CN115719993B - Charging circuit, power supply device, charged device, charging system and chip - Google Patents
Charging circuit, power supply device, charged device, charging system and chip Download PDFInfo
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- CN115719993B CN115719993B CN202310031443.6A CN202310031443A CN115719993B CN 115719993 B CN115719993 B CN 115719993B CN 202310031443 A CN202310031443 A CN 202310031443A CN 115719993 B CN115719993 B CN 115719993B
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- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
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Abstract
The charging circuit at least comprises a charging module and a control module, wherein the charging module outputs charging current to a charging end, the magnitude of the charging current is controlled by a voltage difference between a control end and a power end, the control module can control the magnitude of an equivalent resistor between the power end and the control end, and accordingly the control module can control the magnitude of the voltage difference by controlling the magnitude of the equivalent resistor, and further control the magnitude of the charging current output to the charging end by the charging module. According to the voltage of the charging end, the control module in the charging circuit can timely and accurately control the constant, reduced or cut-off of the charging current in the process of gradually increasing the voltage of the charging end by controlling the equivalent resistance and then controlling the charging current.
Description
Technical Field
The present invention relates to the field of charging, and in particular, to a charging circuit, a power supply device, a device to be charged, a charging system, and a chip.
Background
The charge cut-off voltage is an important parameter in the battery charging process, and refers to the voltage at which the battery rises to complete charging. If the battery reaches the charge cutoff voltage, it is overcharged if it is still charged, which generally has a damage to the battery performance and life. Therefore, it is generally necessary to detect the charge cut-off voltage of the battery in the charging circuit to prevent overcharge.
The determination of the charge cutoff voltage is easily affected by the power supply voltage and the temperature, and the charge cutoff voltage of the battery is easily not accurately detected. In the prior art, in order to realize more accurate charge cut-off voltage judgment, the solution is to carry out fuse trimming on floating charge voltage under specific voltage and temperature. However, if the power supply voltage or temperature changes after trimming is completed, a change in the charge cutoff voltage is caused.
Therefore, how to timely and accurately control the charging current and the charging cutoff during the charging process becomes a technical problem to be solved.
Disclosure of Invention
Based on the above-mentioned current situation, the main objective of the present invention is to provide a charging circuit, a power supply device, a charged device, a charging system and a chip, so as to solve the technical problems of how to accurately control the charging current and the charging cut-off in time.
To this end, according to a first aspect, an embodiment of the present invention discloses a charging circuit including a charging terminal for charging a battery, the charging circuit further including:
the charging module is connected between the power supply end and the charging end and provided with a control end, and is used for converting a power supply provided by the power supply end into a charging current and outputting the charging current to the charging end, wherein the charging current is controlled by a voltage difference between the control end and the power supply end;
the control module is connected between the power supply end and the charging module and connected to the charging end and the control end, and is used for controlling the magnitude of equivalent resistance between the power supply end and the control end so as to control the magnitude of voltage difference, wherein:
when the voltage of the charging end is smaller than a first preset voltage, the control module controls the voltage difference to be constant so as to enable the charging current to be constant;
starting from the voltage of the charging end rising to a first preset voltage, the control module controls the voltage difference to gradually decrease so as to gradually decrease the charging current;
when the voltage of the charging end rises to the cut-off voltage, the control module controls the voltage difference to be reduced to a preset voltage difference threshold value so as to cut off the charging current.
In a second aspect, the present embodiment also discloses a power supply apparatus for supplying a charging power to the outside, the power supply apparatus including the charging circuit as in the first aspect.
In a third aspect, the present embodiment also discloses a charged device, including:
an energy storage unit;
the charging circuit of the first aspect is for controlling charging of the energy storage unit by an external power source.
In a fourth aspect, the present embodiment further discloses a charging system, including:
a power supply device;
a charged device;
the charging circuit of the first aspect for controlling the power supply device to charge the charged device;
the charging circuit is provided in the power supply device or the charged device.
[ beneficial effects ]
The embodiment of the invention discloses a charging circuit, which at least comprises a charging module and a control module, wherein the charging module outputs charging current to a charging end, the magnitude of the charging current is controlled by a voltage difference between a control end and a power end, and the control module can control the magnitude of an equivalent resistor between the power end and the control end, so that the control module can control the magnitude of the voltage difference by controlling the magnitude of the equivalent resistor, and further control the magnitude of the charging current output to the charging end by the charging module. When the voltage of the battery is lower, namely, the voltage of the charging end is smaller than the first preset voltage, the control module controls the equivalent resistance to be constant, so that the voltage difference is kept constant, the charging current is kept constant, and the current is larger, and the battery is charged more quickly. As the charging proceeds, the battery voltage gradually increases, and once the voltage at the charging end increases to the first preset voltage, the charging current controls the magnitude of the equivalent resistor to gradually decrease, so as to cause the magnitude of the voltage difference to gradually decrease, thereby gradually decreasing the charging current to charge the battery at a slower speed. As charging proceeds, once the battery voltage increases to the cutoff voltage, that is, the voltage of the charging terminal increases to the cutoff voltage, the control module controls the equivalent resistance to decrease to a preset resistance threshold value to cause the magnitude of the voltage difference to decrease to the preset voltage difference threshold value, so that the charging current decreases to zero, and the charging is stopped. Therefore, the control module can timely and accurately control the constant, reduced or cut-off of the charging current in the process of gradually increasing the voltage of the charging end by controlling the equivalent resistance and then controlling the charging current according to the voltage of the charging end.
