CN221151018U - Power-down holding circuit and controller - Google Patents

Abstract

The utility model discloses a power-down holding circuit and a controller, wherein the power-down holding circuit is applied to the controller, the controller comprises a load and a power input end connected with a power end of the load, the power-down holding circuit comprises an energy storage module, a voltage detection circuit and a charging circuit, and the energy storage module is electrically connected with the power end of the load; the energy storage module is used for outputting voltage to a power end of the load when the power input end is powered down; the voltage detection circuit is electrically connected with the energy storage module and is used for detecting the voltage of the energy storage module and outputting a corresponding voltage detection signal; the input end of the charging circuit is electrically connected with the power input end, the output end of the charging circuit is electrically connected with the energy storage module, and the controlled end of the charging circuit is electrically connected with the output end of the voltage detection circuit; the charging circuit is used for determining that the voltage of the energy storage module is smaller than a preset voltage according to the voltage detection signal, and starting to work so as to charge the energy storage module. The present utility model aims to improve the reliability of a control system.

Description

Power-down holding circuit and controller

Technical Field

The utility model relates to the technical field of power supply circuit control, in particular to a power failure holding circuit and a controller.

Background

In an industrial control application environment, when an input power supply of a control system is accidentally powered off, a controller is often required to store key data in an operation process after power failure, so that when the power supply of the control system is recovered, the key operation data of the system and the operation state of the system can be recovered to be normal. This often requires that the controller be able to power the CPU minimum system for a period of time after the input power is lost so that the CPU can write critical data into nonvolatile memory such as EEROM, FLASH, MRAM.

However, when the battery in the backup power supply is discharged for many times or is not used for a long time, the voltage of the battery in the backup power supply may not be enough to provide enough power supply time for the controller after the input power supply of the control system is powered down due to voltage reduction after self-discharging, so that the controller saves key data in the operation process.

Disclosure of utility model

The utility model mainly aims to provide a power-down holding circuit and a controller, and aims to enable the controller to store data after a control system is powered down through the power-down holding circuit so as to improve the reliability of the control system.

In order to achieve the above object, the present utility model provides a power-down holding circuit applied to a controller, the controller including a load and a power input terminal connected to a power terminal of the load, the power-down holding circuit comprising:

The energy storage module is electrically connected with the power supply end of the load; the energy storage module is used for outputting voltage to the power supply end of the load when the power supply input end is powered down;

The voltage detection circuit is electrically connected with the energy storage module and is used for detecting the voltage of the energy storage module and outputting a corresponding voltage detection signal;

The input end of the charging circuit is electrically connected with the power input end, the output end of the charging circuit is electrically connected with the energy storage module, and the controlled end of the charging circuit is electrically connected with the output end of the voltage detection circuit; and the charging circuit is used for starting to work when the voltage of the energy storage module is determined to be smaller than the preset voltage according to the voltage detection signal so as to charge the energy storage module.

Optionally, the voltage detection signal includes an absence of an electrical signal; the voltage detection circuit includes:

The battery management chip is provided with an input end and an output end, the input end of the voltage detection circuit comprises the input end of the battery management chip, and the output end of the voltage detection circuit comprises the output end of the battery management chip;

The battery management chip is used for detecting the voltage of the energy storage module and outputting the electric lack signal when the voltage of the energy storage module is smaller than the preset voltage;

And the charging circuit is used for starting to work when the electric lack signal is received so as to charge the energy storage module.

Optionally, the charging circuit includes:

The first end of the voltage conversion circuit is electrically connected with the power input end, the second end of the voltage conversion circuit is electrically connected with the energy storage module, and the third end of the voltage conversion circuit is electrically connected with the output end of the voltage detection circuit;

the voltage conversion circuit is used for receiving the voltage detection signal through the third end, and outputting the voltage accessed by the power input end after voltage conversion when the voltage of the energy storage module is determined to be smaller than the preset voltage according to the voltage detection signal so as to supply power for the energy storage module.

Optionally, the voltage detection signal includes an absence signal, and the voltage conversion circuit includes:

The input end of the voltage stabilizer is electrically connected with the power input end, and the output end of the voltage stabilizer is electrically connected with the energy storage module;

The first end of the switching tube is electrically connected with the controlled end of the voltage stabilizer, the second end of the switching tube is grounded, and the third end of the switching tube is electrically connected with the output end of the voltage detection circuit;

The switching tube is in an off state when the third end of the switching tube receives the electric lack signal, so that the controlled end of the voltage stabilizer is in a working state when receiving a low-level signal, and the energy storage module is charged; and the switching tube is also used for being in a conducting state when the third end of the switching tube does not receive the ischemia signal, so that the controlled end of the voltage stabilizer is in a non-working state when receiving a high-level signal.

