PORTABLE DEVICE CAPABLE OF CONTROLLING OUTPUT CHARACTERISTICS OF ADAPTOR, AND CORRESPONDING METHOD
A portable device capable of controlling output characteristics of an adaptor used for charging a battery of the portable device includes a sensing circuit and a controlling circuit. The sensing circuit senses a condition of the battery. The controlling circuit controls the adaptor to adjust its output characteristics based on the condition of the battery.
The present invention relates to a charging scheme for controlling an adaptor, and more particularly to a portable device capable of controlling output characteristics of the adaptor and corresponding method.
BACKGROUNDGenerally speaking, when a conventional adaptor is connected to an electronic device via a communication interface to charge a battery of the electronic device, the conventional adaptor usually employs a constant current to charge the battery in a constant current mode. However, under some conditions, considering the circuit costs and worse power dissipation, only a smaller constant current can be employed for charging the battery. The smaller current indicates that it is necessary for the conventional adaptor to consume a longer time period to charge the battery. This drawback is unacceptable by users. Accordingly, it is important to provide a novel charging scheme to overcome the shortcoming of the prior art.
SUMMARYTherefore one of the objectives of the present invention is to provide a portable device and method capable of controlling output characteristics of an adaptor used for charging a battery of the portable device, to solve the above-mentioned problems.
According to an embodiment of the present invention, a portable device capable of controlling output characteristics of an adaptor used for charging a battery of the portable device is disclosed. The portable device comprises a sensing circuit and a controlling circuit. The sensing circuit senses a condition of the battery. The controlling circuit controls the adaptor to adjust its output characteristics based on the condition of the battery.
According to an embodiment of the present invention, a method for employing a portable device to control output characteristics of an adaptor which is used for charging a battery of the portable device comprises: sensing a condition of the battery; and controlling the adaptor to adjust its output characteristics based on the condition of the battery.
According to an embodiment of the present invention, an adaptor used for charging a battery of a portable device is disclosed. An output characteristic of the adaptor is configurable according to a condition of the battery.
According to the embodiments, the portable device can communicate with the controllable adaptor via a variety of communication interfaces and control output characteristics of the controllable adaptor, to achieve the purpose of fast charging, avoid thermal damage, enhance/improve the whole charging efficiency, and to save more power.
These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings.
Please refer to
Pd=(Vchg−Vbat)×Ichr
wherein Pd indicates the power dissipation, Vchg indicates the output charging voltage outputted by the adaptor 105 for charging the battery 1103, Vbat indicates the battery voltage, and Ichr indicates the charging current. The battery voltage Vbat can be sensed by the sensing circuit 1104, and accordingly the controlling circuit 1105 can adjust the charging current Ichr and output charging voltage Vchg in order to maximize the charging current Ichr and avoid the power dissipation Pd exceed the power dissipation threshold Pdmax. That is, in order to increase the charging current Ichr as far as possible, the portable device 110 is arranged to decrease the voltage difference between the output charging voltage Vchg and the battery voltage Vbat. Thus, by maximizing the charging current Ichr that can be supplied from the adaptor 105, the battery 1103 can be charged rapidly, and this significantly reduces the whole charging time. In this situation, the controlling circuit 1105 may set the output charging voltage Vchg as a voltage level that is lower than a level calculated based on the maximized charging current Ichr, so that the corresponding power dissipation Pd is slightly smaller than the power dissipation threshold Pdmax and the conductive circuit element 1101 is not damaged. That is, after determining and configuring the charging current Ichr provided by the adaptor 105, the portable device 110 can control the adaptor 105 to selectively output or supply different output charging voltage levels. For example, a first level may be determined based on the above-mentioned equation and the maximized charging current, and a second level may be a level which is slightly lower than the first level. The selection of supplying different output charging voltage levels according to the same charging current provides a flexibility of outputting different powers. The portable device 110 controls the adaptor 105 to select one of multiple charging levels corresponding to different powers and provide the selected voltage for the battery 1103 under different conditions.