Other advantages of the present invention will be set forth in the description of specific technical features and solutions, by which those skilled in the art should understand the advantages that the technical features and solutions bring.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are needed in the description of the embodiments or the prior art will be briefly described, and it is obvious that the drawings in the description below are some embodiments of the present invention, and other drawings can be obtained according to the drawings without inventive effort for a person skilled in the art.
Fig. 1 is a circuit diagram of a charging circuit according to the present embodiment;
fig. 2 is a circuit diagram of a charging circuit according to the second embodiment.
Detailed Description
The following description of the embodiments of the present invention will be made apparent and fully in view of the accompanying drawings, in which some, but not all embodiments of the invention are shown. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
In the description of the present invention, it should be noted that the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.
In the description of the present invention, it should be noted that, unless explicitly specified and limited otherwise, the terms "connected," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be mechanically or electrically connected; the two components can be directly connected or indirectly connected through an intermediate medium, or can be communicated inside the two components, or can be connected wirelessly or in a wired way. The specific meaning of the above terms in the present invention will be understood by those skilled in the art in specific cases.
In addition, the technical features of the different embodiments of the present invention described below may be combined with each other as long as they do not collide with each other.
In order to accurately control the charging current in time and control the charging stop in time when the charging voltage reaches the cut-off voltage, the embodiment discloses a charging circuit, please refer to fig. 1, fig. 1 is a circuit diagram of the charging circuit disclosed in the embodiment. The charging circuit includes a current source module 300 and a charging terminal B for charging the battery, and further includes a charging module 100 and a control module 200. The charging module 100 is connected to the battery through a charging terminal B to charge the battery. The battery in this embodiment means an element having an electric energy storage function. In the charging circuit disclosed in the present embodiment:
the charging module 100 is connected between the power terminal VDD and the charging terminal B, and the charging module 100 has a control terminal C for converting the power supplied from the power terminal VDD into a charging current to be output to the charging terminal B, wherein the charging current is controlled by the voltage difference between the control terminal C and the power terminal VDD. When the voltage difference between the control terminal C and the power supply terminal VDD is kept constant, the magnitude of the charging current is also kept constant; when the voltage difference between the control terminal C and the power terminal VDD changes, the magnitude of the charging current is correspondingly changed. For example, the voltage difference and the magnitude of the charging current may be positively or negatively correlated. In a specific embodiment, the voltage difference is positively correlated with the magnitude of the charging current.
The control module 200 is connected between the power supply terminal VDD and the charging module 100 and connected to the charging terminal B and the control terminal C, and is used for controlling the equivalent resistance between the power supply terminal VDD and the control terminal C to control the voltage difference. When the equivalent resistance between the power supply terminal VDD and the control terminal C is kept constant, the voltage difference between the control terminal C and the power supply terminal VDD is also kept constant; when the equivalent resistance between the power supply terminal VDD and the control terminal C changes, the voltage difference between the control terminal C and the power supply terminal VDD also changes, and the magnitude of the charging current also changes accordingly. For example, the voltage difference and the magnitude of the charging current may be positively or negatively correlated. In a specific embodiment, the voltage difference is positively correlated to the magnitude of the charging current.
Specifically, when the battery charge is low, the voltage of the charging terminal B is less than the first preset voltage, and is in the constant current charging stage. The control module 200 controls the equivalent resistance between the power supply terminal VDD and the control terminal C to be constant so that the voltage difference is constant so that the charging current is large and constant, thereby rapidly charging the battery.
Along with the gradual rise of the battery power, the voltage of the charging terminal B rises to the first preset voltage, and the constant voltage charging stage is entered. From the voltage of the charging terminal B rising to the first preset voltage, the control module 200 controls the equivalent resistance between the power terminal VDD and the control terminal C to gradually decrease, so that the voltage difference gradually decreases, and the charging module 100 charges the battery with the gradually decreasing charging current.
As the battery power continues to rise, when the voltage of the charging terminal B reaches the rising cutoff voltage, the charging cutoff phase is entered, and the control module 200 controls the equivalent resistance to decrease to the preset resistance threshold, so that the voltage difference decreases to the preset voltage difference threshold, and the charging current is stopped, and the charging module 100 stops charging the battery. It should be noted that the resistance threshold may be 0 or any other preset resistance value, and the voltage difference threshold may be 0 or any other preset voltage value.
