TWI554872B - Motherboard and method for power controlling thereof - Google Patents

Description

Motherboard and power control method thereof

The invention relates to a motherboard and a power control method thereof, in particular to a motherboard and a control method thereof applicable to DC power supplies of different voltages.

Currently, commercially available notebook computers and some computer devices such as computer mainframes are provided with a power adapter that provides a DC voltage input as a supply voltage source, and various notebook computers and computer mainframes have a corresponding one. DC voltage input rated specifications. At present, the mainstream specifications are mainly 12 volts and 19 volts, and the positive and negative 10% of the value is an allowable DC voltage input range. In addition, there are common specifications for the connector of the power adapter and the host.

However, the use of universal connector connectors and the presence of different DC voltage sources has led to the possibility of misuse of the power adapter. In particular, many homes and even individual users now have more than one computer device, so there will be a power adapter with a common connector connector but different DC voltage output values at hand, resulting in misuse of the power adapter that does not conform to the specifications. The situation that causes the computer device to malfunction. For example, a power adapter with a rated output of 19 volts is plugged into a 12 volt rated input computer device. If there is no over-voltage protection design, the internal circuit components will be burned out due to overvoltage. The power adapter with a rated output of 12 volts is plugged into a 19 volt rated input computer device. If there is no under-voltage protection design, the computer device cannot operate normally, but the circuit design is not considered for use. The condition causes an unknown bias to cause a large current path between the supply voltage source and the ground, and component damage may also occur.

In view of the above problems, the present invention provides a motherboard and a power control method thereof, so that the motherboard can be applied to different power supplies, and the motherboard circuit can be protected from malfunction or even damage caused by overvoltage or undervoltage. Possible.

The invention provides a motherboard, which is suitable for a computer device, comprising a protection unit, a detection unit, a first processing unit, and a second processing unit. The protection unit has a protection input and a protection output. The protection input is coupled to the supply voltage source, and when the voltage value of the supply voltage source is within the safe voltage range, the protection output is coupled to the protection input, and when the voltage value of the supply voltage source is not within the safe voltage range, The protection output is not coupled to the protection input.

The detecting unit has a power detecting input terminal and a detecting output terminal. The power detection input end is coupled to the protection output end, and when the voltage value of the power detection input end is within the first voltage range, the detection output terminal outputs the first control signal, and when the power detection input terminal voltage value Within the second voltage interval, the detection output outputs a second control signal.

The first processing unit has a first voltage source input, a first control terminal, a first voltage source output, and a voltage conversion circuit. The first voltage source input is coupled to the protection output. The output of the first voltage source is coupled to the power supply end of the motherboard. The first control end is coupled to the detection output end. The voltage conversion circuit has an input coupled to the first voltage source input and an output coupled to the first voltage source output. When the first control terminal receives the first control signal, the turn-on voltage conversion circuit converts the voltage of the first voltage source input terminal and outputs the voltage to the first voltage source output terminal.

The second processing unit has a second voltage source input, a second control terminal, a second voltage source output, and a processing switch. The second voltage source input is coupled to the protection output. The output of the second voltage source is coupled to the power supply end of the motherboard. The second control end is coupled to the detection output end. The processing switch is coupled between the second voltage source input end and the second voltage source output end, and the control end is coupled to the second control end. When the second control terminal receives the second control signal, the conduction processing switch couples the second voltage source output end to the second voltage source input end.

The invention further provides a power control method for a motherboard, which is suitable for use in a computer device. The motherboard provides power to the motherboard. The control method includes the following steps: determining whether the supply voltage source is within a safe voltage range. If If the supply voltage source is not within the safe voltage range, the protection switch is turned off, so that the power supply of the motherboard does not have the capability of supplying voltage. If the supply voltage source is within the safe voltage range, proceed to the next step.

Detect whether the supply voltage source is within a first voltage range. If the supply voltage source is within the first voltage interval, the first processing unit is turned on, and the supply voltage source is converted into the power supply of the motherboard by using a voltage conversion circuit. If the supply voltage source is not within the first voltage interval, the second processing unit is turned on, and the supply voltage source is coupled to the motherboard power supply by the processing switch.

