Integrated inductance type switch chip structure and switch module

Abstract

The invention relates to an integrated inductance type switch chip structure and a switch module, the integrated inductance type switch chip structure comprises a sensing chip and an inductance coil which are packaged into a whole, the sensing chip is provided with a sensing circuit, the sensing circuit comprises a transconductance unit, an internal capacitor and a comparison unit, the two ends of the inductance coil and the two ends of the internal capacitor are connected into the transconductance unit in parallel to form an oscillator, and the comparison unit is used for outputting a switch level signal used for controlling a switch according to the oscillation amplitude of an oscillation starting signal of the oscillator. Through an advanced packaging technology, a bare chip and an inductance coil are integrated in a single chip tube shell, a high-sensitivity switch sensing chip design is realized under a small-size constraint condition, the structure can independently realize a switch sensing function without any peripheral component, meanwhile, the design complexity of a sensing circuit is reduced, and the cost is reduced. And the area of the active region of the chip is further reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of integrated circuit design, and particularly to an integrated inductive switch chip structure and a switch module. Background Art

[0002] Switch modules are widely used in various fields of daily life, such as door handles, smart watches, smart computers, etc. With the continuous improvement of system integration and the increasing reduction of size, higher requirements are put forward for the size of switch modules. However, traditional inductive switch modules need to wind inductive coils on a PCB board and are separately packaged with signal processing chips, occupying a large space. Moreover, the discrete design requires additional integration of peripheral circuits such as filter capacitors and amplifiers, which not only increases the BOM cost but also may lead to a decrease in signal stability due to differences in welding processes. Summary of the Invention

[0003] The purpose of the present invention is to provide an integrated inductive switch chip structure and a switch module, which solve the problems of large space occupation and complex sensing circuit design of traditional inductive switch modules.

[0004] To achieve the above object, the present invention provides an integrated inductive switch chip structure, including a sensing chip and an inductive coil encapsulated as a whole. A sensing circuit is provided on the sensing chip. The sensing circuit includes a transconductance unit, an internal capacitor, and a comparison unit. Both ends of the inductive coil and the internal capacitor are connected in parallel to the transconductance unit to form an oscillator. The comparison unit is used to output a switch level signal for controlling the switch according to the oscillation amplitude of the oscillation signal of the oscillator.

[0005] Optionally, the inductive coil is wound with a copper core wire with insulation.

[0006] Optionally, the inductive coil is a single-layer spiral coil.

[0007] Optionally, the line width of the inductive coil is 0.1 - 1 mm.

[0008] Optionally, the transconductance unit has a transconductance non-inverting input terminal, a transconductance inverting input terminal, a transconductance non-inverting output terminal, and a transconductance inverting output terminal. Both ends of the internal capacitor are respectively connected to the transconductance non-inverting input terminal and the transconductance inverting input terminal. Both ends of the inductive coil are respectively connected to the transconductance non-inverting input terminal and the transconductance inverting input terminal. The transconductance non-inverting input terminal is connected to the transconductance non-inverting output terminal, and the transconductance inverting input terminal is connected to the transconductance inverting output terminal.

[0009] Optionally, the comparison unit includes a first comparator and a second comparator. The first comparator is configured to recover a clock signal from the start-up signal, and the clock signal is used for dynamic control of the second comparator. The second comparator is configured to output the switching level signal according to the oscillation amplitude of the start-up signal.

[0010] Optionally, the first comparator has a first non-inverting input terminal, a first inverting input terminal, and a first output terminal. The first non-inverting input terminal is connected to the transconductance inverting output terminal, the first inverting input terminal is connected to a first reference signal, and the first output terminal is configured to input the clock signal to the second comparator. The second comparator has a second non-inverting input terminal, a second inverting input terminal, and a second output terminal. The second inverting input terminal is connected to the transconductance non-inverting output terminal, the second inverting input terminal is connected to a second reference signal, and the second output terminal is configured to output the switching level signal.

[0011] Optionally, when the oscillation amplitude of the start-up signal is greater than the voltage value corresponding to the first reference signal, the clock signal output by the first output terminal is at a high level; otherwise, the clock signal output by the first output terminal is at a low level.

