TWI851026B - Motherboard battery detection device - Google Patents

Abstract

A motherboard battery detection device includes a first resistor electrically connected to the battery, a first transistor, a second resistor, a capacitor, an regulated voltage generator, and a baseboard management controller. The first transistor is electrically connected to the first resistor and controlled by a control signal to conduct or not conduct, and operates in a saturation region. The second resistor and the capacitor are respectively electrically connected between the first transistor and the ground. The regulated voltage generator adjusts a voltage level of a logic signal to generate the control signal and output it to the first transistor. The baseboard management controller generates and outputs the logic signal to the regulated voltage generator. When the first transistor is turned on under the control of the control signal, the baseboard management controller receives an output voltage positively related to the battery capacity from the first transistor to judge the battery capacity.

Description

Motherboard battery detection device

The present invention relates to a power detection device, and more particularly to a motherboard battery detection device.

The existing server has a memory chip for a motherboard to read and write data and store the current hardware-related configuration of the system. The memory chip is a complementary metal oxide semiconductor (CMOS) random access memory (RAM) chip. The memory chip uses a real time clock (RTC) to maintain the current time. When the server power is turned off, the memory chip receives power from a battery on the motherboard to maintain a state where the real time clock can be read and retain its stored data. When the battery fails to supply power normally, the data originally stored in the memory chip will be lost. Therefore, servers usually monitor the battery level to avoid losing data stored in important memory chips.

The existing server monitors the battery on the motherboard in a way that the battery is directly electrically connected to a power detection port of a baseboard management controller (which is only used by the baseboard management controller to detect the battery power, rather than receiving power from the battery for its own operation) so that the baseboard management controller detects the battery power. The baseboard management controller detects the remaining power of the battery periodically rather than continuously, but because the baseboard management controller is directly electrically connected to the battery, even if the baseboard management controller is not detecting and calculating the remaining power of the battery, the battery still continues to output power to the baseboard management controller, resulting in unnecessary power consumption of the battery. Therefore, a solution must be proposed.

Therefore, the purpose of the present invention is to provide a motherboard battery detection device that can avoid excessive consumption of motherboard battery power.

Therefore, the motherboard battery detection device of the present invention is suitable for detecting a battery, and includes a first resistor, a first transistor, a second resistor, a capacitor, a regulated voltage generator, and a substrate management controller.

The first resistor has a first terminal electrically connected to the battery, and a second terminal.

The first transistor has a first end electrically connected to the second end of the first resistor, a second end, and a control end receiving a control signal. The first transistor is controlled by the control signal to be turned on or off, and operates in a saturation region and has a low on-resistance.

The second resistor is electrically connected between the second end of the first transistor and ground.

The capacitor is electrically connected between the second terminal of the first transistor and ground.

The regulated voltage generator is electrically connected to the control end of the first transistor, receives a logic signal, and regulates the voltage level of the logic signal to generate the control signal and output it to the control end of the first transistor.

The baseboard management controller is electrically connected to the regulating voltage generator and the second end of the first transistor, and generates and outputs the logic signal to the regulating voltage generator. When the first transistor is turned on by the control signal, the baseboard management controller receives an output voltage positively related to the battery power from the second end of the first transistor to determine the battery power.

The effect of the present invention is that the baseboard management controller is not directly electrically connected to the battery, but is electrically connected to the battery through the first transistor, so that the battery can be prevented from continuously outputting power to the baseboard management controller, thereby causing unnecessary power consumption of the battery, and the control signal is generated by the regulating voltage generator so that the first transistor operates in the saturation region and has a low on-resistance after being turned on. In this way, the first transistor has low power loss when it is turned on, which can avoid excessive consumption of the battery power and thus avoid reducing the battery life.

Before the present invention is described in detail, it should be noted that similar components are represented by the same reference numerals in the following description.

1 and 2 , an embodiment of the motherboard battery detection device 2 of the present invention is suitable for detecting a battery 20. The motherboard battery detection device 2 includes a first resistor 21, a first transistor 22, a second resistor 23, a capacitor 24, a regulated voltage generator 25, and a baseboard management controller (BMC) 26.