The utility model has the advantages that the protection unit disclosed in the invention can isolate the power supply and the power supply end of the motherboard when the voltage of the power supply is not within a safe voltage range, so as to protect the motherboard circuit from malfunction or even damage. Possible. The detection unit disclosed in the present invention can further determine the magnitude of the power supply voltage and process it to generate a voltage source that conforms to the internal circuit specifications of the motherboard in the most power-saving manner.

The features, implementations, and utilities of the present invention are described in detail below with reference to the drawings.

100‧‧‧ motherboard

110‧‧‧Protection unit

111‧‧‧Protection input

112‧‧‧Protection output

120‧‧‧Detection unit

121‧‧‧Power detection input

122‧‧‧Detection output

130‧‧‧First Processing Unit

131‧‧‧First voltage source input

132‧‧‧First control terminal

133‧‧‧First voltage source output

140‧‧‧Second processing unit

141‧‧‧second voltage source input

142‧‧‧second control end

143‧‧‧second voltage source output

160‧‧‧ motherboard power supply end

210‧‧‧First voltage divider resistor

215‧‧‧First pressure point

220‧‧‧Second voltage divider resistor

230‧‧‧ Third voltage divider resistor

235‧‧‧second partial pressure point

240‧‧‧ fourth voltage divider resistor

250‧‧‧Protection reference voltage

260‧‧‧First comparator

270‧‧‧Second comparator

280‧‧‧Protection switch control circuit

281‧‧‧ first input

282‧‧‧second input

283‧‧‧Protection switch control output

290‧‧‧Protection switch

360‧‧‧potential coupling resistor

370‧‧‧ cut-off resistor

380‧‧‧Control switch

390‧‧‧protection switch

410‧‧‧First detection resistor

415‧‧‧Detecting the pressure point

420‧‧‧Second detection resistor

430‧‧‧Detection reference voltage

440‧‧‧Detection comparator

FIG. 1 is a schematic diagram of a motherboard and a power control circuit thereof according to an embodiment of the present invention.

FIG. 2 is a schematic diagram of a protection unit according to an embodiment of the present invention.

FIG. 3 is a schematic diagram of a protection unit according to another embodiment of the present invention.

FIG. 4 is a schematic diagram of a detecting unit according to an embodiment of the present invention.

FIG. 5 is a flow chart showing the steps of a power supply control method for a motherboard according to an embodiment of the present invention.

In the context of the specification and subsequent patent applications, the term "coupled" is used herein to include any direct and indirect electrical connection. Therefore, if a first device is coupled In a second device, the first device can be directly electrically connected to the second device, or indirectly connected to the second device through other devices or connection means. In addition, the "positive signal" is a state of a digital logic signal, or can be understood as a general digital logic signal state "1", and the "inverted signal" is the state of another digital logic signal, or can be understood as The general digital logic signal status is "0".

FIG. 1 is a schematic diagram of a motherboard 100 and a power control circuit thereof according to an embodiment of the present invention. The motherboard 100 can be applied to DC power supplies of different voltages, and the power supply of the motherboard is generated at the power supply terminal 160 of the motherboard for the power supply requirements of its internal circuits. The motherboard 100 includes a protection unit 110, a detection unit 120, a first processing unit 130, and a second processing unit 140.

As shown in FIG. 1 , the protection unit 110 has a protection input terminal 111 and a protection output terminal 112. The protection input terminal 111 is coupled to the supply voltage source, and protects the output when the voltage value of the supply voltage source is within a safe voltage range. The terminal 112 is coupled to the protection input 111, and the protection output 112 is not coupled to the protection input 111 when the voltage value of the supply voltage source is not within a safe voltage interval. For example, the current power adapters used in general notebook computers have a DC voltage output of mainly 12 volts and 19 volts. The actual voltage value that can be tolerated by the normal rated negative voltage of 10% is the actual voltage lower limit of 10.8 volts, and the actual voltage upper limit of 19 volts is 20.9 volts.

