Key detection circuit, chip and electronic device
By designing a key detection circuit including a key switch network module, a detection switch module and an analog-to-digital conversion module, the problem of identification errors in traditional keyboard circuits when multiple keys are pressed simultaneously is solved, and power consumption is reduced.
Patent Information
- Application Number
- CN202421217243.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-30
- Publication Date
- 2025-04-11
- Estimated Expiration
- 2034-05-30
AI Technical Summary
Traditional keyboard circuits are prone to recognition errors when multiple keys are pressed at the same time, and their power consumption is high.
Design a button detection circuit, including a button switch network module, a detection switch module and an analog-to-digital conversion module. By converting different voltage signals output by the key switch network module into binary signals, the triggered key combination is identified and scan detection is performed only when the key is pressed to reduce power consumption.
It effectively solves the recognition error when multiple keys are pressed at the same time, and scan detection is performed only when a key is pressed, reducing the power consumption of the entire key detection circuit.
Smart Images
Figure CN222750431U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of integrated circuits, and in particular to a key detection circuit, a chip and an electronic device. Background Art
[0002] Traditional keyboard circuits are generally designed in two layers, one layer of printed circuits arranged horizontally, and the other layer of printed circuits arranged vertically. The keyboard main control chip determines whether the key is triggered by scanning. When a key is pressed, the main control chip first turns on the first column, and then checks row by row whether there is a key triggered in the turned-on column. If no key is triggered, the first column is closed and then the next column is turned on to check row by row until the pressed and triggered key is detected or all columns are checked. However, when three or more keys are pressed at the same time, because the lines are connected in series, other keys that are not pressed may also be detected as triggered. Utility Model Content
[0003] In view of the above problems, the embodiments of the present application provide a key detection circuit, a chip and an electronic device to solve the above technical problems.
[0004] In a first aspect, an embodiment of the present application provides a key detection circuit, comprising:
[0005] at least one key switch network module;
[0006] at least one detection switch module;
[0007] Analog-to-digital conversion module;
[0008] The first end of the key switch network module is connected to the first end of the detection switch module, and the second end of the detection switch module is connected to the first end of the analog-to-digital conversion module;
[0009] When the second end of the key switch network module is grounded, the third end of the detection switch module is used to receive the first voltage; when the second end of the key switch network module is used to receive the first voltage, the third end of the detection switch module is grounded.
[0010] In a second aspect, an embodiment of the present application further provides a chip, comprising the above-mentioned analog-to-digital conversion module.
[0011] In a third aspect, an embodiment of the present application further provides an electronic device comprising the above-mentioned chip.
[0012] The key detection circuit provided by the embodiment of the present application includes: a key switch network module, a detection switch module and an analog-to-digital conversion module; the first end of the key switch network module is connected to the first end of the detection switch module, and the second end of the detection switch module is connected to the first end of the analog-to-digital conversion module; when the second end of the key switch network module is grounded, the third end of the detection switch module is used to receive a first voltage; when the second end of the key switch network module is used to receive the first voltage, the third end of the detection switch module is grounded. By obtaining analog signals with different voltage values when different key combinations in the key switch network module are triggered, and then converting the analog signals with different voltage values into digital signals with different binary values through the digital-to-analog conversion module, the triggered key combination can be identified according to the digital signal with the binary value, which can solve the recognition errors that may occur when multiple keys are pressed in the prior art, and the analog-to-digital conversion module only scans and detects the key switch network when a key is pressed, further reducing the power consumption of the entire key detection circuit.
[0013] These and other aspects of the present application will become more clearly understood in the description of the following embodiments. BRIEF DESCRIPTION OF THE DRAWINGS
[0014] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.
[0015] Figure 1 A schematic diagram of the structure of a key detection circuit provided in an embodiment of the present application is shown;
[0016] Figure 2 A schematic diagram of the structure of a key switch network module provided in an embodiment of the present application is shown;
[0017] Figure 3 A schematic diagram of the structure of an analog-to-digital conversion module provided in an embodiment of the present application is shown;
[0018] Figure 4 A schematic diagram of the structure of a detection switch unit provided in an embodiment of the present application is shown;
[0019] Figure 5 A schematic diagram of the structure of a key sub-network unit provided in an embodiment of the present application is shown;
[0020] Figure 6 A schematic diagram showing a structure of a key switch network module provided by an embodiment of the present application including a single-channel key sub-network unit;
[0021] Figure 7A schematic diagram showing the structure of a key switch network module provided by an embodiment of the present application including a multi-channel key sub-network unit;
[0022] Figure 8 A schematic diagram showing the structure of a key switch network module provided by another embodiment of the present application including a multi-channel key sub-network unit;
[0023] Fig. 9 A schematic diagram of the structure of a chip provided in one embodiment of the present application is shown;
[0024] Fig.10 A schematic structural diagram of an electronic device provided in one embodiment of the present application is shown. DETAILED DESCRIPTION
[0025] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limiting the present application.