As mentioned above, the portable device 110 (or the controlling circuit 1105) can be used for configuring the charging current Ichr supplied by the adaptor 105 based on the battery voltage Vbat, determining the output charging voltage Vchg provided by the adaptor 105 according to the configured charging current Ichr, and controlling the adaptor 105 to output the determined output charging voltage Vchg and the configured charging current Ichr. Accordingly, the portable device 110 including the sensing circuit 1104 and controlling circuit 1105 is capable of controlling output characteristics of the adaptor 105. The output characteristics may indicate (but not limited to) the charging current Ichr or the output charging voltage Vchg. In other examples, the output characteristics may include AC-to-DC switching frequency, AC-to-DC bias current, the precision of output voltage, voltage ripple, and the dynamic loading, etc. The portable device 110 can also be used to control the output characteristics of the adaptor 105 by adjusting at least one characteristic of AC-to-DC switching frequency, AC-to-DC bias current, the precision of output voltage, voltage ripple, and the dynamic loading, etc., so as to adjust the charging current Ichr.
It should be noted that the controlling circuit 1105 can adjust the output charging voltage Vchg after determining/configuring the charging current Ichr in a first embodiment or can adjust the charging current Ichr after determining/configuring the output charging voltage Vchg in a second embodiment according to the equation of power dissipation of conductive circuit element 1101.
In the embodiments, the conductive circuit element 1101 can be implemented with a bipolar junction transistor. The bipolar junction transistor is turned on and becomes saturated when the adaptor 105 is charging the battery 1103. The voltage drop between the collector and emitter of the bipolar junction transistor is marked as VCE which in some examples may be equivalent to 0.25 Volts-0.4 Volts. The voltage different between the output charging voltage Vchg and battery voltage Vbat can be represented by VCE+Ichr*R wherein R indicates the resistance value of the resistor 1102 disposed between the bipolar junction transistor and the battery 1103. The resistance value is very small and can be ignored. The voltage different between the output voltage Vchg and battery voltage Vbat is almost equivalent to VCE. Accordingly, the maximum of charging current Ichr can be calculated or estimated by the following equation:
Imax indicates the maximum of charging current Ichr. For example, if the power dissipation threshold Pdmax is designed as 0.7 W, then the maximum charging current Imax can be configured as 2.8 A−1.75 A that is dependent upon the voltage drop VCE between the collector and emitter of the bipolar junction transistor. If the voltage drop VCE is equal to 0.25 Volts, the maximum charging current Imax can be configured as 2.8 A. If the voltage drop VCE is equal to 0.4 Volts, the maximum charging current Imax can be configured as 1.75 A. The controlling circuit 1105 of portable device 110 is arranged to control the adaptor 105 to output the maximum charging current Imax as the charging current Ichr for the battery 1103 and output the output charging voltage Vchg that is equal to the sum of the voltage drop VCE and battery voltage Vbat. The output charging voltage Vchg supplied by the adaptor 105 can be dynamically adjusted according to the change of the battery voltage Vbat since the battery voltage Vbat can be sensed by the sensing circuit 1104 and the voltage drop VCE can be determined. That is, the portable device 110 can control the adaptor 105 to output the stable maximum current Imax and different charging voltage levels based on the different levels of the battery voltage Vbat. Thus, the battery 1103 can be rapidly charged with the maximum charging current Imax in a constant current mode.