Therefore, if the motherboard 100 design disclosed in the present invention can be applied to both a 12 volt and a 19 volt DC supply voltage source, the safe voltage interval can be defined as between 10.8 volts and 20.9 volts when the input voltage source is input. The voltage is within the safe voltage range, and the protection unit 110 couples its protection output 112 to the protection input terminal 111 with a switching element for power supply of the subsequent circuit. On the other hand, if the voltage of the supply voltage source is greater than the DC voltage of 20.9 volts, it is an "over-voltage" condition. If the DC voltage is less than 10.8 volts, it is "under-voltage". In both cases, both of them may cause malfunction or even damage to the motherboard circuit. At this time, the protection output terminal 112 is not coupled to the protection input terminal 111 to protect the motherboard circuit from the possibility of malfunction or even damage.

As shown in FIG. 1, the detecting unit 120 has a power detecting input terminal 121 and a detecting output terminal 122. The power detecting input terminal 121 is coupled to the protection output terminal 112, and when the power detecting input terminal 121 has a voltage value. Within the first voltage interval, the detection output 122 outputs the first control The signal is detected, and when the voltage value of the power detecting input terminal 121 is within the second voltage range, the detecting output terminal 122 outputs the second control signal. For example, the motherboard 100 disclosed in the present invention has an internal circuit with a rated voltage of 12 volts, so the upper limit of the design can be tolerated to be 13.2 volts.

Therefore, the detecting unit 120 is configured to detect the voltage of the supply voltage source, that is, when the voltage is less than 13.2 volts, that is, the voltage value is determined to be within the second voltage interval, and the supply voltage source can be directly supplied to the motherboard 100. The internal circuit is applied, and unnecessary power consumption is not required to be processed by the extra buck circuit. At this time, the detection output terminal 122 outputs a second control signal to control the subsequent corresponding processing unit; and when the voltage is greater than 13.2 volts That is, the voltage value is determined to be within the first voltage range, and needs to be subjected to the step-down processing to a rated voltage of 12 volts before being applied to the internal circuit of the motherboard 100, and the detection output terminal 122 outputs the first Control signals to control subsequent processing units.

As shown in FIG. 1, the first processing unit 130 has a first voltage source input terminal 131, a first control terminal 132, a first voltage source output terminal 133, and a voltage conversion circuit (not shown), the first voltage source. The input terminal 131 is coupled to the protection output terminal 112, the first voltage source output end 133 is coupled to the motherboard power supply terminal 160, the first control terminal 132 is coupled to the detection output terminal 122, and the voltage conversion circuit has its input coupled to the a voltage source input terminal 131, the output of which is coupled to the first voltage source output terminal 133. When the first control terminal 132 receives the first control signal, the voltage conversion circuit turns on the voltage of the first voltage source input terminal 131 and converts Output to the first voltage source output 133. For example, the voltage of the supply voltage source is in a first voltage interval between 13.2 volts and 20.9 volts. At this time, the first control signal turns on the voltage conversion circuit, and converts the supply voltage source into a voltage of 12 volts to the power supply terminal 160 of the motherboard. It is applied to the internal circuit of the motherboard 100.

In addition, the voltage conversion circuit can be a linear regulator, which uses a linear circuit to step down its input voltage to become an output voltage source with power supply capability. The voltage conversion circuit can also be a switching voltage converter, which uses a pulse-width modulation (PWM) principle and a low on-resistance switching element to perform a step-down with the control circuit. Compared with linear regulators, it has higher conversion efficiency and can reduce the increase of operating temperature, so it can simplify the design related to heat dissipation. However, the frequent switching action may cause electromagnetic interference (electro-magnetic interference, EMI). The problem, in addition to the more additional components required, so the cost and space required are more linearly regulated The device is big. The implementation manners of the voltage conversion circuits mentioned above are all common knowledge in the art, and therefore will not be further described herein. Furthermore, this paragraph is illustrative of the voltage conversion circuit and is not intended to limit the scope of the present invention. Those skilled in the art can, depending on the actual needs of the application, the cost considerations of the design, and The present invention has been implemented in accordance with the spirit of the present invention in terms of improved components and the like introduced by advanced technology.