[0012] When the clock signal output by the first output terminal jumps from a high level to a low level, the falling edge triggers the second comparator to perform a comparison.

[0013] When the oscillation amplitude of the start-up signal is greater than the voltage value corresponding to the second reference signal, the switching level signal output by the second output terminal is at a low level; otherwise, the switching level signal output by the second output terminal is at a high level.

[0014] Optionally, the oscillation amplitude V sen of the start-up signal satisfies the following relationship:

[0015] V sen = η × 2πL sen C × Q × I P

[0016] where η is the efficiency of the oscillator, L sen is the inductance value of the inductor coil, C is the capacitance value of the internal capacitor, Q is the quality factor of the oscillator, and I P is the load current of the oscillator.

[0017] Based on this, the present invention also provides a switch module, which includes a target metal object and the integrated inductive switch chip structure as described above. The target metal object is disposed opposite to the integrated inductive switch chip structure, and the inductance value of the inductive coil in the integrated inductive switch chip structure is positively correlated with the relative distance between the target metal object and the integrated inductive switch chip structure;

[0018] When the relative distance is less than a preset value, the switch level signal output by the integrated inductive switch chip structure is a low level; otherwise, the output switch level signal is a high level.

[0019] In the integrated inductive switch chip structure and the switch module provided by the present invention, at least the following beneficial effects are achieved:

[0020] 1) Through advanced packaging technology, the chip die and the inductive coil are integrated inside a single chip package. Under the constraint of small size, a high-sensitivity switch sensing chip design is realized. This chip structure can independently implement the switch sensing function without any peripheral components;

[0021] 2) A switch scheme based on signal amplitude sensing is proposed, which reduces the design complexity of the sensing circuit and further reduces the area of the active region of the chip. Description of the Drawings

[0022] Those of ordinary skill in the art will understand that the provided drawings are used to better understand the present invention and do not constitute any limitation to the scope of the present invention. Among them:

[0023] Figure 1 is a packaging schematic diagram of the integrated inductive switch chip structure provided by an embodiment of the present invention;

[0024] Figure 2 is a sensing circuit diagram of the integrated inductive switch chip structure provided by an embodiment of the present invention;

[0025] Figure 3 is a schematic diagram of the switch module before being pressed provided by an embodiment of the present invention;

[0026] Figure 4 is a schematic diagram of the switch module after being pressed provided by an embodiment of the present invention.

[0027] Among them,

[0028] 10 - integrated inductive switch chip structure; 20 - target metal object;

[0029] 100 - sensing chip; 110 - sensing circuit; 111 - transconductance unit; 112 - internal capacitor; 113 - first comparator; 114 - second comparator; 120 - inductive coil. Detailed implementation manners

[0030] To make the objectives, advantages and features of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that the accompanying drawings are in a very simplified form and use non-precise scales, only for the purpose of facilitating and clearly assisting in explaining the objectives of the implementation manners of the present invention. To make the objectives, features and advantages of the present invention more obvious and understandable, please refer to the accompanying drawings. It should be noted that the structures, scales, sizes, etc. shown in the drawings of this specification are only used to cooperate with the content disclosed in the specification for those skilled in this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention. Any modification of the structure, change of the proportional relationship or adjustment of the size, under the condition of being the same or similar to the effects that the present invention can produce and the objectives that can be achieved, should still fall within the scope covered by the technical content disclosed by the present invention.

[0031] As used in the present invention, the singular forms "a", "an" and "the" include plural objects unless the context clearly indicates otherwise. As used in the present invention, the term "or" is generally used in the sense of including "and / or" unless the context clearly indicates otherwise. As used in the present invention, the term "several" is generally used in the sense of including "at least one" unless the context clearly indicates otherwise. As used in the present invention, the term "at least two" is generally used in the sense of including "two or more" unless the context clearly indicates otherwise.

[0032] Please refer to Figure 1 and Figure 2 , an integrated inductive switch chip structure 10 is provided in an embodiment of the present invention, which includes a sensing chip 100 and an inductance coil 120 encapsulated as a whole. A sensing circuit 110 is disposed on the sensing chip 100. The sensing circuit 110 includes a transconductance unit 111, an internal capacitor 112 and a comparison unit. Both ends of the inductance coil 120 and the internal capacitor 112 are connected in parallel to the transconductance unit 111 to form an oscillator. The comparison unit is configured to output a switch level signal for controlling a switch according to the oscillation amplitude of the oscillation signal of the oscillator.

