CN115576406A - Power-down detection and power supply maintenance function circuit and electronic equipment - Google Patents

Abstract

The invention discloses a power failure detection and power supply maintenance functional circuit and electronic equipment. The power failure detection and power supply maintenance functional circuit comprises: a power supply output terminal for connecting to an electric load; an energy storage circuit; and an input terminal of a power supply maintenance control circuit It is connected with the output terminal of the energy storage circuit, and the output terminal of the power supply maintenance control circuit is connected with the output terminal of the power supply, and is used to control the electrical connection between the energy storage circuit and the output terminal of the power supply when it is turned on; the energy storage voltage detection circuit, the energy storage voltage detection circuit The detection end of the energy storage circuit is connected to the output end of the energy storage circuit, and the output end of the energy storage voltage detection circuit is connected to the controlled end of the power supply maintenance control circuit for detecting the output voltage of the energy storage circuit, and when the output voltage of the energy storage circuit is less than When the first preset voltage is reached, the power supply maintenance control circuit is controlled to disconnect the electrical connection between the energy storage circuit and the output terminal of the power supply, so that the energy storage circuit stops supplying power to the electric load. The invention can solve the problem of poor stability of the existing power-down storage scheme.

Description

Power-down detection and power supply maintenance function circuit and electronic equipment

technical field

The invention relates to the technical field of electronic equipment, in particular to a power failure detection and power supply maintenance function circuit and electronic equipment.

Background technique

The integration of industrial products is becoming more and more complex. CPUs, MCUs, FPGAs and other processors are widely used in products. These complex integrated circuit products need to maintain normal power supply for a certain period of time when the input power suddenly loses power. In order to store the data in the power-off state, and at the same time avoid damage to the SD card or EMMC memory due to improper operation of the software when the power is off. In the existing technology, some solutions are to continue to discharge the supercapacitor after power failure without control, resulting in abnormal system startup due to the previous voltage not falling to 0V when the power is turned on again, affecting the usability of the product and poor user experience .

Contents of the invention

The main purpose of the present invention is to propose a power failure detection and power supply maintenance function circuit, aiming to solve the problem of poor stability of the existing power failure storage scheme.

In order to achieve the above object, the power-down detection and power supply maintenance function circuit proposed by the present invention includes:

A power supply output terminal, the power supply output terminal is used to connect to an electrical load;

energy storage circuit;

A power supply maintenance control circuit, the input terminal of the power supply maintenance control circuit is connected to the output terminal of the energy storage circuit, the output terminal of the power supply maintenance control circuit is connected to the output terminal of the power supply, and the power supply maintenance control circuit is used for When turned on, control the energy storage circuit to be electrically connected to the output terminal of the power supply;

An energy storage voltage detection circuit, the detection end of the energy storage voltage detection circuit is connected to the output end of the energy storage circuit, the output end of the energy storage voltage detection circuit is connected to the controlled end of the power supply maintenance control circuit, The energy storage voltage detection circuit is used to detect the output voltage of the energy storage circuit, and when the output voltage of the energy storage circuit is lower than a first preset voltage, control the power supply maintenance control circuit to disconnect the energy storage The electric connection between the circuit and the output terminal of the power supply is used to stop the energy storage circuit from supplying power to the electric load.

Optionally, the power-down detection and power supply maintenance function circuit also includes:

A power input terminal, the power input terminal is connected to the power output terminal, and is used to connect to the input power supply;

A power detection circuit, the detection end of the power detection circuit is connected to the power input end, the output end of the power detection circuit is connected to the controlled end of the power supply maintenance control circuit, and the power detection circuit is used to detect the the output voltage of the input terminal of the power supply, and when the output voltage of the input terminal of the power supply is greater than a second preset voltage, control the power supply maintenance control circuit to disconnect the electrical connection between the energy storage circuit and the output terminal of the power supply, so that the energy storage circuit stops supplying power to the electric load.

Optionally, the power supply detection circuit is further configured to output a power supply maintenance signal to the power supply maintenance control circuit when the output voltage of the power input terminal is lower than a second preset voltage, so that the power supply maintenance control circuit controls the The energy storage circuit is electrically connected to the output end of the power supply, so that the energy storage circuit supplies power to the electric load.

Optionally, the power supply end of the power detection circuit is connected to the power output end, and the power detection circuit is further configured to output a power-off signal to the power supply maintenance control circuit when the power supply end is powered off, so as to The power supply maintenance control circuit controls the energy storage circuit to be disconnected from the output terminal of the power supply, so that the energy storage circuit stops supplying power to the load.

Optionally, the power-down detection and power supply maintenance function circuit also includes:

A power conversion circuit, the input end of the power conversion circuit is connected to the power input end, the output end of the power conversion circuit is respectively connected to the power output end and the input end of the energy storage circuit, and the power conversion circuit is used to The connected input power is converted into a power supply voltage and then output;

The power detection circuit has a first detection end and a second detection end, the first detection end of the power detection circuit is connected to the power input end, the second detection end of the power detection circuit is connected to the power conversion circuit The output terminal connection;

The power detection circuit is used to detect the output voltage of the power input terminal and the output voltage of the power conversion circuit, and the output voltage at the power input terminal is less than a second preset voltage, and/or the power conversion circuit When the output voltage is less than the third preset voltage, output a power supply maintenance signal to the power supply maintenance control circuit, so that the power supply maintenance control circuit controls the electrical connection between the energy storage circuit and the output terminal of the power supply, so that the power storage The energy circuit supplies power to the electrical load.

Optionally, the power detection circuit is further configured to output a power-off signal to the A power supply maintenance control circuit, so that the power supply maintenance control circuit controls the electrical connection between the energy storage circuit and the output terminal of the power supply, so that the energy storage circuit stops supplying power to the electric load.

Optionally, the second preset voltage is greater than the undervoltage threshold of the power conversion circuit;

The undervoltage threshold of the power conversion circuit is the minimum input voltage when the power conversion circuit works normally.