Optionally, the power-down holding circuit further includes:

The first end of the current limiting circuit is electrically connected with the output end of the charging circuit, the second end of the current limiting circuit is electrically connected with the energy storage module, and the current limiting circuit is used for limiting the output voltage of the charging circuit to be below a preset current value.

Optionally, the voltage detection circuit further includes:

The switching circuit is arranged on a passage between the energy storage module and the input end of the voltage detection circuit in series, the input end of the switching circuit is electrically connected with the energy storage module, the output end of the switching circuit is connected with the input end of the voltage detection circuit, and the controlled end of the switching circuit is connected with the power supply input end;

The switching circuit is used for conducting a passage between the energy storage module and the input end of the voltage detection circuit when the power input end is electrified; and the power supply input end is used for disconnecting a passage between the energy storage module and the input end of the voltage detection circuit when the power supply input end is powered down.

Optionally, the voltage detection circuit further includes:

the first end of the anti-backflow circuit is electrically connected with the power end of the load, and the second end of the anti-backflow circuit is electrically connected with the energy storage module;

And the anti-backflow circuit is used for preventing the voltage of the power supply end of the load from being backflow and outputting to the energy storage module.

Optionally, the anti-backflow circuit includes:

And the anode of the diode is electrically connected with the energy storage module, and the cathode of the diode is electrically connected with the power end of the load.

The utility model also provides a controller comprising the power-down holding circuit.

The utility model provides a power-down holding circuit which is applied to a controller, wherein the controller comprises a load and a power input end connected with a power end of the load, the power-down holding circuit comprises an energy storage module, a voltage detection circuit and a charging circuit, and the energy storage module is electrically connected with the power end of the load; the energy storage module is used for outputting voltage to the power supply end of the load when the power supply input end is powered down; the voltage detection circuit is electrically connected with the energy storage module, and is used for detecting the voltage of the energy storage module and outputting a corresponding voltage detection signal; the input end of the charging circuit is electrically connected with the power input end, the output end of the charging circuit is electrically connected with the energy storage module, and the controlled end of the charging circuit is electrically connected with the output end of the voltage detection circuit; and the charging circuit is used for starting to work when the voltage of the energy storage module is determined to be smaller than the preset voltage according to the voltage detection signal so as to charge the energy storage module.

In practical application, when the power input end is electrified, the voltage accessed by the power input end is used for supplying power to the load, meanwhile, the voltage detection circuit detects the voltage of the energy storage module and outputs a corresponding voltage detection signal to the charging circuit, the charging circuit starts working when determining that the voltage of the energy storage module is smaller than a preset voltage according to the voltage detection signal, and the voltage accessed by the power input end is output to the energy storage module so as to charge the energy storage module.

Drawings

In order to more clearly illustrate the embodiments of the present utility model or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, and it is obvious that the drawings in the following description are only some embodiments of the present utility model, and other drawings may be obtained according to the structures shown in these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic diagram of a circuit module of an embodiment of a power down holding circuit of the present utility model;

FIG. 2 is a schematic diagram of a circuit module of another embodiment of a power down holding circuit according to the present utility model;

FIG. 3 is a schematic circuit diagram of a power down holding circuit according to another embodiment of the present utility model;

FIG. 4 is a schematic circuit diagram of a power down holding circuit according to another embodiment of the present utility model;

FIG. 5 is a schematic circuit diagram of a power down holding circuit according to another embodiment of the present utility model;

FIG. 6 is a schematic diagram of a circuit module of another embodiment of a power down holding circuit according to the present utility model;

Fig. 7 is a schematic circuit diagram of an embodiment of a power-down holding circuit according to the present utility model.

Reference numerals illustrate:

Reference numerals	Name of the name	Reference numerals	Name of the name
				10	Energy storage module	20	Voltage detection circuit
21	Battery management chip	22	Switching circuit
				30	Charging circuit	31	Voltage conversion circuit
40	Current limiting circuit	50	Anti-backflow circuit

The achievement of the objects, functional features and advantages of the present utility model will be further described with reference to the accompanying drawings, in conjunction with the embodiments.