[0033] In this embodiment, through advanced packaging technology, the chip die and the inductance coil 120 are integrated inside a single chip package. Under the constraint of a small size, a highly sensitive switch sensing chip 100 is designed. This chip structure can independently implement the switch sensing function without any peripheral components. In addition, the comparison unit outputs a switch level signal for controlling the switch based on the oscillation amplitude of the oscillation signal, thereby realizing the control of the switch module, reducing the design complexity of the sensing circuit 110, and further reducing the area of the active region of the chip.

[0034] In this embodiment, the inductance coil 120 is wound with a copper core wire with insulation. The copper core wire has good electrical conductivity and insulation reliability, which is a better choice, but the present application is not limited thereto.

[0035] In this embodiment, the inductance coil 120 is a single-layer spiral coil, which has a small distributed capacitance and a high resonance frequency, and is more suitable for an oscillator, but the present application is not limited thereto.

[0036] In this embodiment, the wire width of the inductance coil 120 is 0.1 - 1 mm, but the present application is not limited thereto.

[0037] Please continue to refer to Figure 1 , the transconductance unit 111 has a transconductance non-inverting input terminal, a transconductance inverting input terminal, a transconductance non-inverting output terminal, and a transconductance inverting output terminal. Both ends of the internal capacitor 112 are respectively connected to the transconductance non-inverting input terminal and the transconductance inverting input terminal. Both ends of the inductance coil 120 are respectively connected to the transconductance non-inverting input terminal and the transconductance inverting input terminal. The transconductance non-inverting input terminal is connected to the transconductance non-inverting output terminal, and the transconductance inverting input terminal is connected to the transconductance inverting output terminal. In this embodiment, the transconductance unit 111 is configured to convert the input voltage signal into a current signal for driving oscillation, control the amplification multiple of the signal through the transconductance value, and jointly determine the oscillation frequency with components such as the internal capacitor 112 and the inductance coil 120 in the sensing circuit 110. At the same time, the energy storage characteristics of the inductance coil 120 and the internal capacitor 112 can also be utilized to provide energy compensation through the transconductance unit 111.

[0038] In this embodiment, the inductance coil 120 is connected to the transconductance unit 111 inside the sensing circuit 110 through a metal lead. After the sensing circuit 110 is powered on normally, the oscillator starts to oscillate at a fixed frequency f under the action of the external inductance coil 120 and the internal capacitor 112 sen , and its frequency is related to the inductance coil 120 and the internal capacitor 112, and satisfies the following relationship:

[0039]

[0040] The corresponding oscillation amplitude V sen satisfies the following relationship:

[0041] V sen = η × 2πL sen C × Q × I P

[0042] In the formula, η is the efficiency of the oscillator, L sen is the inductance value of the inductance coil 120, C is the capacitance value of the internal capacitor 112, Q is the quality factor of the oscillator, and I P is the load current of the oscillator.

[0043] According to the above oscillation amplitude formula, it can be obtained that when the inductance value in the resonant circuit changes, the corresponding oscillation amplitude also changes. Based on this, a comparison unit is introduced in the sensing circuit 110 of the present application, which is used to output a switching level signal for controlling the switch according to the oscillation amplitude of the oscillator, thereby realizing the switching control of the switch module.

[0044] Specifically, the comparison unit includes a first comparator 113 and a second comparator 114. The first comparator 113 is used to recover a clock signal from the startup signal, and the clock signal is used for the dynamic control of the second comparator 114. The second comparator 114 is used to output a switching level signal for controlling the switch according to the oscillation amplitude of the startup signal.

[0045] Further, the first comparator 113 has a first non-inverting input terminal, a first inverting input terminal and a first output terminal. The first non-inverting input terminal is connected to the transconductance inverting output terminal, the first inverting input terminal is connected to a first reference signal, and the first output terminal is used to input the clock signal to the second comparator 114. The second comparator 114 has a second non-inverting input terminal, a second inverting input terminal and a second output terminal. The second inverting input terminal is connected to the transconductance non-inverting output terminal, the second inverting input terminal is connected to a second reference signal, and the second output terminal is used to output the switching level signal.