Optionally, the power detection circuit includes:

A signal output circuit, the output end of the signal output circuit is connected to the controlled end of the power supply maintenance control circuit;

A first detection circuit, the detection terminal of the first detection circuit is connected to the input terminal of the power supply, the output terminal of the first detection circuit is connected to the first controlled terminal of the signal output circuit, and the first detection circuit The circuit is used to detect the output voltage of the input terminal of the power supply, and when the output voltage of the input terminal of the power supply is less than the second preset voltage, output the first power-down signal to the signal output circuit, and output at the input terminal of the power supply outputting a first power-on signal to the signal output circuit when the voltage is greater than the second preset voltage;

A second detection circuit, the detection end of the second detection circuit is connected to the output end of the power conversion circuit, the output end of the second detection circuit is connected to the second controlled end of the signal output circuit, the The second detection circuit is used to detect the output voltage of the power conversion circuit, and when the output voltage of the power conversion circuit is less than a third preset voltage, output a second power-down signal to the signal output circuit, and when the output voltage of the power conversion circuit is less than a third preset voltage, When the output voltage of the power conversion circuit is greater than the third preset voltage, output a second power-on signal to the signal output circuit;

The signal output circuit is configured to output a power supply maintenance signal to the power supply maintenance control circuit when receiving the first power-down signal and/or the second power-down signal, so that the power supply maintenance control circuit controls the energy storage A circuit is electrically connected to the output terminal of the power supply, so that the energy storage circuit supplies power to an electrical load; and,

The signal output circuit is further configured to output a power-off signal to the power supply maintenance control circuit when receiving the first power-on signal and the second power-on signal, so that the power supply maintenance control circuit controls the energy storage circuit Disconnecting the electrical connection with the output end of the power supply, so that the energy storage circuit stops supplying power to the electric load.

Optionally, the first detection circuit includes a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, and a first comparator, and the first terminal of the first resistor is connected to The power input terminal is connected, the second end of the first resistor is connected to the first end of the second resistor, the second end of the second resistor is grounded, and the second end of the first resistor is also connected to the The positive input terminal of the first comparator is connected, the first terminal of the third resistor is grounded, the second terminal of the third resistor is connected to the first terminal of the fourth resistor, and the fourth resistor The two terminals are connected to the output terminal of the power supply, the common terminal of the third resistor and the fourth resistor is connected to the inverting input terminal of the first comparator, and the power supply terminal of the first comparator is connected to the fourth resistor. The second end of the resistor is connected, the output end of the first comparator is connected to the first controlled end of the signal output circuit, and the fifth resistor is arranged in parallel between the output end of the first comparator and the positive direction Between the input terminals, the sixth resistor is arranged in parallel between the power supply terminal and the output terminal of the first comparator.

Optionally, the second detection circuit includes an eighth resistor, a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor, a thirteenth resistor, and a second comparator, and the eighth resistor One end is connected to the output end of the power conversion circuit, the second end of the eighth resistor is connected to the first end of the ninth resistor, the second end of the ninth resistor is grounded, and the eighth resistor The second end of the second comparator is also connected to the positive input end of the second comparator, the first end of the tenth resistor is grounded, and the second end of the tenth resistor is connected to the first end of the eleventh resistor , the second end of the eleventh resistor is connected to the output end of the power supply, the common end of the tenth resistor and the eleventh resistor is connected to the inverting input end of the second comparator, and the second comparator The output terminal of the device is connected to the second controlled terminal of the signal output circuit, the first terminal of the twelfth resistor is connected to the output terminal of the power supply, and the second terminal of the twelfth resistor is connected to the second terminal of the twelfth resistor. The output ends of the two comparators are connected, and the thirteenth resistor is arranged in parallel between the output end of the second comparator and the positive input end.

Optionally, the energy storage voltage detection circuit includes a fourteenth resistor, a fifteenth resistor, a sixteenth resistor, a third comparator, and a third switch tube, and the first end of the fourteenth resistor is connected to the The output end of the energy storage circuit is connected, the second end of the fourteenth resistor is connected to the first end of the fifteenth resistor, the second end of the fifteenth resistor is grounded, and the third comparator The reverse input terminal is connected to the second terminal of the fourteenth resistor, the output terminal of the third comparator is connected to the controlled terminal of the third switch tube, and the first terminal of the sixteenth resistor is connected to the The output end of the energy storage circuit is connected, the second end of the sixteenth resistor is connected to the output end of the third comparator, and the first end of the third switching tube is connected to the power supply maintenance control circuit. The controlled end is connected, and the second end of the third switching tube is grounded.

The present invention also proposes an electronic device, including a processor and the above-mentioned power-down detection and power supply maintenance function circuit; wherein,

The power supply end of the processor is connected with the power output end of the power failure detection and power supply maintenance function circuit.

Optionally, the signal receiving end of the processor is further connected to the output end of the power detection circuit, and the processor is configured to store data when receiving the power supply maintenance signal output by the power detection circuit.

The technical solution of the present invention sets the energy storage voltage detection circuit, so that the energy storage voltage detection circuit can detect the output voltage of the energy storage circuit, and when the output voltage of the energy storage circuit is lower than the first preset voltage, that is, in the subsequent load processing After the power-off data storage is completed, the control power supply maintenance control circuit disconnects the connection between the energy storage circuit and the output terminal of the power supply, so that the power supply voltage value of the subsequent load processor before power-on can be lower than the required voltage value, avoiding the subsequent stage load processor. An exception occurs when the load processor is powered on again, which improves the safety and stability of the power-off detection and power supply maintenance function circuits, and solves the problem of poor stability of the existing power-off storage scheme.

Description of drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. For those skilled in the art, other drawings can also be obtained according to the structures shown in these drawings without creative effort.

Fig. 1 is a functional module schematic diagram of an embodiment of the power-down detection and power supply maintenance functional circuit of the present invention;

2 is a schematic diagram of functional modules of another embodiment of the power-down detection and power supply maintenance functional circuit of the present invention;

3 is a schematic diagram of functional modules of another embodiment of the power-down detection and power supply maintenance functional circuit of the present invention;

FIG. 4 is a schematic diagram of the circuit structure of an embodiment of the power failure detection and power supply maintenance function circuit of the present invention.

Explanation of reference numbers:

The realization of the purpose of the present invention, functional characteristics and advantages will be further described in conjunction with the embodiments and with reference to the accompanying drawings.

detailed description

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

It should be noted that if there is a directional indication (such as up, down, left, right, front, back...) in the embodiment of the present invention, the directional indication is only used to explain the position in a certain posture (as shown in the accompanying drawing). If the specific posture changes, the directional indication will also change accordingly.

In addition, if there are descriptions involving "first", "second" and so on in the embodiments of the present invention, the descriptions of "first", "second" and so on are only for descriptive purposes, and should not be interpreted as indicating or implying Its relative importance or implicitly indicates the number of technical features indicated. Thus, the features defined as "first" and "second" may explicitly or implicitly include at least one of these features. In addition, the technical solutions of the various embodiments can be combined with each other, but it must be based on the realization of those skilled in the art. When the combination of technical solutions is contradictory or cannot be realized, it should be considered that the combination of technical solutions does not exist , nor within the scope of protection required by the present invention.

The invention proposes a power-down detection and power supply maintenance function circuit.

At present, in the existing technology, some solutions are to continue to discharge the supercapacitor after power-off without control, which will cause the system to start abnormally when the power is turned on again because the previous voltage did not drop to 0V, which will affect the usability of the product and the user. Poor experience.

