TWI403062B - Automatic charger protection circuit of a charger of a electronic device and method - Google Patents

Description

Automatic protection circuit of charging device of electronic device and method thereof

The present invention relates to an automatic protection circuit for a charging device, and more particularly to an automatic protection circuit for a charging device suitable for a single cell battery.

Conventional notebook computers are usually designed to use a rechargeable battery of 4 cells (4 cells) or 6 cells (6 cells), so the supply voltage is usually 19 volts or even higher. However, as the portability of notebook computers has received increasing attention in recent years, the demand for mini notebook computers (usually having a panel of less than or equal to 10 inches, or a weight of less than 2 kilograms) has also begun to grow rapidly. In order to save the size and weight of the notebook, the design of the rechargeable battery has become a big consideration. In general, when using a single rechargeable battery unit, the notebook computer requires a supply voltage of approximately 4 volts, which is less than the 19 volts of a conventional notebook. Once the user couples the transformer for a traditional notebook computer that accepts 19 volts to a single rechargeable battery unit notebook, excessive voltage can cause damage to the internal components of the computer. On the other hand, if the user couples a transformer with a supply voltage lower than 4 volts to a single rechargeable battery unit notebook, too low a voltage may cause a short circuit, which may also cause damage to the internal components of the computer.

Therefore, there is a need for an automatic protection circuit suitable for a single cell battery charging device to prevent damage to the computer caused by the user using the wrong transformer.

According to another embodiment of the present invention, an automatic protection circuit for a charging device of an electronic device includes a first switching circuit, a voltage detecting device, and a second switching circuit. The first switch circuit is coupled between the first voltage supply source and the main system of the electronic device for conducting according to the first state of the indication signal to provide the first supply voltage supplied by the first voltage supply source to the main system. The voltage detecting device is configured to detect a voltage range of the first supply voltage to generate a detection result, and output an indication signal according to the detection result. The second switching circuit is coupled between the second voltage supply source and the main system for conducting according to the second state of the indication signal to provide the second supply voltage supplied by the second voltage supply source to the main system, where A voltage supply source is an external voltage supply source of one of the electronic devices, and the second voltage supply source is an internal voltage supply source of one of the electronic devices.

According to another embodiment of the present invention, an automatic protection method for a charging device of an electronic device is provided for protecting a charging device of an electronic device, wherein the electronic device is selectively coupled to a first voltage supply source or a second voltage. a supply source, the first voltage supply source is an external voltage supply source of the electronic device, and the second voltage supply source is an internal voltage supply source of the electronic device. The automatic protection method of the charging device includes: receiving a first supply voltage from the first voltage supply source; determining whether the first supply voltage is between a voltage range; and when the first supply voltage is within the voltage range The first supply voltage is supplied to the electronic device, and the first supply voltage is not supplied to the electronic device when the first supply voltage is not between the voltage ranges.

In order to make the manufacturing, operating methods, objects and advantages of the present invention more apparent, the following detailed description of the preferred embodiments and the accompanying drawings

Example:

Fig. 1 is a diagram showing an automatic protection circuit of a charging device according to an embodiment of the present invention. An electronic device 100 includes an automatic protection circuit 101 (hereinafter referred to as an automatic protection circuit 101), a main system 102, a battery device 103, and a charging device 104. The electronic device may be a computer device, such as a notebook computer. The main system 102 may be a system including chips and circuits inside the electronic device, for example, including a south bridge wafer, a north bridge wafer, a central processing unit, etc., and the battery device 103 may be an electronic device. The device has a battery device inside a single cell. The charging device 104 is used to control the battery device 103 to be charged according to an external supply voltage source. The automatic protection circuit 101 can detect the voltage value of the external supply voltage supplied to the electronic device 100 to avoid providing too high or too low supply power to the electronic device to cause damage to the electronic device. The automatic protection circuit 101 includes switching circuits 111 and 113 and a voltage detecting device 112. The switch circuit 111 is coupled between an external voltage supply source (for example, a power line, a transformer, etc.) and the main system 102 of the electronic device for conducting according to a first state of an indication signal S _IND to provide an external voltage. The supply voltage V _ADP supplied from the supply source is supplied to the main system 102. The voltage detecting device 112 is configured to detect a voltage value of the supply voltage V _ADP to generate a detection result, and output an indication signal S _IND according to the detection result. The switch circuit 113 is coupled between the battery device 103 and the main system 102 for conducting according to a second state of the indication signal S _IND to provide the supply voltage V _BAT supplied by the battery device 103 to the main system 102. In addition, the voltage detecting device 112 can also generate a charging signal S _{AC_IN} to the charging device 104 for controlling the battery device 103 to simultaneously charge according to the external supply voltage source.

