TW202046109A - Motherboard battery detection device - Google Patents

Abstract

A motherboard battery detection device, comprising a transistor, a first resistor, a second resistor, a baseboard management controller, and a voltage follower, the baseboard management controller controls the transistor is turned on or turned off, the voltage follower receives a first input voltage from the second resistor and receives an identical second input voltage, and outputs the same voltage as the second input voltage to the baseboard management controller, the baseboard management controller receives a first output voltage from the voltage follower, when the transistor is not conducting, the substrate baseboard controller receives a second output voltage from the voltage follower when the transistor is switched to be conductive, and the baseboard management controller compares the first output voltage with whether the difference of the second output voltage is greater than a predetermined voltage value to determine whether the battery is not present.

Description

Motherboard battery detection device

The invention relates to a power detection device, in particular to a detection device for a motherboard battery.

The existing server has a CMOS (Complementary Metal-Oxide-Semiconductor) RAM (Random Access Memory) chip used to read and write data on one of its motherboards and store the current hardware-related configuration of the system, (hereinafter CMOS RAM chip Abbreviation), the CMOS RAM chip uses a real time clock (RTC; Real Time Clock) to maintain the current time. When the server power is turned off, the CMOS RAM chip uses a battery on the motherboard as shown in Figure 1. 21 receives electrical energy to maintain the state where the real-time clock can be read, and retains its stored data. When the battery 21 fails to supply power normally, the data originally stored in the CMOS RAM chip will be lost. Therefore, the server usually monitors the battery power to avoid loss of important CMOS RAM chip content.

The existing server monitors the power of the battery 21 on its motherboard mainly by a battery detection device. The battery detection device includes a first voltage divider 22, a transistor 23, and a second divider. The voltage divider 24 and a baseboard management controller 25. The first voltage divider 22 includes a first resistor 221 electrically connected to the battery 21 and a second resistor 222 connected to ground. The transistor 23 includes an electrical connection to the The drain of the first resistor 221, a source electrically connected to the second resistor 222, and a gate electrically connected to the baseboard management controller 25 and the second voltage divider 24. The second voltage divider 24 includes A first resistor 241 electrically connected to the gate and a second resistor 242 connected to ground. The baseboard management controller 25 includes a universal input/output interface electrically connected to the first resistor 241 of the second voltage divider 24 Pin (GPIO: General Purpose Input Output) 251, and an analog-to-digital conversion unit 252 electrically connected to the source.

When the battery 21 is normally powered, the transistor 23 is turned on/off controlled by the baseboard management controller 25 via the universal input/output pin 251, and the analog-to-digital conversion unit 252 can receive information related to it through the second resistor 222 The output voltage of the battery 21, when the battery 21 is zero, the transistor 23 is turned on/off controlled by the baseboard management controller 25 through the universal input/output pin 251, and the analog-to-digital conversion unit 252 passes through The second resistor 222 receives the zero output voltage related to the battery 21. However, if the battery 21 is not present on the motherboard (that is, not electrically connected to the first resistor 221), according to the above detection mechanism, the analog digital The voltage value received by the conversion unit 252 via the second resistor 222 is still zero volts. In other words, when zero volts are detected, it is impossible to know whether the battery is absent or the battery is exhausted. Furthermore, in order to avoid misjudgment when the analog-to-digital conversion unit 252 converts the voltage, the overall circuit needs to meet the requirement of extremely low leakage current, so the voltage divider resistance values of the first voltage divider 22 and the second voltage divider 24 must be changed. Turn it down, however, if it is adjusted too low, the output current of the battery will increase, and the battery will consume too much power, which will reduce its life. However, if the voltage divider resistance value is adjusted too high, the output current will decrease, which will make the board management control The power level detected by the analog-to-digital conversion unit 252 of the device 25 is too low, which may cause misjudgment.

In summary, the existing battery detection devices for motherboard batteries have the following disadvantages:

1. It is impossible to detect the absence of the battery.

2. The judgment structure of the transistor 23 will cause errors when the analog-to-digital conversion unit 252 performs the value conversion and thus misjudge the battery voltage.

Therefore, it is necessary to improve the existing battery detection device for detecting the battery on the motherboard.

Therefore, the purpose of the present invention is to provide a motherboard battery detection device.

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

The transistor includes a first terminal, a grounded second terminal, and a control terminal.

The first resistor includes a first end electrically connected to the first end of the transistor, and a second end.

The second resistor includes a first end electrically connected to the second end of the first resistor, and a second end, and the second end of the second resistor is used to electrically connect the battery.