The embodiment of the invention discloses a charging circuit, which at least comprises a charging module 100 and a control module 200, wherein the charging module 100 outputs charging current to a charging end B, the magnitude of the charging current is controlled by a voltage difference between a control end C and a power end, and the control module 200 can control the magnitude of an equivalent resistor between the power end and the control end C, so that the control module 200 can control the magnitude of the voltage difference by controlling the magnitude of the equivalent resistor, and further control the magnitude of the charging current output by the charging module 100 to the charging end B. When the battery voltage is low, that is, when the voltage of the charging terminal B is smaller than the first preset voltage, the control module 200 controls the equivalent resistance to be constant, so that the voltage difference is kept constant, and the charging current is kept constant and is larger, so as to charge the battery more quickly. As the charging proceeds, the battery voltage gradually increases, and once the voltage of the charging terminal B increases to the first preset voltage, the charging current controls the magnitude of the equivalent resistor to gradually decrease, so as to cause the magnitude of the voltage difference to gradually decrease, thereby gradually decreasing the charging current to charge the battery at a slower speed. As the charging proceeds, once the battery voltage increases to the off-voltage, i.e., the voltage of the charging terminal B increases to the off-voltage, the control module 200 controls the equivalent resistance to decrease to the preset resistance threshold to cause the magnitude of the voltage difference to decrease to the preset voltage difference threshold, thereby reducing the charging current to zero, and the charging is stopped. Therefore, the control module 200 can timely and accurately control the constant, reduced or cut-off of the charging current in the process of gradually increasing the voltage of the charging terminal B by controlling the equivalent resistance and further controlling the charging current according to the voltage of the charging terminal B.
Referring to fig. 2, fig. 1 is a circuit diagram of a charging circuit according to the present embodiment. In an embodiment of the present invention, the charging module 100 includes a mirror sub-module 110 and a voltage acquisition sub-module 232. The mirroring sub-module 110 includes a mirrored branch 112 and a mirroring branch 111 controlled by the control end C. The mirror circuit 111 is connected between the power terminal VDD and the charging terminal B, and is configured to output a charging current to the charging terminal B.
Through the design of the mirror image branch 111 and the mirrored branch 112, the control module 200 not only can control the magnitude of the charging current through the control end C, but also can ensure the stability and control accuracy of the charging current through the mirror image principle, and can influence the magnitude of the charging current provided by the mirror image branch 111 to the charging end B through controlling the magnitude of the current of the mirrored branch 112, thereby further ensuring the control accuracy and stability of the charging current.
In some embodiments, the voltage acquisition sub-module 232 is serially connected between the power supply terminal VDD and ground in sequence by the mirror leg 112 and the voltage acquisition sub-module 232 for generating the mirror current mirrored by the mirror leg 111, and the end of the voltage acquisition sub-module 232 remote from ground forms a voltage acquisition terminal a. The control module 200 is connected with the voltage acquisition end A, so that the control module 200 can timely acquire the voltage information of the voltage acquisition end A, and the charging current can be accurately obtained according to the voltage information of the voltage acquisition end A, so that the accuracy of the charging current size control is further improved.
In some embodiments, the charging module 100 further includes a clamping module 250, where the clamping module 250 is connected between the low potential terminal D and the charging terminal B of the mirrored branch 112, and is used for clamping the voltage of the low potential terminal D and the voltage of the charging terminal B. The clamping module 250 is arranged, so that the consistency of the low potential end D of the mirrored branch 112 and the potential of the charging end B can be effectively ensured, the consistency of the charging current and the mirroring current is ensured, and the accuracy of controlling the charging current is further improved.
In some embodiments, mirrored leg 112 includes transistor M9, mirrored leg 111 includes transistor M10, voltage acquisition sub-module 232 includes resistor R2, and clamp module 250 includes amplifier OTA2 and transistor M11. The control terminal of the transistor M9 and the control terminal of the transistor M10 are both connected to the control terminal C, and the first pole of the transistor M9 and the first pole of the transistor M10 are both connected to the power supply terminal VDD, and the second pole of the transistor M9 is the low potential terminal D; the positive input end of the amplifier OTA2 is simultaneously connected with the first pole and the low potential end D of the transistor M11, and the negative input end of the amplifier OTA2 is connected with the second pole and the charging end B of the transistor M10; the second pole of the transistor M11 is grounded through the resistor R2, and the common connection point of the transistor M11 and the resistor R2 is the voltage acquisition terminal a.
In a preferred embodiment of the present invention, the charging circuit further includes a voltage sampling module 400, where the voltage sampling module 400 is connected between the charging terminal B and the ground GND, and is configured to perform voltage division sampling on the voltage of the charging terminal B to obtain a sampled voltage.