[0046] It should be noted that the oscillation signal itself belongs to a sine signal. For the convenience of comparison, the sine signal obtained each time needs to ensure a fixed phase. Therefore, the clock signal generated by the first comparator 113 is to ensure the phase consistency.

[0047] In this embodiment, when the oscillation amplitude of the startup signal is greater than the voltage value V corresponding to the first reference signal ref1 the clock signal output by the first output terminal is at a high level. On the contrary, the clock signal output by the first output terminal is at a low level;

[0048] When the clock signal output by the first output terminal jumps from a high level to a low level, the falling edge triggers the second comparator to make a comparison;

[0049] When the oscillation amplitude of the startup signal is greater than the voltage value V corresponding to the second reference signal ref2 the switching level signal output by the second output terminal is at a low level. On the contrary, the switching level signal output by the second output terminal is at a high level.

[0050] In this embodiment, when the clock signal output at the first output terminal is at a low level, the second comparator 114 enters the latching state. At this time, the result of the switch level signal is always the output result of the second comparator 114 last time until a new comparison result is generated by the second comparator 114 next time. When the clock signal output at the first output terminal jumps from a low level to a high level, the output result of the second comparator 114 does not change, and the input terminal of the second comparator 114 is reset. When the clock signal output at the first output terminal jumps from a high level to a low level, the falling edge triggers the second comparator to perform a comparison.

[0051] It should be noted that whether it is the high / low level signal output at the first output terminal or the high / low level signal output at the second output terminal can be adjusted according to the circuit design and trigger control. For example, when the oscillation amplitude of the oscillation signal is greater than the voltage value V corresponding to the second reference signal ref2 , the second output terminal outputs a low level signal, triggering the switch module to switch from the closed state to the open state.

[0052] Based on this, in combination with Figure 3 and Figure 4 , an embodiment of the present invention further provides a switch module, including a target metal object 20 and the integrated inductive switch chip structure 10 as above. The target metal object 20 is disposed opposite to the integrated inductive switch chip structure 10. The inductance value of the inductor coil 120 in the integrated inductive switch chip structure 10 is positively correlated with the relative distance between the target metal object 20 and the integrated inductive switch chip structure 10;

[0053] When the relative distance is less than a preset value, the switch level signal output by the integrated inductive switch chip structure 10 is at a low level; otherwise, the output switch level signal is at a high level.

[0054] For example, taking a typical application of this switch module as an example, the target metal object 20 is a button and is placed above the integrated inductive switch chip structure 10. When the button is pressed under the influence of external factors (such as a human hand), the magnetic field generated by the alternating current signal in the inductor coil 120 will generate eddy currents inside the target metal object 20. The magnetic field generated by these eddy currents will in turn act on the inductor coil 120. Ultimately, as a result, the inductance value corresponding to the inductor coil 120 changes, and this change in the inductance value will affect the oscillation amplitude of the oscillation signal, thereby affecting the switch state of the switch module. In this embodiment, when the relative distance between the target metal object 20 and the integrated inductive switch chip structure 10 is less than the preset value, the integrated inductive switch chip structure 10 outputs a high level signal, and the switch module switches to the open state; otherwise, the integrated inductive switch chip structure 10 outputs a low level signal, and the switch module switches to the closed state.

[0055] In summary, the embodiments of the present invention provide an integrated inductive switch chip structure and a switch module. Through advanced packaging technology, the chip die and the inductor coil 120 are integrated inside a single chip package. Under the constraint of small size, a highly sensitive switch sensing chip 100 is designed. This chip structure can independently implement the switch sensing function without any peripheral components. In addition, the comparison unit outputs a switch level signal for controlling the switch based on the oscillation amplitude of the oscillation signal, thereby realizing the control of the switch module, reducing the design complexity of the sensing circuit 110, and further reducing the area of the active region of the chip.