The substrate management controller is electrically connected to the control terminal of the transistor, and controls the transistor to switch to one of a conductive state and a non-conductive state.

The voltage follower includes a non-reverse terminal electrically connected to the first terminal of the second resistor, a reverse terminal, and an output terminal electrically connected to the reverse terminal. The first terminal receives a first input voltage, the reverse terminal receives a second input voltage the same as the first input voltage, and the output terminal outputs the same voltage as the second input voltage.

When the transistor is in the non-conducting state, the substrate management controller receives a first output voltage that is directly related to the voltage output from the output terminal of the voltage follower. When the transistor is switched to the conducting state, the substrate The management controller receives a second output voltage that is positively correlated with the voltage output from the output terminal of the voltage follower, and the baseboard management controller compares whether the difference between the first output voltage and the second output voltage is greater than a predetermined value. Set the voltage value to determine whether the battery does not exist.

The effect of the present invention is that by the characteristic that the voltage follower has an overall gain value of 1, when the substrate management controller controls the conduction or non-conduction of the transistor, the detected battery voltage is transmitted to the substrate management controller and communicated with The preset voltage value is compared to determine whether the battery exists.

Referring to Fig. 2, an embodiment of the motherboard battery detection device of the present invention is suitable for detecting a battery 3. The motherboard battery detection device includes a transistor 4, a first resistor 5, a second resistor 6, A baseboard management controller 7, a voltage follower 8, and a voltage divider 9.

The transistor 4 includes a first terminal 41, a grounded second terminal 42, and a control terminal 43. The transistor 4 is an N-type MOSFET (N-type Metal Oxide Semiconductor). Field Effect Transistor), where the first terminal 41 is a drain, the second terminal 42 is a source, and the control terminal 43 is a gate. It should be supplemented that the transistor 4 of this embodiment can also be a P-type MOSFET (N-type Metal Oxide Semiconductor Field Effect Transistor), wherein the first terminal 41 Is a source, the second terminal 42 is a drain, and the control terminal 43 is a gate; or a bipolar junction transistor (BJT: Bipolar Junction Transistor), wherein the first terminal 41 is a collector, and the The second terminal 42 is the emitter, and the control terminal 43 is the base.

The first resistor 5 includes a first terminal 51 and a second terminal 52. The ground terminal 51 is electrically connected to the first terminal 41 of the transistor 4.

The second resistor 6 includes a first terminal 61 and a second terminal 62. The first terminal 61 is electrically connected to the second terminal 52 of the first resistor 5, and the second terminal 62 is electrically connected to the battery 3 .

The baseboard management controller 7 includes a universal input/output pin 71 and an analog-to-digital conversion unit 72. The universal input/output pin 71 is electrically connected to the second terminal 42 of the transistor 4. The universal input/output The pin 71 is used to output a logic signal to the control terminal of the transistor 4. The logic signal is set by the substrate management controller 7 to change between a high level and a low level to control the transistor 4 to switch to a In one of the conducting state and the non-conducting state, the analog-to-digital conversion unit 72 is an analog-digital converter (ADC: Analog Digital Converter), which receives the analog voltage output from the voltage follower 8.

The voltage follower 8 is a negative feedback amplifier, and includes a non-reverse terminal 81, a reverse terminal 82, and an output terminal 85. The non-reverse terminal 81 is electrically connected to the second resistor 6 The first terminal 61, the reverse terminal 82 and the output terminal 85 are electrically connected, so that the voltage follower 8 becomes a Unity-Gain Buffer with an overall amplifier gain of 1. Therefore, the voltage follows The overall amplifier gain of the coupler 8 is 1, and the non-inverting terminal 81 receives a first input voltage from the first terminal 61 of the second resistor 6, and the inverting terminal 82 receives a voltage equal to the first input voltage. The second input voltage, the output terminal 85 outputs the same voltage as the second input voltage. With reference to FIG. 3, the detailed circuit of the voltage follower 8 is further described. In this embodiment, the voltage follower 8 is It is realized by using an operational amplifier of model LM358 with the feedback resistor 83 and the ground resistor 84.