As shown in FIG. 1, the second processing unit 140 has a second voltage source input terminal 141, a second control terminal 142, a second voltage source output terminal 143, and a processing switch (not shown), and a second voltage source input. The terminal 141 is coupled to the protection output 112, the second voltage source output 143 is coupled to the motherboard power supply 160, and the second control terminal 142 is coupled to the detection output 122. The processing switch is coupled to the channel. The second voltage source input terminal 141 and the second voltage source output terminal 143 are coupled to the second control terminal 142. When the second control terminal 142 receives the second control signal, the second processing terminal is turned on to enable the second The voltage source output terminal 143 is coupled to the second voltage source input terminal 141; and when the voltage of the supply voltage source is in the second voltage interval between 10.8 volts and 13.2 volts, the voltage value can conform to the internal circuit of the motherboard. The voltage specification is acceptable, so the second control signal turns on the processing switch, and the supply voltage source is coupled to the power supply terminal 160 of the motherboard for application by the internal circuit of the motherboard 100.

In addition, the processing switch may be a P-type metal oxide semiconductor field effect transistor, but is not limited thereto. That is, when the voltage of the gate as the control terminal is close to 0 volt, the channel between the drain and the source is turned on, and the second voltage source output 143 is coupled to the second voltage source input 141; When the voltage of the gate is close to the voltage of the input terminal 141 of the second voltage source, the channel is turned off.

In summary, the motherboard 100 disclosed in the present invention can isolate the power supply and the power supply terminal 160 of the motherboard when the voltage of the power supply is not within a safe voltage range, thereby protecting the motherboard circuit from malfunction or even The possibility of damage. When the voltage of the power supply is within a safe voltage interval, the magnitude of the voltage is further determined and processed to generate a voltage source that conforms to the internal circuit specifications of the motherboard 100.

FIG. 2 is a schematic diagram of a protection unit 110 according to an embodiment of the present invention. The protection unit 110 includes a first voltage dividing resistor 210, a second voltage dividing resistor 220, a third voltage dividing resistor 230, a fourth voltage dividing resistor 240, a protection reference voltage 250, a first comparator 260, a second comparator 270, and protection. Switch control circuit 280, and protection switch 290.

As shown in FIG. 2 , the first voltage dividing resistor 210 is coupled between the protection input terminal 111 and the first voltage dividing point 215 . The second voltage dividing resistor 220 is coupled between the first voltage dividing point 215 and the ground. The third voltage dividing resistor 230 is coupled between the protection input terminal 111 and the second voltage dividing point 235. The fourth voltage dividing resistor 240 is coupled between the second voltage dividing point 235 and the ground. The first comparator 260 has a positive terminal input coupled to the protection reference voltage 250, a negative terminal input coupled to the first voltage dividing point 215, and has an output terminal. The second comparator 260 has a positive terminal input coupled to the second voltage dividing point 235, a negative terminal input coupled to the protection reference voltage 250, and having an output terminal. The protection switch control circuit 280 has a first input 281 coupled to the output of the first comparator 260, a second input 282 coupled to the output of the second comparator 270, and having a protection switch control output 283, according to the An input 281 and a second input 282 signal are output to output a protection switch control signal. The protection switch 290 has a channel coupled between the protection input terminal 111 and the protection output terminal 112, and a control end coupled to the protection switch control output terminal 283, and according to the protection switch control signal to turn off or turn on the protection switch 290. The channel.

For example, the protection reference voltage 250 is 2.5 volts, the first comparator 260 is used to compare whether the voltage of the supply voltage source is greater than the upper limit of the specification of 19 volts, and the second comparator 270 is used to compare whether the voltage of the supply voltage source is compared. Less than the lower specification limit of 12 volts. In practical applications, if the voltage divider resistors are implemented by the resistors that can be obtained, the first voltage divider resistor 210 can be selected to be 1 million ohms, and the second voltage divider resistor 220 is 137 kilo ohms, and the first comparator 260 can be compared. The threshold value is 20.8 volts, which is close to the upper limit of the specification of 19 volts, that is, when the voltage of the supply voltage source is greater than 20.8 volts, the first comparator 260 outputs the inverted signal 0, and when the voltage of the supply voltage source is less than 20.8 volts, the first Comparator 260 outputs a positive phase signal of one. In addition, the third voltage dividing resistor 230 is selected to be 1 million ohms, and the fourth voltage dividing resistor 240 is 300 kilo ohms. The comparison threshold value of the second comparator 270 is 10.8 volts, which is the lower specification limit of the rated 12 volts. That is, when the voltage of the supply voltage source is greater than 10.8 volts, the second comparator 270 outputs a positive phase signal 1, and when the voltage of the supply voltage source is greater than 10.8 volts, the second comparator 270 outputs an inverted signal of zero.

