CN115833282A - Charging circuit and charging control method - Google Patents
Charging circuit and charging control method Download PDFInfo
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- CN115833282A CN115833282A CN202111091434.3A CN202111091434A CN115833282A CN 115833282 A CN115833282 A CN 115833282A CN 202111091434 A CN202111091434 A CN 202111091434A CN 115833282 A CN115833282 A CN 115833282A
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Abstract
A charging circuit and a charging control method are provided. The charging circuit includes: the power level circuit is used for operating at least one power switch according to the operation signal so as to convert the input power supply into a charging power supply and charge the battery; the control circuit is coupled with the power stage circuit and used for generating an operation signal according to the current feedback signal and the voltage feedback signal; a voltage feedback circuit for comparing a voltage sensing signal related to a charging voltage of the charging power supply with a voltage reference level to generate a voltage feedback signal; a battery cell voltage drop sensing circuit coupled to a battery cell of the battery to sense a battery cell voltage drop of the battery cell to generate a cell voltage drop sensing signal; and the adjusting circuit is coupled with the cell voltage drop sensing circuit and used for generating an adjusting signal according to the cell voltage drop sensing signal so as to adaptively adjust the voltage reference level.
Description
Technical Field
The present invention relates to a charging circuit, and more particularly, to a charging circuit and a charging control method for shortening a charging time by adaptively adjusting a voltage reference level.
Background
Referring to fig. 1A, a schematic diagram of a conventional charging circuit is shown. The known charging circuit 10 comprises a control circuit 11, a power stage circuit 12 and a feedback circuit 13. The power stage circuit 12 is configured to correspondingly operate the power switches QA and QB therein according to the operation signals UG and LG to control the on state of the inductor L, so as to convert the input power Vin into the charging power Vch for charging the battery 19. The charging power supply Vch corresponds to the charging voltage Vbat and the charging current Ibat. The control circuit 11 is coupled to the power stage circuit 12 for generating the operation signals UG and LG according to the feedback signal FB.
The feedback circuit 13 is configured to generate the feedback signal FB according to the charging current Ibat and the charging voltage Vbat. The power stage circuit 12 includes power switches QA and QB and an inductor L. The power switch QA is coupled between the input power Vin and the first end LX1 of the inductor L, and the power switch QB is coupled between the ground potential GND and the first end LX1 of the inductor L. The operation signals UG and LG are respectively used to control the power switch QA and the power switch QB, so as to switch the first end LX1 of the inductor L between the input power Vin and the ground potential GND. The charging power Vch is coupled to the second terminal LX2 of the inductor L, so as to convert the input power Vin into the charging power Vch for charging the battery 19.
Fig. 1B is a graph showing the charging voltage Vbat (indicated by a thick black solid line in fig. 1B) and the charging current Ibat (indicated by a thick black dashed line in fig. 1B) of the conventional charging circuit as a function of time. As shown in fig. 1B, in the prior art charging circuit 10, during the former stage from time t0 to time t1, the charging current Ibat is adjusted to the fixed current Ict to charge the battery 19; during the period from the time point t1 to the later stage of the time point t2, the charging voltage Vbat is adjusted to the fixed voltage Vct to charge the battery 19.
During the latter period, i.e. the charging period in which the charging voltage Vbat is adjusted to the fixed voltage Vct, the charging current Ibat still continues to charge the battery cell 191 inside the battery 19, because the charging voltage Vbat is adjusted to the fixed voltage Vct, and as the voltage of the battery cell 191 gradually increases, the charging current Ibat flows through the resistor Rpr including the chemical resistor in the battery 19, the voltage drop thereof gradually decreases, and the charging current Ibat gradually decreases. When the charging current Ibat decreases to the charging current Ibf close to zero current, indicating that the charging of the battery 19 is completed, the charging efficiency is lower during the period from the time point t1 to the later stage of the time point t2 due to the gradual decrease of the charging current Ibat, and the longer the period of the later stage during which the charging efficiency is lower, the longer the charging time is.
