventh MOS transistor Q1912 of the main battery charging control unit 181 are all turned on. Since the TPS2121 chip has a backflow prevention characteristic, the charging power supply 20 can charge the main battery 11 through the ETA6956Q4Y chip and the main battery charging control unit 181. That is, the second control module 16 does not output the second control signal and the charging power supply 20 charges the main battery 11 or the backup battery 12, or the second control module 16 does not output the second control signal and the power management circuit 10 operates normally, the main battery charging control unit 181 is in a conducting state, and the charging power supply 20 can charge the main battery 11 through the ETA6956Q4Y chip and the main battery charging control unit 181. Otherwise, the main battery charging control unit 181 is in an off state, and the charging power supply 20 cannot charge the main battery 11 through the main battery charging control unit 181.

The invention provides a power management circuit, and the power management circuit 10 comprises a main battery 11, a backup battery 12, a reference voltage module 13 and a voltage management module 14. The main battery 11 outputs a first voltage, the auxiliary battery 12 outputs a second voltage, and the reference voltage module 13 outputs a reference voltage. The voltage management module 14 receives the first voltage, the second voltage, and the reference voltage, and the voltage management module 14 outputs the working voltage to the load. The voltage management module 14 includes a voltage dividing unit 141, and the first voltage is converted into a third voltage by the voltage dividing unit 141.

When the first voltage and the second voltage are both invalid voltages, the working voltage output by the voltage management module 14 is in a high impedance state. When the first voltage is an active voltage and the second voltage is an inactive voltage, the working voltage output by the voltage management module 14 is the first voltage. When the second voltage is an effective voltage and the first voltage is an invalid voltage, the working voltage is the second voltage. When the first voltage and the second voltage are both effective voltages, based on the third voltage being greater than the reference voltage, the working voltage output by the voltage management module 14 is the first voltage. When the first voltage and the second voltage are both effective voltages, the working voltage output by the voltage management module 14 is the second voltage based on the third voltage being less than the reference voltage. Therefore, the voltage management circuit 10 can switch the voltages output by the main battery 11 and the backup battery 12. The voltage management circuit 10 does not need to detect an in-place detection signal of the cover of the battery compartment, and on the premise that the first voltage and the second voltage are both effective voltages, the voltage management circuit 10 directly uses the third voltage as a detection signal to switch the power supply. The power supply switching process is completed only by a hardware circuit, and software is not needed to participate in judgment and control. Therefore, the circuit structure of the power management circuit 10 is simple, and the technical problem that the existing power management circuit is complex is effectively solved.

In view of the foregoing, it is intended that the present invention cover the preferred embodiment of the invention and not be limited thereto, but that various changes and modifications can be made therein by those skilled in the art without departing from the spirit and scope of the invention.

Claims

1. A power management circuit having a function of controlling a voltage input of a backup battery, the power management circuit comprising:

a main battery for outputting a first voltage;

a backup battery for outputting a second voltage;

a reference voltage module for outputting a reference voltage;

the voltage management module receives a first voltage, a second voltage and a reference voltage and outputs a working voltage to a load; the voltage management module comprises a voltage division unit, and the first voltage is converted into a third voltage through the voltage division unit;

when the first voltage and the second voltage are both invalid voltages, the working voltage is in a high impedance state, when the first voltage is an effective voltage and the second voltage is the invalid voltage, the working voltage is the first voltage, and when the second voltage is the effective voltage and the first voltage is the invalid voltage, the working voltage is the second voltage;

when the first voltage and the second voltage are both the effective voltages, if the third voltage is greater than the reference voltage, the working voltage is the first voltage, and if the third voltage is less than the reference voltage, the working voltage is the second voltage;

the power management circuit comprises a second control module, the second control module outputs a second control signal, the voltage management module receives the second control signal, and the voltage management module receives whether the second voltage is received or not based on the second control signal;

the power management circuit comprises a voltage path management module, the voltage path management module comprises a first input end and a first output end, the first input end is connected with a charging power supply, and the first output end is connected with the main battery and used for protecting the main battery during charging;

the voltage path management module comprises a second input end and a second output end, the second input end is connected with the output end of the voltage management module, the second output end is connected with the load, and the voltage path management module is used for stabilizing the working voltage and managing paths of the working voltage and the output voltage of the charging power supply;

based on the second control module not receiving the reference voltage signal and the second control module not receiving the charging voltage signal and the second control module receiving the key signal, the second control module outputs the second control signal to the voltage management module, and the voltage management module receives the second voltage;

or based on that the second control module receives the reference voltage signal and the second control module does not receive the enable signal, the second control module outputs the second control signal to the voltage management module, and the voltage management module receives the second voltage.

2. The power management circuit with function of controlling voltage input of backup battery according to claim 1, wherein said power management circuit comprises a first control module, said first control module outputting a first control signal, said voltage management module receiving said first voltage or not based on said first control signal.