Further, the protection switch control circuit 280 determines the protection switch control signal based on the outputs of the first comparator 260 and the second comparator 270. For example, when the outputs of the first comparator 260 and the second comparator 270 are both inverted signals 0, that is, the voltage of the supply voltage source is between 10.8 volts and 20.8 volts, the protection switch control signal control is turned on the protection switch 290. The supply voltage source is coupled to the protection output 112. Otherwise indicating the supply voltage source The voltage is not between 10.8 volts and 20.8 volts. Therefore, the protection switch control signal controls the cut-off protection switch 290 to isolate the power supply and the power supply terminal 160 of the motherboard, thereby protecting the motherboard circuit from the possibility of malfunction or even damage.

FIG. 3 is a schematic diagram of a protection unit 110 according to another embodiment of the present invention. The protection switch control circuit 280 is implemented in a circuit configuration. The protection switch 390 is a P-type metal oxide semiconductor field effect transistor. The output stages of the first comparator 260 and the second comparator 270 are open-drain configurations, for example, implemented by an N-type metal oxide semiconductor field effect transistor, the channel of which is coupled to the comparator. Between the output and the ground. The protection switch control circuit 280 includes a potential coupling resistor 360, a cutoff resistor 370, and a control switch 380.

Further, the control switch 380 is coupled between the protection switch control output 283 and the ground, and its control end is coupled to the first input 281 and the second input 282. The potential coupling resistor 360 is coupled between the protection input terminal 111 and the control terminal of the control switch 380. The cutoff resistor 370 is coupled between the protection input terminal 111 and the protection switch control output terminal 283. The open-circuit output stage of the first and second comparators 260, 270 and the potential coupling resistor 360 form a wired-AND configuration, that is, as long as the first and second comparators 260, 270 An output is an inverted signal 0, that is, an inverted signal 0 is formed on the control terminal of the control switch 380, and the channel of the control switch 380 is further turned off, and the protection switch control output 283 is coupled to the protection input terminal 111 via the off resistor 370. And further, the protection switch 390 of the P-type metal oxide semiconductor field effect transistor is turned off. When the outputs of the first and second comparators 260 and 270 are both positive phase signals 1, a positive phase signal 1 is formed on the control terminal of the control switch 380, and the voltage thereof is the voltage of the protection input terminal 111, and is further turned on. The protection switch output 283 is coupled to the ground, that is, the voltage is 0 volts, thereby turning on the protection switch 390 of the P-type metal oxide semiconductor field effect transistor, and coupling the supply voltage source to the protection output. End 112.

FIG. 4 is a schematic diagram of a detecting unit 120 according to an embodiment of the present invention. The detecting unit 120 includes a first detecting resistor 410, a second detecting resistor 420, a detecting reference voltage 430, and a detecting comparator 440. The first detecting resistor 410 is coupled between the power detecting input terminal 122 and the detecting voltage dividing point 415. The second detecting resistor 420 is coupled between the detecting voltage dividing point 415 and the ground. The detection terminal 440 has a positive terminal input coupled to the detection voltage dividing point 415, a negative terminal input coupled to the detection reference voltage 430, and an output terminal coupled to the detection output terminal 122.

For example, the detection reference voltage 430 is 2.5 volts, and the detection comparator 440 It is used to compare whether the voltage of the supply voltage source is greater than the upper limit of the rated 12 volts. Therefore, in practical applications, if the resistor is available, the first detection resistor 410 can be selected to be 1 million ohms. The resistance 420 is 240 kilo ohms, and the comparison threshold of the detection comparator 440 is 12.9 volts, which is close to the upper limit of the specification of 12 volts, that is, when the voltage of the supply voltage source is greater than 12.9 volts, the detection comparator 440 outputs the positive phase. The signal 1 further activates the first processing unit 130; and when the voltage of the supply voltage source is less than 12.9 volts, the detection comparator 440 outputs the inverted signal 0 to turn on the second processing unit 140.