In view of the above, the present invention provides a charging circuit and a charging control method capable of shortening the charging time, which are directed to the deficiencies of the prior art.
Disclosure of Invention
In one aspect, the present invention provides a charging circuit, comprising: the power stage circuit is used for operating at least one power switch according to an operation signal so as to convert an input power supply into a charging power supply to charge a battery, wherein the charging power supply comprises a charging voltage and a charging current; a control circuit coupled to the power stage circuit for generating the operation signal according to a current feedback signal and a voltage feedback signal; a current feedback circuit for comparing a current sense signal related to the charging current with a current reference level to generate the current feedback signal; a voltage feedback circuit for comparing a voltage sensing signal related to the charging voltage with a voltage reference level to generate the voltage feedback signal; a battery cell voltage drop sensing circuit coupled to a battery cell of the battery for sensing a battery cell voltage drop of the battery cell to generate a cell voltage drop sensing signal; and an adjusting circuit coupled to the cell voltage drop sensing circuit for generating an adjusting signal according to the cell voltage drop sensing signal to adaptively adjust the voltage reference level.
In another aspect, the present invention provides a charging control method for converting an input power into a charging power to charge a battery, the charging control method comprising: operating at least one power switch according to an operation signal to convert the input power into the charging power, wherein the charging power comprises a charging voltage and a charging current; generating the operation signal according to a current feedback signal and a voltage feedback signal; comparing a current sensing signal related to the charging current with a current reference level to generate the current feedback signal; comparing a voltage sensing signal related to the charging voltage with a voltage reference level to generate the voltage feedback signal; and a reference level adjustment step, comprising: sensing a cell voltage drop inside the battery to generate a cell voltage drop sensing signal; and generating an adjustment signal according to the core drop sensing signal to adaptively adjust the voltage reference level.
In one embodiment, the adjusting circuit adaptively adjusts the voltage reference level according to the core voltage drop sensing signal exceeding a predetermined threshold.
In one embodiment, the adjusting circuit includes a step-down circuit for adjusting a step signal to an enable level when the core drop sensing signal exceeds the predetermined threshold, so as to indicate that the core drop sensing signal exceeds the predetermined threshold, and then adjusting the voltage reference level down by a predetermined difference.
In one embodiment, the charging circuit further includes a timing circuit coupled to the adjusting circuit, and configured to time a timeout period when the step signal is at a disable level, indicating that the core drop detection signal does not exceed the predetermined threshold, and generate an end adjusting signal when the timing circuit ends the timeout period and the step signal is at the disable level, so as to end the adaptive adjustment of the voltage reference level.
In one embodiment, the control circuit generates an end adjustment signal to end the adaptive adjustment of the voltage reference level when the voltage reference level is not higher than a predetermined threshold level.
In one embodiment, the cell voltage drop sensing circuit includes an analog-to-digital conversion circuit for converting the cell voltage drop in analog form into the cell voltage drop sensing signal in digital form.
In one embodiment, the power stage circuit includes a switched inductor power stage circuit, a switched capacitor power stage circuit, a low dropout regulator, or an ac-dc converter circuit.
In an embodiment, the charging control method further includes: setting an enable signal as an enable level to enable the reference level adjustment step.
In an embodiment, the charging control method further includes: when a protection signal is at the forbidden level, the voltage reference level is set to the preset threshold level to end the reference level adjustment step.
In one embodiment, the step of adaptively decreasing the voltage reference level when the core drop sensing signal exceeds the predetermined threshold further comprises: after the predetermined difference is reduced by the voltage reference level, the voltage reference level is maintained for a predetermined period.
The invention has the advantage that the charging time can be shortened by regulating and reducing the voltage reference level.
The purpose, technical content, features and effects of the present invention will be more readily understood by the following detailed description of specific embodiments.
Drawings
Fig. 1A is a schematic diagram illustrating a conventional charging circuit.
Fig. 1B is a graph showing the relationship between the charging voltage and the charging current of the conventional charging circuit and the time.
FIG. 2A is a block diagram of a charging circuit according to an embodiment of the invention.