Detailed Description

The following description of the embodiments of the present utility model will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are only some, but not all embodiments of the utility model. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

Furthermore, descriptions such as those referred to as "first," "second," and the like, are provided for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implying an order of magnitude of the indicated technical features in the present disclosure. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In addition, the technical solutions of the embodiments may be combined with each other, but it is necessary to base that the technical solutions can be realized by those skilled in the art, and when the technical solutions are contradictory or cannot be realized, the combination of the technical solutions should be considered to be absent and not within the scope of protection claimed in the present utility model.

The utility model provides a power-down holding circuit which is applied to a controller, wherein the controller comprises a load and a power input end connected with a power end of the load, the load comprises a main controller and a memory, and the main controller comprises an MCU (micro control unit), a DSP (DIGITAL SIGNAL Process, digital signal processing Chip), an FPGA (Field Programmable GATE ARRAY, programmable logic gate array Chip), a PLC (programmable logic controller), an SOC (System On Chip) and the like. The memory includes nonvolatile memory such as EEPROM (ELECTRICALLY ERASABLE PROGRAMMABLE READ-only, electrically erasable programmable read Only memory), FLASH memory, MRAM (Magnetoresistive Random Access Memory, magnetic random Access memory), etc.

Referring to fig. 1, in an embodiment of the present utility model, the power-down holding circuit includes:

The energy storage module 10 is electrically connected with the power supply end of the load; the energy storage module 10 is configured to output a voltage to a power supply terminal of the load when the power supply input terminal is powered down;

The voltage detection circuit 20 is electrically connected with the energy storage module 10, and the voltage detection circuit 20 is used for detecting the voltage of the energy storage module 10 and outputting a corresponding voltage detection signal;

The input end of the charging circuit 30 is electrically connected with the power input end, the output end of the charging circuit 30 is electrically connected with the energy storage module 10, and the controlled end of the charging circuit 30 is electrically connected with the output end of the voltage detection circuit 20; the charging circuit 30 is configured to determine, according to the voltage detection signal, that the voltage of the energy storage module 10 is less than a preset voltage, and start to operate to charge the energy storage module 10.

In this embodiment, the energy storage module 10 may be implemented by a rechargeable battery such as a lead-acid battery, a lithium-magnesium battery, a zinc-manganese battery, or the like; optionally, the voltage detection circuit 20 may be implemented by a voltage sampling circuit, such as a resistor divider circuit, an analog-to-digital conversion circuit, etc., so as to sample the battery voltage of the energy storage module 10 and output a corresponding voltage detection signal, so that the later circuit can determine a specific voltage value of the energy storage module 10; alternatively, the voltage detection circuit 20 may also be implemented directly by a voltage detection chip, so as to directly compare the voltage of the current energy storage module 10 with a preset voltage, and output a corresponding voltage detection signal according to the comparison result. The charging circuit 30 may be implemented by a circuit comprising a voltage conversion circuit 31 and a main controller, where when the main controller determines that the voltage of the energy storage module 10 is lower than a preset voltage according to a voltage detection signal output by the voltage detection circuit 20, the main controller outputs a corresponding control signal to the voltage conversion circuit 31 to control the voltage conversion circuit 31 to convert the voltage connected to the power input terminal into a voltage and output the voltage to the energy storage module 10, so as to charge the energy storage module 10. Specifically, the power input end may be connected to a dc power supply, when the dc power supply connected to the power input end normally supplies power to the control system, the load is directly supplied with dc voltage, in this process, the voltage detection circuit 20 detects the voltage of the energy storage module 10 in real time, and outputs a corresponding voltage detection signal to the charging circuit 30, the charging circuit 30 determines whether the energy storage module 10 needs to be charged according to the voltage detection signal, for example, when the charging circuit 30 determines that the voltage of the energy storage module 10 is less than a preset voltage according to the voltage detection signal, the charging circuit 30 starts to operate, and outputs the voltage of the dc power supply to the energy storage module 10 to charge the energy storage module 10, and when the charging circuit 30 determines that the voltage of the energy storage module 10 is greater than the preset voltage according to the voltage detection signal, it is indicated that the energy storage module 10 is sufficient in power, and the charging circuit 30 does not need to operate. The preset voltage is set in advance by a developer, and it should be noted that the preset voltage needs to ensure the time for the energy storage module 10 to supply power to the load, so that the minimum system of the main controller can save the operation data before power failure. For example, the main controller can save the key data in the operation process after power failure, namely, the key data is written into the nonvolatile memory EEROM, FLASH, MRAM and the like, so that the key operation data of the system and the operation state of the system can be restored to be normal when the power is on again.

