Low-power-consumption Hall circuit, wireless magnetic axis keyboard and working method

Abstract

The invention relates to a low-power-consumption Hall circuit, a wireless magnetic axis keyboard and a working method, and the low-power-consumption Hall circuit comprises a constant current source which provides constant current for the Hall circuit; the Hall device is driven by the current provided by the constant current source and outputs a Hall signal; the power supply on-off control module is used for controlling the working state of the constant current source, the power supply on-off control module comprises an enabling end, and the enabling end receives a level enabling signal; wherein when the level enable signal is a high level, the constant current source works, and the Hall device works; and when the level enable signal is at a low level, the constant current source stops working, and the Hall circuit enters a waiting state. According to the low-power-consumption Hall circuit, the Hall circuit can be controlled to enter the waiting mode so as to reduce power consumption, and meanwhile the response speed of the Hall circuit is not affected.

Description

Technical Field

[0001] The invention relates to the field of electromagnetic signal application, and in particular to a low-power consumption Hall circuit and a wireless magnetic axis keyboard. Background Art

[0002] Figure 1 FIG. 1 is a block diagram showing the structure of a linear Hall circuit in the prior art. Figure 1 As shown, a current source is integrated inside the circuit, which provides a constant current for the Hall device, the amplifier circuit and the output circuit. After the Hall device detects the magnetic field, a voltage difference is generated at both ends of the Hall device perpendicular to the current direction. This voltage difference is sent to the amplifier as a differential signal, and the amplified signal is output after being sorted by the output stage.

[0003] Hall circuits are generally used in mechanical keyboards. A general keyboard has more than one hundred keys, and each key is equipped with a magnetic induction circuit, that is, a Hall circuit. The working current of the Hall circuit is 1mA to 3mA, so the power consumption of the entire keyboard is very high. Considering that wireless mechanical keyboards cannot be powered at any time, high-power consumption solutions cannot be applied to wireless mechanical keyboards. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention discloses a low-power consumption Hall circuit and a wireless magnetic axis keyboard.

[0005] The technical solution adopted by the present invention is as follows:

[0006] A low-power Hall circuit comprises: a constant current source, which provides a constant current for the Hall circuit; a Hall device, which is driven by the current provided by the constant current source and outputs a Hall signal; a power supply disconnection control module, which is used to control the working state of the constant current source, and the power supply disconnection control module comprises an enable terminal, which receives a level enable signal; wherein, when the level enable signal is at a high level, the constant current source works, and the Hall device works; when the level enable signal is at a low level, the constant current source stops working, and the Hall circuit enters a waiting state.

[0007] Its further technical solution is that it also includes: an amplifier, which receives the Hall signal and outputs an amplified voltage; an output control module, which compares the amplified voltage with a reference voltage and outputs a control signal; an output circuit, which receives the control signal and outputs a key output signal; wherein: when the amplified voltage is less than the reference voltage, the output control module reduces the output current of the output circuit and pulls up the output voltage of the output circuit to a set high level value as a key output signal; when the amplified voltage is greater than the reference voltage, the control signal controls the output circuit to output a linear signal as the key output signal.

[0008] A further technical solution is that when the level enable signal is at a low level, the operating current of the Hall circuit is 5uA to 20uA, and the circuit enters a waiting mode.

[0009] A further technical solution is that the output current of the constant current source is 20uA to 50uA.

[0010] A wireless magnetic axis keyboard provided with a low-power Hall circuit as described in any of the above items, characterized in that it includes: a key that sends a trigger signal when triggered; a control chip that sends a high-level enable signal to the enable end of the power disconnection control module when receiving the trigger signal of the key, and sends a low-level enable signal to the enable end of the power disconnection control module when not receiving the trigger signal of the key.

[0011] Its further technical solution is that there are multiple keys, and each key corresponds to a low-power Hall circuit; the wireless magnetic axis keyboard also includes a monitoring circuit; the monitoring circuit receives key output signals output by multiple low-power Hall circuits, and when it is determined that the key output signals are all low-level, a monitoring signal is sent to the control chip; after receiving the monitoring signal, the control chip sends a low level to the enable end of all low-power Hall circuits as a level enable signal.

[0012] A working method of a low-power Hall circuit is realized by the low-power Hall circuit as described above, comprising: an enable end of a power supply disconnection control module receives a level enable signal and determines the level of the level enable signal; when the level enable signal is at a high level, the constant current source works and the Hall device works; when the level enable signal is at a low level, the constant current source stops working and the Hall circuit enters a waiting state.