Fig. 2B is a diagram illustrating a charging voltage cell drop and a charging current versus time relationship of a charging circuit according to an embodiment of the present invention and the prior art.
Fig. 2C is a diagram of the cell voltage drop and charging current versus time for a charging circuit according to an embodiment of the present invention and the prior art.
Fig. 3A-3F are schematic diagrams illustrating a flow of steps of a charging control method according to an embodiment of the invention.
Fig. 4 is a flowchart illustrating a charging control method according to an embodiment of the invention.
Fig. 5 is a flowchart illustrating a charging control method according to another embodiment of the invention.
Fig. 6 is a flowchart illustrating a charging control method according to still another embodiment of the invention.
Fig. 7A-7K show synchronous or asynchronous buck, boost, buck-boost, boost-buck, and flyback power stage circuits for switched inductor power stage circuits.
Fig. 8 shows an embodiment of a switched capacitor power stage circuit.
Fig. 9 shows an embodiment of a low dropout linear regulator.
Fig. 10 shows an embodiment of an ac-dc converter circuit.
Description of the symbols in the drawings
10,20: charging circuit
11,21: control circuit
12,22: power stage circuit
13,23: current feedback circuit
14,24: voltage feedback circuit
19,29: battery with a battery cell
25: battery cell voltage drop sensing circuit
26: adjusting circuit
261: step-down circuit
27: timing circuit
291: battery core
30,40,50,60: charging control method
301 to 308,401 to 413,501 to 518,601 to 619,3051,3061,30611,30612,30613a,30613b: step (ii) of
GND: ground potential
Ibat: charging current
Ict: fixed current
Ibf: final charging current
L: inductance
LG, UG: operating signal
LX1: first end
LX2: second end
And Oif: current feedback signal
Ovf: voltage feedback signal
QA, QB: power switch
And Rpr: resistance (RC)
Sa: adjusting signals
Sf1, sf2: end adjust signal
t0, t1, t1', t2, t2': point in time
Vbat: charging voltage
Vbc: cell voltage drop
Vch: charging power supply
Vct: fixed voltage
And (2) Vibat: current sensing signal
Vin: input power supply
VrefCC: current reference level
VrefCV: voltage reference level
Vth: preset threshold value
Vvbat: voltage sensing signal
Vvbc: core drop sensing signal
Detailed Description
The drawings in the present application are schematic and are intended to show the coupling relationship between circuits and the relationship between signal waveforms, and the circuits, signal waveforms and frequencies are not drawn to scale.
FIG. 2A is a block diagram of a charging circuit according to an embodiment of the present invention. As shown in fig. 2A, the charging circuit 20 of the present invention includes a control circuit 21, a power stage circuit 22, a current feedback circuit 23, a voltage feedback circuit 24, a cell voltage drop sensing circuit 25, an adjusting circuit 26, and a timing circuit 27. The power stage circuit 22 is configured to correspondingly operate the power switches QA and QB therein according to the operation signals UG and LG, so as to convert the input power Vin into the charging power Vch for charging the battery 29. The charging power source Vch corresponds to the charging voltage Vbat and/or the charging current Ibat. The control circuit 21 is coupled to the power stage circuit 22 for generating the operation signals UG and LG according to the current feedback signal Oif and the voltage feedback signal Ovf.
The power stage circuit 22 shown in fig. 2A is a step-down power stage circuit in a switching inductance type power stage circuit, and according to the present invention, the power stage circuit 22 is not limited to a switching inductance type power stage circuit, and may be a switching capacitance type power stage circuit, a low dropout linear regulator, or an ac/dc conversion circuit. The switched inductor power stage circuit may be, for example, a synchronous or asynchronous buck, boost, or flyback power stage circuit, as shown in fig. 7A-7K. Additionally, FIG. 8 shows an embodiment of a switched capacitor power stage circuit; FIG. 9 illustrates an embodiment of a low dropout linear regulator; fig. 10 shows an embodiment of an ac-dc converter circuit.