The first resistor 21 has a first end electrically connected to the battery 20, and a second end. The first transistor 22 has a first end electrically connected to the second end of the first resistor 21, a control end receiving a control signal, and a second end controlled by the control end to selectively conduct with the first end of the first transistor 22. The first transistor 22 is controlled by the control signal to selectively conduct or not conduct its first end and its second end, and operates in a saturation region and has a low conduction resistance (R _DS(ON) ). The second resistor 23 is electrically connected between the second end of the first transistor 22 and the ground. The capacitor 24 is electrically connected between the second end of the first transistor 22 and the ground. In the present embodiment, the first transistor 22 is an N-type metal-oxide-semiconductor field-effect transistor (hereinafter referred to as MOSFET), wherein the drain, source and gate are the first end, the second end and the control end of the first transistor 22, respectively, but not limited thereto. In other embodiments, the first transistor 22 may be an NPN bipolar junction transistor (hereinafter referred to as BJT), a PNP BJT, or a P-type MOSFET.

The regulated voltage generator 25 is electrically connected to the control end of the first transistor 22, receives a logic signal, and regulates the voltage level of the logic signal to generate the control signal and output it to the control end of the first transistor 22. In this embodiment, the logic signal is set by the baseboard management controller 26 to change between a first logic level, such as a high level (such as 3.3V) and a second logic level, such as a low level (such as 0V). When the battery 20 power level needs to be known, the baseboard management controller 26 sets the logic signal to have the first logic level (i.e., high level), but not limited to this, when the first transistor 22 is a P-MOSFET or a PNP type BJT, when the battery 20 power level needs to be known, the baseboard management controller 26 sets the logic signal to have the second logic level (i.e., low level). The regulated voltage generator 25 includes a level offset circuit 251 and a third resistor 252.

The third resistor 252 has a first end electrically connected to the control end of the first transistor 22, and a second end electrically connected to the level shift circuit 251 and receiving the control signal.

The level shift circuit 251 receives the logic signal and level shifts the logic signal to generate the control signal. The voltage level of the control signal is greater than the high level of the logic signal. Specifically, when the logic signal has the high level, the level shift circuit 251 level shifts the logic signal so that the voltage level of the control signal generated by it is greater than the high level of the logic signal. When the logic signal has the low level, the level shift circuit 251 does not level shift the logic signal. In this embodiment, the level shift circuit 251 includes fourth to eighth resistors R4, R5, R6, R7, R8, second and third transistors M2, M3, and first to fourth diodes D1, D2, D3, D4.

The fourth resistor R4 has a first end for receiving the logic signal, and a second end for grounding. The second transistor M2 has a first end, a second end for grounding, and a control end electrically connected to the first end of the fourth resistor R4 and receiving the logic signal. The second transistor M2 is controlled by the logic signal to conduct or not conduct. The first and second diodes D1, D2 are connected in series between the second end and the control end of the second transistor M2. The first and second diodes D1, D2 each have a cathode and an anode, the anodes of the first and second diodes D1, D2 are electrically connected to each other, and the cathodes of the first and second diodes D1, D2 are electrically connected to the second end of the second transistor M2 and the control end, respectively. The third transistor M3 has a first end electrically connected to the second end of the third resistor 252, a second end grounded, and a control end electrically connected to the first end of the second transistor M2. The third and fourth diodes D3 and D4 are connected in series between the second end and the control end of the third transistor M3. The third and fourth diodes D3 and D4 each have a cathode and an anode, the anodes of the third and fourth diodes D3 and D4 are electrically connected to each other, and the cathodes of the third and fourth diodes D3 and D4 are electrically connected to the second end and the control end of the third transistor M3, respectively. The fifth resistor R5 has a first end for receiving an input voltage Vin (the voltage value of the input voltage Vin is greater than the maximum value of the battery 20, the input voltage Vin, for example, is 12V), and a second end electrically connected to the first end of the second transistor M2. The voltage level of the input voltage Vin is greater than the high level of the logic signal. The sixth resistor R6 is electrically connected between the first end of the fifth resistor R5 and the second end of the third resistor 252. The seventh resistor R7 is electrically connected to the control end of the second transistor M2 and receives the logic signal. The eighth resistor R8 is electrically connected between the first end of the second transistor M2 and the control end of the third transistor M3. Each of the first to fourth diodes D1-D4 is a Zener diode. In this embodiment, when the second transistor M2 is controlled by the logic signal to be turned on, the third transistor M3 is not turned on, and the input voltage Vin is used as the control signal, and the first transistor 22 is controlled by the control signal to be turned on. When the second transistor M2 is controlled by the logic signal to be turned off, the third transistor M3 is turned on, and the potential of the second end of the third transistor M3 is used as the control signal, and the first transistor 22 is controlled by the control signal to be turned off. The second and third transistors M2, M3 are each an N-type MOSFET, wherein the drain, source and gate are the first terminal, the second terminal and the control terminal of each of the second and third transistors M2, M3, respectively, but not limited thereto. In other embodiments, the second and third transistors M2, M3 can each be an NPN-type BJT, a PNP-type BJT, or a P-type MOSFET. The seventh and eighth resistors R7, R8, the second and third transistors M2, M3, and the first to fourth diodes D1, D2, D3, D4 can be, for example but not limited to, disposed in a six-pin SOT-363 package.