The utility model provides a power-down holding circuit, which comprises an energy storage module 10, a voltage detection circuit 20 and a charging circuit 30; the energy storage module 10 is configured to output a voltage to a power supply terminal of the load when the power supply input terminal is powered down; the voltage detection circuit 20 is configured to detect a voltage of the energy storage module 10 and output a corresponding voltage detection signal; the charging circuit 30 is configured to start operating to charge the energy storage module 10 when it is determined that the voltage of the energy storage module 10 is less than a preset voltage according to the voltage detection signal. Through the above arrangement, in practical application, when the power input end is powered on, the voltage connected to the power input end is used for supplying power to the load, meanwhile, the voltage detection circuit 20 detects the voltage of the energy storage module 10 and outputs a corresponding voltage detection signal to the charging circuit 30, the charging circuit 30 starts working when determining that the voltage of the energy storage module 10 is smaller than the preset voltage according to the voltage detection signal, and the voltage connected to the power input end is output to the energy storage module 10 so as to charge the energy storage module 10, so that when the power input end is powered off, the energy storage module 10 can be ensured to have sufficient electric quantity for supplying power to the load, so that the load can work normally, and the reliability of the power-down holding circuit is improved.

In an embodiment of the present utility model, referring to fig. 2, the voltage detection signal includes an absence signal; the voltage detection circuit 20 includes:

A battery management chip 21, the battery management chip 21 having an input and an output, the input of the voltage detection circuit 20 including the input of the battery management chip 21, the output of the voltage detection circuit 20 including the output of the battery management chip 21;

The battery management chip 21 is configured to detect a voltage of the energy storage module 10, and output the electric lack signal when the voltage of the energy storage module 10 is less than the preset voltage;

The charging circuit 30 is configured to start to operate to charge the energy storage module 10 when the ischemia signal is received.

In the present embodiment, the battery management chip 21 can directly compare the magnitude relation between the voltage of the current energy storage module 10 and the preset voltage, and output a corresponding signal. It can be appreciated that the battery management chip 21 may also output a full electrical signal to the charging circuit 30 when the voltage of the energy storage module 10 reaches the preset voltage, so that the charging circuit 30 stops working to stop charging the energy storage module 10.

Specifically, taking fig. 7 as an example for illustration, the battery management chip 21 has an input terminal as an IN pin, and an output terminal as an OUT pin of the battery management chip 21, wherein the battery management chip 21 further includes a current compensation control pin COMP, and the COMP pin is used for controlling an output voltage of the battery management chip 21. And a compensation capacitor is arranged between the COMP pin and the OUT pin of the battery management chip 21, so that the stability of an internal circuit of the power management chip is improved. IN combination with the above embodiment, when the input terminal IN pin of the battery management chip 21 detects that the voltage of the energy storage module 10 is smaller than the preset voltage, the OUT pin outputs the power-off signal to the controlled terminal of the charging circuit 30, so that the charging circuit 30 starts to work when receiving the power-off signal, and outputs the voltage of the power input terminal to the energy storage module 10 to supply power to the energy storage module 10. IN the charging process, the voltage of the energy storage module 10 starts to rise until the input terminal IN pin of the battery management chip 21 detects that the voltage of the energy storage module 10 is greater than the preset voltage, the output pin outputs a full electrical signal to the controlled terminal of the charging circuit 30, so that the charging circuit 30 stops working when receiving the full electrical signal, the charging current drops, and the charging is stopped. The lack signal and the full signal are voltage detection signals.

It is understood that at least one of a microcontroller, a voltage monitoring circuit, a temperature monitoring circuit, a current measuring circuit, and a protection circuit may be integrated within the battery management chip 21. Therefore, the voltage detection circuit 20 is realized by adopting the battery management chip 21, so that not only the wiring area on the circuit board can be reduced, but also the stability and the safety of the power failure maintaining circuit can be effectively improved.

In another embodiment of the present utility model, referring to fig. 3, the charging circuit 30 includes:

A voltage conversion circuit 31, wherein a first end of the voltage conversion circuit 31 is electrically connected to the power input terminal, a second end of the voltage conversion circuit 31 is electrically connected to the energy storage module 10, and a third end of the voltage conversion circuit 31 is electrically connected to the output terminal of the voltage detection circuit 20;

The voltage conversion circuit 31 is configured to receive the voltage detection signal via the third terminal, and determine, according to the voltage detection signal, that the voltage of the energy storage module 10 is less than the preset voltage, and output the voltage connected to the power input terminal after voltage conversion, so as to supply power to the energy storage module 10.