According to an embodiment of the invention, the voltage detecting device 112 includes a voltage stabilizing device 201 and a voltage detecting circuit 202. The voltage stabilizing device 201 is configured to receive the supply voltage V _ADP and correspondingly generate an output voltage V _Z . The voltage detecting circuit 202 is configured to generate two converted voltages V ₁ and V ₂ according to the output voltage V _Z , and generate the detection result according to the converted voltages V ₁ and V ₂ and a reference voltage V _REF .

2 is an internal circuit diagram showing an automatic protection circuit of a charging device according to an embodiment of the present invention. The automatic protection circuit 101A includes switching circuits 111A, 113A and a voltage detecting device 112A. The voltage detecting device 112A includes a voltage stabilizing device 201A and a voltage detecting circuit 202A. According to an embodiment of the invention, the voltage stabilizing device 201A may be a diode 211, such as a Zener diode, which is reversed to an external voltage supply. As shown, the diode 211 has a cathode coupling. Connected to an external voltage supply source and an anode coupled to a ground point. The switch circuit 203A includes a switch device 203A coupled between the external voltage supply source and the main system 102 (refer to FIG. 1), and the switch device 204A is coupled between the switch device 203A and the voltage detecting device 202A. The switch circuit 113A includes a switch device 205A coupled between the main system 102 and the battery device 103 (refer to FIG. 1).

According to an embodiment of the present invention, the switching device 203A may be a PMOS transistor 213 having two ends for coupling an external voltage supply source and the main system 102, and the switch 204A is an NMOS transistor 214 coupled in parallel with a resistor. R is between the gate of the PMOS transistor 213 and the ground point for controlling the conduction state of the PMOS transistor 213 according to the indication signal. The switching device 205A can be a PMOS transistor 215. It should be noted that the above-described types of transistors and transistors are only used to illustrate a preferred embodiment of the present invention, and are not intended to limit the scope of the present invention, as is known to those skilled in the art. It is also possible to design other components or according to any logic circuit, and therefore, while a few modifications and refinements can be made without departing from the spirit and scope of the invention, the scope of the invention is defined by the scope of the appended claims. quasi. In addition, it is worth noting that since the switching circuits 111A and 113A can actually use any logic circuit design, according to another embodiment of the present invention, the voltage detecting circuit 202A can be turned on for different switching circuits 111A and 113A. The two control signals S _ACG , S _BTG are generated correspondingly according to the indication signal S _{IND for} respectively controlling the switch circuits 111A and 113A, and thus the present invention is not limited to the use of one or more indication/control signals.

According to an embodiment of the present invention, the diode 211 is reversely connected to the external voltage supply source. When the supply voltage V _{ADP is} less than the breakdown voltage of the diode 211, the output voltage V _Z is substantially equal to the supply voltage V _ADP . For example, when the voltage value of the supply voltage V _ADP matches the operating voltage of the electronic device 100 (eg, V _ADP = 5 volts), the output voltage V2 will be substantially equal to 5 volts. At this time, the voltage detecting circuit 202A detects that the output voltage V _Z is within a predetermined operating voltage range of the electronic device 100 (for example, 4-6 volts), thereby outputting the indicating signal S _IND having a high signal level, or having High signal level two control signals S _ACG and S _BTG . The control signal S _ACG having a high signal level can conduct the crystal 214 and further conduct the crystal 213 through the transistor 214. Therefore, when the automatic protection circuit 101 detects that the voltage value of the supply voltage V _ADP is between the predetermined operating voltage range of the electronic device 100, the automatic protection circuit 101 supplies the supply voltage V _ADP to the electronic device. At this time, since the control signal S _BTG also has a high signal level, the crystal 215 is not conducted, and thus the supply voltage V _{BAT of the} battery device 103 is not supplied to the electronic device. In addition, the voltage detecting circuit 202A can also generate a charging signal S _{AC_IN} to the charging device 104 of the electronic device to indicate that the system currently has a correct external supply voltage source to control the battery device 103 to simultaneously charge according to the external supply voltage source.