3. The power management circuit with function of controlling voltage input of backup battery according to claim 2, wherein said first control module outputs said first control signal to said voltage management module based on said first control module receiving said reference voltage signal or said first control module receiving said charging voltage signal or said first control module receiving said key signal, and said voltage management module receives said first voltage.

4. The power management circuit with function of controlling voltage input of a backup battery according to claim 3, wherein the voltage management module comprises a TPS2121 chip, the TPS2121 chip comprises an IN1 pin, an IN2 pin, a CP2 pin, a PR1 pin and an OUT pin, the IN1 pin is connected with the main battery, the IN1 pin is used for inputting the first voltage, the IN2 pin is connected with the backup battery, and the IN2 pin is used for inputting the second voltage;

5. The power management circuit with the function of controlling the voltage input of the backup battery according to claim 4, wherein the TPS2121 chip further includes an OV1 pin and an OV2 pin, the key signal output module includes a power-on key, the first control module and the second control module each include a seventh MOS transistor, the first control module includes a first MOS transistor, a drain of the first MOS transistor is connected to the main battery and the OV1 pin, a source of the first MOS transistor is grounded, a gate of the first MOS transistor receives the charging voltage signal, the reference voltage signal, and the key signal, a gate of the first MOS transistor is connected to the power supply and a drain of the seventh MOS transistor, a gate of the seventh MOS transistor is connected to the power-on key, and a source of the seventh MOS transistor is grounded;

the second control module comprises a second MOS tube, a fifth MOS tube and a sixth MOS tube, wherein the drain electrode of the second MOS tube is respectively connected with the standby battery and the OV2 pin, the source electrode of the second MOS tube is grounded, the grid electrode of the second MOS tube is connected with a power supply and the drain electrode of the fifth MOS tube, the grid electrode of the fifth MOS tube receives the reference voltage signal, and the source electrode of the fifth MOS tube is grounded; the grid electrode of the second MOS tube also receives the enabling signal; the grid electrode of the second MOS tube is also connected with a power supply and the drain electrode of the sixth MOS tube, the grid electrode of the sixth MOS tube receives the charging voltage signal, and the source electrode of the sixth MOS tube is grounded; the grid electrode of the second MOS tube also receives the key signal, the drain electrode of the seventh MOS tube is connected with the grid electrode of the second MOS tube and the power supply, the grid electrode of the seventh MOS tube is connected with the start-up key, and the source electrode of the seventh MOS tube is grounded.

6. The power management circuit with function of controlling voltage input of a backup battery according to claim 5, wherein said voltage path management module comprises an ETA6956Q4Y chip, said ETA6956Q4Y chip comprises a VAC pin, a VBUS pin, a BAT pin, and a SYS pin, said VAC pin and said VBUS pin are connected to said charging power source, and said BAT pin is connected to said main battery; the BAT pin is further connected with the OUT pin, and the SYS pin is connected with the load.

7. The power management circuit of claim 6, wherein the voltage path management module comprises a main battery charging control unit, the main battery charging control unit is connected between the voltage path management module and the main battery, and the main battery charging control unit is configured to control the charging power supply to charge the main battery; the second control module comprises a conducting signal output unit, the conducting signal output unit is connected with the main battery charging control unit, and based on the fact that the second control module does not output the second control signal, the conducting signal output unit receives the reference voltage signal or the charging voltage signal, the conducting signal output unit outputs a conducting signal, and the conducting signal is used for matching with the charging voltage signal or the reference voltage signal to control the on-off of a circuit of the main battery charging control unit;

the main battery charging control unit comprises a third MOS tube and a fourth MOS tube which are connected in parallel, a source electrode of the third MOS tube and a source electrode of the fourth MOS tube are both connected with the BAT pin, and a drain electrode of the third MOS tube and a drain electrode of the fourth MOS tube are both connected with the main battery; the grid electrode of the third MOS tube receives the charging voltage signal and the reference voltage signal respectively; the grid electrode of the fourth MOS tube is respectively connected with the charging voltage signal and the reference voltage signal;

the conduction signal output unit comprises an eighth MOS tube, the grid electrode of the eighth MOS tube is connected with the grid electrode of the second MOS tube, the source electrode of the eighth MOS tube is grounded, and the drain electrode of the eighth MOS tube outputs a conduction signal to the grid electrodes of the third MOS tube and the fourth MOS tube.

8. The power management circuit with function of controlling voltage input of backup battery according to claim 4, wherein said voltage management module comprises a voltage adjustment unit, said TPS2121 chip further comprises an ST pin, one end of said voltage adjustment unit is connected to said voltage division unit, the other end of said voltage adjustment unit is connected to said ST pin, for switching said first voltage to said second voltage when said third voltage is smaller than said reference voltage, and controlling said voltage adjustment unit to pull down said third voltage by said ST pin, and switching said second voltage to said first voltage when said third voltage is larger than said reference voltage, and controlling said voltage adjustment unit to pull up said third voltage by said ST pin.