[0026] In order to enable those skilled in the art to better understand the solutions of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of the present application.
[0027] In the embodiments of the present application, it should be noted that, in this article, relational terms such as first and second, etc. are merely used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations.
[0028] In addition, the "plurality" in the embodiments of the present application refers to two or more than two. In view of this, in the embodiments of the present application, "plurality" can also be understood as "at least two". "At least one" can be understood as one or more, for example, one, two or more. For example, including at least one means including one, two or more, and there is no limit on which ones are included. For example, including at least one of A, B and C, then A, B, C, A and B, A and C, B and C, or A, B and C can be included.
[0029] It should be noted that in the embodiments of the present application, "connection" can be understood as electrical connection, and the connection between two electrical components can be a direct or indirect connection between the two electrical components. For example, the connection between A and B can be either a direct connection between A and B or an indirect connection between A and B through one or more other electrical components.
[0030] An embodiment of the present application provides a structural diagram of a key detection circuit 10, such as Figure 1 As shown, the key detection circuit 10 includes: at least one key switch network module 100, at least one detection switch module 200 and an analog-to-digital conversion module 300. The first end of the key switch network module 100 is connected to the first end of the detection switch module 200, and the second end of the detection switch module 200 is connected to the first end of the analog-to-digital conversion module 300; when the second end of the key switch network module 100 is grounded, the third end of the detection switch module 200 is used to receive a first voltage; when the second end of the key switch network module 100 receives the first voltage, the third end of the detection switch module 200 is grounded ( Figure 1 When a physical key is pressed, the key switch network module 100 is triggered to perform key scanning detection, and the analog-to-digital conversion module 300 receives the voltage analog signal output by the key switch network module 100 through the detection switch module 200, and converts the voltage analog signal into a voltage digital signal represented by binary, and determines the pressed physical key combination according to the voltage digital signal represented by binary.
[0031] As an implementation method, a comparison table of key combinations and voltage digital signals may be preset, and the pressed physical key combination may be determined through the comparison table.
[0032] In some embodiments, see Figure 2 As shown, the key switch network module 100 includes a first number of key sub-network units 110, and the first end of the key sub-network unit 110 is connected to the first end of the detection switch module 200. When the third end of the detection switch module 200 receives the first voltage, the second end of the key sub-network unit 110 is grounded; when the third end of the detection switch module 200 is grounded, the second end of the key sub-network unit 110 receives the first voltage ( Figure 2 ). The first number is greater than or equal to 1, that is, the key switch network 100 includes at least one key sub-network unit 110. It should be noted that if the key switch network 100 includes at least two key sub-network units 110, the key combination corresponding to each key sub-network unit should be different.
[0033] In some embodiments, see Figure 3As shown, the detection switch module 200 includes a first number of detection switch unit modules 210. The number of the detection switch units 210 is equal to the number of the key sub-network units 110, the first end of the detection switch unit 210 is connected to the first end of the key sub-network unit 110, and the second end of the detection switch unit 210 is connected to the first end of the analog-to-digital conversion module 300. When any one or more physical keys in the key sub-network unit 110 are pressed, the detection switch unit 210 corresponding to the key sub-network unit 110 will also switch to the on state, so that the voltage analog signal output by the key sub-network unit 110 can be transmitted to the analog-to-digital conversion module 300.
[0034] As an implementation, see Figure 4 As shown, the analog-to-digital conversion module 300 includes at least one analog-to-digital converter ADC, the detection switch unit 210 includes a first number of detection switches Sw, and the detection switch unit 210 further includes at least one detection voltage-dividing resistor Rw. The first end of the detection switch Sw is correspondingly connected to the first end of each key sub-network unit 110, the second end of the detection switch Sw is connected to an analog-to-digital converter ADC, and the first end of the detection voltage-dividing resistor Rw is connected to the second end of the detection switch Sw. When the second end of the key sub-network unit 110 receives the first voltage, the second end of the detection voltage-dividing resistor Rw is grounded; when the second end of the key sub-network unit 110 is grounded, the second end of the detection voltage-dividing resistor Rw receives the first voltage. By detecting the voltage-dividing resistor Rw, the received key scan detection voltage analog signal can be further optimized within the preferred resolution range of the analog-to-digital converter ADC. Among them, when a physical key in the key layout corresponding to the key sub-network unit 110 is pressed, the key sub-network unit 110 outputs a voltage analog signal. At this time, the detection switch Sw switches from the normal open state to the working closed state, and transmits the received voltage analog signal to the analog-to-digital converter ADC. Conversely, when no physical key in the key layout corresponding to the key sub-network unit 110 is pressed, the detection switch Sw is in the open state, and the key sub-network unit 110 will not be scanned and detected, thereby further reducing the power consumption of the entire key detection circuit.