When the voltage value of the supply voltage V _ADP is less than the operating voltage of the electronic device 100 (eg, V _ADP = 3 volts), the output voltage V _Z will be substantially equal to 3 volts. At this time, the voltage detecting circuit 202A detects that the output voltage V _{Z is} not within the predetermined operating voltage range of the electronic device 100 (for example, 4-6 volts), so the output signal S _IND having a low signal level is output. Or two control signals S _ACG and S _BTG with low signal levels. The control signal S _ACG with low signal level does not conduct the transistors 214 and 213. Therefore, when the automatic protection circuit 101 detects that the voltage value of the supply voltage V _ADP is less than the predetermined operating voltage of the electronic device 100, the automatic protection circuit 101 does not provide the supply voltage V _ADP to the electronic device to protect the internal components of the electronic device. A short circuit may occur due to a low supply voltage, which may cause damage to the electronic device. At this time, since the control signal S _BTG also has a low signal level, the transistor 215 is turned on, and thus the supply voltage V _{BAT of the} battery device 103 is supplied to the electronic device. At the same time, the charging signal S _{AC_IN} also has a corresponding signal level to indicate that the system does not currently have a correct external supply voltage source, and the control battery device 103 will not be charged at this time.

On the other hand, when the diode 211 is reversely connected to the external voltage supply source, when the voltage value of the supply voltage V _ADP is greater than the breakdown voltage of the diode 211, the reversed diode 211 collapses and a corresponding output voltage value is generated. . For example, when the supply voltage V _ADP is higher than the operating voltage of the electronic device 100 (eg, V _ADP =19 volts), the output voltage V _Z may be substantially between 7 and 8 volts due to the collapsed diode 211. At this time, the voltage detecting circuit 202A detects that the voltage value of the output voltage V _Z is not within the predetermined operating voltage range of the electronic device 100 (for example, 4-6 volts), so the output signal signal with a low signal level is output. _IND , or two control signals S _ACG and S _BTG with low signal levels. The control signal S _ACG with low signal level does not conduct the transistors 214 and 213. Therefore, when the automatic protection circuit 101 detects that the voltage value of the supply voltage V _ADP is greater than the predetermined operating voltage of the electronic device 100, the automatic protection circuit 101 also does not provide the supply voltage V _ADP to the electronic device for protecting the internal components of the electronic device. The internal components will not be burnt due to excessive supply voltage. At this time, since the control signal S _BTG also has a low signal level, the transistor 215 is turned on, and thus the supply voltage V _{BAT of the} battery device 103 is supplied to the electronic device. At the same time, the charging signal S _{AC_IN} also has a corresponding signal level to indicate that the system does not currently have a correct external supply voltage source, and therefore, the control battery device 103 will not be charged at this time.