，該第四電阻92的電阻值為

，該輸出端的輸出電壓為

，則該類比數位轉換單元72接收到的信號的電壓值為

。The voltage divider 9 includes a third resistor 91 and a fourth resistor 92. The third resistor 91 has a first terminal 911 electrically connected to the output terminal 85 of the voltage follower 8 and an electrically connected The second end 912 of the analog-to-digital conversion unit 72. The fourth resistor 92 has a first end 921 electrically connected to the second end 912 of the third resistor 91, and a grounded second end 922. Generally speaking, the analog The digital converter has its corresponding resolution, that is, it has the voltage range of the analog signal that can be correctly received and the corresponding number of discrete digital signals that can be output. For example, if the analog-to-digital converter is 16 bits, its The signal voltage range that can be received is between 0 and 1.8 volts. When the voltage value of the received signal is higher than 1.8 volts, it must be converted by a voltage divider resistor before it can be accurately received. Based on practical design experience In other words, the optimal voltage division value is 3/4 of the maximum value of the signal voltage range that the analog-to-digital converter can receive, that is, the resistance ratio of the third resistor and the fourth resistor is 1:3. In this embodiment, Since the voltage value of the output signal of the voltage follower 8 does not necessarily correspond to the correct receiving range of the analog-to-digital conversion unit 72, the third resistor is designed and adjusted by matching the receiving voltage range of the analog-to-digital conversion unit 72 The resistance value of 91 and the fourth resistor 92 can be divided into the output voltage of the output terminal 85 of the voltage follower 8 and then transmitted to the analog-to-digital conversion unit 72 so that it can be accurately received. The resistance value of the three resistor 91 is

, The resistance value of the fourth resistor 92 is

, The output voltage of the output terminal is

, Then the voltage value of the signal received by the analog-to-digital conversion unit 72 is

.

When the transistor 4 is in the non-conducting state, the baseboard management controller 7 receives a first terminal 921 of the fourth resistor 92 that is positively correlated with the voltage output by the output terminal 85 of the voltage follower 8 Output voltage. When the transistor 4 is switched to the on state, the baseboard management controller 7 then receives from the first terminal 921 of the fourth resistor 92 a positive correlation with the output terminal 85 of the voltage follower 8 The substrate management controller 7 compares whether the difference between the first output voltage and the second output voltage is greater than a preset voltage value to determine whether the battery does not exist. When the substrate management If the comparison result of the controller 7 is yes, it is judged that the battery does not exist, and when the comparison result of the baseboard management controller 7 is no, it is judged that the battery exists, and the battery power can be further judged, as described in more detail below.

First, the baseboard management controller 7 outputs a disable signal via the universal input/output pin 71, that is, a logic signal at a low level to the control terminal 43 of the transistor 4, so that the transistor 4 Not conducting, the analog-to-digital conversion unit 72 receives the first output voltage from the first terminal 921 of the fourth resistor 92, and then, the baseboard management controller 7 outputs an enable through the universal input/output pin 71 Signal, that is, a logic signal at a high level to the control terminal 43 of the transistor 4, so that the transistor 4 is switched on, and the analog-to-digital conversion unit 72 receives the signal from the first terminal 921 of the fourth resistor 92 For the second output voltage, the baseboard management controller 7 performs analog-to-digital conversion of the first and second output voltages via the analog-to-digital conversion unit 72 and compares the difference between the first output voltage and the second output voltage to determine The presence or absence of the battery or power.

，該第二電阻6的電阻值為1

，先依照電池是否存在於主機板，將各種狀況表列如下，並接著進一步探討各種狀況下該實施例的運作機制：   狀況一： 有電池，電池正常供電 (3.3V) 狀況二： 有電池，電池電量為零 (0V) 狀況三： 無電池 電晶體不導通 3.3V(第一輸出電壓) 0V(第一輸出電壓) 3V 電晶體導通 3V(第二輸出電壓) 0V(第二輸出電壓) 0V 第一、第二電壓差值 0.3V 0V 3V Generally speaking, the DC bias voltage Vcc of the voltage follower 8 is 3 volts, and the voltage of the battery 2 is 3.3 volts when not in use. In use, because the transistor is turned on, the voltage of the second resistor 6 The first terminal 61 forms a voltage drop, and in this embodiment, the preset voltage value is assumed to be 1 volt, and the resistance value of the first resistor 5 is 10

, The resistance value of the second resistor 6 is 1

First, according to whether the battery exists on the motherboard, the various conditions are listed as follows, and then the operation mechanism of this embodiment under various conditions is further discussed: Condition 1: There is a battery, the battery is normally powered (3.3V) Condition 2: There is a battery, and the battery power is zero (0V) Condition 3: No battery Transistor does not conduct 3.3V (first output voltage) 0V (first output voltage) 3V Transistor on 3V (second output voltage) 0V (second output voltage) 0V The first and second voltage difference 0.3V 0V 3V