FIG. 5 is a flow chart showing the steps of a power supply control method for a motherboard according to an embodiment of the present invention. The method is applicable to a computer device. The motherboard provides a power supply for the motherboard. The control method includes the following steps.

As shown in step 510, it is determined whether the supply voltage source is within a safe voltage interval. If the supply voltage source is not within the safe voltage range, as shown in step 530, the protection switch is turned off, so that the power supply of the motherboard does not have the capability of supplying voltage. If the supply voltage source is within the safe voltage range, then step 550 is performed.

As shown in step 550, it is detected whether the supply voltage source is within a first voltage interval. If the supply voltage source is within the first voltage interval, as shown in step 570, the first processing unit is turned on, and the supply voltage source is converted to the power supply of the motherboard by a voltage conversion circuit. If the supply voltage source is not within the first voltage interval, as shown in step 590, the second processing unit is turned on, and the supply voltage source is coupled to the motherboard power supply by the processing switch.

The step 510 may further include: determining, by using a first comparator, whether the supply voltage source is greater than an upper limit of the safe voltage interval, and using a second comparator to determine whether the supply voltage source is less than a lower limit of the safe voltage interval, such as two If none of them are available, the supply voltage source is within the safe voltage range.

In addition, in step 550, the method further includes the step of detecting whether the supply voltage source is greater than a lower limit of the first voltage interval by using a detection comparator, and if so, supplying the voltage source within the first voltage interval.

The utility model has the advantages that the protection unit disclosed in the invention can isolate the power supply and the power supply end of the motherboard when the voltage of the power supply is not within a safe voltage range, so as to protect the motherboard circuit from malfunction or even damage. Possible. The detecting unit disclosed in the present invention can further determine the magnitude of the power supply voltage and process it accordingly to save power. This produces a voltage source that conforms to the internal circuit specifications of the motherboard.

Although the embodiments of the present invention are disclosed above, it is not intended to limit the present invention, and those skilled in the art, regardless of the spirit and scope of the present invention, the shapes, structures, and features described in the scope of the present application. And the number of modifications may be made, and the scope of patent protection of the present invention shall be determined by the scope of the patent application attached to the specification.

100‧‧‧ motherboard

110‧‧‧Protection unit

111‧‧‧Protection input

112‧‧‧Protection output

120‧‧‧Detection unit

121‧‧‧Power detection input

122‧‧‧Detection output

130‧‧‧First Processing Unit

131‧‧‧First voltage source input

132‧‧‧First control terminal

133‧‧‧First voltage source output

140‧‧‧Second processing unit

141‧‧‧second voltage source input

142‧‧‧second control end

143‧‧‧second voltage source output

160‧‧‧ motherboard power supply end

Claims (8)