The current feedback circuit 23 is used for comparing the current sensing signal Vibat related to the charging current Ibat with the current reference level VrefCC to generate the current feedback signal Oif. The voltage feedback circuit 24 is used for comparing the voltage sensing signal Vvbat related to the charging voltage Vbat with the voltage reference level VrefCV to generate the voltage feedback signal Ovf. The cell drop sensing circuit 25 is coupled to the cell 291 of the battery 29 to sense a cell drop Vbc of the cell 291 to generate a cell drop sensing signal Vvbc. In one embodiment, the cell voltage drop sensing circuit 25 includes an analog-to-digital converter (ADC) for converting the cell voltage drop Vbc having an analog form into a cell voltage drop sensing signal Vvbc having a digital form.
The adjusting circuit 26 is coupled to the cell drop sensing circuit 25 for generating an adjusting signal Sa according to the cell drop sensing signal Vvbc to adaptively adjust the voltage reference level VrefCV. In one embodiment, the adjusting circuit 26 adaptively adjusts the voltage reference level VrefCV according to the core voltage drop sensing signal Vvbc exceeding a predetermined threshold Vth. In one embodiment, the predetermined threshold Vth is, for example, but not limited to, 4.2V or 4.4V. As shown in fig. 2A, in one embodiment, the adjusting circuit 26 includes a step down circuit 261 for adjusting the step signal to an enable level when the core drop sensing signal Vvbc exceeds the predetermined threshold Vth, so as to indicate that the core drop sensing signal Vvbc exceeds the predetermined threshold Vth and to adjust the voltage reference level VrefCV by a predetermined difference. In one embodiment, the predetermined difference is, for example, but not limited to, 10mv. In one embodiment, the adjusting circuit 26 maintains the adjusted and reduced voltage reference level VrefCV for a predetermined period of time after adjusting and reducing the voltage reference level VrefCV by a predetermined difference. In one embodiment, the predetermined time is, for example but not limited to, 32 microseconds (ms), 64ms, 128ms or 256ms.
The timing circuit 27 is coupled to the adjusting circuit 26 and is configured to time an over-time period when the core drop sensing signal Vvbc does not exceed the predetermined threshold Vth according to the step signal at the disable level. The timing circuit 27 generates the end adjustment signal Sf1 to end the adaptive adjustment voltage reference level VrefCV when the time-out period ends and the step signal is still at the disable level. In one embodiment, the time-out period is, for example, but not limited to, 0.5s or 1s. The control circuit 21 generates the end adjustment signal Sf2 to end the adaptively adjusted voltage reference level VrefCV when the voltage reference level VrefCV is not higher than the predetermined bottom limit.
The power stage circuit 22 includes power switches QA and QB and an inductor L. The power switch QA is coupled between the input power Vin and the first end LX1 of the inductor L, and the power switch QB is coupled between the ground potential GND and the first end LX1 of the inductor L. The operation signals UG and LG are respectively used to control the power switch QA and the power switch QB, so as to switch the first end LX1 of the inductor L between the input power Vin and the ground potential GND. The charging power Vch is coupled to the second terminal LX2 of the inductor L, so as to convert the input power Vin into the charging power Vch for charging the battery 29.
Fig. 2B is a diagram illustrating the charging voltage Vbat cell drop and the charging current Ibat of the charging circuit according to the prior art as a function of time according to an embodiment of the present invention. Fig. 2C is a diagram of the relationship between the cell voltage drop Vbc and the charging current Ibat of the charging circuit according to the prior art and an embodiment of the present invention. In fig. 2B and 2C, the gray-scale lines are the characteristic curves of the prior art, and the black lines are the characteristic curves of the present invention. As shown in fig. 2B and 2C, the charging circuit of the present invention requires significantly less time to charge the battery than the prior art of fig. 1A.
As shown in fig. 2B, in the conventional technique, as described above, the charging efficiency is low due to the gradual decrease of the charging current Ibat during the subsequent period from the time point t1 to the time point t2, and the longer the subsequent period during which the charging efficiency is low, the longer the charging time is.