[0013] Its further technical solution is: the amplifier receives the Hall signal and outputs an amplified voltage; the output control module generates a reference voltage and compares the amplified voltage with the reference voltage; the output circuit receives the control signal and outputs a key output signal, wherein: when the amplified voltage is less than the reference voltage, the output control module reduces the output current of the output circuit and pulls up the output voltage of the output circuit to a set high level value as the key output signal; when the amplified voltage is greater than the reference voltage, the output control module controls the output circuit to output a linear signal as the key output signal.

[0014] A working method of a wireless magnetic axis keyboard is realized by the wireless magnetic axis keyboard as described above, comprising: sending a trigger signal when a key is triggered; when a control chip receives the trigger signal of the key, sending a high-level enable signal, and when the control chip does not receive the trigger signal of the key, sending a low-level enable signal.

[0015] Its further technical solution is that the working method further includes: the monitoring circuit receives multiple key output signals; the monitoring circuit determines the level values ​​of all key output signals, and when the level values ​​are all set high level values, sends a monitoring signal to the control chip; after the control chip receives the control signal, it sends a low level to the enable end of all low-power Hall circuits as a level enable signal.

[0016] The beneficial effects of the embodiments of the present invention are as follows:

[0017] The low-power Hall circuit in the embodiment of the present invention can control the Hall circuit to enter a waiting mode to reduce power consumption by adding a power disconnection control module and setting an enable terminal that can receive an external signal in the power disconnection control module, while the response speed of the Hall circuit is not affected;

[0018] The low-power Hall circuit in the embodiment of the present invention has a built-in constant current source that does not change with the power supply voltage, and ensures high sensitivity and high consistency of the magnetic induction output under the use condition that the battery voltage changes.

[0019] The low-power Hall circuit in the embodiment of the present invention also adds an output control module, which reduces the output stage operating current when the key is not triggered and sends a high level to the subsequent processing circuit, so that when the low-power Hall circuit is installed in the magnetic axis keyboard, further energy-saving processing can be performed.

[0020] The wireless magnetic axis keyboard in the embodiment of the present invention can reduce the power consumption of the entire keyboard without affecting the response speed of the magnetic axis keyboard because a low-power Hall circuit is installed.

[0021] The existing magnetic axis keyboard market is concentrated on wired keyboards, which have power cords to connect to the power supply, so there is no requirement for low power consumption of the Hall circuit. Wireless keyboards have an increasing market share due to their portability and simple peripherals. The magnetic axis keyboard in the embodiment of the present invention can achieve both low power consumption and high response speed, and the technical effect is better than the existing technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 The figure is a schematic block diagram of the structure of a linear Hall circuit in the prior art.

[0023] Figure 2 Schematic diagram of a low power consumption Hall circuit in an embodiment of the present invention.

[0024] Figure 3 It is a partial structural schematic diagram of the wireless magnetic axis keyboard in an embodiment of the present invention.

[0025] Figure 4 4 is a flowchart of the low power consumption Hall circuit in an embodiment of the present invention. DETAILED DESCRIPTION

[0026] The specific implementation of the present invention will be described below in conjunction with the accompanying drawings.

[0027] Example 1

[0028] Figure 2 Schematic diagram of a low power consumption Hall circuit in an embodiment of the present invention. Figure 2 As shown, the low-power Hall circuit includes a constant current source, a Hall device and a power supply disconnection control module. The constant current source is used to provide a constant current for the Hall circuit. The Hall device is driven by the current provided by the constant current source and outputs a Hall signal. The power supply disconnection control module is used to control the working state of the constant current source. The power supply disconnection control module includes an enable terminal, which is used to receive a level enable signal. When the level enable signal is high, the constant current source works and the Hall device works. When the level enable signal is low, the constant current source stops working and the Hall circuit enters a waiting state.

[0029] Relative to Figure 1 The prior art shown in the figure, this embodiment adds a power supply disconnection control module on the basis of the existing linear Hall circuit, and also adds an enable terminal as a control port. When the enable terminal inputs a high level, the constant current source starts to work, and the constant current source provides a constant working current for the entire low-power Hall circuit. When the enable terminal inputs a low level, the constant current source stops working, and the working current of the entire low-power Hall circuit drops to 5uA~20uA, and the circuit enters the waiting mode. At this time, the working current of the low-power Hall circuit is the working current of the startup circuit. The startup circuit is not turned off in the waiting mode, and its working current is 5uA~20uA. The startup circuit is used to provide an initial startup signal to the current source, and then the current source provides current to each functional module. In this embodiment, due to the requirement of high reporting rate, only the current source is turned off to keep the startup circuit with a small current working. When this waiting mode is started again, since the circuit startup process is skipped, once the enable terminal is turned on, the entire circuit can start working quickly, so the response speed of this waiting mode is much faster than the sleep state in the prior art.