[0035] In some embodiments, see Figure 5As shown, the key sub-network unit 110 includes a first key sub-network sub-unit 1101, a second key sub-network sub-unit 1102, and a third key sub-network sub-unit 1103. The first end of the first key sub-network sub-unit 1101 is connected to the first end of the second key sub-network sub-unit 1102, the second end of the first key sub-network sub-unit 1101 is connected to the first end of the third key sub-network sub-unit 1103, the third end of the first key sub-network sub-unit 1101 is connected to the first end of the detection switch module 200, and the second end of the second key sub-network sub-unit 1102 is connected to the second end of the third key sub-network sub-unit 1103. When the third end of the detection switch module 200 is used to receive the first voltage ( Figure 5 (not shown), the third terminal of the second button sub-network sub-unit is grounded. When the third terminal of the detection switch module 200 is grounded, the third terminal of the second button sub-network sub-unit is used to receive the first voltage.
[0036] In some embodiments, please refer to Figure 5 As shown, the first key sub-network sub-unit includes a second number of first branch resistors (such as Figure 5 The first branch resistors are in series. The first end of the first branch resistor R1 in the first branch resistor in the series structure is connected to the first end of the second key sub-network sub-unit 1102. Figure 5 The second end of R1 to Rn) shown is connected to the first end of the next first branch resistor, for example Figure 5 The second end of the first branch resistor R1 is connected to the first end of the next first branch resistor R2. Figure 5 The second end of the resistors R1 to Rn shown in the figure is connected to the first end of the third key sub-network sub-unit 1103. The second end of the last first branch resistor Rn in the first branch resistor of the series structure is also connected to the first end of the detection switch module 200.
[0037] In some embodiments, please refer to Figure 5 and Figure 6As shown, the second button sub-network subunit 1102 includes a second branch resistor R00 and a second branch switch K00. The first end of the second branch resistor R00 is connected to the first end of the first button sub-network subunit 1101, the second end of the second branch resistor R00 is connected to the first end of the second branch switch K00, and the second end of the second branch switch K00 is connected to the second end of the third button sub-network subunit 1103. When the third end of the detection switch module 200 is used to receive the first voltage (not shown in the figure), the third end of the second branch switch K00 is grounded. When the third end of the detection switch module 200 is grounded, the third end of the second branch switch K00 is used to receive the first voltage.
[0038] In some embodiments, please refer to Figure 5 and Figure 6 As shown, the third key sub-network unit 1103 includes a second number of third branch resistors (such as Figure 5 The third branch resistors R01 to R0n) and the third branch switch (as shown Figure 5 The first end of the third branch resistor is connected to the second end of the first branch resistor (as shown in FIG. Figure 5 The first end of the third branch resistor R01 is connected to the second end of the first branch resistor R1, and the connection relationship between the third branch resistors R02 to R0n and the first branch resistors R2 to Rn is similar). The second end of the third branch resistor is connected to the first end of the third branch switch (such as Figure 5 The second end of the third branch resistor R01 is connected to the first end of the third branch switch K01, and the connection relationship between the third branch resistors R02 to R0n and the third branch switches K01 to K0n is similar). The second end of the third branch switches K01 to K0n is connected to the second end of the second button sub-network sub-unit 1102.
[0039] Wherein, the resolution digit of analog-to-digital converter ADC is greater than the above-mentioned second quantity. The digit of analog-to-digital converter (ADC) refers to the digit of the digital signal output by the analog-to-digital converter, and the digit of the analog-to-digital converter determines the resolution of the analog-to-digital converter, that is, how many discrete levels the analog signal can be discretized into. Specifically, the digit represents the binary digit of the analog-to-digital converter output digital signal. For example, a 12-bit analog-to-digital converter will generate a 12-bit binary number ranging from 000000000000 to 1111111111111, that is, 2^12 (4096) different discrete levels can be provided. The digit determines the number of discrete levels that the analog-to-digital converter can represent, thereby affecting its measurement accuracy and signal resolution, that is, the range of the number of key combinations represented in the embodiment of the present application, and the larger the digit of the analog-to-digital converter, the more physical key combinations can be identified.