Referring to fig. 2B, in the charging circuit according to the present invention, a characteristic curve of the charging voltage Vbat (as indicated by a thick black solid line in fig. 2B) and the charging current Ibat (as indicated by a thick black dashed line in fig. 2B) versus time is shown, wherein the current feedback circuit 23 controls the feedback control to adjust the charging current Ibat to the fixed current Ict from the time point t0 to the time point t1' for charging the battery 19. During the later period from the time point t1 'to the time point t2', the voltage feedback circuit 14 controls the feedback control, and during the later period, a predetermined difference is adjusted down each time in a step-down manner to adaptively adjust the voltage reference level VrefCV down, so that the charging voltage Vbat gradually decreases, until the voltage reference level VrefCV is not higher than a predetermined bottom limit, the control circuit 21 generates the end adjustment signal Sf2 to end the adaptive adjustment of the voltage reference level VrefCV, so as to adjust the charging voltage Vbat the fixed voltage Vct.
Comparing the characteristic curves according to the present invention with the prior art, between the time points t1 and t1', the voltage reference level VrefCV according to the present invention is set at the voltage Vct' higher than the voltage Vct, so that during this period, the charging circuit according to the present invention charges the battery 19 with a higher constant current Ict than the prior art, thereby shortening the charging time.
As shown in fig. 2C, fig. 2C is a diagram illustrating a relationship between a cell voltage drop Vbc and a charging current Ibat of a charging circuit according to an embodiment of the present invention and a related art as a function of time. As described above, the charging circuit according to the present invention has a shorter charging time than the related art. When the core voltage drop sensing signal Vvbc related to the battery core voltage drop Vbc exceeds the preset threshold Vth, the voltage reference level VrefCV is adjusted down by a preset difference, and for example, the adjusted down voltage reference level VrefCV is maintained for a preset time, due to the continuous charging, when the core voltage drop sensing signal Vvbc exceeds the preset threshold Vth again, the voltage reference level VrefCV is adjusted down by a preset difference, and the adjusted down voltage reference level VrefCV is maintained for a preset time again until the voltage reference level VrefCV is not higher than the preset bottom limit level, the reference level adjustment step is ended, which is the step of adaptively adjusting down the voltage reference level VrefCV.
Fig. 3A-3F are flow charts illustrating steps of a charging control method according to an embodiment of the invention. As shown in fig. 3A, the charging control method 30 of the present invention includes in step 301, operating at least one power switch according to an operation signal to control a conduction state of an inductor, so as to convert an input power into a charging power, wherein the charging power includes a charging voltage and a charging current. Next, in step 302, an operation signal is generated according to the current feedback signal and the voltage feedback signal. Then, in step 303, a current sensing signal related to the charging current is compared with a current reference level to generate a current feedback signal. Next, in step 304, a voltage feedback signal is generated by comparing a voltage sense signal associated with the charging voltage with a voltage reference level. Then, a reference level adjustment step is performed, which includes step 305, sensing a cell voltage drop inside the battery to generate a cell voltage drop sensing signal. Next, in step 306, an adjustment signal is generated according to the core drop sensing signal to adaptively adjust the voltage reference level.
As shown in FIG. 3B, in one embodiment, step 306 may include step 3061 of adaptively adjusting the voltage reference level according to the core drop sensing signal exceeding a predetermined threshold. As shown in fig. 3C, in one embodiment, the step 3061 may include the step 30611 of adjusting the step signal to an enable level when the core drop sensing signal exceeds a predetermined threshold, so as to indicate that the core drop sensing signal exceeds the predetermined threshold, and adjusting the voltage reference level by a predetermined difference. Next, in step 30612, the voltage reference level is maintained for a predetermined period of time. Thereafter, the method continues to step 30613a, when the step signal is at the forbidden level, indicating that the core drop sensing signal does not exceed the preset threshold, a timeout period is timed, and when the timeout period ends, and the step signal is at the forbidden level, an end adjustment signal is generated to end the reference level adjustment step. In another embodiment, step 30613b may be continued by generating an end adjustment signal when the voltage reference level is not higher than the predetermined threshold level, so as to end the reference level adjusting step.