By carrying out partial pressure sampling on the voltage of the charging end B, the sampling voltage of the battery can be obtained in a partial pressure sampling mode, the proportion between the sampling voltage and a plurality of partial pressure resistors is related, but not the absolute value of the partial pressure resistors, so that the influence of the power supply voltage and the temperature on the sampling resistor is counteracted through the relative relation of the partial pressure resistors, the influence of the temperature, the power supply voltage and other factors on the detection of the sampling voltage is avoided, and the accuracy of the detection of the sampling voltage is improved. Therefore, the voltage sampling module 400 disclosed in this embodiment can avoid the influence of temperature and power supply voltage, thereby improving the accuracy of detecting the voltage of the charging terminal B.
In a specific embodiment, the voltage sampling module 400 includes a resistor R3 and a resistor R4 connected in series, and a common connection node E between the resistor R3 and the resistor R4 is connected to the control module 200, so that the control module 200 can receive information of the sampled voltage.
In a specific embodiment, the resistor R3 and the resistor R4 are resistors of the same type, so that the influence of temperature and power supply voltage on the resistor R3 and the resistor R4 is consistent in the same environment, and further, the influence of factors such as temperature on the resistor R3 and the resistor R4 can be almost completely counteracted, and the influence of factors such as power supply voltage and temperature on the charging cut-off voltage is avoided.
For example, the ratio of the resistance values of the resistor R3 and the resistor R4 is 1:1, when the resistance value of the resistor R3 becomes 1.2 times the original resistance value due to a change in factors such as temperature, the resistance value of the resistor R4 becomes 1.2 times the original resistance value because the resistor R4 is also under the same influence, and the ratio of the resistance values of the resistor R3 and the resistor R4 is still 1:1. the sampling voltage is only related to the ratio of the resistance values of the resistor R3 and the resistor R4 and is irrelevant to the respective resistance values of the resistor R3 and the resistor R4, so that the sampling voltage is not affected by factors such as temperature, the accuracy of detecting the sampling voltage is ensured, and the accuracy of charging current control is further ensured.
In the present embodiment, the control module 200 includes a resistance variable module 210, a constant current source module 220, and a resistance control module 240. The variable resistance module 210 is connected between the power supply terminal VDD and the control terminal C, the resistance of the variable resistance module 210 is a variable resistance, and the voltage drop across the variable resistance module 210 is a voltage difference. The resistance of the variable resistance module 210, i.e., the equivalent resistance between the power supply terminal VDD and the control terminal C, is positively or negatively correlated to the voltage drop across the variable resistance module 210. In an embodiment of the present invention, current flows from the power supply terminal VDD to the control terminal C through the resistance variable module 210.
In the present embodiment, the constant current source module 220 is connected between the control terminal C and the ground GND, for keeping the current flowing from the power terminal VDD to the control terminal C constant through the resistance variable module 210. In a particular embodiment, the constant current source module 220 includes a current source Icom.
Since the constant current source module 220 can ensure that the current flowing from the power supply terminal VDD to the control terminal C through the variable resistance module 210 remains constant, the current flowing through the variable resistance module 210 remains constant, and thus the proportional relationship between the resistance of the variable resistance module 210 and the voltage drop across the variable resistance module 210 is ensured. When the resistance of the resistance variable module 210 is constant, the voltage drop across the resistance variable module 210 is also kept constant, so that the control terminal voltage of the mirrored leg 111 and the control terminal voltage of the mirrored leg 112 are both kept constant, so that the mirrored current and the charging current are both kept constant; when the resistance of the variable resistance module 210 becomes smaller, the voltage drop across the variable resistance module 210 is reduced, and thus the voltages at the control terminals of the mirrored and mirrored branches 111 and 112 are gradually increased, thereby gradually reducing the charging current.
In some embodiments, the resistance control module 240 is connected between the charging module 100 and the resistance variable module 210, and is configured to control the variable resistance to be smaller from the voltage of the charging terminal B rising to the first preset voltage, and make the magnitude of the variable resistance positively correlated with the magnitude of the charging current. The resistance control module controls the resistance of the resistance control module 240 according to the voltage of the charging end B and the charging current, so as to control the charging current, and the charging current can be controlled to be related to the charging current and the voltage of the charging end B, so that the problem that the voltage of the charging end B is too high or too low can be effectively avoided, and the accuracy and the safety of the charging current control are further improved.