In order to solve the above problems, with reference to Figures 1 to 4, in one embodiment, the power-down detection and power supply maintenance function circuit includes:

A power supply output terminal, the power supply output terminal is used to connect to an electrical load;

Energy storage circuit 10;

A power supply maintenance control circuit 20, the input terminal of the power supply maintenance control circuit 20 is connected to the output terminal of the energy storage circuit 10, the output terminal of the power supply maintenance control circuit 20 is connected to the output terminal of the power supply, and the power supply maintenance control circuit 20 is connected to the output terminal of the power supply. The control circuit 20 is used to control the electrical connection between the energy storage circuit 10 and the output terminal of the power supply when it is turned on;

An energy storage voltage detection circuit 30, the detection end of the energy storage voltage detection circuit 30 is connected to the output end of the energy storage circuit 10, the output end of the energy storage voltage detection circuit 30 is connected to the power supply maintenance control circuit 20 The controlled end is connected, the storage voltage detection circuit 30 is used to detect the output voltage of the storage circuit 10, and when the output voltage of the storage circuit 10 is less than the first preset voltage, control the power supply to maintain The control circuit 20 disconnects the electrical connection between the energy storage circuit 10 and the output terminal of the power supply, so that the energy storage circuit 10 stops supplying power to the load.

In this embodiment, the output end of the power supply is used to connect to loads such as processors, and the output end of the power supply can also be connected to the power supply circuit to provide normal power supply for the connected subsequent loads. When the power supply circuit is powered off , the energy storage circuit 10 provides temporary power supply, so that the subsequent load processor can store the data in time to prevent data loss due to power failure. Energy storage circuit 10 can be realized by selecting energy storage devices such as energy storage capacitors and rechargeable batteries. When the load supplies power normally, a part of the electric energy output by the power supply circuit is stored for temporary power supply. The electric energy in the energy storage circuit 10 may also come from other circuits. The power supply maintenance control circuit 20 can be implemented by selecting a switch tube to control the connection or disconnection of the path between the energy storage circuit 10 and the output terminal of the power supply. The power supply maintenance control circuit 20 is used to control the The energy storage circuit 10 is electrically connected to the output terminal of the power supply, so that the energy storage circuit 10 provides temporary power supply for the subsequent load processor. The energy storage voltage detection circuit 30 can be realized by selecting a voltage dividing resistor, a comparator and a switch tube, etc., the positive input terminal of the comparator is connected to the output voltage of the energy storage circuit 10, and a negative input terminal of the comparator is connected to a The reference voltage, in this way, can use the low level and high level output by the comparator to control the turn-on or turn-off of the switch tube, thereby controlling the connection or disconnection of the path between the energy storage circuit 10 and the output terminal of the power supply.

It should be noted that if there is no energy storage voltage detection circuit 30, after the data of the subsequent load processor is saved, the load processor is gradually in a standby or shutdown state. At this time, the subsequent load is very small, and the electric energy stored in the energy storage circuit 10 is discharged The time to 0V will be very long, that is, the time for the output of the power supply to drop to 0V is very long. However, the post-load processor usually has clear requirements, that is, the power supply voltage value must be less than a certain value before re-powering on, otherwise there will be abnormalities after the post-load processor is powered on, such as the system cannot be started, etc. Therefore, this In the embodiment, an energy storage voltage detection circuit 30 is provided to quickly control the energy storage circuit 10 and The path between the output ends of the power supply is disconnected, so that the energy storage circuit 10 stops supplying power to the subsequent load processor, so as to ensure that the system can start normally when the power is turned on next time. The first preset voltage value can be set to be less than or equal to the output voltage of the energy storage circuit 10 after the power-down data storage is completed by the subsequent load processor. When the output voltage of the energy storage circuit 10 drops to the first preset voltage value, It means that the post-load processor has completed the work of power-down data storage. For example, when the energy storage circuit 10 supplies power to the subsequent load processor, the initial voltage is 5V, and the output voltage value of the energy storage circuit 10 is reduced to 4V after the subsequent load processor finishes storing the data. Set the voltage value to 4V or less than 4V. In this way, the power supply can be disconnected after the post-load processor completes data storage, so as to ensure that the system can start normally when the power is turned on next time.

Referring to Fig. 4, Fig. 4 is a schematic diagram of a circuit structure of an implementation of a power failure detection and power supply maintenance function circuit. The energy storage circuit 10 in the figure is composed of an energy storage capacitor C2 and an eighteenth resistor R18, and the energy storage capacitor C2 is stored from the power input The electric energy input by the terminal, the power supply maintenance control circuit 20 is composed of NMOS transistor Q4, PMOS transistor Q5 and pull-down resistor R17, when the NMOS transistor Q4 receives a high-level power supply maintenance signal, it is turned on, and the voltage at the gate terminal of the PMOS transistor Q5 is pulled down , so that the PMOS transistor Q5 is turned on, so that the energy storage capacitor C2 is electrically connected to the output end of the power supply, so as to temporarily supply power to the subsequent load processor. The energy storage voltage detection circuit 30 is composed of a comparator U3, a fourteenth resistor R14, a fifteenth resistor R15, a sixteenth resistor R16 and an NMOS transistor Q3. The comparator U3 is a comparator integrated with a power reference source inside. The voltage value of the integrated reference source is the first preset voltage value. When the output voltage of the energy storage circuit 10 is greater than the first preset voltage value, the comparator U3 outputs a low level to control the NMOS transistor Q3 to turn off. At this time, the NMOS transistor Q3 The gate terminal of Q4 receives a high-level power supply to keep the signal turned on. When the output voltage of the energy storage circuit 10 is lower than the first preset voltage value, the comparator U3 outputs a high level to control the conduction of the NMOS transistor Q3, thereby pulling down the voltage of the gate terminal of the NMOS transistor Q4, that is, the output power is cut off. The signal is sent to the NMOS transistor Q4, so that the NMOS transistor Q4 is turned off, so that the PMOS transistor Q5 is turned off, so that the energy storage circuit 10 is disconnected from the output terminal of the power supply, and the power supply for the subsequent load processor is stopped to ensure that the next power-on The system can start normally.

In the present invention, by setting the energy storage voltage detection circuit 30, the energy storage voltage detection circuit 30 can detect the output voltage of the energy storage circuit 10, and when the output voltage of the energy storage circuit 10 is less than the first preset voltage, that is, in the subsequent stage After the load processor completes the power-down data storage, control the power supply maintenance control circuit 20 to disconnect the energy storage circuit 10 from the output terminal of the power supply, so that the power supply voltage value of the subsequent load processor before power-on again can be less than the required voltage value , to avoid abnormality when the post-stage load processor is powered on again, and improve the safety and stability of the power failure detection and power supply maintenance function circuit.