The baseboard management controller 26 is electrically connected to the first end of the fourth resistor R4 of the level shift circuit 251 of the regulating voltage generator 25 and the second end of the first transistor 22, and generates and outputs the logic signal to the first end of the fourth resistor R4. When the first transistor 22 is turned on by the control signal, the baseboard management controller 26 receives an output voltage positively related to the power of the battery 20 from the second end of the first transistor 22 to determine the power of the battery 20. In this embodiment, the baseboard management controller 26 includes an analog-to-digital conversion unit 261 and a general purpose input output pin (GPIO) 262.

The analog-to-digital conversion unit 261 is electrically connected to the second end of the first transistor 22 to receive the output voltage in analog form, and performs analog-to-digital conversion on the output voltage to generate a digital signal related to the power of the battery 20, so that the baseboard management controller 26 can judge the power of the battery 20 accordingly. The analog-to-digital conversion unit 261 is an analog-to-digital converter (ADC). For example, the baseboard management controller 26 stores a lookup table, which has a plurality of digital values corresponding to different digital signals, and a plurality of battery powers corresponding to the digital values. In this embodiment, the lookup table is stored in the internal memory (not shown) of the baseboard management controller 26 in a table form, but is not limited thereto. In other embodiments, the lookup table can be stored in a table in a memory coupled to the baseboard management controller 26, or in a parameter form in a firmware executed by the baseboard management controller 26. The baseboard management controller 26 obtains a corresponding digital value according to the digital signal generated by the analog-to-digital conversion unit 261, and searches the lookup table according to the corresponding digital value to obtain a battery power corresponding to the corresponding digital value, but is not limited thereto. It should be noted that when the battery 20 has sufficient power, the battery 20 can stably output the rated battery voltage, that is, the battery voltage provided by the battery 20 can meet the standard battery voltage defined by its specification. When the power of the battery 20 gradually decreases, the battery voltage output by the battery 20 will also decay accordingly according to a voltage decay curve, so the baseboard management controller 26 can obtain the current reference power of the battery 20 based on the received output voltage that is positively correlated to the power of the battery 20 and the lookup table stored in the baseboard management controller 26.

The universal input-output pin 262 is electrically connected to the first end of the fourth resistor R4 of the level shift circuit 251 of the regulated voltage generator 25. The baseboard management controller 26 outputs the logic signal to the first end of the fourth resistor R4 through the universal input-output pin 262.

Further referring to FIG3, the change of a drain-source current _ID of an on-resistance R _DS(ON) of the first transistor 22 is explained. It can be inferred from FIG3 that when the control signal with a voltage value of 12V (i.e., V _GS =12V) is applied to the control terminal of the first transistor 22, the first transistor 22 is turned on and operates in the saturation region, the drain-source current _ID can be operated to be greater than 1A, and the on-resistance R _DS(ON) can be controlled to be less than 3Ω. In short, the first transistor 22 of the motherboard battery detection device 2 of the present invention operates in the saturation region and has a low on-resistance. In this way, the first transistor 22 has low power loss when conducting, which can avoid excessive consumption of the battery 20 and thus avoid reducing the life of the battery 20. Furthermore, since the first transistor 22 has a low on-resistance, the conduction effect between the drain and the source of the first transistor 22 is better, which can prevent the baseboard management controller 26 from receiving the incorrect output voltage through the second end of the first transistor 22.