In the embodiment of the present invention, the resistance variable module 210 includes a first shunt branch 211 and a second shunt branch 212 connected between the power supply terminal VDD and the control terminal C, respectively, and the first shunt branch 211 and the second shunt branch 212 are connected in parallel. When the voltage of the charging terminal B is less than the first preset voltage, the first shunt branch 211 is fully turned on and the second shunt branch 212 is turned off, and the variable resistance is kept constant, so that the voltage difference is kept constant, and thus the charging current is kept constant. From the voltage of the charging terminal B rising to the first preset voltage, the first shunt branch 211 is gradually opened and the second shunt branch 212 is gradually turned on, so that the variable resistance is gradually reduced, so that the voltage difference is gradually reduced, and the charging current is gradually reduced accordingly. When the voltage of the charging end B rises to the off voltage, the first shunt branch 211 is completely disconnected and the second shunt branch 212 is completely turned on, so that the variable resistance is reduced to a preset resistance threshold, the voltage difference is reduced to a preset voltage threshold, and the voltage of the control end of the mirror branch 111 is further increased, that is, the voltage difference between the control end and the first pole of the transistor M10 is smaller than the on voltage of the transistor M10, so that the transistor M10 is disconnected, the charging current is turned off, and the charging is turned off.
In a specific embodiment, the first shunt branch 211 includes a transistor M8, the second shunt branch 212 includes a transistor M6, and the specific resistance of the transistor M8 and the specific resistance of the transistor M6 can be set according to the actual parameters of the transistor M9 and the transistor M10, so long as the on-resistance of the transistor M6 is smaller than the on-resistance of the transistor M8, so that the voltage difference when the transistor M6 is fully turned on and the transistor M8 is fully turned off is smaller than the on-voltage of the transistor M10.
In an embodiment of the present invention, the resistance control module 240 includes a first current division control sub-module 241 and a second current division control sub-module 242. The first current dividing sub-module 241 is connected between the current sampling end a and the control end of the first current dividing branch 211; the second current-dividing sub-module 242 is connected between the charging terminal B and the control terminal of the second current-dividing branch 212 and is connected to the first preset voltage. It should be noted that the second current-dividing sub-module 242 may be directly connected to the charging terminal B or may be connected to the charging terminal B through the voltage sampling module 400. In a preferred embodiment, the second current sharing sub-module 242 is connected to the charging terminal B, i.e., through the voltage sampling module 400.
From the voltage of the charging terminal B rising to the first preset voltage, the second current dividing sub-module 242 controls the second current dividing branch 212 to be gradually turned on, so as to gradually decrease the variable resistance, and the mirror current is reduced, so that the first current dividing sub-module 241 is caused to control the first current dividing branch 211 to be gradually turned off, so that the variable resistance is reduced to the preset resistance threshold.
In a specific embodiment, the first current-dividing sub-module 241 includes a transconductance amplifier OTA3, an inverting input terminal of the transconductance amplifier OTA3 is connected to the current sampling terminal a to receive the voltage of the current sampling terminal a, and a non-inverting input terminal of the transconductance amplifier OTA3 receives the second reference voltage vref_cc. When the battery electric quantity is small and the battery is in a constant-current charging stage, the charging current is large, the mirror current is correspondingly large, the voltage of the current sampling end A is also large, and when the voltage of the current sampling end A is consistent with the second reference voltage VREF_CC, the transconductance amplifier OTA3 controls the transistor M8 to be completely conducted; when the battery power is gradually increased and enters the constant voltage charging stage, when the charging current is gradually reduced, the mirror current is correspondingly gradually reduced, and the voltage of the current sampling end A is also gradually reduced, so that the conduction capability of the transconductance amplifier OTA3 control transistor M8 is gradually reduced.
In a specific embodiment, the second current-dividing sub-module 242 includes a transconductance amplifier OTA1, wherein an inverting input terminal of the transconductance amplifier OTA1 is connected to the common connection node E to receive the sampling voltage, and a non-inverting input terminal of the transconductance amplifier OTA1 receives the first reference voltage vref_cv. When the battery electric quantity is low and the battery is in a constant-current charging stage, the voltage of the charging end B is low, the sampling voltage is low, at the moment, the sampling voltage is far smaller than the first reference voltage VREF_CV, and the transconductance amplifier OTA1 controls the transistor M6 to be completely disconnected; when the battery electric quantity gradually increases to enter a constant voltage charging stage, the sampling voltage gradually increases, the conduction capability of the transconductance amplifier OTA1 control transistor M6 gradually increases, and the transistor M6 shunts the transistor M8; when the battery level rises to the off voltage, the transconductance amplifier OTA1 controls the transistor M6 to be fully turned on, and at this time, the transconductance amplifier OTA3 controls the transistor M8 to be fully turned off, so that the transistor M6 shorts the transistor M8. The on-resistance of the transistor M6 is smaller than that of the transistor M8, and the equivalent resistance when the transistor M6 is fully turned on and the transistor M8 is fully turned off is smaller than that when the transistor M8 is fully turned on and the transistor M6 is fully turned off, that is, the voltage difference when the transistor M6 is fully turned on and the transistor M8 is fully turned off is smaller than that when the transistor M8 is fully turned on and the transistor M6 is fully turned off. It can be seen that from the transistor M8 being fully on and the transistor M6 being fully off to the transistor M6 being fully on and the transistor M8 being fully off, the equivalent resistance is gradually reduced, the voltage difference is also gradually reduced, the turn-on capability of the transistor M9 and the transistor M10 is gradually reduced, the mirror current and the charging current are both gradually reduced until the voltage at the charging terminal B is increased to the off voltage, the transistor M9 and the transistor M10 are fully off, the mirror current and the charging current are both reduced to zero, and the charging is turned off.