As shown in fig. 3D, step 305 may include step 3051 of converting the cell drop voltage having an analog form into a cell drop voltage sensing signal having a digital form. As shown in fig. 3E, the charging control method 30 of the present invention may further include a step 307 of setting the enable signal to an enable level to enable the reference level adjustment step. As shown in fig. 3F, the charging control method 30 of the present invention may further include a step 308 of setting the voltage reference level to a predetermined threshold level when the protection signal is the disable level, so as to end the reference level adjusting step.
Fig. 4 is a flowchart illustrating a charging control method according to an embodiment of the invention. As shown in fig. 4, the charging control method 40 of the present invention may include a step 401 of setting a protection signal at an enable level by software to start a protection mechanism. Next, in step 402, the hardware determines whether the analog-to-digital conversion circuit (ADC) is turned on and whether the activation signal associated with the channel of the ADC for detecting the cell voltage drop is at the enable level. If yes, go to step 403; if not, proceed to step 410. In step 403, the hardware determines whether the cell voltage drop is greater than a predetermined threshold. If yes, go to step 404; if not, go back to step 402. In one embodiment, the predetermined threshold is, for example, but not limited to, 4.2V or 4.4V.
In step 404, the hardware sends a signal to the system notifying that a predetermined threshold has been exceeded. Then, in step 405, the hardware determines whether the step signal is at the enable level to start the reference level adjustment procedure. If yes, go to step 406; if not, proceed to step 409. In step 406, the voltage reference level is adjusted by hardware by a predetermined difference. In one embodiment, the predetermined difference is, for example, but not limited to, 10mV. Next, in step 407, it is determined whether the voltage reference level is less than or equal to a predetermined threshold level. If yes, proceed to step 410; if not, proceed to step 408. In step 408, the voltage reference level is maintained for a predetermined period of time. In one embodiment, the predetermined time is, for example, but not limited to, 32ms, 64ms, 128ms, 256ms. After step 408 is completed, the process then returns to step 402.
In step 409, the hardware times and determines whether the timeout period has expired. If yes, go to step 410; if not, go back to step 402. In one embodiment, the timeout period is, for example, but not limited to, 0.5s or 1s. In step 410, the hardware configures the voltage reference level to be a predetermined threshold level and sends a signal to the system to notify the end of the process. Next, in step 411, the hardware determines whether the protection signal is at the enable level. If yes, go back to step 402; if not, proceed to step 413. In another embodiment, in step 412, the voltage reference level is set to the predetermined floor level when the protection signal is set at the disable level. Thereafter, in step 413, all processes are ended.
Fig. 5 is a flowchart illustrating a charging control method according to another embodiment of the invention. The present embodiment employs hardware to implement the charging control method. The present embodiment is different from the embodiment of fig. 4 in that the charging control method 50 of the present embodiment includes a step 501 of inserting an external power source. Then, in step 502, the software registers the initial settings. In one embodiment, the initial settings include, but are not limited to, initial settings of a predetermined threshold level, a predetermined threshold, a step signal, a predetermined time, a voltage reference level, and the like. In one embodiment, the step signal is initially set to the enable level. Then, in step 503, the software sets the ADC related parameters and sets the enable signal related to the channel of the ADC for detecting the cell voltage drop at the enable level (continuous mode measurement cell voltage drop). Next, in step 504, the software determines whether the voltage drop of the battery cell is less than the maximum external voltage of the battery and whether the battery exists. If yes, go to step 505; if not, go back to step 503. In step 505, the software sets the protection signal to the enable level to start the protection mechanism. Then, in step 506, the voltage reference level is set to the maximum value of the external voltage of the battery by software. In one embodiment, the maximum external voltage of the battery is, for example, but not limited to, 4.7V. After step 506 is completed, the process proceeds to steps 507 to 518. Steps 507-518 are similar to steps 402-413 of FIG. 4, and thus a detailed description thereof is omitted. Another difference between this embodiment and the embodiment of fig. 4 is that after the end of step 515, the software receiving signal sets the enable signal to the disable level, the protection signal to the disable level, and the voltage reference level to the maximum value of the external voltage of the battery.