[0056] The above description is only a description of the preferred embodiments of the present invention and does not limit the scope of the present invention in any way. Any changes and modifications made by those of ordinary skill in the art of the present invention based on the above disclosure belong to the protection scope of the present invention. Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations fall within the scope of the present invention and its equivalent technologies, the present invention is also intended to include these modifications and variations.

Claims

1. An integrated inductive switch chip structure, characterized in that, It includes a sensing chip and an inductance coil encapsulated as a whole. A sensing circuit is provided on the sensing chip. The sensing circuit includes a transconductance unit, an internal capacitor, and a comparison unit. The two ends of the inductance coil and the internal capacitor are connected in parallel to the transconductance unit to form an oscillator. The comparison unit is used to output a switching level signal for controlling a switch according to the oscillation amplitude of the oscillation signal of the oscillator.

2. The integrated inductive switch chip structure according to claim 1, wherein, The inductance coil is wound with a copper core wire with insulation.

3. The integrated inductive switch chip structure according to claim 1, wherein The inductance coil is a single-layer spiral coil.

4. The integrated inductive switch chip structure according to claim 1, wherein The line width of the inductance coil is 0.1 - 1 mm.

5. The integrated inductive switch chip structure according to claim 1, characterized in that, The transconductance unit has a transconductance non-inverting input terminal, a transconductance inverting input terminal, a transconductance non-inverting output terminal, and a transconductance inverting output terminal. The two ends of the internal capacitor are respectively connected to the transconductance non-inverting input terminal and the transconductance inverting input terminal. The two ends of the inductance coil are respectively connected to the transconductance non-inverting input terminal and the transconductance inverting input terminal. The transconductance non-inverting input terminal is connected to the transconductance non-inverting output terminal, and the transconductance inverting input terminal is connected to the transconductance inverting output terminal.

6. The integrated inductive switch chip structure according to claim 5, characterized in that The comparison unit includes a first comparator and a second comparator. The first comparator is used to recover a clock signal from the oscillation signal. The clock signal is used for the dynamic control of the second comparator. The second comparator is used to output the switching level signal according to the oscillation amplitude of the oscillation signal.

7. The integrated inductive switch chip structure according to claim 6, characterized in that, The first comparator has a first non-inverting input terminal, a first inverting input terminal, and a first output terminal. The first non-inverting input terminal is connected to the transconductance inverting output terminal. The first inverting input terminal is connected to a first reference signal. The first output terminal is used to input the clock signal to the second comparator. The second comparator has a second non-inverting input terminal, a second inverting input terminal, and a second output terminal. The second inverting input terminal is connected to the transconductance non-inverting output terminal. The second inverting input terminal is connected to a second reference signal. The second output terminal is used to output the switching level signal.

8. The integrated inductive switch chip structure according to claim 7, characterized in that, When the oscillation amplitude of the oscillation signal is greater than the voltage value corresponding to the first reference signal, the clock signal output by the first output terminal is at a high level. Conversely, the clock signal output by the first output terminal is at a low level. When the clock signal output by the first output terminal jumps from a high level to a low level, the falling edge triggers the second comparator to perform a comparison. When the oscillation amplitude of the oscillation signal is greater than the voltage value corresponding to the second reference signal, the switching level signal output by the second output terminal is at a low level. Conversely, the switching level signal output by the second output terminal is at a high level.

9. The integrated inductive switch chip structure according to claim 1 or 8, characterized in that, The oscillation amplitude V of the oscillation signal sen satisfies the following relational expression: V sen = η × 2πL sen C × Q × I P Where η is the efficiency of the oscillator, L sen is the inductance value of the inductor coil, C is the capacitance value of the internal capacitor, Q is the quality factor of the oscillator, I P is the load current of the oscillator.

10. A switch module, characterized in that, It includes a target metal object and the integrated inductive switch chip structure according to any one of claims 1 - 9. The target metal object is disposed opposite to the integrated inductive switch chip structure. The inductance value of the inductance coil in the integrated inductive switch chip structure is positively correlated with the relative distance between the target metal object and the integrated inductive switch chip structure. When the relative distance is less than a preset value, the switching level signal output by the integrated inductive switch chip structure is at a low level. Conversely, the output switching level signal is at a high level.

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