[0030] The working principle of the Hall device is to pass a control current I in the x direction of the Hall device. C , a magnetic field B is applied in the thickness z direction, then an electromotive force U is generated in the y direction H , its size can be expressed as:

[0031]

[0032] Where: R H is the Hall coefficient, which is determined by the properties of the semiconductor material; d is the thickness of the semiconductor. Let K H =R H / d, then K HIt is called the sensitivity coefficient, the electromotive force U H (That is, the output voltage U H ) can be expressed as:

[0033] U H =K H *I c *B

[0034] It can be seen that the output voltage U of the Hall device H With control current I C It is proportional to the magnetic field strength B, and the smaller the thickness d of the Hall device, the higher the sensitivity and the output voltage U H The larger the value of .

[0035] In the prior art, wireless keyboards are powered by lithium batteries or dry batteries. The battery voltage will become lower and lower until the battery is exhausted. Therefore, the internal current source of the linear Hall circuit is an operating current that changes with the power supply voltage. From the working principle of the Hall device, it can be seen that the output sensitivity of the Hall circuit is proportional to the current flowing through the Hall device. As the battery voltage changes, the output value of the Hall device will be affected.

[0036] In view of this situation, a constant current source is provided in this embodiment, which provides a constant current Ib that does not change with the power supply voltage. Preferably, the value of the constant current Ib is 20uA to 50uA. Under the use condition where the battery voltage changes, the high sensitivity and high consistency of the magnetic induction output can be guaranteed.

[0037] At the same time, this embodiment sets a power disconnection control module and sets an enable terminal on the power disconnection control module that can receive an external input signal, so as to directly control the Hall circuit to enter the waiting mode to reduce power consumption, while the response speed of the Hall circuit is not affected.

[0038] Further, such as Figure 2 As shown, in this embodiment, the low power consumption Hall circuit further includes an amplifier, an output control module and an output circuit.

[0039] The amplifier receives the Hall signal output by the Hall device and outputs an amplified voltage V op The output control module generates a fixed reference voltage V t , the output control module compares and amplifies the voltage V op and reference voltage V t , and outputs a control signal to an output circuit. The output circuit receives the control signal and outputs a key output signal.

[0040] When the amplified voltage V op Less than the reference voltage V t, the level enable signal is judged to be low level, the output control module shuts off part of the output stage drive current, reduces the output current of the output circuit, preferably reduces the output current to 10% of the normal working state, and at the same time pulls the output voltage of the output circuit up to the set high level value as the key output signal. When the amplified voltage V op Greater than the reference voltage V t The output control module controls the output circuit to output a linear signal as a key output signal.

[0041] In the output characteristics of a conventional linear Hall circuit, the input of the linear Hall circuit is the magnetic induction intensity, and the output is a voltage proportional to the input. The linear Hall circuit has high sensitivity and excellent linearity.

[0042] In the output characteristic diagram of the conventional linear Hall circuit, the X-axis is the magnetic flux, the unit is Gs (Gauss, Guass), the N pole is a negative value, the S pole is a positive value, and the Y-axis is the output voltage. When the magnetic flux acting on the Hall device is 0Gs, the output voltage is set to half of the power supply voltage, that is, Vout = 1 / 2Vcc. The disadvantage of this output characteristic is that when there is no magnetic field, the working current of the circuit output stage also needs to be maintained at a constant value, and the power consumption of the circuit is large. This embodiment adds an output control module on the basis of the conventional linear Hall circuit to reduce the power consumption of the Hall circuit. By turning off the output stage drive current, that is, reducing the output current of the output circuit, the power consumption of the Hall circuit can be reduced to two-thirds of the original at the lowest.

[0043] This embodiment adds an output control module. When the level enable signal at the enable end is at a low level, that is, when the button is not triggered, part of the output stage working current can be shut down, and a set high level value can be sent as a button output signal to the subsequent processing circuit for further energy-saving processing.

[0044] Example 2

[0045] Figure 3 The diagram is a partial structural diagram of a wireless magnetic axis keyboard in an embodiment of the present invention. Based on the low-power Hall circuit of embodiment 1, embodiment 2 is a wireless magnetic axis keyboard provided with a low-power Hall circuit.

[0046] A magnetic axis keyboard is a computer keyboard axis that uses the interaction between magnetism and Hall sensors to achieve key triggering.