Fig. 6 is a flowchart illustrating a charging control method according to still another embodiment of the invention. In the embodiment, software is adopted to give an instruction to hardware through a communication interface to implement the charging control method. Steps 601 to 609 and 611 to 619 are similar to steps 501 to 518 of fig. 5, and detailed description thereof is omitted. The difference between this embodiment and the embodiment of fig. 5 is that after step 609 ends, step 610 is proceeded, after the software receives the signal sent by the hardware, the software reads the register within the preset time and issues the instruction to the hardware to execute the reference level adjustment procedure, and resets the timer for the preset time. In one embodiment, the predetermined time is, for example, but not limited to, 0.5s.
The present invention provides a charging circuit and a control method thereof, which can shorten the charging time by adjusting and reducing the voltage reference level.
The present invention has been described in terms of the preferred embodiment, but the above description is only for the purpose of facilitating the understanding of the present invention by those skilled in the art, and is not intended to limit the broadest scope of the present invention. The embodiments described are not limited to single use, but may be used in combination, for example, two or more embodiments may be combined, and some components in one embodiment may be substituted for corresponding components in another embodiment. Further, equivalent variations and combinations are contemplated by those skilled in the art within the spirit of the present invention, and the term "processing or computing or generating an output result based on a signal" is not limited to the signal itself, and includes, if necessary, performing voltage-to-current conversion, current-to-voltage conversion, and/or scaling on the signal, and then processing or computing the converted signal to generate an output result. It is understood that equivalent variations and combinations, not all of which are intended to be within the scope of this invention, will occur to those skilled in the art and are intended to be within the scope of this invention. Accordingly, the scope of the present invention should be determined to encompass all such equivalent variations as described above.
Claims (17)
1. A charging circuit, comprising:
the power stage circuit is used for operating at least one power switch according to an operation signal so as to convert an input power supply into a charging power supply to charge a battery, wherein the charging power supply comprises a charging voltage and a charging current;
a control circuit coupled to the power stage circuit for generating the operation signal according to a current feedback signal and a voltage feedback signal;
a current feedback circuit for comparing a current sense signal related to the charging current with a current reference level to generate the current feedback signal;
a voltage feedback circuit for comparing a voltage sensing signal related to the charging voltage with a voltage reference level to generate the voltage feedback signal;
a battery core voltage drop sensing circuit coupled to a battery core of the battery for sensing a battery core voltage drop of the battery core to generate a core voltage drop sensing signal; and
and the adjusting circuit is coupled with the cell voltage drop sensing circuit and used for generating an adjusting signal according to the cell voltage drop sensing signal so as to adaptively adjust the voltage reference level.
2. The charging circuit of claim 1, wherein the adjustment circuit adaptively adjusts the voltage reference level according to the core drop sensing signal exceeding a predetermined threshold.
3. The charging circuit of claim 2, wherein the adjusting circuit comprises a step-down circuit for adjusting a step signal to an enable level when the core drop sensing signal exceeds the predetermined threshold, indicating that the core drop sensing signal exceeds the predetermined threshold, and for adjusting the voltage reference level down by a predetermined difference.
4. The charging circuit of claim 3, further comprising a timing circuit coupled to the adjusting circuit and configured to time a timeout period when the step signal is at a disable level indicating that the core drop detection signal does not exceed the predetermined threshold, wherein the timing circuit generates an end adjusting signal at an end of the timeout period when the step signal is at the disable level to end the adaptive adjustment of the voltage reference level.
5. The charging circuit of claim 3, wherein the control circuit generates an end adjustment signal to end adaptively adjusting the voltage reference level when the voltage reference level is not higher than a predetermined threshold.