Referring to FIG. 4 , it is another embodiment of the regulating voltage generator 25 of the embodiment. In this embodiment, a regulating voltage generator 25′ replaces the regulating voltage generator 25 in FIG. 2 . The difference between the two is that the regulating voltage generator 25′ includes a third resistor 253 and a fourth resistor 254. The regulating voltage generator 25′ is actually a voltage divider. When the logic signal has the high level (e.g., 3.3V), the regulating voltage generator 25′ makes the voltage level of the control signal outputted by the regulating voltage generator 25′ a predetermined voltage value (e.g., 2.5V), but is not limited thereto. The first transistor 22 is, for example, a field effect transistor of type 2N7002 (slower switching speed) or a field effect transistor of type FDV301N (faster switching speed, better).

The third resistor 253 (e.g., 1KΩ) has a first end electrically connected to the universal input/output pin 262 of the baseboard management controller 26 (see FIG. 1 ) to receive the logic signal, and a second end electrically connected to the control end of the first transistor 22 and outputting the control signal. The fourth resistor 254 (e.g., 47KΩ) is electrically connected between the second end of the third resistor 253 and ground.

Referring to FIG. 5 , the change of a drain-source current _ID of the first transistor 22 due to an on-resistance R _DS(ON) is described in another embodiment. It can be inferred from FIG. 5 that when the voltage level of the control signal received by the control terminal of the first transistor 22 is 3.3V (i.e., V _GS =3.3V), the first transistor 22 operates in the saturation region and has a low on-resistance. In this way, the motherboard battery detection device 2 of the present invention has low power consumption, which can avoid excessive consumption of the battery 20, thereby avoiding a reduction in the life of the battery 20.

In summary, in the motherboard battery detection device 2 of the present invention, the baseboard management controller 26 is not directly electrically connected to the battery 20, but is electrically connected to the battery 20 via the first transistor 22, and the first transistor 22 is not always turned on, so that the battery 20 can be prevented from continuously outputting power to the baseboard management controller 26, thereby causing unnecessary power consumption of the battery 20. In addition, the motherboard battery detection device 2 of the present invention utilizes the regulated voltage generator 25, 25' to generate the control signal so that the first transistor 22 operates in the saturation region and has a low on-resistance after being turned on. In this way, the first transistor 22 has low power loss when turned on, which can avoid excessive consumption of the power of the battery 20, thereby preventing the battery 20 from having its life reduced. Furthermore, since the first transistor 22 has a low on-resistance, the conduction effect between the drain and the source of the first transistor 22 is better, which can prevent the baseboard management controller 26 from receiving an incorrect output voltage through the second end of the first transistor 22, thereby preventing the baseboard management controller 26 from misjudging the battery 20 power.

However, the above is only an embodiment of the present invention and should not be used to limit the scope of implementation of the present invention. All simple equivalent changes and modifications made according to the scope of the patent application of the present invention and the content of the patent specification are still within the scope of the present patent.

2: Motherboard battery detection device 20: Battery 21: First resistor 22: First transistor 23: Second resistor 24: Capacitor 25, 25': Regulated voltage generator 251: Level shift circuit 252: Third resistor 253, 254: Third and fourth resistors 26: Baseboard management controller 261: Analog-to-digital conversion unit 262: Universal input and output pins R4, R5: Fourth and fifth resistors R6, R7: Sixth and seventh resistors R8: Eighth resistor M2, M3: Second and third transistors D1, D2, D3, D4: First to fourth diodes V _GS : First transistor gate-source voltage

Other features and effects of the present invention will be clearly presented in the embodiments with reference to the drawings, wherein: FIG. 1 is a circuit block diagram illustrating an embodiment of the motherboard battery detection device of the present invention; FIG. 2 is a circuit block diagram illustrating an embodiment of a regulated voltage generator of the embodiment; FIG. 3 is a curve diagram illustrating the change of a conduction resistance of a first transistor of the embodiment to a drain-source current; FIG. 4 is a circuit block diagram illustrating another embodiment of the regulated voltage generator of the embodiment; and FIG. 5 is a curve diagram illustrating the change of a conduction resistance of a first transistor of the other embodiment to a drain-source current.