[0047] like Figure 3 As shown, embodiment 2 includes a button and a control chip. When the button is triggered, a trigger signal is sent. When the control chip receives the trigger signal, a high-level enable signal is sent to the enable end of the low-power Hall circuit. When the control chip does not receive the trigger signal, a low-level enable signal is sent to the enable end of the low-power Hall circuit.

[0048] With this setting, combined with Example 1, it can be seen that when the button is triggered, that is, when the button is pressed, the constant current source starts working, and the constant current source provides a constant operating current for the entire low-power Hall circuit. When the button is not triggered, the constant current source stops working, and the operating current of the entire low-power Hall circuit drops to 5uA~20uA, the circuit enters the waiting mode, and the output control module shuts off part of the output stage current.

[0049] Figure 3 Only one low-power Hall circuit is shown as an example. For a keyboard, there are multiple keys, and each key corresponds to a low-power Hall circuit. The wireless magnetic axis keyboard also includes a monitoring circuit. The monitoring circuit receives the key output signals of multiple low-power Hall circuits. When the monitoring circuit determines that all key output signals are set high level values, that is, all keys are not triggered, a monitoring signal is sent to the control chip. After receiving the monitoring signal, the control chip sends a low level to the enable end of all low-power Hall circuits as a level enable signal.

[0050] In this way, the output signals of all the keys on the entire keyboard can be monitored. If all the keys are not triggered within a certain period of time, it is determined that the computer has not been operated. At this time, the control chip sends a low level to the enable end of all the Hall circuits on the keyboard, and all low-power Hall circuits enter waiting mode.

[0051] For magnetic axis keyboards, by adjusting the trigger position and stroke length, the magnetic axis can achieve fast triggering within a very short stroke, greatly improving the keystroke speed. Taking ordinary mechanical axes as an example, it takes about 12mm of stroke to complete two triggers, while the magnetic axis only needs 5mm. In addition to fast triggering within a very short stroke, the magnetic axis also needs to distinguish the size of the stroke and accurately grade it. These require the magnetic induction circuit to have the characteristics of high sensitivity and high response speed.

[0052] In this embodiment, since the trigger signal of the key is realized by a low-power Hall circuit, when entering the waiting state, the Hall circuit is not completely dormant, so there is no dormant wake-up process, which can speed up the reaction speed and respond to the key trigger signal in time. The technical effect of achieving both low power consumption and high response speed of the wireless magnetic axis keyboard is achieved.

[0053] Example 3

[0054] Based on the low power consumption Hall circuit of Example 1, this embodiment proposes a working method of the low power consumption Hall circuit. Figure 4 FIG. 2 is a flowchart of the low power consumption Hall circuit in the embodiment of the present invention. Figure 4 As shown in the figure, the working process of the low power Hall circuit includes:

[0055] The enable end of the power supply disconnection control module receives a level enable signal, judges the level enable signal, and controls the working state of the constant current source.

[0056] When the level enable signal is high, the constant current source works and the Hall device works.

[0057] When the level enable signal is low, the constant current source stops working and the low power consumption Hall circuit enters a waiting state.

[0058] Furthermore, the amplifier receives the Hall signal output by the Hall device and outputs an amplified voltage V op .

[0059] The output control module generates a fixed reference voltage V t , and compare the amplified voltage V op and reference voltage V t , and then output the control signal.

[0060] The output circuit receives the control signal and outputs a key output signal.

[0061] Where: When the amplified voltage V op Less than the reference voltage V t , the output control module shuts off part of the output stage current, reduces the output current of the output circuit, and pulls the output voltage of the output circuit up to the set high level value as the key output signal. op Greater than the reference voltage V t , the control signal controls the output circuit to output a linear signal as a key output signal.

[0062] Furthermore, the invention also includes a working method of a wireless magnetic axis keyboard based on a working method of a low-power Hall circuit. The wireless magnetic axis keyboard has a plurality of keys, each of which corresponds to a low-power Hall circuit. The wireless magnetic axis keyboard also includes a monitoring circuit.

[0063] The monitoring circuit receives a plurality of key output signals.

[0064] The monitoring circuit determines all key output signals. If all key output signals are set high level values, the monitoring circuit sends a monitoring signal to the control chip.

[0065] The control chip sends a low level as a level enable signal to the enable terminals of all low-power Hall circuits.

[0066] Through the working method of the low-power Hall circuit in this embodiment, when the level enable signal at the enable end is at a low level, that is, when the key is not triggered, part of the output stage working current can be turned off, and a set high level value is sent as a key output signal to the subsequent processing circuit for further energy-saving processing. In this way, the power consumption is reduced without affecting the response speed, making this low-power Hall circuit more suitable for application in wireless magnetic axis keyboards.