In this embodiment, the charging circuit further includes a current source module 300, and the current source module 300 is configured to provide an operating current to the resistance control module 240.
In a particular embodiment, the current source module 300 includes a current source sub-module 320 and a tail current sub-module 310. Wherein the current source sub-module 320 is configured to generate a stable reference current; tail current sub-module 310 is used to mirror the reference current to provide the bias current required for operation of control module 200 to control module 200.
In a particular embodiment, tail current sub-module 310 includes a first tail current leg 311 and a second tail current leg 312. The first tail current branch 311 is configured to mirror the reference current, so as to obtain and provide a first bias current It1 to the first current-dividing control sub-module 241; the second tail current branch 312 is used to mirror the reference current to obtain and provide a second bias current It2 to the second shunt control sub-module 242.
In summary, the current source sub-module 320 generates the stable reference current, the first tail current branch 311 and the second tail current branch 312 mirror the reference current to obtain the stable first bias current It1 and the second bias current It2, respectively, the transconductance amplifier OTA1 receives the first bias current It1 to enable the transconductance amplifier OTA1 to control the turn-on capability of the transistor M6, and the transconductance amplifier OTA3 receives the second bias current It2 to enable the transconductance amplifier OTA3 to control the turn-on capability of the transistor M8.
When the battery power is low, the voltage of the charging end B is smaller than the first preset voltage, the sampling voltage is far smaller than the second reference voltage VREF_CV, and the transconductance amplifier OTA1 controls the transistor M6 to be completely disconnected; at this time, the voltage of the current sampling terminal a is consistent with the first reference voltage vref_cc, and the transconductance amplifier OTA3 controls the transistor M8 to be fully turned on. In this constant current charging phase, transistor M6 remains fully off and transistor M8 remains fully on, so that the magnitude of the equivalent resistance is unchanged, and the current magnitude of the constant current source Icom is constant and flows completely through transistor M8, so that the voltage drop across the resistance variable module 210 remains constant, i.e. the voltage difference remains constant, and so that the turn-on capability of transistor M9 and transistor M10 remains constant, both the mirror current and the charging current remain constant.
As the battery power increases gradually until the voltage of the charging terminal B increases to the first preset voltage, and since the voltage of the charging terminal B reaches the first preset voltage, the sampling voltage approaches the second reference voltage vref_cv gradually, the transconductance amplifier OTA1 controls the transistor M6 to be turned on gradually, so that a part of the current of the constant current source Icom flows through the transistor M6, and since the transistor M6 is connected in parallel with the transistor M8, the equivalent resistance decreases gradually, so that the voltage drop across the voltage drop resistor variable module 210 on the resistor variable module 210, that is, the voltage difference decreases gradually, so that the turn-on capability of the transistor M9 and the transistor M10 decreases, and the mirror current and the charging current decrease gradually; in addition, the voltage of the current sampling terminal a is gradually reduced, so that the transconductance amplifier OTA3 controls the conduction capability of the transistor M8 to be gradually reduced, so that the current flowing through the transistor M8 is further gradually reduced and the current flowing through the transistor M6 is gradually increased. In this constant voltage charging stage, the transistor M6 is gradually turned on and the transistor M8 is gradually turned off, so that the equivalent resistance gradually decreases, and the current of the constant current source Icom is constant in magnitude and flows through the transistor M6 and the transistor M8, so that the voltage difference remains constant, and the mirror current and the charging current both gradually decrease.
As the battery power continues to rise, when the voltage of the charging end B rises to the cut-off voltage, the sampling voltage rises to be consistent with the second reference voltage vref_cv, and the transconductance amplifier OTA1 controls the transistor M6 to be fully turned on; at this time, the voltage of the current sampling terminal a is far smaller than the first reference voltage vref_cc, and the transconductance amplifier OTA3 controls the transistor M8 to be completely turned off, so that the current of the constant current source Icom completely flows through the transistor M6. In this charge-off phase, the transistor M6 is fully turned on and the transistor M8 is fully turned off, so that the equivalent resistance is reduced to the resistance threshold, and the voltage drop across the resistance variable module 210 is reduced to the voltage difference threshold, that is, the voltage difference is reduced to the voltage difference threshold, so that the transistors M9 and M10 cannot be turned on, and the mirror current and the charging current are both reduced to zero, so that the charging is immediately turned off.