2: Motherboard battery detection device

20:Battery

21: First resistor

22: First transistor

23: Second resistor

24: Capacitor

25: Regulated voltage generator

26: Baseboard management controller

261:Analog-to-digital conversion unit

262: Universal input and output pins

Claims (7)

A motherboard battery detection device is used for detecting a battery, comprising: a first resistor having a first end electrically connected to the battery and a second end; a first transistor having a first end electrically connected to the second end of the first resistor, a second end, and a control end receiving a control signal, the first transistor being controlled by the control signal to conduct or not conduct, and operating in a saturation region and having a low on-resistance; a second resistor electrically connected between the second end of the first transistor and ground; a capacitor electrically connected between the second end of the first transistor and ground; a regulating voltage generator electrically connected to the control end of the first transistor and receiving a logic signal and regulating the voltage level of the logic signal to generate the control signal and output it to the control end of the first transistor; and a baseboard management controller electrically connected to the regulating voltage generator. The voltage generator and the second end of the first transistor generate and output the logic signal to the regulating voltage generator. When the first transistor is turned on by the control signal, the baseboard management controller receives an output voltage positively related to the battery power from the second end of the first transistor to determine the power of the battery. The regulating voltage generator includes a level shift circuit, a third resistor, a fourth resistor, a second transistor, a first diode, a second diode, a third transistor, a third diode, a fourth diode, a sixth resistor, and a fifth resistor. The level shift circuit is electrically connected to the baseboard management controller to receive the logic signal and level-shift the logic signal to generate the control signal. The voltage level of the control signal is greater than a high level of the logic signal. The third resistor has an electrical connection to the The first transistor has a first end of the control end, and a second end electrically connected to the level shift circuit and receiving the control signal. The fourth resistor has a first end electrically connected to the baseboard management controller to receive the logic signal, and a second end grounded. The second transistor has a first end, a second end grounded, and a control end electrically connected to the first end of the fourth resistor and receiving the logic signal. The second transistor is The logic signal controls the conduction or non-conduction, the first diode and the second diode are connected in series between the second end of the second transistor and the control end, the first and second diodes each have a cathode and an anode, the anodes of the first and second diodes are electrically connected to each other, the third transistor has a first end electrically connected to the second end of the third resistor, a second end grounded, and an anode electrically connected to the The control end of the first end of the second transistor, when the second transistor is turned on, the third transistor is not turned on, when the second transistor is not turned on, the third transistor is turned on, the third diode and the fourth diode are connected in series between the second end of the third transistor and the control end, the third and fourth diodes each have a cathode and an anode, the anodes of the third and fourth diodes are electrically connected to each other The fifth resistor has a first end for receiving an input voltage and a second end electrically connected to the first end of the second transistor, the voltage level of the input voltage is greater than a high level of the logic signal, and the sixth resistor is electrically connected between the first end of the fifth resistor and the second end of the third resistor, wherein when the second transistor is controlled by the logic signal to be turned on, the input voltage serves as the control signal. The motherboard battery detection device as described in claim 1, wherein the logic signal is set by the baseboard management controller to change between the high level and a low level, and when the logic signal has the high level, the level shift circuit shifts the level of the logic signal so that the voltage level of the control signal generated by it is greater than the high level of the logic signal. The motherboard battery detection device as described in claim 1, wherein the level shift circuit further includes a seventh resistor electrically connected to the control end of the second transistor and receiving the logic signal, and an eighth resistor electrically connected between the first end of the second transistor and the control end of the third transistor. A motherboard battery detection device as described in claim 1, wherein each of the first to fourth diodes is a Zener diode. The motherboard battery detection device as described in claim 1, wherein the regulated voltage generator includes a third resistor having a first end electrically connected to the baseboard management controller to receive the logic signal, and a second end electrically connected to the control end of the first transistor and outputting the control signal, and a fourth resistor electrically connected between the second end of the third resistor of the regulated voltage generator and ground. The motherboard battery detection device as described in claim 1, wherein the baseboard management controller includes an analog-to-digital conversion unit electrically connected to the second end of the first transistor to receive the output voltage, and performs analog-to-digital conversion on the output voltage to generate a digital signal related to the battery power, so that the baseboard management controller can judge the battery power accordingly. The motherboard battery detection device as described in claim 8, wherein the baseboard management controller further includes a universal input-output pin electrically connected to the regulated voltage generator, and the universal input-output pin is used to output the logic signal to the regulated voltage generator.

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