Please refer to
Please refer to
In order to make readers easily understand the spirit of the present invention,
Step 405: The controlling circuit 1105 of portable device 110 (i.e. a charging host) communicates with the adaptor 105 via a specific communication interface such as a USB communication interface;
Step 410: The controlling circuit 1105 of portable device 110 checks whether the adaptor 105 is a controllable adaptor or not. If the adaptor 105 is controllable, the flow proceeds to Step 415, otherwise, the flow proceeds to Step 450;
Step 415: The controlling circuit 1105 of portable device 110 determines or calculates the maximum charging current Imax according to the power dissipation threshold Pdmax and the voltage drop VCE across the conductive circuit element 1101, and configures the charging current Ichr as the maximum charging current Imax;
Step 420: The sensing circuit 1104 senses the battery voltage Vbat, and the controlling circuit 1105 gradually raise up the charging voltage Vchg provided by the adaptor 105 according to the sensed battery voltage Vbat and the voltage drop VCE;
Step 425: The sensing circuit 1104 is arranged to sense the charging current Ichr and check whether the charging current Ichr reaches the maximum charging current Imax that has been configured. If the charging current Ichr reaches the maximum charging current Imax, the flow proceeds to Step 430, otherwise, the flow proceeds back to Step 420.
Step 430: The sensing circuit 1104 is arranged to sense and check whether the actual power dissipation of the conductive circuit element 1101 exceed above the power dissipation threshold Pdmax or not by using a temperature sensor to detect the operating temperature of conductive circuit element 1101. If the detected temperature is lower than a temperature threshold, this may indicate that the actual power dissipation of conductive circuit element 1101 does not exceed above the power dissipation threshold Pdmax and the flow proceeds to Step 435; otherwise, the flow proceeds to Step 450;
Step 435: The controlling circuit 1105 of portable device 110 sets/configures the adjusted output charging voltage Vchg provided by the adaptor 105;
Step 440: The sensing circuit 1104 is arranged to sense the battery voltage Vbat, and the controlling circuit 1105 is arranged to estimate whether the sensed battery voltage Vbat is changed or not. If the sensed battery voltage Vbat is changed, the flow proceeds to Step 420; otherwise, the flow proceeds to Step 445.
Step 445: The controlling circuit 1105 controls and keeps the adaptor 105 to output the output charging voltage Vchg that has been set/configured in Step 435; and
Step 450: End.
In Step 405, the portable device 110 is arranged to communicate with the adaptor 105 via the specific communication interface such as USB communication interface.
In practice, the USB communication interface may be implemented by using a USB cable, and the portable device 110 can send information or commands to the adaptor 105 via data line (i.e. D+ or D−) and/or power supply line (i.e. VBUS) of the USB cable so as to control/adjust the output characteristics of the adaptor 105. It should be noted that the above-mentioned example is not meant to a limitation of the present invention. Other examples of using different communication interfaces or using different communication protocols to control/adjust the output characteristics of the adaptor 105 should fall within the scope of the present invention.
In Step 410, before controlling the output characteristics of the adaptor 105, the portable device 110 is arranged to check whether the adaptor 105 is a controllable adaptor capable of supporting this controllable scheme. In this embodiment, the adaptor 105 is a controllable adaptor, and the flow proceeds to Step 415 so that the portable device 110 begins to control the output characteristics of the adaptor 105. However, if another adaptor not supporting this controllable scheme is connected to the portable device 110, the flow proceeds to Step 450 and the portable device 100 is not arranged to control the output characteristics of this adaptor.
In Step 415, the controlling circuit 1105 is arranged to configure the charging current Ichr as the maximum charging current Imax so as to achieve the purpose of fast charging. However, in other embodiments, the controlling circuit 1105 can configure the charging current Ichr as a current that is slightly smaller than the maximum charging current Imax, to achieve the purpose of fast charging. This modification can also reduce the whole charging time effectively.
The above-mentioned temperature sensor employed by the sensing circuit 1104 may be implemented by using a negative temperature coefficient (NTC) thermistor or a positive temperature coefficient (PTC) thermistor. The modifications of implementation of the temperature sensor should fall within the scope of the present invention.