Referring to Figures 1 to 4, in one embodiment, the power-down detection and power supply maintenance function circuit also includes:

The power input terminal is used to connect to the input power;

A power detection circuit 40, the detection end of the power detection circuit 40 is connected to the power input end, the output end of the power detection circuit 40 is connected to the controlled end of the power supply maintenance control circuit 20, and the power detection circuit 40 is used to detect the output voltage of the input terminal of the power supply, and when the output voltage of the input terminal of the power supply is greater than a second preset voltage, control the power supply maintenance control circuit 20 to disconnect the energy storage circuit 10 from the output of the power supply The electrical connection between the terminals, so that the energy storage circuit 10 stops supplying power to the electrical load.

In this embodiment, the power supply input terminal can be connected with the power supply output terminal, so that the input power supply can provide normal power supply for the subsequent load. When the power supply input terminal is powered off, the energy storage circuit 10 will provide Temporary power supply. The second preset voltage is the minimum voltage when the system can work normally. For example, when the voltage at the input terminal of the power supply is greater than 5V, the post-stage load processor can work normally, but when the voltage at the input terminal of the power supply is less than 5V, the post-stage load processor cannot If it is working normally, then 5V can be set as the second preset voltage. In this way, when the output voltage of the power input terminal is greater than the second preset voltage, it is characterized as the power input terminal is powered on, and when the output voltage of the power input terminal is lower than the second preset voltage When the voltage is set, it is characterized by power failure at the input terminal of the power supply. The power supply detection circuit 40 can be realized by selecting a voltage dividing resistor, a comparator and a switch tube, so that when the output voltage of the power supply input terminal is greater than the second preset voltage, that is, when the power supply input terminal is powered on, the power-off signal is output to the power supply maintenance control Circuit 20, so that the power supply maintenance control circuit 20 controls the energy storage circuit 10 to disconnect the electrical connection with the output end of the power supply, so that the connected input power supply supplies power to the subsequent load again, ensuring the normal operation of the subsequent load after power-on again .

Optionally, the power supply detection circuit 40 is further configured to output a power supply maintenance signal to the power supply maintenance control circuit 20 when the output voltage of the power input terminal is lower than a second preset voltage, so that the power supply maintenance control circuit 20 controls the electrical connection between the energy storage circuit 10 and the output end of the power supply, so that the energy storage circuit 10 supplies power to the electric load.

In this embodiment, the power supply detection circuit 40 can be implemented by selecting a voltage dividing resistor, a comparator and a switch tube, so that when the output voltage of the power supply input terminal is lower than the second preset voltage, that is, when the power supply input terminal is powered off, the output power supply Keep the signal to the power supply maintenance control circuit 20, so that the power supply maintenance control circuit 20 controls the energy storage circuit 10 to be electrically connected to the output end of the power supply, so that the energy storage circuit 10 temporarily supplies power to the subsequent load, so that the subsequent load processor can complete the data Stored work. The power detection circuit 40 can use the comparator to realize the output of the power supply maintenance signal and the power-off signal, and connect the second preset voltage to the comparator as a reference voltage, so that the output voltage of the power detection circuit 40 at the power input terminal can be lower than the second The power supply maintenance signal is output when the voltage is preset, and the power-off signal is output when the output voltage of the power input terminal is greater than the second preset voltage, so as to realize the control of the power supply maintenance control circuit 20 .

Optionally, the power supply terminal of the power supply detection circuit 40 is connected to the power supply output terminal, and the power supply detection circuit 40 is also used to output a power-off signal to the power supply maintenance control circuit when the power supply terminal is powered off 20, so that the power supply maintenance control circuit 20 controls the energy storage circuit 10 to disconnect the electrical connection with the output end of the power supply, so that the energy storage circuit 10 stops supplying power to the electric load.

In this embodiment, the power supply end of the power detection circuit 40 is connected to the power output end. When the power supply end is powered off, the power detection circuit 40 cannot work normally. At this time, the power detection circuit 40 can be regarded as outputting a low-level interrupt The electric signal is sent to the power supply maintenance control circuit 20, thereby controlling the energy storage circuit 10 to stop supplying power to the electric load. In this embodiment, the output end of the power supply is connected to the power supply end of the power detection circuit 40 , and the input power is used as the power supply, and no additional power supply is required to supply power to the power detection circuit 40 . At the same time, when the power supply terminal is powered off, for example, when the power supply maintenance control circuit 20 controls the energy storage circuit 10 to be electrically connected to the output terminal of the power supply, and the energy storage circuit 10 has 0 electric energy, the power supply detection circuit 40 cannot work normally at this moment. The power detection circuit 40 can be regarded as outputting a low-level power-off signal to the power supply maintenance control circuit 20, so as to control the energy storage circuit 10 to disconnect the electrical connection with the output terminal of the power supply, avoid abnormalities when the system is powered on again, and improve the Brownout detection and power retention functions for circuit safety.

Referring to Figures 1 to 4, in one embodiment, the power-down detection and power supply maintenance function circuit also includes:

Power conversion circuit 50, the input end of described power conversion circuit 50 is connected with power input end, the output end of described power conversion circuit 50 is connected with described power output end and the input end of energy storage circuit 10 respectively, and described power conversion circuit The circuit 50 is used to convert the connected input power into a power supply voltage and then output it;

The power detection circuit 40 has a first detection terminal and a second detection terminal, the first detection terminal of the power detection circuit 40 is connected to the power input terminal, and the second detection terminal of the power detection circuit 40 is connected to the power input terminal. The output terminal of the power conversion circuit 50 is connected;

The power detection circuit 40 is used to detect the output voltage of the power input terminal and the output voltage of the power conversion circuit 50, and the output voltage at the power input terminal is less than a second preset voltage, and/or the power conversion When the output voltage of the circuit 50 is lower than the third preset voltage, output a power supply maintenance signal to the power supply maintenance control circuit 20, so that the power supply maintenance control circuit 20 controls the electrical connection between the energy storage circuit 10 and the output terminal of the power supply , so that the energy storage circuit 10 supplies power to the electric load.