A motherboard, coupled to a computer device and coupled to a supply voltage source, comprising: a protection unit having a protection input and a protection output coupled to the supply voltage source, and when the supply The voltage value of the voltage source is within a safe voltage range, the protection output is coupled to the protection input, and when the voltage value of the supply voltage source is not within a safe voltage range, the protection output is not coupled to The protection input terminal, wherein the protection unit further comprises: a first comparator, wherein the positive terminal input is coupled to a protection reference voltage, the negative terminal input is coupled to a first voltage dividing point, and has an output terminal; a second comparator having a positive input coupled to a second voltage dividing point, a negative terminal input coupled to the protection reference voltage, and having an output; a protection switch control circuit having a first input coupling Connected to the output of the first comparator, a second input is coupled to the output of the second comparator, and has a protection switch control output, according to the first input and the second input signal lose a protection switch control signal; and a protection switch having a channel coupled between the protection input end and the protection output end, and a control end coupled to the protection switch control output end, and controlling the signal according to the protection switch Closing or turning on the channel of the protection switch; The output stage of the first comparator and the second comparator is configured as an open circuit, and the protection switch control circuit further includes a control switch, and the channel is coupled to the protection switch output end and the ground end And the control terminal is coupled to the first input and the second input, and when any output of the first comparator and the second comparator is an inverted signal, it is on the control end of the control switch Forming an inversion signal, and further blocking the channel of the control switch, thereby turning off the protection switch; a detection unit having a power detection input end and a detection output end, the power detection input end coupled to the protection The output end, and when the voltage value of the power detection input terminal is within the first voltage interval, the detection output terminal outputs a first control signal, and when the voltage value of the power detection input terminal is in the second voltage interval The detection output terminal outputs a second control signal; a first processing unit has a first voltage source input terminal, a first control terminal, a first voltage source output terminal, and a voltage conversion circuit. The first The voltage source input end is coupled to the protection output end, the first voltage source output end is coupled to a motherboard power supply end, the first control end is coupled to the detection output end, and the voltage conversion circuit has an input coupling To the first voltage source input end, the output is coupled to the first voltage source output end, and when the first control end receives the first control signal, turn on the voltage conversion circuit to input the voltage of the first voltage source input end Converting and outputting to the first voltage source output; a second processing unit having a second voltage source input terminal, a second control terminal, a second voltage source output terminal, and a processing switch, the second voltage source input terminal being coupled to the protection output terminal, The second voltage source output end is coupled to the power supply end of the motherboard, the second control end is coupled to the detection output end, and the processing switch is coupled to the second voltage source input end and the second voltage source Between the output terminals, the control terminal is coupled to the second control terminal, and when the second control terminal receives the second control signal, the processing switch is turned on to connect the second voltage source output terminal to the second voltage source. Input. The motherboard of claim 1, wherein the protection unit further comprises: a first voltage dividing resistor coupled between the protection input terminal and the first voltage dividing point; and a second voltage dividing resistor, The first voltage dividing resistor is coupled between the first voltage dividing point and the grounding point; a third voltage dividing resistor is coupled between the protection input end and the second voltage dividing point; a fourth voltage dividing resistor is coupled to The second voltage dividing point is between the grounding end. The motherboard of claim 2, wherein the protection open relationship is a P-type metal oxide semiconductor field effect transistor, the protection switch control circuit further comprises: a potential coupling resistor coupled to the protection input terminal The control terminal is connected between the control terminal and the protection switch output terminal. The motherboard of claim 1, wherein the detecting unit further comprises: a first detecting resistor coupled between the power detecting input end and a detecting voltage dividing point; and a second detecting The measuring resistor is coupled between the detecting voltage dividing point and the grounding end; a detecting reference voltage; and a detecting comparator, wherein the positive end input is coupled to the detecting voltage dividing point, and the negative end input The detection reference voltage is coupled to the detection reference terminal, and the output end thereof is coupled to the detection output end. The motherboard of claim 1, wherein the voltage conversion circuit is a linear regulator or a switching voltage conversion circuit. The motherboard of claim 1, wherein the processing relationship is a P-type metal oxide semiconductor field effect transistor. A power supply control method for a motherboard, which is suitable for use in a computer device, wherein the motherboard provides a motherboard power supply, the control method includes the following steps: determining whether a supply voltage source is within a safe voltage interval, and if not, The protection switch is turned off, so that the power supply of the motherboard does not have the capability of supplying voltage, and if so, the next step is performed; determining whether the supply voltage source is greater than the upper limit of the safe voltage interval by using a first comparator, and using a second comparator Determining whether the supply voltage source is less than a lower limit of the safe voltage interval, if neither is, the supply voltage source is within the safe voltage interval; and detecting whether the supply voltage source is within a first voltage interval, If yes, a first processing unit is turned on, and the power is supplied by a voltage conversion circuit. The voltage source is converted to the power of the motherboard, and if not, a second processing unit is turned on, and the supply voltage source is coupled to the power supply of the motherboard by using a processing switch. The power supply control method of the motherboard of claim 7, wherein the step of detecting whether the supply voltage source is within the first voltage interval further comprises detecting whether the supply voltage source is detected by using a detection comparator Greater than the lower limit of the first voltage interval, if yes, the supply voltage source is within the first voltage interval.