Figure 3 is a diagram showing the internal circuit of a voltage detecting circuit according to an embodiment of the present invention. The voltage detection circuit 202A includes a voltage conversion circuit 301, comparators 302 and 303, and a logic circuit 304. The voltage conversion circuit 301 can be, for example, a voltage divider for generating the conversion voltages V ₁ and V ₂ according to the output voltage V _{Z of the} voltage stabilizing device 201A. The comparators 302 and 303 are coupled to the voltage conversion circuit 301 and a reference voltage generating device (not shown). The reference voltage generating device can be a bandgap reference voltage generating device for generating a stable low reference. The voltage V _{REF is} , for example, 1.2 volts. Comparators 302 and 303 are respectively used to compare the voltages of the converted voltages V ₁ and V ₂ and the reference voltage V _REF , and respectively output corresponding comparison results. The logic circuit 304 receives the comparison result from the comparators 302 and 303, and performs a logic operation on the comparison result for outputting the indication signal S _IND having a corresponding signal level (state) with the comparison result, or the control signals S _ACG and S _{BTG .} . According to an embodiment of the present invention, the logic circuit 304 can be flexibly designed according to the input signal coupling manner of the comparators 302 and 303. For example, when the comparator 302 outputs a comparison result with a high signal level, it is used to represent the conversion voltage V. _{1 is} greater than the reference voltage V _REF , and when the comparator 303 outputs a comparison result having a high signal level to represent that the conversion voltage V _{2 is} less than the reference voltage V _REF , the logic circuit 304 can be an AND gate The two comparison results are used to perform an operation to output a corresponding indication signal S _IND or control signals S _ACG and S _BTG . In addition, according to another embodiment of the present invention, the resistors R ₁ , R ₂ , R _{3 of the} voltage conversion circuit 301 can also be specially designed such that two threshold voltages (for example, 4 volts) defining a predetermined operating voltage range of the electronic device are defined. The voltage value (for example, 1.2 volts) of the reference voltage can be respectively approximated after being converted by the voltage conversion circuit 301 with 6 volts. In this way, the voltage detecting circuit 202A can be designed such that when the output voltage V _Z is converted, the converted voltage V _{1 is} greater than the reference voltage V _REF , and the converted voltage V _{2 is} less than the reference voltage V _REF (assuming the converted voltage V ₁ >V) ₂ ), the logic circuit 304 can output an indication signal S _IND having a first state (such as the high signal level described in the above embodiment), or control signals S _ACG and S _BTG having corresponding signal levels, to provide appropriate Supply voltage to the electronic device. Similarly, when the converted voltages V ₁ and V ₂ after the output voltage V _{Z has} been converted are greater than the reference voltage V _REF , or the converted voltages V ₁ and V _{2 are both} less than the reference voltage V _REF , the logic circuit 304 can output the second The indication signal S _{IND of the} state (such as the low signal level described in the above embodiment) or the control signals S _ACG and S _BTG having the corresponding signal level are used to prevent an erroneous supply voltage from being supplied to the electronic device.

4 is a flow chart showing an automatic protection method for a charging device for protecting an electronic device according to an embodiment of the present invention. First, a supply voltage is received from an external voltage supply source (step S401). Next, it is determined whether the voltage value of the supply voltage is between a voltage range (step S402), and the voltage range can be designed to be within a predetermined operating range of the electronic device. Finally, when the supply voltage is between the voltage ranges, the supply voltage is supplied to the electronic device, and when the supply voltage is not between the voltage ranges, the supply voltage is not supplied to the electronic device (step S403).

The present invention has been described above with reference to the preferred embodiments thereof, and is not intended to limit the scope of the present invention, and the invention may be modified and modified without departing from the spirit and scope of the invention. The scope of the invention is defined by the scope of the appended claims.

100‧‧‧Electronic devices

101, 101A‧‧‧Automatic protection circuit

102‧‧‧Main system

103‧‧‧ battery device

104‧‧‧Charging device

111, 111A, 113, 113A‧‧‧ switch circuit

112, 112A‧‧‧ voltage detection device

201, 201A‧‧‧ voltage regulator

202, 202A‧‧‧ voltage detection circuit

203A, 204A, 205A‧‧‧ switchgear

211‧‧‧ diode

213, 214, 215‧‧‧ transistors

301‧‧‧Voltage conversion circuit

302, 303‧‧‧ comparator

304‧‧‧Logical Circuit

R, R ₁ , R ₂ , R ₃ ‧‧‧ resistance

S _ACG , S _BTG , S _IND , S _{AC_IN} ‧‧‧ signals

V ₁ , V ₂ , V _ADP , V _BAT , V _REF , V _Z ‧‧‧ voltage

Fig. 1 is a diagram showing an automatic protection circuit of a charging device according to an embodiment of the present invention.