In this embodiment, the power conversion circuit 50 can be implemented by selecting a DC-DC voltage conversion circuit, an AC-DC voltage conversion circuit, etc., and the power conversion circuit 50 selects a corresponding power conversion circuit 50 according to actual usage requirements, for example, it is used in In industrial communication, the input power connected to the power input terminal is usually 24V. When it is applied to communication equipment, the input power connected to the power input terminal is usually 48V, and the processors that need to save data when the power is off are basically Therefore, the power conversion circuit 50 can select the corresponding power conversion circuit 50 to convert the input power into the power supply required by the processor according to the actual use requirements. The power detection circuit 40 can be made up of two voltage detection circuits, and each voltage detection circuit can be realized by selecting a voltage dividing resistor, a comparator and a switching tube. The two detection terminals of the power detection circuit 40 respectively detect the output voltage of the power input terminal and the The output voltage of the conversion circuit 50. In this way, when an abnormal power-down occurs at the input terminal of the power supply, or the failure of the power conversion circuit 50 causes an abnormal output voltage, that is, the output voltage at the input terminal of the power supply is lower than the second preset voltage, or the output voltage of the power conversion circuit 50 is lower than the third preset voltage. voltage, the power supply detection circuit 40 outputs a power supply maintenance signal to the power supply maintenance control circuit 20, so that the power supply maintenance control circuit 20 controls the electrical connection of the energy storage circuit 10 to the output terminal of the power supply, so that the energy storage circuit 10 temporarily supplies power to the subsequent load. In order to enable the post-load processor to complete the work of data storage during abnormal power failure.

Optionally, the power detection circuit 40 is further configured to output a power-off signal to The power supply maintenance control circuit 20 enables the power supply maintenance control circuit 20 to control the energy storage circuit 10 to disconnect the electrical connection with the output end of the power supply, so that the energy storage circuit 10 stops supplying power to the load.

It can be understood that when the power supply input terminal is powered off and then powered on again, since it takes a certain amount of time to convert the output of the power conversion circuit 50 after power on again, in order to avoid the need to control the energy storage circuit 10 before a stable power supply voltage is established, Stopping the power supply to the subsequent load processor will cause problems such as data storage failure. In this embodiment, the power detection circuit 40 also has a second detection terminal connected to the output terminal of the power conversion circuit 50 . When the power detection circuit 40 detects that the output voltage of the power input terminal is greater than the second preset voltage and the output voltage of the power conversion circuit 50 is greater than the third preset voltage, that is, when the power input terminal and the power conversion circuit 50 are both working normally, the Outputting a power-off signal to the power supply maintenance control circuit 20, so that the power supply maintenance control circuit 20 controls the energy storage circuit 10 to disconnect the electrical connection with the output terminal of the power supply, and resumes power supply by the input power supply connected. In this way, the energy storage circuit 10 stops supplying power to the subsequent load processor after the power conversion circuit 50 has established a stable power supply voltage, which can avoid data storage failures caused by disconnecting the energy storage circuit 10 when the power supply is not normally established. And other problems, improve the stability of power failure detection and power supply maintenance function circuit.

1 to 4, in one embodiment, the second preset voltage is greater than the undervoltage threshold of the power conversion circuit 50;

The undervoltage threshold of the power conversion circuit 50 is the minimum input voltage when the power conversion circuit 50 works normally.

It can be understood that, in order to ensure that the subsequent load can still be maintained in a normal working state before the energy storage circuit 10 supplies power to the load, it is necessary to set the output voltage at the input terminal of the power supply when the output voltage at the input terminal of the power supply drops to the second preset voltage. It should be greater than the undervoltage threshold of the power conversion circuit 50 , that is, greater than the minimum input voltage required by the power conversion circuit 50 for normal operation. In this way, before the output voltage at the input terminal of the power supply drops to the second preset voltage, the power conversion circuit 50 can still convert the output voltage at the input terminal of the power supply to the power supply voltage required by the post-stage load processor, so as to ensure that the energy storage circuit 10 Power supply before powering the post-load processor. And when the output voltage of the power input terminal is lower than the second preset voltage, the power conversion circuit 50 cannot convert the output voltage of the power input terminal to the power supply voltage required by the subsequent load processor, that is, the power conversion circuit 50 cannot work normally. In other words, the power detection circuit 40 can output the power supply maintenance signal to the power supply maintenance control circuit 20 in advance before the power conversion circuit 50 fails to work normally, so as to control the connection between the energy storage circuit 10 and the output terminal of the power supply, so that the power conversion circuit 50 The output end can be powered off after the energy storage circuit 10 supplies power, which ensures the power supply state of the subsequent load processor, enables the subsequent load processor to perform power-down storage in time and normally, and improves the power-down detection and power supply maintenance function circuit. stability.

1 to 4, in one embodiment, the power detection circuit 40 includes:

A signal output circuit, the output end of the signal output circuit is connected to the controlled end of the power supply maintenance control circuit 20;

A first detection circuit, the detection terminal of the first detection circuit is connected to the input terminal of the power supply, the output terminal of the first detection circuit is connected to the first controlled terminal of the signal output circuit, and the first detection circuit The circuit is used to detect the output voltage of the input terminal of the power supply, and when the output voltage of the input terminal of the power supply is less than the second preset voltage, output the first power-down signal to the signal output circuit, and output at the input terminal of the power supply outputting a first power-on signal to the signal output circuit when the voltage is greater than the second preset voltage;

A second detection circuit, the detection end of the second detection circuit is connected to the output end of the power conversion circuit 50, the output end of the second detection circuit is connected to the second controlled end of the signal output circuit, the The second detection circuit is used to detect the output voltage of the power conversion circuit 50, and output a second power-down signal to the signal output circuit when the output voltage of the power conversion circuit 50 is less than a third preset voltage, and outputting a second power-on signal to the signal output circuit when the output voltage of the power conversion circuit 50 is greater than a third preset voltage;

The signal output circuit is configured to output a power supply maintenance signal to the power supply maintenance control circuit 20 when receiving the first power down signal and/or the second power down signal, so that the power supply maintenance control circuit 20 controls the The energy storage circuit 10 is electrically connected to the output terminal of the power supply, so that the energy storage circuit 10 supplies power to an electric load; and,

The signal output circuit is also configured to output a power-off signal to the power supply maintenance control circuit 20 when receiving the first power-on signal and the second power-on signal, so that the power supply maintenance control circuit 20 controls the storage The energy storage circuit 10 is electrically disconnected from the output terminal of the power supply, so that the energy storage circuit 10 stops supplying power to the electric load.

Referring to Fig. 4, Fig. 4 is a schematic circuit structure diagram of an embodiment of a power-down detection and power supply maintenance function circuit. In this embodiment, the power detection circuit 40 is composed of a signal output circuit, a first detection circuit and a second detection circuit, wherein , the signal output circuit is composed of switch tubes Q1, Q2 and the seventh resistor R7, one end of the seventh resistor is connected to the output terminal of the power supply, and the other end is connected to the controlled terminal of the power supply maintenance control circuit 20, when the switch tubes Q1 and Q2 are both conducting When on, the controlled terminal of the power supply maintenance control circuit 20 is pulled down to a low level, that is, a power-off signal is output to the power supply maintenance control circuit 20 . When one of the switch tubes Q1 or Q2 is turned off, the controlled terminal of the power supply maintenance control circuit 20 is at a high level, that is, outputs a power supply maintenance signal to the power supply maintenance control circuit 20 .