），此時，該第一、第二輸出電壓的差值不大於該預設電壓值。1. The battery 2 exists and can supply power normally: If the baseboard management controller 7 controls the transistor 4 to be non-conductive via the universal input and output pin 71, and the battery discharge path is equivalent to an open circuit, the analog-to-digital conversion unit 72 receives The first output voltage obtained is a voltage proportional to the voltage value of the battery 2 when it is not in use. Therefore, the first output voltage is 3.3 volts (for the convenience of description, it is assumed that the third resistor 91 and the fourth The voltage division ratio of the two resistors 92 is 1, that is, the resistance of the third resistor 91 is zero); if the baseboard management controller 7 controls the transistor 4 to be turned on through the universal input and output pin 71, the analogy The second output voltage received by the digital conversion unit 72 is the divided voltage of the battery 2 at the second end 62 of the second resistor 6 (

), at this time, the difference between the first and second output voltages is not greater than the preset voltage value.

2. The battery 2 exists and the power is zero: if the baseboard management controller 7 controls the transistor 4 to be non-conductive via the universal input and output pin 71, the first output voltage received by the analog-to-digital conversion unit 72 This is the voltage of the battery 2 when it is not in use. Therefore, the first output voltage is 0 volts at this time. If the baseboard management controller 7 controls the transistor 4 to be turned on through the universal input and output pin 71, the The second output voltage received by the analog-to-digital conversion unit 72 is the divided voltage of the battery 2 at the second end 62 of the second resistor 6. Therefore, the second output voltage is 0 volts at this time, then the first The difference of a second output voltage is not greater than the preset voltage value.

3. The battery 2 does not exist: if the baseboard management controller 7 controls the transistor 4 to be non-conductive via the universal input/output pin 71, the first output voltage received by the analog-to-digital conversion unit 72 is the voltage The DC bias voltage Vcc (3 volts) of the follower 8 (that is, the non-inverting terminal 81 is regarded as an open circuit with the battery 2 and the transistor 4, so the transistors Q1~Q4 of the voltage follower 8 are not Q5~Q6 are turned on, so the first output voltage received by the analog-to-digital conversion unit 72 is the DC bias voltage Vcc of the voltage follower 8), if the baseboard management controller 7 receives the universal input The output pin 71 controls the transistor 4 to be turned on. For the non-inverting terminal 81, it is grounded. Therefore, the received first input voltage is zero volts, and the inverting terminal 82 is also due to the virtual short characteristic. A second input voltage of zero volt is received, so the output terminal 85 outputs a second output voltage of zero volt. At this time, the difference between the first and second output voltages is greater than the preset voltage value.

It can be seen from the above three situations that when the difference between the first output voltage and the second output voltage is greater than the preset voltage value, it means that the battery does not exist, and when the difference between the first output voltage and the second output voltage is not Greater than the preset voltage value, it means that the battery exists, and when the first and second output voltages received by the analog-to-digital conversion unit 72 are both zero, it means that the battery power is zero, and when the analog-to-digital conversion unit 72 The received first and second output voltages are not zero, which means that the battery power is not zero.

In this embodiment, the substrate management controller 7 controls the conduction/non-conduction of the transistor 4 through the universal input and output pins 71, and the analog-to-digital conversion unit 72 of the substrate management controller 7 receives the voltage value transmitted by the voltage follower 8 The difference in the battery status is then judged, and then has the following advantages:

1. The voltage follower 8 directly detects the partial voltage of the battery 3 in the second resistor 6, without considering the leakage current of the transistor 4, and thus will not cause errors in the conversion value of the analog-to-digital conversion unit 72.

2. With the gain value of the voltage follower 8 being 1, the voltage value of the battery 3 can be completely output, and the transistor 4 can be controlled to be conductive or non-conductive, and then the output value of the voltage follower 8 can be used to determine whether the battery 3 is The voltage difference between the two states can accurately determine whether the battery 3 is present on the motherboard and has power, or whether the battery 3 is present on the motherboard and has no power, or the battery 3 does not exist on the motherboard.

In summary, the motherboard battery detection device of the present invention uses the characteristic that the gain value of the voltage follower is 1 to detect the voltage value of the battery when the baseboard management controller controls the conduction or non-conduction of the transistor It is completely transmitted to the baseboard management controller, and the baseboard management controller compares the received voltage value with the preset voltage value to determine whether the battery exists, so it can indeed achieve the purpose of the invention.

However, the above are only examples of the present invention. When the scope of implementation of the present invention cannot be limited by this, all simple equivalent changes and modifications made in accordance with the scope of the patent application of the present invention and the content of the patent specification still belong to Within the scope of the patent for the present invention.