2 is an internal circuit diagram showing an automatic protection circuit of a charging device according to an embodiment of the present invention.

Figure 3 is a diagram showing the internal circuit of a voltage detecting circuit according to an embodiment of the present invention.

4 is a flow chart showing an automatic protection method for a charging device for protecting an electronic device according to an embodiment of the present invention.

100‧‧‧Electronic devices

101‧‧‧Automatic protection circuit

102‧‧‧Main system

103‧‧‧ battery device

104‧‧‧Charging device

111, 113‧‧‧ switch circuit

112‧‧‧Voltage detection device

201‧‧‧Vistor

202‧‧‧Voltage detection circuit

S _IND , S _{AC_IN} ‧‧‧ signal

V _ADP , V _BAT , V _Z ‧‧‧ voltage

Claims (34)

An automatic protection circuit for a charging device of an electronic device, comprising: a first switching circuit coupled between a first voltage supply source and a main system of an electronic device for using a first state according to an indication signal Turning on to provide a first supply voltage supplied by the first voltage supply source to the main system; a voltage detecting device for detecting a voltage value of the first supply voltage to generate a detection result, and according to The detection result is outputting the indication signal; and a second switching circuit is coupled between the second voltage supply source and the main system for conducting according to the second state of the indication signal to provide the second a second supply voltage supplied by the voltage supply source to the main system, wherein the first voltage supply source is an external voltage supply source of the electronic device, and the second voltage supply source is an internal voltage supply of the electronic device a source, and wherein when the first supply voltage is greater than a first threshold voltage or less than a second threshold voltage, the indication signal has the second state, and when the first supply voltage is between When between said first threshold voltage and the second threshold voltage, the indication signal has the first state, wherein said first threshold voltage is greater than the second threshold voltage. The automatic protection circuit of the charging device of the electronic device of claim 1, wherein the voltage detecting device comprises: a voltage stabilizing device for receiving the first supply voltage and correspondingly generating an output voltage; a voltage detecting circuit includes a voltage converting circuit for generating a first switching voltage and a second switching voltage according to the output voltage, and the The voltage detecting circuit generates the detection result according to the first conversion voltage, the second conversion voltage, and a reference voltage; wherein the first conversion voltage is greater than the second conversion voltage. An automatic protection circuit for a charging device of an electronic device according to claim 2, wherein the voltage regulator device is a diode. The automatic protection circuit of the charging device of the electronic device of claim 3, wherein the diode has a cathode coupled to the first voltage supply source, and an anode coupled to a ground point. An automatic protection circuit for a charging device of an electronic device according to claim 3, wherein the diode is a Zener diode. The automatic protection circuit of the charging device of the electronic device of claim 1, wherein the first switching circuit comprises: a first switch coupled between the first voltage supply source and the main system; The second switch is coupled between the first switch and the voltage detecting device, wherein when the indicating signal has the first state, the first switch is electrically connected to the second switch. The automatic protection circuit of the charging device of the electronic device of claim 6, wherein the first switch is a first transistor, and has a first end point and a second end point respectively coupled to the a first voltage supply source and the main system, and the second switch is a second transistor coupled in parallel with a first resistor between a third end of the first transistor and the ground point, the first The second switch has a fourth terminal coupled to the voltage detecting device. An automatic protection circuit for a charging device of an electronic device according to claim 1, wherein the second switching circuit comprises a transistor. An automatic protection circuit for a charging device of an electronic device according to claim 1, wherein the electronic device is a notebook computer, and wherein the second voltage supply source is a battery having a single battery cell Device. The automatic protection circuit of the charging device of the electronic device of claim 9, wherein the first threshold voltage and the second threshold voltage are within a predetermined operating voltage range of the electronic device. The automatic protection circuit of the charging device of the electronic device of claim 2, wherein the voltage detecting circuit further comprises: a first comparator coupled to the voltage converting circuit for comparing the first conversion a voltage and a voltage of the reference voltage, and output a first comparison result; a second comparator coupled to the voltage conversion circuit for comparing the voltage of the second conversion voltage and the reference voltage, and outputting a a second comparison result; and a logic circuit coupled to the first comparator and the second comparator, configured to output the indication signal according to the first comparison result and the second comparison result, where the