In this embodiment, the voltage conversion circuit 31 may be implemented by a voltage change circuit composed of a plurality of switching transistors, resistors, capacitors, inductors, or the like, or by a voltage conversion chip.

Specifically, referring to fig. 7, in an embodiment of the present utility model, the voltage conversion circuit 31 includes:

The input end of the voltage stabilizer is electrically connected with the power input end, and the output end of the voltage stabilizer is electrically connected with the energy storage module 10;

The first end of the switching tube is electrically connected with the controlled end of the voltage stabilizer, the second end of the switching tube is grounded, and the third end of the switching tube is electrically connected with the output end of the voltage detection circuit 20;

the switching tube is configured to be in an off state when the third end of the switching tube receives the electrical-deficiency signal, so that the controlled end of the voltage stabilizer is in an operating state when receiving a low-level signal, so as to charge the energy storage module 10; and the switching tube is also used for being in a conducting state when the third end of the switching tube does not receive the ischemia signal, so that the controlled end of the voltage stabilizer is in a non-working state when receiving a high-level signal.

In this embodiment, the voltage regulator may be implemented by an LDO voltage regulator, a buck voltage regulator chip, or the like; the switching tube can be realized by adopting a triode, an IGBT tube, an MOS tube and the like.

Taking the voltage regulator as an LDO voltage regulator and the switching tube as the triode Q1 for illustration, the adjusting pin ADJ pin of the LDO voltage regulator is a controlled end of the voltage regulator, when the ADJ pin receives the voltage detection signal of the voltage detection circuit 20, the output voltage of the LDO voltage regulator is adjusted according to the voltage detection signal, for example, when the voltage of the energy storage module 10 is smaller than the preset voltage, the ADJ pin adjusts the output voltage of the LDO voltage regulator to output a stable charging voltage to the energy storage module 10, so as to charge the energy storage module 10; when the voltage of the energy storage module 10 is greater than the preset voltage, the ADJ pin adjusts the output current of the LDO regulator to zero, and the energy storage module 10 is stopped being charged. The switching tube is an NPN triode Q1, the base electrode of the triode is electrically connected with the output end of the voltage detection circuit 20, the collector electrode of the triode is electrically connected with the ADJ pin of the LDO voltage stabilizer, and the emitter electrode of the triode is grounded.

Specifically, when the voltage detection circuit 20 outputs a corresponding voltage detection signal to the triode Q1, that is, when the voltage of the energy storage module 10 is lower than a preset value, the voltage detection circuit 20 outputs a voltage-lack signal to the base electrode of the triode, for example, the voltage-lack signal is a low level signal, the base electrode of the triode Q1 is a current, the triode Q1 is turned off, the ADJ pin of the LDO voltage stabilizer receives the low level signal to start working, the voltage connected to the input end of the power supply is subjected to voltage conversion, and then a constant voltage is output to the input end of the energy storage module 10, that is, a constant current is generated to charge the energy storage module 10; in the process of charging the energy storage module 10, the voltage of the energy storage module 10 gradually rises, when the voltage of the energy storage module 10 is greater than a preset voltage, the voltage detection circuit 20 outputs a corresponding full electric signal to the base electrode of the triode Q1, the full electric signal is a high-level signal at this time, that is, the base electrode of the triode Q1 has current flowing in until the conduction condition of the triode Q1 is reached, the triode Q1 is conducted, so that the ADJ pin receives the high-level signal, the output voltage of the LDO voltage stabilizer starts to be regulated, and when the output voltage of the LDO is regulated to the lowest value, the energy storage module 10 is stopped to be charged, and the charging is stopped.

Through the arrangement, the charging circuit 30 not only can convert the voltage accessed by the power supply access terminal into the charging voltage matched with the energy storage module 10, but also can eliminate the ripple wave in a part of the access voltage, effectively improves the stability of the output charging voltage, and further ensures the stability of charging the energy storage module 10.

Furthermore, in an embodiment of the present utility model, referring to fig. 4, the voltage detection circuit 20 further includes:

The switch circuit 22 is arranged in series on a path between the energy storage module 10 and the input end of the voltage detection circuit 20, the input end of the switch circuit 22 is electrically connected with the energy storage module 10, the output end of the switch circuit 22 is connected with the input end of the voltage detection circuit 20, and the controlled end of the switch circuit 22 is connected with the power supply input end;

the switch circuit 22 is configured to conduct a path between the energy storage module 10 and the input terminal of the voltage detection circuit 20 when the power input terminal is powered on; and is configured to disconnect a path between the energy storage module 10 and the input of the voltage detection circuit 20 when the power supply input is powered down.