The embodiment of the invention also discloses a power supply device which is used for providing a charging power supply for the outside and comprises the charging circuit.
The embodiment of the invention also discloses a charged device which comprises an energy storage unit and a charging circuit. The charging circuit is used for controlling the external power supply to charge the energy storage unit.
In a specific embodiment, the charged device is a headset and/or a headset charging cartridge.
The embodiment of the invention also discloses a charging system which comprises a power supply device and a charged device, wherein the charging circuit is arranged in the power supply device or the charged device.
The charging circuit is the charging circuit and is used for controlling the power supply equipment to charge the charged equipment.
The embodiment of the invention also discloses a chip for controlling charging, which comprises the charging circuit.
Those skilled in the art will appreciate that the above-described preferred embodiments can be freely combined and stacked without conflict.
It will be understood that the above-described embodiments are merely illustrative and not restrictive, and that all obvious or equivalent modifications and substitutions to the details given above may be made by those skilled in the art without departing from the underlying principles of the invention, are intended to be included within the scope of the appended claims.
Claims (15)
1. A charging circuit comprising a current source module and a charging terminal (B) for charging a battery, characterized in that the charging circuit further comprises:
a charging module (100) connected between a power supply terminal (VDD) and the charging terminal (B) and having a control terminal (C) for converting a power supply provided by the power supply terminal (VDD) into a charging current to be output to the charging terminal (B), wherein the charging current is controlled by a voltage difference between the control terminal (C) and the power supply terminal (VDD); the charging module (100) comprises a transistor (M10), a control terminal of the transistor (M10) being connected to the control terminal (C) to control the magnitude of the charging current by the degree of conduction of the transistor (M10);
the control module (200) is connected between the power supply terminal (VDD) and the charging module (100) and connected to the charging terminal (B) and the control terminal (C), and is configured to control the magnitude of the equivalent resistance between the power supply terminal (VDD) and the control terminal (C), so as to control the magnitude of the voltage difference, thereby controlling the conduction degree of the transistor (M10), and further controlling the magnitude of the charging current, where:
when the voltage of the charging end (B) is smaller than a first preset voltage, the control module (200) controls the voltage difference to be constant so as to enable the charging current to be constant;
starting from the voltage of the charging end (B) rising to a first preset voltage, the control module (200) controls the voltage difference to gradually decrease so as to gradually decrease the charging current;
when the voltage of the charging end (B) rises to a cut-off voltage, the control module (200) controls the voltage difference to be reduced to a preset voltage difference threshold value so as to cut off the charging current;
the current source module is connected between the power supply terminal (VDD) and the control module (200).
2. The charging circuit of claim 1, wherein the charging module (100) comprises:
the mirror sub-module (110) comprises a mirror-imaged branch (112) and a mirror-imaged branch (111) which are controlled by the control end (C); the mirror branch (111) is connected between the power supply terminal (VDD) and the charging terminal (B) and is configured to output the charging current to the charging terminal (B);
a voltage acquisition sub-module (232), wherein the mirrored branch (112) and the voltage acquisition sub-module (232) are sequentially connected in series between the power supply terminal (VDD) and ground, and are used for generating a mirrored current mirrored by the mirroring branch (111); one end of the voltage acquisition sub-module (232) far away from the ground forms a voltage acquisition end (A).
3. The charging circuit of claim 2, wherein the charging module (100) further comprises a clamping module (250), the clamping module (250) being connected between the low potential terminal (D) of the mirrored branch (112) and the charging terminal (B) for clamping the voltage of the low potential terminal (D) and the voltage of the charging terminal (B).
4. The charging circuit of claim 2, wherein the control module (200) comprises:
a variable resistance module (210) connected between the power supply terminal (VDD) and the control terminal (C), wherein the resistance of the variable resistance module (210) is a variable resistance and the voltage drop across the variable resistance module (210) is the voltage difference, and the resistance of the variable resistance module (210) is an equivalent resistance between the power supply terminal (VDD) and the control terminal (C);
a constant current source module (220) connected between the control terminal (C) and Ground (GND) for keeping constant a current flowing from the power supply terminal (VDD) to the control terminal (C) via the resistance variable module (210);
and the resistance control module (240) is connected between the charging module (100) and the resistance variable module (210) and is used for controlling the variable resistance to be small from the voltage of the charging end (B) to a first preset voltage, and making the variable resistance and the charging current positively correlated.
5. The charging circuit of claim 4, wherein the resistance variable module (210) comprises a first shunt branch (211) and a second shunt branch (212) connected between the power supply terminal (VDD) and the control terminal (C), respectively;
when the voltage of the charging end (B) is smaller than a first preset voltage, the first shunt branch (211) is completely conducted and the second shunt branch (212) is disconnected, and the variable resistance is kept constant;
starting from the voltage of the charging end (B) rising to a first preset voltage, the first shunt branch (211) is gradually disconnected and the second shunt branch (212) is gradually turned on, so that the variable resistance is gradually reduced;
when the voltage of the charging end (B) rises to a cut-off voltage, the first shunt branch (211) is disconnected and the second shunt branch (212) is fully conducted, so that the variable resistance is reduced to a preset resistance threshold value.