Additionally, the portable device 110 can inform the adaptor 105 of the condition of the battery 1103, and control the adaptor 105 to dynamically provide/supply different output characteristics corresponding to different operation modes. According to a third embodiment of the present invention, the adaptor 105 comprises a normal mode and a green mode (or called sleep mode). Under the normal mode, the controlling circuit 1105 of portable device 110 controls the adaptor 105 to provide normal output characteristics such as a normal output power. The normal output characteristics may include AC-to-DC switching frequency, AC-to-DC bias current, the precision of output voltage, voltage ripple, and/or the dynamic loading, etc. The controlling circuit 1105 can control the sensing circuit 1104 to sense the condition of the battery 1103 (i.e. the loading condition), and control the adaptor 105 to decrease the output characteristics of the adaptor 105 if it has been not required for the adaptor 105 to charge the battery 1103. In this situation, the controlling circuit 1105 is arranged to control the adaptor 105 to exit from the normal mode and enter the green mode or sleep mode. That is, the portable device 110 can sense the loading condition and control the adaptor 105 exit from the normal mode and enter the green mode or sleep mode according to the sensing result. In addition, the controlling circuit 1105 can also control the adaptor 105 to decrease the output characteristics and control the adaptor 105 to enter the green mode or sleep mode if the controlling circuit 1105 estimates that the portable device 110 switches from a heavy loading condition to a light loading condition.
Additionally, in other embodiments, the adaptor 105 may be designed as an adaptor device operating under the green mode or sleep mode according to the default setting. Under the green mode or sleep mode, the controlling circuit 1105 of portable device 110 controls the adaptor 105 to provide the decreased/reduced output characteristics such as a lower output power. The controlling circuit 1105 can check whether the adaptor 105 is connected to portable device 110 to charge the battery 1103, and can control the adaptor 105 to increase the output characteristics of the adaptor 105 and control the adaptor 105 to exit from the green mode or sleep mode to enter the normal mode if it is required for the adaptor 105 to charge the battery 1103. That is, the portable device 110 can sense the loading condition and control the adaptor 105 exit from the green mode or sleep mode and enter the normal mode according to the sensing result. In addition, the controlling circuit 1105 can also control the adaptor 105 to increase the output characteristics of the adaptor 105 so as to control the adaptor 105 to enter the normal mode if the controlling circuit 1105 estimates that the portable device 110 switches from a light loading condition to a heavy loading condition.
In addition, the portable device 110 as shown in
According to the above-mentioned embodiments, the portable device 110 can communicate with the controllable adaptor 105 via a variety of communication interfaces and control output characteristics of the controllable adaptor 105, to achieve the purpose of fast charging, avoid thermal damage, enhance/improve the whole charging efficiency, and to save more power.
Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.
Claims
1. A portable device capable of controlling output characteristics of an adaptor which is used for charging a battery of the portable device, comprising:
- a sensing circuit, for sensing a condition of the battery; and
- a controlling circuit, coupled to the sensing circuit, for controlling the adaptor to adjust its output characteristics based on the condition of the battery.
2. The portable device of claim 1, wherein the output characteristics comprises a charging current, a charging voltage, a switching frequency, a bias current, a precision of output voltage, a voltage ripple, and a dynamic loading.
3. The portable device of claim 1, wherein the sensing circuit is arranged to sense a battery voltage of the battery, and the controlling circuit is arranged to control the adaptor according to the sensed battery voltage.
4. The portable device of claim 3, wherein the controlling circuit is arranged to configure a charging current and then to adjust a charging voltage according to the sensed battery voltage.
5. The portable device of claim 3, wherein the controlling circuit is arranged to configure a charging current as a maximum charging current which can be supplied by the adaptor based on the sensed battery voltage.
6. The portable device of claim 5, wherein the controlling circuit is arranged to determine the charging voltage provided by the adaptor according to the maximum charging current and a power dissipation threshold, and to control the adaptor to output the determined output voltage and the maximum charging current.
7. The portable device of claim 6, further comprising:
- a conductive circuit element, coupled between the battery and an input of the portable device;
- wherein the sensing circuit is arranged to sense a voltage drop across the conductive circuit element and the controlling circuit is arranged to estimate the maximum charging current according to the power dissipation threshold and the voltage drop.
8. The portable device of claim 3, wherein the charging current determined by the controlling circuit is inversely proportional to a voltage difference between the charging voltage and the sensed battery voltage.