21: battery 22: The first voltage divider 221: first resistance 222: second resistor 23: Transistor 24: second voltage divider 241: first resistance 242: second resistor 25: baseboard management controller 251: General-purpose input and output pins 252: Analog-to-digital conversion unit 3: battery 4: Transistor 41: first end 42: second end 43: control terminal 5: The first resistance 51: first end 52: second end 6: second resistor 61: first end 62: second end 7: baseboard management controller 71: General-purpose input and output pins 72: Analog-to-digital conversion unit 8: Voltage follower 81: non-reverse end 82: reverse end 85: output 91: third resistor 911: first end 912: second end 92: second resistor 921: first end 922: second end Vcc: DC bias Q1~Q10: Transistor

Other features and effects of the present invention will be clearly presented in the embodiments with reference to the drawings, in which: Figure 1 is a circuit diagram illustrating a conventional motherboard battery detection device; 2 is a circuit diagram illustrating an embodiment of the battery detection device for the motherboard of the present invention; and Fig. 3 is a circuit diagram to assist in explaining the specific methods of some circuits of this embodiment.

3: battery

4: Transistor

41: first end

42: second end

43: control terminal

5: The first resistance

51: first end

52: second end

6: second resistor

61: first end

62: second end

7: baseboard management controller

71: General-purpose input and output pins

72: Analog-to-digital conversion unit

8: Voltage follower

81: non-reverse end

82: reverse end

85: output

91: first resistance

911: first end

912: second end

92: second resistor

921: first end

922: second end

Claims (9)

A motherboard battery detection device is suitable for detecting a battery. The motherboard battery detection device includes: A transistor including a first terminal, a grounded second terminal, and a control terminal; A first resistor, including a first end electrically connected to the first end of the transistor, and a second end; A second resistor, including a first end electrically connected to the second end of the first resistor, and a second end, and the second end of the second resistor is used to electrically connect the battery; A substrate management controller, which is electrically connected to the control terminal of the transistor, and controls the transistor to switch to one of a conducting state and a non-conducting state; and A voltage follower includes a non-reverse end electrically connected to the first end of the second resistor, a reverse end, and an output end electrically connected to the reverse end. The non-reverse end is from the second resistor The first terminal of the receiving terminal receives a first input voltage, the inverting terminal receives a second input voltage the same as the first input voltage, and the output terminal outputs the same voltage as the second input voltage, When the transistor is in the non-conducting state, the baseboard management controller receives a first output voltage that is directly related to the voltage output by the output terminal of the voltage follower, When the transistor is switched in the on state, the baseboard management controller receives a second output voltage that is directly related to the voltage output by the output terminal of the voltage follower, The baseboard management controller compares whether the difference between the first output voltage and the second output voltage is greater than a preset voltage value to determine whether the battery does not exist. The motherboard battery detection device according to claim 1, wherein when the difference between the first output voltage and the second output voltage is greater than the preset voltage value, the battery does not exist. The motherboard battery detection device according to claim 2, wherein the first output voltage is an operating voltage of the voltage follower. The motherboard battery detection device according to claim 1, wherein, when the difference between the first output voltage and the second output voltage is not greater than the preset voltage value, the battery exists. The motherboard battery detection device according to claim 1, wherein the baseboard management controller includes a universal input/output pin electrically connected to the control terminal of the transistor, and the universal input/output pin is used to output a The logic signal is sent to the control terminal of the transistor, and the logic signal is set by the substrate management controller to change between a high level and a low level. The motherboard battery detection device according to claim 1, wherein the baseboard management controller further includes an analog-to-digital conversion unit that receives the first output voltage and the second output voltage. The motherboard battery detection device according to claim 1, further comprising a voltage divider electrically connecting the output terminal of the voltage follower and the analog-to-digital conversion unit, the voltage divider according to a voltage division ratio The voltage output from the output terminal of the follower is converted into the first output voltage and the second output voltage. The motherboard battery detection device according to claim 1, wherein the voltage follower is a negative feedback amplifier. The motherboard battery detection device according to claim 7, wherein the voltage divider includes a third resistor and a fourth resistor, and the third resistor has a first resistor electrically connected to the output terminal of the voltage follower One end, and a second end electrically connected to the analog-to-digital conversion unit, the fourth resistor has a first end electrically connected to the second end of the third resistor, and a second end that is grounded. When the transistor is in In the non-conductive state, the baseboard management controller receives a first output voltage from the first terminal of the fourth resistor that is directly related to the voltage output from the output terminal of the voltage follower. When the transistor is switched to the conductive In the state, the baseboard management controller receives a second output voltage from the first terminal of the fourth resistor, which is positively correlated with the output voltage of the output terminal of the voltage follower.

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