[0040] Please continue reading Figure 7 , Figure 7 The detection switch module 200 includes a first number of detection switch units 2201, each of which includes at least one detection switch (e.g. Figure 7 ) and at least one detection voltage divider resistor (e.g. Figure 7 The first end of the detection switch is connected to the first end of the key switch network module, the second end of the detection switch is connected to the analog-to-digital conversion module 300, and the first end of the detection voltage divider resistor is connected to the second end of the detection switch (for example Figure 7 The first end of the detection voltage-dividing resistor Rw0 in the key switch network module 100 is connected to the second end of the detection switch Sw0), when the second end of the key switch network module 100 is used to receive the first voltage, the second end of the detection voltage-dividing resistor is grounded (for example Figure 7 The second ends of the detection voltage-dividing resistors Rw0 to Rw1 are grounded). When the second end of the key switch network module 100 is grounded, the second end of the detection voltage-dividing resistor is used to receive the first voltage ( Figure 7 not shown).
[0041] Please continue reading Figure 8 , Figure 8 This is another implementation of the detection switch module of the embodiment of the present application. The detection switch module 200 also includes a detection voltage divider resistor Rw3, and the detection switch unit 2001 includes a detection switch (for example Figure 8The first end of the detection voltage-dividing resistor Rw3 is connected to the second end of the detection switch unit 2001. When the second end of the key switch network 100 is used to receive the first voltage, the second end of the detection voltage-dividing resistor Rw3 is grounded. When the second end of the key switch network 100 is grounded, the second end of the detection voltage-dividing resistor Rw3 is used to receive the first voltage ( Figure 8 not shown).
[0042] As an exemplary embodiment, Figure 6 As shown, when the detection switch Sw is in the disconnected state, no key detection is performed, and the key switch network module 100 does not generate additional power consumption, thereby reducing the power consumption of the entire key detection circuit. When the detection switch Sw is in the closed state, if the keys corresponding to the third branch switches K01 and K02 are pressed, the third branch switches K01 and K02 will change from the disconnected state to the closed state, while the other third branch switches K03 to K0n will remain in the disconnected state. At this time, the key switch network module 100 will output a first output voltage at the first end, and the voltage value of the first output voltage is unique, that is, the voltage value of the first output voltage corresponding to any combination of different third branch switches K01 to K0n is different. The first output voltage is transmitted to the analog-to-digital converter ADC through the closed detection switch Sw, and the first output voltage is detected by the analog-to-digital converter ADC, and different code values corresponding to different voltage values can be obtained. Then, according to the different code value ranges in which the different code values are located, and according to the pre-set code value range and key combination comparison table, it can be determined that the key combination of the third branch switches K01 and K02 is pressed.
[0043] The present application embodiment also provides a chip 20, see Fig. 9 As shown, the chip 20 includes the above-mentioned detection switch module 200 and analog-to-digital conversion module 300. Chip (Integrated Circuit, IC) is also called chip, and the chip 20 can be but is not limited to SOC (System on Chip) chip, SIP (system in package) chip.
[0044] The present application embodiment also provides an electronic device 30, see Fig.10As shown, the electronic device 30 includes a device body and a chip 20 as described above, which is arranged in the device body. The electronic device 30 can be, but is not limited to, a weight scale, a body fat scale, a nutrition scale, an infrared electronic thermometer, a pulse oximeter, a human body composition analyzer, a mobile power supply, a wireless charger, a fast charger, a car charger, an adapter, a display, a USB (Universal Serial Bus) docking station, a stylus, a true wireless headset, a car central control screen, a car, a smart wearable device, a mobile terminal, and a smart home device. Smart wearable devices include, but are not limited to, smart watches, smart bracelets, and cervical massagers. Mobile terminals include, but are not limited to, smart phones, laptops, tablet computers, and POS (point of sales terminal). Smart home devices include, but are not limited to, smart sockets, smart rice cookers, smart sweepers, and smart lights.
[0045] The above are only preferred embodiments of the present application, and are not intended to limit the present application in any form. Although the present application has been disclosed as above with preferred embodiments, it is not intended to limit the present application. Any technical personnel in the field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present application. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present application without departing from the content of the technical solution of the present application are still within the scope of the technical solution of the present application.
Claims
1. A key detection circuit, characterized in that: include: at least one key switch network module; at least one detection switch module; Analog-to-digital conversion module; The first end of the key switch network module is connected to the first end of the detection switch module, and the second end of the detection switch module is connected to the first end of the analog-to-digital conversion module; When the second end of the key switch network module is grounded, the third end of the detection switch module is used to receive the first voltage; when the second end of the key switch network module is used to receive the first voltage, the third end of the detection switch module is grounded.