reference voltage is less than The first switching voltage, and when the reference voltage is greater than the second switching voltage, the logic circuit outputs the indication signal having the first state. The automatic protection circuit of the charging device of the electronic device of claim 11, wherein when the reference voltage is greater than the first conversion voltage, or when the reference voltage is less than the second conversion voltage, the logic circuit output has The indication signal of the second state. A charging device for an electronic device as claimed in claim 1 The automatic protection circuit, wherein when the first supply voltage is supplied to the electronic device, the second voltage supply source is chargeable according to the first supply voltage. An automatic protection method for a charging device of an electronic device for protecting a charging device of an electronic device, wherein the electronic device is selectively coupled to a first voltage supply source or a second voltage supply source, the first voltage supply source An external voltage supply source of the electronic device, and the second voltage supply source is an internal voltage supply source of the electronic device, the automatic protection method of the charging device includes: receiving a first supply from the first voltage supply source a voltage; determining whether the voltage value of the first supply voltage is between a voltage range; and providing the first supply voltage to the electronic device when the first supply voltage is between the voltage ranges, and when When the first supply voltage is not between the voltage ranges, the first supply voltage is not provided to the electronic device. The automatic protection method for a charging device of an electronic device according to claim 14, wherein the voltage range is a predetermined operating voltage range of the electronic device. The automatic protection method for a charging device of an electronic device according to claim 15, wherein the predetermined operating voltage range is substantially between 4 volts and 6 volts. An automatic protection method for a charging device of an electronic device according to claim 14, wherein the electronic device is a notebook computer, and wherein the second voltage supply source is a battery having a single battery unit Device. Charging device for an electronic device as described in claim 14 The automatic protection method further includes: generating a first conversion voltage and a second conversion voltage by using a voltage conversion circuit according to the first supply voltage, wherein the first conversion voltage is greater than the second conversion voltage; comparing the first Converting a voltage, a voltage of the second conversion voltage and a reference voltage to generate a comparison result; and generating an indication signal according to the comparison result, wherein when the reference voltage is less than the first conversion voltage, and when the reference voltage is greater than The logic circuit outputs the indication signal having a first state for providing the first supply voltage to the electronic device. The automatic protection method for a charging device of an electronic device according to claim 18, wherein the reference voltage is greater than the first conversion voltage and the second conversion voltage, or when the reference voltage is less than the first conversion voltage The logic circuit outputs the indication signal having a second state for not providing the first supply voltage to the electronic device. The automatic protection method for a charging device of an electronic device according to claim 18, wherein the voltage range is defined by a first threshold voltage and a second threshold voltage, and the first threshold voltage and the second The voltage value corresponding to the threshold voltage is converted to the reference voltage after being converted by the voltage conversion circuit, wherein the first threshold voltage is greater than the second threshold voltage. The automatic protection method for a charging device of an electronic device according to claim 20, wherein the indication signal has the first when the first supply voltage is between the first threshold voltage and the second threshold voltage One a state for providing the first supply voltage to the electronic device, and when the first supply voltage is greater than the first threshold voltage or less than the second threshold voltage, the indication signal has the second state for not providing The first supply voltage is to the electronic device. An automatic protection method for a charging device of an electronic device according to claim 18, wherein the reference voltage is 1.2 volts. A battery device with an overvoltage protection electronic device includes: a battery device; a voltage detecting device for detecting a voltage value of a supply voltage to generate a detection result, and outputting an indication according to the detection result And a charging device configured to control the battery device to be charged according to the supply voltage according to a first state of the indication signal, and to control the battery device not to be charged according to the supply voltage according to a second state of the indication signal, wherein When the supply voltage is greater than a first threshold voltage or less than a second threshold voltage, the indication signal has the second state, and when the supply voltage is between the first threshold voltage and the second threshold voltage, The indication signal has the first state, wherein the first threshold voltage is greater than the second threshold