Optionally, the first detection circuit includes a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6 and a first comparator U1. The first end of a resistor R1 is connected to the power input end, the second end of the first resistor R1 is connected to the first end of the second resistor R2, and the second end of the second resistor R2 is grounded, The second terminal of the first resistor R1 is also connected to the positive input terminal of the first comparator U1, the first terminal of the third resistor R3 is grounded, and the second terminal of the third resistor R3 is connected to the positive input terminal of the first comparator U1. The first end of the fourth resistor R4 is connected, the second end of the fourth resistor R4 is connected to the output end of the power supply, the common end of the third resistor R3 and the fourth resistor R4 is connected to the first comparator U1 The reverse input end is connected, the power supply end of the first comparator U1 is connected to the second end of the fourth resistor R4, and the output end of the first comparator U1 is connected to the first controlled signal output circuit of the signal output circuit. The fifth resistor R5 is connected in parallel between the output terminal and the positive input terminal of the first comparator U1, and the sixth resistor R6 is connected in parallel between the power supply terminal and the positive input terminal of the first comparator U1. between the output terminals.

Referring to Fig. 4, the first detection circuit is composed of a first comparator U1, resistors R1-R6, and a capacitor C1. The first capacitor C1 and the first resistor R1 form an RC filter circuit to filter out spurious abnormal waveforms on the input power supply VIN, Avoid false triggering of power-down and under-voltage alarms. The positive input terminal of the first comparator U1 is connected to the common terminal of the first resistor R1 and the second resistor R2, that is, the detection terminal of the power input, and the negative input terminal of the comparator U1 is connected to the third resistor R3 and the fourth resistor R3. The common terminal of the resistor R4 is connected, that is, the second preset voltage reference terminal. The output voltage VIN of the power supply input terminal is divided by R1 and R2, and the value is Vref1=VIN*R2/(R1+R2), and the voltage of the power supply output terminal is obtained by The voltage divided by the third resistor R3 and the fourth resistor R4 is the second preset voltage Vref2=VCC2*R3/(R3+R4), which can be adjusted by adjusting the resistance values of the third resistor R3 and the fourth resistor R4 The second preset voltage, when Vref1 is less than Vref2 , the first comparator U1 outputs a low-level first power-down signal to turn off the first switch tube Q1 . When Vref1 is greater than Vref2, the first comparator U1 outputs a high-level first power-on signal to turn on the first switch transistor Q1.

Optionally, the second detection circuit includes an eighth resistor R8, a ninth resistor R9, a tenth resistor R10, an eleventh resistor R11, a twelfth resistor R12, a thirteenth resistor R13, and a second comparator U2, The first end of the eighth resistor R8 is connected to the output end of the power conversion circuit 50, the second end of the eighth resistor R8 is connected to the first end of the ninth resistor R9, and the ninth resistor The second end of R9 is grounded, the second end of the eighth resistor R8 is also connected to the positive input end of the second comparator U2, the first end of the tenth resistor R10 is grounded, and the tenth resistor R10 is grounded. The second end of R10 is connected to the first end of the eleventh resistor R11, the second end of the eleventh resistor R11 is connected to the output end of the power supply, and the common connection between the tenth resistor R10 and the eleventh resistor R11 is terminal is connected with the inverting input terminal of the second comparator U2, the output terminal of the second comparator U2 is connected with the second controlled terminal of the signal output circuit, and the first of the twelfth resistor R12 end is connected to the output end of the power supply, the second end of the twelfth resistor R12 is connected to the output end of the second comparator U2, and the thirteenth resistor R13 is connected in parallel to the second comparator U2 Between the output terminal and the positive input terminal.

The second detection circuit is composed of the second comparator U2 and resistors R8~R13. The second comparator U2 and the first comparator U1 can be two independent comparator chips, or a single chip that directly uses integrated dual comparators. to realise. The thirteenth resistor R13 is used to set the hysteresis threshold of the comparator to eliminate jitter and interference. The positive input terminal of the second comparator U2 is connected to the common terminal of the eighth resistor R8 and the ninth resistor R9, that is, power conversion At the output power detection terminal of the circuit 50, the value of the output voltage VCC1 of the power conversion circuit 50 after being divided by the eighth resistor R8 and the ninth resistor R9 is Vref3=VCC1*R9/(R8+R9), and the value of the second comparator U2 The reverse input terminal is connected to the common terminal of the tenth resistor R10 and the eleventh resistor R11, that is, the third preset voltage reference terminal, and the voltage at the output terminal of the power supply is divided by the tenth resistor R10 and the eleventh resistor R11. That is, the third preset voltage Vref4=VCC2*R10/(R10+R11), the third preset voltage can be adjusted by adjusting the resistance values of the tenth resistor R10 and the eleventh resistor R11. Similar to the first detection circuit, when Vref3 is smaller than Vref4, the second comparator U2 outputs a low-level second power-down signal to turn off the second switching tube Q2. When Vref3 is greater than Vref4, the second comparator U2 outputs a high-level second power-on signal to turn on the second switch transistor Q2. In this way, when the output voltages of the power input terminal and the power conversion circuit 50 are both normal, the signal output circuit outputs a power-off signal, so that the energy storage circuit 10 stops working as a subsequent stage after the power conversion circuit 50 has established a stable power supply voltage. The power supply of the load processor can avoid problems such as data storage failure caused by disconnecting the energy storage circuit 10 before the power supply is normally established. At the same time, when the output voltage of any one of the power input terminal and the power conversion circuit 50 is abnormal, the signal output circuit will output a power supply holding signal, so that the energy storage circuit 10 can supply power for the subsequent load processor, and can switch under various abnormal conditions. Supplying power to the energy storage circuit 10 improves the stability of the power failure detection and power supply maintenance functional circuit. In addition, it can be understood that some of the existing power-down storage schemes use two resistors to divide the voltage to control the switch of the Mos tube to trigger the power-down signal, but due to the Vgs(th)_min and Vgs(th) of the Mos _max usually has a 2V error range, and after the multiples of the two voltage divider resistors are converted to the circuit, the error of the trigger point of power failure and undervoltage is relatively large, which may easily lead to unstable circuit status. Therefore, in this embodiment, the first detection circuit and the second detection circuit are composed of comparators and resistors, the device cost is low, and the power-down and undervoltage trigger points can be set with higher precision according to the requirements, which improves the circuit State stability.