6. The charging circuit of claim 5, wherein the resistance control module (240) comprises:
the first shunt control sub-module (241) is connected between the current sampling end (A) and the control end of the first shunt branch (211);
a second shunt sub-module (242) connected between the charging terminal (B) and the control terminal of the second shunt branch (212) and connected to the first preset voltage;
starting from the voltage of the charging end (B) rising to a first preset voltage, the second shunt sub-module (242) controls the second shunt branch (212) to be gradually turned on, so that the variable resistance is gradually reduced, and the mirror current is reduced, so that the first shunt sub-module (241) is caused to control the first shunt branch (211) to be gradually turned off, and the variable resistance is reduced to a preset resistance threshold.
7. The charging circuit of claim 6, further comprising a voltage sampling module (400), wherein the voltage sampling module (400) is connected between the charging terminal (B) and Ground (GND) for voltage division sampling of the voltage of the charging terminal (B) to obtain a sampled voltage.
8. The charging circuit of claim 7, wherein the constant current source module (220) comprises a current source Icom, the first current dividing sub-module (241) comprises an amplifier OTA1, and an inverting input terminal of the amplifier OTA1 is connected to the current sampling terminal (a); the voltage sampling module (400) comprises a resistor R3 and a resistor R4 which are connected in series, and a common connection node (E) between the resistor R3 and the resistor R4 is connected with the second shunt control sub-module (242).
9. The charging circuit of claim 7, further comprising:
a current source sub-module (320) for generating a stable reference current;
a tail current sub-module (310) for mirroring the reference current to provide the control module (200) with a bias current required for the operation of the control module (200).
10. The charging circuit of claim 9, wherein the tail current sub-module (310) comprises:
a first tail current branch (311) for mirroring the reference current to obtain and provide a first bias current to the first shunt control sub-module (241);
a second tail current branch (312) for mirroring the reference current to obtain and provide a second bias current to the second shunt control sub-module (242).
11. A power supply apparatus for supplying a charging power to an outside, characterized in that the power supply apparatus comprises the charging circuit according to any one of claims 1 to 10.
12. A charged apparatus characterized by comprising:
an energy storage unit;
a charging circuit as claimed in any one of claims 1 to 10 for controlling the charging of the energy storage unit by an external power source.
13. The charged device according to claim 12, wherein the charged device is a headset and/or a headset charging box.
14. A charging system, comprising:
a power supply device;
a charged device;
a charging circuit as claimed in any one of claims 1 to 10, for controlling a power supply device to charge a charged device;
the charging circuit is provided in the power supply device or the charged device.
15. A chip for controlling charging, characterized by comprising a charging circuit according to any of claims 1-10.
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| CN214755593U (en) * | 2021-03-11 | 2021-11-16 | 深圳拓邦股份有限公司 | Constant voltage and constant current charging control circuit and switching power supply |
| CN114499126A (en) * | 2022-04-14 | 2022-05-13 | 深圳市思远半导体有限公司 | Self-adaptive constant-on-time step-down direct current converter and on-time control circuit |
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| JP4820190B2 (en) * | 2006-03-09 | 2011-11-24 | 株式会社リコー | Overcurrent detection circuit |
| CN101282045B (en) * | 2008-04-28 | 2010-08-11 | 炬力集成电路设计有限公司 | Battery charging apparatus as well as control method thereof |
| CN105186636B (en) * | 2015-10-30 | 2018-09-11 | 杭州士兰微电子股份有限公司 | power charging circuit |
| CN108258762A (en) * | 2018-01-26 | 2018-07-06 | 深圳还是威健康科技有限公司 | A kind of quick-charging circuit and intelligent terminal for pre-installing battery system |
| CN111934404B (en) * | 2020-10-15 | 2021-01-29 | 北京思凌科半导体技术有限公司 | Charging circuit |
| JP2022117354A (en) * | 2021-01-29 | 2022-08-10 | 株式会社デンソーテン | Charge control apparatus and charge control method |
| CN216851374U (en) * | 2022-01-24 | 2022-06-28 | 富满微电子集团股份有限公司 | Pre-charging circuit and chip |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN214755593U (en) * | 2021-03-11 | 2021-11-16 | 深圳拓邦股份有限公司 | Constant voltage and constant current charging control circuit and switching power supply |
| CN114499126A (en) * | 2022-04-14 | 2022-05-13 | 深圳市思远半导体有限公司 | Self-adaptive constant-on-time step-down direct current converter and on-time control circuit |
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