[0067] In the present invention, the functions of the power disconnection control module, the output control module and the output circuit in each embodiment only involve the judgment of the level and the output of a specific level signal. The basic circuit functions in the prior art are used here. Those skilled in the art can use various circuit structures in the prior art to implement them. The specific circuit structure is not within the scope of protection of this patent.

[0068] The above description is an explanation of the present invention, not a limitation of the present invention. The scope of the present invention is defined in the claims. The present invention may be modified in any form without violating the basic structure of the present invention.

Claims

1. A low power consumption Hall circuit, characterized in that: include: Constant current source, providing constant current for the Hall circuit; A Hall device is driven by the current provided by the constant current source and outputs a Hall signal; A power supply disconnection control module, used for controlling the working state of the constant current source, the power supply disconnection control module comprises an enable terminal, the enable terminal receives a level enable signal; Among them, when the level enable signal is at a high level, the constant current source works and the Hall device works; when the level enable signal is at a low level, the constant current source stops working and the Hall circuit enters a waiting state.

2. The low power consumption Hall circuit according to claim 1, characterized in that: Also includes: An amplifier, receiving the Hall signal and outputting an amplified voltage; An output control module compares the amplified voltage with a reference voltage and outputs a control signal; An output circuit receives the control signal and outputs a key output signal; Wherein: when the amplified voltage is less than the reference voltage, the output control module reduces the output current of the output circuit and pulls up the output voltage of the output circuit to a set high level value as a key output signal; when the amplified voltage is greater than the reference voltage, the control signal controls the output circuit to output a linear signal as the key output signal.

3. The low power consumption Hall circuit according to claim 1, characterized in that: When the level enable signal is at a low level, the operating current of the Hall circuit is 5uA to 20uA, and the circuit enters a waiting mode.

4. The low power consumption Hall circuit according to claim 1, characterized in that: The output current of the constant current source is 20uA-50uA.

5. A wireless magnetic axis keyboard provided with the low-power Hall circuit according to any one of claims 1 to 4, characterized in that: include: The button sends a trigger signal when it is triggered; The control chip sends a high-level enable signal to the enable end of the power disconnection control module when receiving the trigger signal of the button, and sends a low-level enable signal to the enable end of the power disconnection control module when not receiving the trigger signal of the button.

6. The wireless magnetic axis keyboard with low power consumption Hall circuit according to claim 5, characterized in that: There are multiple keys, and each key corresponds to a low-power Hall circuit; the wireless magnetic axis keyboard also includes a monitoring circuit; the monitoring circuit receives key output signals output by multiple low-power Hall circuits, and when it is determined that the key output signals are all low-level, sends a monitoring signal to the control chip; After receiving the monitoring signal, the control chip sends a low level as a level enable signal to the enable ends of all low-power Hall circuits.

7. A method for operating a low power consumption Hall circuit, characterized in that: The method is implemented by the low-power Hall circuit according to any one of claims 1 to 4, comprising: The enable end of the power supply disconnection control module receives a level enable signal and determines the level of the level enable signal; when the level enable signal is at a high level, the constant current source works and the Hall device works; When the level enable signal is at a low level, the constant current source stops working, and the Hall circuit enters a waiting state.

8. The working method of the low power consumption Hall circuit according to claim 7, characterized in that: The amplifier receives the Hall signal and outputs an amplified voltage; The output control module generates a reference voltage and compares the amplified voltage with the reference voltage; The output circuit receives the control signal and outputs a key output signal, Wherein: when the amplified voltage is less than the reference voltage, the output control module reduces the output current of the output circuit and pulls up the output voltage of the output circuit to a set high level value as a key output signal; when the amplified voltage is greater than the reference voltage, the output control module controls the output circuit to output a linear signal as the key output signal.

9. A method for operating a wireless magnetic axis keyboard, characterized in that: The wireless magnetic axis keyboard is implemented by any one of claims 5 to 6, comprising: A trigger signal is sent when the button is triggered; When the control chip receives the trigger signal of the key, it sends a high-level enable signal. When the control chip does not receive the trigger signal of the key, it sends a low-level enable signal.

10. The working method of the wireless magnetic axis keyboard according to claim 9, characterized in that: The working method further comprises: The monitoring circuit receives a plurality of key output signals; The monitoring circuit determines the level values ​​of all key output signals, and when the level values ​​are all set high level values, sends a monitoring signal to the control chip; After receiving the control signal, the control chip sends a low level as a level enable signal to the enable terminals of all low-power Hall circuits.

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