Referring to FIG. 4, in one embodiment, the energy storage voltage detection circuit 30 includes a fourteenth resistor R14, a fifteenth resistor R15, a sixteenth resistor R16, a third comparator U3 and a third switch tube Q3, so The first end of the fourteenth resistor R14 is connected to the output end of the energy storage circuit 10, the second end of the fourteenth resistor R14 is connected to the first end of the fifteenth resistor R15, and the first end of the fifteenth resistor R15 is connected. The second end of the fifteenth resistor R15 is grounded, the inverting input end of the third comparator U3 is connected to the second end of the fourteenth resistor R14, and the output end of the third comparator U3 is connected to the second end of the fourth comparator U3. The controlled end of the three switching tubes Q3 is connected, the first end of the sixteenth resistor R16 is connected to the output end of the energy storage circuit 10, and the second end of the sixteenth resistor R16 is compared with the third The output terminal of the switch U3 is connected, the first terminal of the third switching tube Q3 is connected to the controlled terminal of the power supply maintenance control circuit 20, and the second terminal of the third switching tube Q3 is grounded.

Referring to Fig. 4, Fig. 4 is a schematic diagram of a circuit structure of an implementation of a power failure detection and power supply maintenance function circuit. The energy storage circuit 10 in the figure is composed of an energy storage capacitor C2 and an eighteenth resistor R18, and the energy storage capacitor C2 is stored from the power input The electric energy input by the terminal, the power supply maintenance control circuit 20 is composed of NMOS transistor Q4, PMOS transistor Q5 and pull-down resistor R17, when the NMOS transistor Q4 receives a high-level power supply maintenance signal, it is turned on, and the voltage at the gate terminal of the PMOS transistor Q5 is pulled down , so that the PMOS transistor Q5 is turned on, so that the energy storage capacitor C2 is electrically connected to the output end of the power supply, so as to temporarily supply power to the subsequent load processor. The energy storage voltage detection circuit 30 is composed of a third comparator U3, a fourteenth resistor R14, a fifteenth resistor R15, a sixteenth resistor R16, and an NMOS transistor Q3. The third comparator U3 is integrated with a power reference source Comparator, the voltage value of the internal integrated reference source is the first preset voltage value, when the output voltage of the energy storage circuit 10 is greater than the first preset voltage value, the third comparator The comparator U3 outputs a low level to control the NMOS transistor Q3 is turned off, and at this time, the gate terminal of the NMOS transistor Q4 receives a high-level power supply to keep the signal turned on. And when the output voltage of the energy storage circuit 10 is less than the first preset voltage value, the third comparator U3 outputs a high level to control the NMOS transistor Q3 to turn on, thereby pulling down the voltage of the gate terminal of the NMOS transistor Q4, and also That is, the power-off signal is output to the NMOS transistor Q4, so that the NMOS transistor Q4 is turned off, so that the PMOS transistor Q5 is turned off, so that the energy storage circuit 10 is disconnected from the output terminal of the power supply, and the power supply for the subsequent load processor is stopped, so as to ensure The system can start normally when the power is turned on for the first time.

The present invention also proposes an electronic device, including a processor and the above-mentioned power-down detection and power supply maintenance function circuit; wherein,

The power supply end of the processor is connected with the power output end of the power failure detection and power supply maintenance function circuit.

Optionally, the signal receiving end of the processor is also connected to the output end of the power detection circuit 40 , and the processor is configured to store data when receiving the power supply hold signal output by the power detection circuit 40 .

In this embodiment, the power supply output terminal of the power failure detection and power supply maintenance function circuit is used to connect to the processor, and the signal receiving terminal of the processor is connected to the output terminal of the power supply detection circuit 40 in the power failure detection and power supply maintenance function circuit In this way, when the power supply input end is powered off, the power supply detection circuit 40 outputs a power supply hold signal, and at this time switches to supply power to the energy storage circuit 10, and at the same time, the processor starts to store data when receiving the power supply hold signal, so that the processor can obtain the power supply in time. Notify the system of power failure and store data in time, avoiding data loss and improving the stability and safety of electronic equipment. In addition, the electronic device includes the above-mentioned power-down detection and power supply maintenance function circuit. The specific structure of the power-down detection and power supply maintenance function circuit refers to the above-mentioned embodiments. Since this electronic device adopts all the technical solutions of all the above-mentioned embodiments, it It has at least all the beneficial effects brought by the technical solutions of the above-mentioned embodiments, which will not be described here one by one.

The above is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. Under the inventive concept of the present invention, the equivalent structural transformation made by using the description of the present invention and the contents of the accompanying drawings, or direct/indirect use All other relevant technical fields are included in the patent protection scope of the present invention.

Claims (13)

1. A power down detection and power supply retention function circuit, comprising:

the power supply output end is used for connecting an electric load;

a tank circuit;

the input end of the power supply holding control circuit is connected with the output end of the energy storage circuit, the output end of the power supply holding control circuit is connected with the power supply output end, and the power supply holding control circuit is used for controlling the energy storage circuit to be electrically connected with the power supply output end when the power supply holding control circuit is conducted;

energy storage voltage detection circuitry, energy storage voltage detection circuitry's sense terminal with energy storage circuitry's output is connected, energy storage voltage detection circuitry's output with power supply keeps control circuit's controlled end to be connected, energy storage voltage detection circuitry is used for detecting energy storage circuitry's output voltage, and when energy storage circuitry's output voltage is less than first predetermined voltage, control power supply keeps control circuit disconnection energy storage circuitry with electricity between the power output end is connected, so that energy storage circuitry stops to supply power for the power consumption load.

2. The power down detection and power supply retention functional circuit of claim 1, further comprising:

the power input end is connected with the power output end and used for being connected with an input power supply;

the power supply detection circuit, the sense terminal of power supply detection circuit with the power input end is connected, power supply detection circuit's output with power supply keeps control circuit's controlled end to be connected, power supply detection circuit is used for detecting the output voltage of power input end, and when power input end's output voltage is greater than the second and predetermines voltage, control power supply keeps control circuit disconnection energy storage circuit with electricity between the power output end is connected, so that energy storage circuit stops to supply power for the power consumption load.

3. The power-down detection and power-supply maintaining functional circuit of claim 2, wherein the power supply detection circuit is further configured to output a power-supply maintaining signal to the power-supply maintaining control circuit when the output voltage at the power supply input terminal is less than a second preset voltage, so that the power-supply maintaining control circuit controls the energy storage circuit to be electrically connected with the power supply output terminal, so that the energy storage circuit supplies power to an electrical load.

4. The power down detection and power supply maintaining function circuit as claimed in claim 2, wherein a power supply terminal of the power supply detection circuit is connected to the power supply output terminal, and the power supply detection circuit is further configured to output a power down signal to the power supply maintaining control circuit when the power supply terminal is powered down, so that the power supply maintaining control circuit controls the energy storage circuit to be electrically disconnected from the power supply output terminal, so that the energy storage circuit stops supplying power to an electrical load.