voltage. The battery device of the electronic device with overvoltage protection according to claim 23, wherein the voltage detecting device comprises: a voltage stabilizing device for receiving the supply voltage and correspondingly generating an output voltage; The voltage detection circuit includes a voltage conversion circuit for generating a first conversion voltage and a second conversion voltage according to the output voltage, and the voltage detection circuit is configured according to the first conversion voltage, the second conversion voltage, and A reference voltage generates the detection result; wherein the first conversion voltage is greater than the second conversion voltage. The battery device of the electronic device with overvoltage protection according to claim 24, wherein the voltage regulator device is a Zener diode, and the Zener diode has a cathode coupled to the supply voltage and An anode is coupled to a ground point. The battery device of the electronic device with overvoltage protection according to claim 24, wherein the voltage detecting circuit comprises: a first comparator coupled to the voltage converting circuit for comparing the first converting a voltage and a voltage of the reference voltage, and output a first comparison result; a second comparator coupled to the voltage conversion circuit for comparing the voltage of the second conversion voltage and the reference voltage, and outputting a a second comparison result; and a logic circuit coupled to the first comparator and the second comparator, configured to output the indication signal according to the first comparison result and the second comparison result, where the reference voltage is less than The first conversion voltage, and when the reference voltage is greater than the second conversion voltage, the logic circuit outputs the indication signal having the first state, wherein when the reference voltage is greater than the first conversion voltage, or when the reference voltage When less than the second switching voltage, the logic circuit outputs the indication signal having the second state. The battery device of the electronic device with overvoltage protection according to claim 23, further comprising a switch circuit coupled between the supply voltage and the charging device for the first according to the indication signal The state is turned on to provide the supply voltage to the charging device, and the charging device controls the The battery device is charged according to the supply voltage. The battery device of the electronic device with overvoltage protection according to claim 27, wherein the switch circuit comprises: a first switch coupled between the supply voltage and the charging device; and a second switch And being coupled between the first switch and the voltage detecting device, wherein when the indicating signal has the first state, the first switch and the second switch are turned on. The battery device of the electronic device with overvoltage protection according to claim 28, wherein the first switch is a first transistor, and the first transistor has a first end point and a second end point. The second switch is a second transistor, and the second transistor is coupled in parallel with a first resistor to a third end of the first transistor. The second switch further has a fourth end coupled to the voltage detecting device. The battery device of the electronic device with overvoltage protection according to claim 23, wherein the battery device is a single battery unit. An overvoltage protection method for a battery device of an electronic device, comprising: receiving a supply voltage from a voltage supply source; determining whether a voltage value of the supply voltage is between a voltage range; and when the supply voltage is within the voltage range In between, the battery device is controlled to be charged according to the supply voltage, and when the supply voltage is not between the voltage ranges, the battery device is controlled not to be charged according to the supply voltage. A battery pack for an electronic device as claimed in claim 31 And an overvoltage protection method, wherein the voltage range is defined by a first threshold voltage and a second threshold voltage, wherein the first threshold voltage is greater than the second threshold voltage. The overvoltage protection method for the battery device of the electronic device of claim 31, further comprising: generating a first conversion voltage and a second conversion voltage by using a voltage conversion circuit according to the supply voltage, wherein the first Converting the voltage to be greater than the second conversion voltage; comparing the voltage of the first conversion voltage, the second conversion voltage, and a reference voltage to generate a comparison result; and generating an indication signal according to the comparison result, wherein the reference voltage Less than the first conversion voltage, and when the reference voltage is greater than the second conversion voltage, a logic circuit outputs the indication signal having a first state to control the battery device to charge according to the supply voltage, when the reference voltage is greater than The first conversion voltage and the second conversion voltage, or when the reference voltage is less than the first conversion voltage and the second conversion voltage, the logic circuit outputs the indication signal having a second state to control the battery device It is not charged according to the supply voltage. The overvoltage protection method for a battery device of an electronic device according to claim 31, wherein the battery device is a single battery unit.