In this embodiment, the switching circuit 22 may be implemented by using a switching device such as a relay or a contactor, or a switching transistor such as a MOS transistor, an IGBT transistor, a thyristor, or a triode.

Specifically, taking the switch circuit 22 as an NPN transistor Q2 for example, a base electrode of the transistor is electrically connected to the power input terminal, a collector electrode of the transistor is electrically connected to the energy storage module 10, and an emitter electrode of the transistor is electrically connected to the input terminal of the voltage detection circuit 20.

IN combination with the above embodiment, after the power input terminal is powered on, the voltage accessed by the power input terminal normally supplies power to the load, and the IN pin of the battery management chip 21 detects the voltage of the emitter of the triode Q2 IN real time and outputs a corresponding voltage detection signal to the charging circuit 30. The emitter voltage refers to the voltage of the emitter with respect to the collector. When the power input terminal is powered on, the transistor Q2 is always in a conductive state, so that the battery management chip 21 can detect the voltage of the energy storage module 10. When the voltage of the energy storage module 10 is smaller than the preset voltage, the OUT pin of the power management chip does not output current, and the base electrode of the triode Q1 does not flow in, so that the triode Q1 is in an off state, and when the ADJ pin of the LDO voltage stabilizer recognizes a low-level signal, the voltage accessed by the power input end is subjected to voltage conversion and then constant output voltage is output to the energy storage module 10; IN the process of charging the energy storage module 10, the voltage of the energy storage module 10 gradually rises, the IN pin of the battery management chip 21 senses the voltage of the energy storage module 10, when the voltage of the energy storage module 10 is larger than a preset value, the OUT pin of the battery management chip 21 outputs current so that the base electrode of the triode Q1 has current, the triode Q1 is conducted, the ADJ pin of the LDO voltage stabilizer recognizes a high-level signal, the output voltage starts to be regulated, when the energy storage module 10 is close to a full charge state, the triode Q2 is conducted IN a saturated mode, the output current of the LDO voltage stabilizer is reduced to the minimum value, and the charging is finished.

It can be appreciated that the voltage detection circuit 20 needs to be electrically connected to the energy storage module 10, so that the electric quantity in the energy storage module 10 is consumed at the same time when the voltage detection circuit works, i.e. when the voltage detection signal is output to the outside. For example, in the above embodiment, the voltage detection circuit 20 using the resistor divider circuit may generate additional static power consumption when sampling the voltage of the energy storage module 10. Similarly, the battery management chip 21 directly uses the voltage output from the energy storage module 10 as its own operating voltage when in an operating state. Therefore, through the above arrangement, when the power supply access terminal is suddenly powered down, the path between the voltage detection circuit 20 and the energy storage module 10 is disconnected, so that the voltage detection circuit 20 stops working, that is, the voltage of the energy storage module 10 is stopped being consumed, so that the energy storage module 10 only supplies power to the load, and the stability of the load working when the power supply access terminal of the controller is powered down is effectively ensured.

In an embodiment of the present utility model, referring to fig. 5, the power-down holding circuit further includes:

The first end of the current limiting circuit 40 is electrically connected with the output end of the charging circuit 30, the second end of the current limiting circuit 40 is electrically connected with the energy storage module 10, and the current limiting circuit 40 is used for limiting the output voltage of the charging circuit 30 to be below a preset current value.

In this embodiment, the current limiting circuit 40 may be implemented by using a current limiting resistor, a capacitor, a fuse, or the like.

Specifically, taking the current limiting circuit 40 as an example of the current limiting resistor, in conjunction with the above embodiment, since the LDO voltage regulator of the charging circuit 30 outputs a voltage to the energy storage module 10 when the voltage of the energy storage module 10 is smaller than the preset voltage, in order to avoid damage to electronic components of the post-stage circuit electrically connected to the output terminal of the LDO voltage regulator caused by the excessive transient output voltage generated during the operation of the LDO voltage regulator, the output terminal of the charging circuit 30 is provided with the current limiting resistor R2, the first terminal of R2 is electrically connected to the output terminal of the LDO voltage regulator, the second terminal of R2 is electrically connected to the energy storage module 10, and the magnitude of the current value output by the output terminal of the voltage regulator is determined by the resistor R2. That is, the control of the output current of the charging circuit 30 is achieved by adjusting the resistance value of the current limiting resistor R2 to limit the output voltage of the charging circuit 30 to a preset current value or less.