5. The power down detection and power supply retention functional circuit of claim 2, further comprising:

the input end of the power supply conversion circuit is connected with the power supply input end, the output end of the power supply conversion circuit is respectively connected with the power supply output end and the input end of the energy storage circuit, and the power supply conversion circuit is used for converting an input power supply which is accessed into a power supply voltage and then outputting the power supply voltage;

the power supply detection circuit is provided with a first detection end and a second detection end, the first detection end of the power supply detection circuit is connected with the power supply input end, and the second detection end of the power supply detection circuit is connected with the output end of the power supply conversion circuit;

the power supply detection circuit is used for detecting the output voltage of the power supply input end and the output voltage of the power supply conversion circuit, outputting a power supply holding signal to the power supply holding control circuit when the output voltage of the power supply input end is smaller than a second preset voltage and/or the output voltage of the power supply conversion circuit is smaller than a third preset voltage, so that the power supply holding control circuit controls the energy storage circuit to be electrically connected with the power supply output end, and the energy storage circuit supplies power for an electric load.

6. The power down detection and power supply maintenance functional circuit of claim 5, wherein the power supply detection circuit is further configured to output a power down signal to the power supply maintenance control circuit when the output voltage of the power supply input terminal is greater than a second preset voltage and the output voltage of the power conversion circuit is greater than a third preset voltage, so that the power supply maintenance control circuit controls the energy storage circuit to be electrically disconnected from the power supply output terminal, so that the energy storage circuit stops supplying power to an electrical load.

7. The power down detection and power supply retention function circuit of claim 5, wherein the second predetermined voltage is greater than an under-voltage threshold of the power conversion circuit;

the undervoltage threshold value of the power conversion circuit is the minimum input voltage of the power conversion circuit during normal operation.

8. The power down detection and power supply retention function circuit of claim 5, wherein the power supply detection circuit comprises:

the output end of the signal output circuit is connected with the controlled end of the power supply maintaining control circuit;

the detection end of the first detection circuit is connected with the power supply input end, the output end of the first detection circuit is connected with the first controlled end of the signal output circuit, the first detection circuit is used for detecting the output voltage of the power supply input end, outputting a first power-down signal to the signal output circuit when the output voltage of the power supply input end is smaller than a second preset voltage, and outputting a first power-up signal to the signal output circuit when the output voltage of the power supply input end is larger than the second preset voltage;

the detection end of the second detection circuit is connected with the output end of the power supply conversion circuit, the output end of the second detection circuit is connected with the second controlled end of the signal output circuit, the second detection circuit is used for detecting the output voltage of the power supply conversion circuit, outputting a second power-down signal to the signal output circuit when the output voltage of the power supply conversion circuit is smaller than a third preset voltage, and outputting a second power-up signal to the signal output circuit when the output voltage of the power supply conversion circuit is larger than the third preset voltage;

the signal output circuit is used for outputting a power supply maintaining signal to the power supply maintaining control circuit when receiving a first power down signal and/or a second power down signal, so that the power supply maintaining control circuit controls the energy storage circuit to be electrically connected with the power supply output end, and the energy storage circuit supplies power to an electric load; and the number of the first and second groups,

the signal output circuit is further used for outputting a power-off signal to the power supply maintaining control circuit when receiving the first power-on signal and the second power-on signal, so that the power supply maintaining control circuit controls the energy storage circuit to be electrically disconnected from the power output end, and the energy storage circuit stops supplying power to an electric load.

9. The power failure detection and power supply maintaining function circuit as claimed in claim 8, wherein the first detection circuit comprises a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor and a first comparator, a first end of the first resistor is connected to the power supply input terminal, a second end of the first resistor is connected to the first end of the second resistor, a second end of the second resistor is grounded, a second end of the first resistor is further connected to a forward input terminal of the first comparator, a first end of the third resistor is grounded, a second end of the third resistor is connected to a first end of the fourth resistor, a second end of the fourth resistor is connected to a power supply output terminal, a common end of the third resistor and the fourth resistor is connected to an inverting input terminal of the first comparator, a power supply terminal of the first comparator is connected to a second end of the fourth resistor, an output terminal of the first comparator is connected to a first controlled terminal of the signal output circuit, a common end of the fifth resistor is connected in parallel between the first controlled terminal of the first comparator and the sixth terminal, and the forward output terminal of the first comparator is connected in parallel to the power supply output terminal of the signal output circuit.

10. The power down detection and power supply maintenance functional circuit according to claim 8, wherein the second detection circuit includes an eighth resistor, a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor, a thirteenth resistor and a second comparator, a first end of the eighth resistor is connected to the output terminal of the power conversion circuit, a second end of the eighth resistor is connected to the first end of the ninth resistor, a second end of the ninth resistor is grounded, a second end of the eighth resistor is further connected to a positive input terminal of the second comparator, a first end of the tenth resistor is grounded, a second end of the tenth resistor is connected to the first end of the eleventh resistor, a second end of the eleventh resistor is connected to a power output terminal, a common end of the tenth resistor and the eleventh resistor is connected to a negative input terminal of the second comparator, an output terminal of the second comparator is connected to the second controlled terminal of the signal output circuit, a first end of the twelfth resistor is connected to the power output terminal, a second end of the twelfth resistor is connected to the thirteenth output terminal of the second comparator, and the positive output terminal of the second comparator is connected in parallel with the positive input terminal of the second comparator.

11. The power failure detection and power supply maintaining function circuit as claimed in claim 1, wherein the energy storage voltage detection circuit includes a fourteenth resistor, a fifteenth resistor, a sixteenth resistor, a third comparator and a third switching tube, a first end of the fourteenth resistor is connected to the output terminal of the energy storage circuit, a second end of the fourteenth resistor is connected to the first end of the fifteenth resistor, a second end of the fifteenth resistor is grounded, an inverting input terminal of the third comparator is connected to the second end of the fourteenth resistor, an output terminal of the third comparator is connected to the controlled terminal of the third switching tube, a first end of the sixteenth resistor is connected to the output terminal of the energy storage circuit, a second end of the sixteenth resistor is connected to the output terminal of the third comparator, a first end of the third switching tube is connected to the controlled terminal of the power supply maintaining control circuit, and a second end of the third switching tube is grounded.

12. An electronic device comprising a processor and a power down detection and power supply retention function circuit as claimed in any one of claims 1 to 11; wherein,

and the power supply end of the processor is connected with the power supply output end of the power failure detection and power supply maintaining functional circuit.

13. The electronic device of claim 12, wherein the signal receiving end of the processor is further connected to the output end of the power detection circuit, and the processor is configured to perform data storage when receiving the power supply holding signal output by the power detection circuit.

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