6. The charging circuit of claim 1, wherein the cell drop sensing circuit comprises an analog-to-digital conversion circuit for converting the cell drop in analog form into the cell drop sensing signal in digital form.
7. The charging circuit of claim 1, wherein the power stage circuit comprises a switched inductor power stage circuit, a switched capacitor power stage circuit, a low dropout regulator, or an ac-to-dc converter circuit.
8. A charging control method is used for converting an input power supply into a charging power supply to charge a battery, and comprises the following steps:
operating at least one power switch according to an operation signal to convert the input power into the charging power, wherein the charging power comprises a charging voltage and a charging current;
generating the operation signal according to a current feedback signal and a voltage feedback signal;
comparing a current sensing signal related to the charging current with a current reference level to generate the current feedback signal;
comparing a voltage sensing signal related to the charging voltage with a voltage reference level to generate the voltage feedback signal; and
a reference level adjustment step, comprising:
sensing a cell voltage drop inside the battery to generate a cell voltage drop sensing signal; and
generating an adjusting signal according to the core drop sensing signal to adaptively adjust the voltage reference level.
9. The charge control method of claim 8, wherein generating the adjustment signal to adaptively adjust the voltage reference level according to the core drop sensing signal comprises: when the core voltage drop sensing signal exceeds a preset threshold, the voltage reference level is adjusted and reduced.
10. The charge control method of claim 9, wherein the step of adaptively decreasing the voltage reference level according to the core voltage drop sensing signal exceeding the predetermined threshold comprises: when the core voltage drop sensing signal exceeds the preset threshold, the step signal is adjusted to an enable level to indicate that the core voltage drop sensing signal exceeds the preset threshold, and the voltage reference level is adjusted to be reduced by a preset difference value.
11. The charge control method of claim 10, wherein the step of adaptively decreasing the voltage reference level according to the core voltage drop sensing signal exceeding the predetermined threshold further comprises: and according to the step signal at a forbidden level, when the core drop sensing signal does not exceed the preset threshold value, timing a time-out period, at an ending point of the time-out period, and when the step signal is at the forbidden level, generating an ending adjustment signal to end the reference level adjustment step.
12. The charge control method according to claim 10, wherein the step of adaptively decreasing the voltage reference level according to the core voltage drop sensing signal exceeding the predetermined threshold further comprises: when the voltage reference level is not higher than a predetermined threshold level, an end adjustment signal is generated to end the reference level adjustment step.
13. The charge control method according to claim 8, wherein the step of sensing a cell voltage drop inside the battery to generate a cell voltage drop sensing signal comprises: converting the cell voltage drop in analog form into the cell voltage drop sensing signal in digital form.
14. The charge control method according to claim 8, further comprising: setting an enable signal as an enable level to enable the reference level adjustment step.
15. The charge control method according to claim 12, further comprising: when a protection signal is at the forbidden level, the voltage reference level is set to the preset threshold level to end the reference level adjustment step.
16. The charge control method according to claim 10, wherein the step of adaptively decreasing the voltage reference level according to the core voltage drop sensing signal exceeding the predetermined threshold further comprises: after the predetermined difference is reduced by the voltage reference level, the voltage reference level is maintained for a predetermined period.
17. The charge control method of claim 8, wherein the power switch belongs to a power stage circuit, wherein the power stage circuit comprises a switched inductor power stage circuit, a switched capacitor power stage circuit, a low dropout regulator or an ac-dc converter circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111091434.3A CN115833282A (en) | 2021-09-17 | 2021-09-17 | Charging circuit and charging control method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111091434.3A CN115833282A (en) | 2021-09-17 | 2021-09-17 | Charging circuit and charging control method |
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| Publication Number | Publication Date |
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| CN115833282A true CN115833282A (en) | 2023-03-21 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN202111091434.3A Pending CN115833282A (en) | 2021-09-17 | 2021-09-17 | Charging circuit and charging control method |
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| CN (1) | CN115833282A (en) |
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- 2021-09-17 CN CN202111091434.3A patent/CN115833282A/en active Pending
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