9. The portable device of claim 3, wherein the controlling circuit is arranged to configure a charging voltage and then to adjust a charging current according to the sensed battery voltage.
10. The portable device of claim 9, wherein the controlling circuit is arranged to configure the charging voltage and then to adjust the charging current according to the sensed battery voltage, to keep the adaptor supply/provide a rated output power substantially.
11. The portable device of claim 1, wherein the sensing circuit is arranged to sense a loading of the battery, and the controlling circuit is arranged to control the adaptor to decrease the output characteristics of the adaptor and control the adaptor to enter a green mode or a sleep mode when the loading switches from a heavy loading condition to a light loading condition.
12. The portable device of claim 1, wherein the sensing circuit is arranged to sense a loading of the battery, and the controlling circuit is arranged to control the adaptor to raise up the output characteristics of the adaptor and control the adaptor to exit from a green mode or a sleep mode when the loading switches from a light loading condition to a heavy loading condition.
13. A method for employing a portable device to control output characteristics of an adaptor which is used for charging a battery of the portable device, comprising:
- sensing a condition of the battery; and
- controlling the adaptor to adjust its output characteristics based on the condition of the battery.
14. The method of claim 13, wherein the output characteristics comprises a charging current, a charging voltage, a switching frequency, a bias current, a precision of output voltage, a voltage ripple, and a dynamic loading.
15. The method of claim 13, wherein the step of sensing the condition of the battery comprises:
- sensing a battery voltage of the battery; and
- the step of controlling the adaptor to adjust its output characteristics based on the condition of the battery comprises:
- controlling the adaptor according to the sensed battery voltage.
16. The method of claim 15, wherein the step of controlling the adaptor according to the sensed battery voltage comprises:
- configuring a charging current; and
- adjusting a charging voltage according to the sensed battery voltage.
17. The method of claim 15, wherein the step of controlling the adaptor according to the sensed battery voltage comprises:
- configuring a charging current as a maximum charging current which can be supplied by the adaptor based on the sensed battery voltage.
18. The method of claim 17, wherein the step of controlling the adaptor according to the sensed battery voltage further comprises:
- determining the charging voltage provided by the adaptor according to the maximum charging current and a power dissipation threshold; and
- controlling the adaptor to output the determined output voltage and the maximum charging current.
19. The method of claim 18, further comprising:
- sensing a voltage drop across a conductive circuit element coupled between the battery and an input of the portable device; and
- estimating the maximum charging current according to the power dissipation threshold and the voltage drop.
20. The method of claim 15, wherein the charging current is inversely proportional to a voltage difference between the charging voltage and the sensed battery voltage.
21. The method of claim 15, wherein the step of controlling the adaptor according to the sensed battery voltage comprises:
- configuring a charging voltage; and
- adjusting a charging current according to the sensed battery voltage.
22. The method of claim 21, wherein the step of controlling the adaptor according to the sensed battery voltage further comprises:
- keeping the adaptor supply/provide a rated output power substantially.
23. The method of claim 13, wherein the step of sensing the condition of the battery comprises:
- sensing a loading of the battery; and
- the method further comprises:
- controlling the adaptor to decrease the output characteristics of the adaptor and controlling the adaptor to enter a green mode or a sleep mode when the loading switches from a heavy loading condition to a light loading condition.
24. The method of claim 13, wherein the step of sensing the condition of the battery comprises:
- sensing a loading of the battery; and
- the method further comprises:
- controlling the adaptor to raise up the output characteristics of the adaptor and controlling the adaptor to exit from a green mode or a sleep mode when the loading switches from a light loading condition to a heavy loading condition.
25. An adaptor used for charging a battery of a portable device, wherein an output characteristic of the adaptor is configurable according to a condition of the battery.
Type: Application
Filed: Jun 3, 2014
Publication Date: Jun 9, 2016
Inventors: Chih-Yuan Hsu (Hsinchu City), Chi-Ming Lee (Hsinchu City)
Application Number: 14/777,526