It will be appreciated that, according to ohm's law, the current is proportional to the resistance, and the resistance of the current limiting resistor R2 can be set in advance by a developer to determine the maximum value of the output current of the charging circuit 30.

In fig. 7, the current limiting resistor R2 and the resistor R3 form a voltage dividing circuit, and prevent an element in the subsequent circuit of the charging circuit 30 from receiving an excessively high voltage.

The arrangement of the current limiting resistor prevents the damage to electronic components caused by the current impact of the charging circuit 30 when the charging circuit is just started, improves the stability of the circuit, and prevents the output current of the charging circuit 30 from changing too fast, thereby reducing the fluctuation and interference of the circuit and further improving the stability and reliability of the power failure holding circuit.

It should be appreciated that, since the purpose of the energy storage module 10 is to supply power to the load briefly after the power input is lost, the primary power supply is essentially carried by the dc power source to which the power input is connected. Therefore, in general, the voltage of the dc power source connected to the power input terminal is higher than the voltage of the energy storage module 10. When the control system is accidentally powered down, there may be a backflow of current into the energy storage module 10, causing some damage to the energy storage module 10.

To this end, in an embodiment of the present utility model, referring to fig. 6, the voltage detection circuit 20 further includes:

A backflow prevention circuit 50, wherein a first end of the backflow prevention circuit 50 is electrically connected with a power supply end of the load, and a second end of the backflow prevention circuit 50 is electrically connected with the energy storage module 10;

The anti-backflow circuit 50 is configured to prevent a voltage at the power supply terminal of the load from being backflow and output to the energy storage module 10.

In the present embodiment, the anti-backflow circuit 50 may be implemented using a diode, a constant current source, a transient voltage suppressor, or the like.

Specifically, taking the backflow preventing circuit 50 as an example, referring to fig. 7, the diode D3 is a backflow preventing diode, the anode of the diode D3 is electrically connected to the input end of the energy storage module 10, and the cathode of the diode D3 is electrically connected to the load. When the power input end is electrified, a unidirectional conduction circuit is arranged between the power input end and the load, namely a diode D1, the voltage accessed by the power input end is directly supplied to the load through the diode D1, when the battery management chip 21 detects that the voltage of the energy storage module 10BT is lower than a preset voltage, the base electrode of the triode Q1 is not provided with current and is in an off state, the ADJ pin of the LDO voltage stabilizer receives a low-level signal and then outputs a constant voltage to the energy storage module 10 after voltage conversion of the DC power DC so as to charge the energy storage module 10, when the voltage of the energy storage module 10BT gradually rises to the preset voltage, the pin of the battery management chip 21OUT outputs current so that the base electrode of the triode Q1 is provided with current, and therefore the triode Q1 is in an on state, and the ADJ pin of the LDO voltage stabilizer regulates the output voltage after detecting the high-level signal until the charging current is reduced to a very low value, and the charging is ended. When the power input terminal is powered down, the output current of the energy storage module 10 flows into the load through the anti-backflow diode D3 to supply power to the load. Therefore, the energy storage module 10 can be ensured to have enough electric quantity to charge the load when the control system is powered down, namely, the main controller can be ensured to write key data into the nonvolatile memory such as EEROM, FLASH, MRAM, so that key operation data of the system and the state of the system operation can be recovered to be normal when the power is on again, and the reliability of the power-down maintaining circuit is improved.

It should be noted that, after the power input end is powered down, since the voltage value of the dc voltage connected to the power input end is greater than the voltage value of the energy storage module 10, the backflow prevention diode D3 can prevent the backflow phenomenon from occurring, which damages the energy storage module 10, so that the energy storage module 10 cannot normally supply power to the load, and further the load cannot normally work after the power input end is powered down. Therefore, the anti-backflow circuit 50 effectively protects the energy storage module 10 when the power input end is powered down, so that the reliability of the power failure holding circuit is improved, and the reliability of a control system is further improved.

The utility model also provides a controller comprising the power-down holding circuit.

It is noted that, because the controller of the present utility model is based on the power-down holding circuit, embodiments of the controller of the present utility model include all technical solutions of all embodiments of the power-down holding circuit, and the achieved technical effects are identical, and are not described herein again.

The foregoing description is only of the optional embodiments of the present utility model, and is not intended to limit the scope of the utility model, and all equivalent mechanical changes made by the description of the present utility model and the accompanying drawings or direct/indirect application in other related technical fields are included in the scope of the utility model.