2. The key detection circuit according to claim 1, characterized in that: The key switch network module includes a first number of key sub-network units, and a first end of the key sub-network unit is connected to a first end of the detection switch module; When the third end of the detection switch module is used to receive the first voltage, the second end of the button sub-network unit is grounded; when the third end of the detection switch module is grounded, the second end of the button sub-network unit is used to receive the first voltage.
3. The key detection circuit according to claim 1, characterized in that: The detection switch module includes a first number of detection switch units; The first end of the detection switch unit is connected to the first end of the key switch network module, and the second end of the detection switch unit is connected to the first end of the analog-to-digital conversion module.
4. The key detection circuit according to claim 1, characterized in that: The analog-to-digital conversion module includes at least one analog-to-digital converter; The second end of the detection switch module is connected to one of the analog-to-digital converters.
5. The key detection circuit as claimed in claim 3, characterized in that: The detection switch unit comprises at least one detection switch and at least one detection voltage-dividing resistor; The first end of the detection switch is connected to the first end of the key switch network module, and the second end of the detection switch is connected to the analog-to-digital conversion module; The first end of the detection voltage-dividing resistor is connected to the second end of the detection switch; When the second end of the key switch network module is used to receive the first voltage, the second end of the detection voltage divider resistor is grounded; when the second end of the key switch network module is grounded, the second end of the detection voltage divider resistor is used to receive the first voltage.
6. The key detection circuit according to claim 3, characterized in that: The detection switch module further includes at least one detection voltage-dividing resistor, and the detection switch unit includes a detection switch; the first end of the detection voltage-dividing resistor is connected to the second end of the detection switch unit; When the second end of the key switch network module is used to receive the first voltage, the second end of the detection voltage divider resistor is grounded; when the second end of the key switch network module is grounded, the second end of the detection voltage divider resistor is used to receive the first voltage.
7. The key detection circuit according to claim 2, characterized in that: The button sub-network unit includes: a first button sub-network sub-unit, a second button sub-network sub-unit and a third button sub-network sub-unit; The first end of the first button sub-network subunit is connected to the first end of the second button sub-network subunit, the second end of the first button sub-network subunit is connected to the first end of the third button sub-network subunit, the third end of the first button sub-network subunit is connected to the first end of the detection switch module, and the second end of the second button sub-network subunit is connected to the second end of the third button sub-network subunit; When the third end of the detection switch module is used to receive the first voltage, the third end of the second button sub-network sub-unit is grounded; when the third end of the detection switch module is grounded, the third end of the second button sub-network sub-unit is used to receive the first voltage.
8. The key detection circuit according to claim 7, characterized in that: The first key sub-network sub-unit includes a second number of first branch resistors, and the first branch resistors are connected in series; A first end of a first of the first branch resistors connected in series is connected to a first end of the second button sub-network sub-unit; The second end of each of the first branch resistors in series is connected to the first end of the next first branch resistor, and the second end of each of the first branch resistors in series is also connected to the first end of the third key sub-network sub-unit; The second end of the last first branch resistor in the series-connected first branch resistors is also connected to the first end of the detection switch module.
9. The key detection circuit according to claim 7, characterized in that: The second key sub-network sub-unit includes a second branch resistor and a second branch switch; The first end of the second branch resistor is connected to the first end of the first button sub-network subunit, the second end of the second branch resistor is connected to the first end of the second branch switch, and the second end of the second branch switch is connected to the second end of the third button sub-network subunit; When the third end of the detection switch module is used to receive the first voltage, the third end of the second branch switch is grounded; when the third end of the detection switch module is grounded, the third end of the second button sub-network sub-unit is used to receive the first voltage.
10. The key detection circuit according to claim 8, characterized in that: The third button sub-network sub-unit includes a second number of third branch resistors and third branch switches; The first end of the third branch resistor is correspondingly connected to the second end of the first branch resistor, the second end of the third branch resistor is connected to the first end of the third branch switch, and the second end of the third branch switch is connected to the second end of the second button sub-network sub-unit.
11. The key detection circuit according to claim 8, characterized in that: The number of bits of resolution of the analog-to-digital conversion module is greater than the second number.
12. A chip, characterized in that: It comprises the detection switch module and the analog-to-digital conversion module as described in any one of claims 1 to 11.
13. An electronic device, characterized in that: The invention comprises a device body and the chip as claimed in claim 12 arranged in the device body.