Claims (9)

1. A power down holding circuit for use with a controller, the controller comprising a load and a power input connected to a power supply terminal of the load, the power down holding circuit comprising:

The energy storage module is electrically connected with the power supply end of the load; the energy storage module is used for outputting voltage to the power supply end of the load when the power supply input end is powered down;

The voltage detection circuit is electrically connected with the energy storage module and is used for detecting the voltage of the energy storage module and outputting a corresponding voltage detection signal;

The input end of the charging circuit is electrically connected with the power input end, the output end of the charging circuit is electrically connected with the energy storage module, and the controlled end of the charging circuit is electrically connected with the output end of the voltage detection circuit; and the charging circuit is used for starting to work when the voltage of the energy storage module is determined to be smaller than the preset voltage according to the voltage detection signal so as to charge the energy storage module.

2. The power down holding circuit of claim 1, wherein the voltage detection signal comprises an absence of an electrical signal; the voltage detection circuit includes:

The battery management chip is provided with an input end and an output end, the input end of the voltage detection circuit comprises the input end of the battery management chip, and the output end of the voltage detection circuit comprises the output end of the battery management chip;

The battery management chip is used for detecting the voltage of the energy storage module and outputting the electric lack signal when the voltage of the energy storage module is smaller than the preset voltage;

And the charging circuit is used for starting to work when the electric lack signal is received so as to charge the energy storage module.

3. The power down holding circuit of claim 1, wherein the charging circuit comprises:

The first end of the voltage conversion circuit is electrically connected with the power input end, the second end of the voltage conversion circuit is electrically connected with the energy storage module, and the third end of the voltage conversion circuit is electrically connected with the output end of the voltage detection circuit;

the voltage conversion circuit is used for receiving the voltage detection signal through the third end, and outputting the voltage accessed by the power input end after voltage conversion when the voltage of the energy storage module is determined to be smaller than the preset voltage according to the voltage detection signal so as to supply power for the energy storage module.

4. The power down holding circuit of claim 3, wherein the voltage detection signal comprises an absence of electrical signal, the voltage conversion circuit comprising:

The input end of the voltage stabilizer is electrically connected with the power input end, and the output end of the voltage stabilizer is electrically connected with the energy storage module;

The first end of the switching tube is electrically connected with the controlled end of the voltage stabilizer, the second end of the switching tube is grounded, and the third end of the switching tube is electrically connected with the output end of the voltage detection circuit;

The switching tube is in an off state when the third end of the switching tube receives the electric lack signal, so that the controlled end of the voltage stabilizer is in a working state when receiving a low-level signal, and the energy storage module is charged; and the switching tube is also used for being in a conducting state when the third end of the switching tube does not receive the ischemia signal, so that the controlled end of the voltage stabilizer is in a non-working state when receiving a high-level signal.

5. The power down holding circuit according to any one of claims 1 to 4, wherein the power down holding circuit further comprises:

The first end of the current limiting circuit is electrically connected with the output end of the charging circuit, the second end of the current limiting circuit is electrically connected with the energy storage module, and the current limiting circuit is used for limiting the output voltage of the charging circuit to be below a preset current value.

6. The power down holding circuit according to any one of claims 1 to 4, wherein the voltage detection circuit further comprises:

The switching circuit is arranged on a passage between the energy storage module and the input end of the voltage detection circuit in series, the input end of the switching circuit is electrically connected with the energy storage module, the output end of the switching circuit is connected with the input end of the voltage detection circuit, and the controlled end of the switching circuit is connected with the power supply input end;

The switching circuit is used for conducting a passage between the energy storage module and the input end of the voltage detection circuit when the power input end is electrified; and the power supply input end is used for disconnecting a passage between the energy storage module and the input end of the voltage detection circuit when the power supply input end is powered down.

7. The power down holding circuit according to any one of claims 1 to 4, wherein the voltage detection circuit further comprises:

the first end of the anti-backflow circuit is electrically connected with the power end of the load, and the second end of the anti-backflow circuit is electrically connected with the energy storage module;

And the anti-backflow circuit is used for preventing the voltage of the power supply end of the load from being backflow and outputting to the energy storage module.

8. The power down holding circuit of claim 7, wherein the anti-reverse current circuit comprises:

And the anode of the diode is electrically connected with the energy storage module, and the cathode of the diode is electrically connected with the power end of the load.

9. A controller comprising a power down holding circuit as claimed in any one of claims 1 to 8.