CN115493626A - Sensing sensitivity testing device and method, and capacitance sensing equipment - Google Patents

Abstract

A sensing sensitivity testing device and method, and a capacitive sensing device, wherein the device comprises: a sensing sensitivity capacitor array and a sensing sensor channel selection switch group coupled between a sensing channel to be tested and the sensing sensitivity capacitor array; the sensing sensor channel selection switch group is used for selecting the sensing channel to be tested; the sensing sensitivity capacitor array comprises one or more sensitivity capacitors and a capacitance selection switch group, wherein the capacitance selection switch group is used for controlling the size of the sensitivity capacitor connected to the sensing channel. The invention can realize more flexible and fine sensitivity test for the sensing sensitivity test.

Description

Sensing sensitivity test device and method, capacitive sensing device

technical field

The invention relates to the field of capacitive proximity sensor equipment, in particular to a sensing sensitivity testing device and method, and also to a capacitance sensing device.

Background technique

Capacitive sensors are more and more widely used in personal computers, multimedia players, game consoles, consumer electronics, mobile communication equipment, home electronics and other fields. Sensing sensitivity and implementation cost of capacitive sensing devices are factors that many electronic systems pay attention to.

As shown in FIG. 1 , the traditional sensing sensitivity test method is to connect the pad 11 of the sensor channel of the capacitive sensing device 10 to a capacitive sensor 20 of a suitable size through a metal connection outside the capacitive sensing device 10, Then use objects such as copper pillars and fingers to touch/close to the capacitive sensor 20, observe the magnitude of the signal sensed by the capacitive sensing device 10, or observe whether the capacitive sensing device 10 outputs valid sensing results, so as to This is used to test the sensing sensitivity.

The traditional sensing sensitivity test method has the following disadvantages:

(1) The accuracy of this test method is relatively low, and the sensing sensitivity of the sensing device cannot be accurately measured. Since the capacitance increased by objects such as copper pillars and fingers close to the capacitive sensor is a large value (for example, 0.4pF), it can only measure the signal strength under this capacitance increment, and it is difficult to test the finer Sensing sensitivity at granular capacitance increments (eg, 0.1 pF).

(2) This test method lacks flexibility, which is mainly reflected in two aspects. First, it is impossible to fine-tune the increased capacitance during testing, such as measuring the signal change caused by every 0.1pF increase in capacitance. Second, since the sensing channel of the capacitive sensing device needs to be coupled to a capacitive sensor of a certain size, the sum of the capacitive sensor and the parasitic capacitance of the sensing channel itself is equivalent to the "background capacitance", but if you want to measure Sensing sensitivities under different "background capacitances" require re-creation of test devices (such as PCB boards), which is very inflexible.

(3) This method increases the test cost. In order to test the sensing sensitivity, it is necessary to make a special test device (such as a PCB board), and it is also necessary to use objects such as copper pillars to assist the test, which increases the test cost.

Contents of the invention

Embodiments of the present invention provide a sensing sensitivity testing device and method to improve the testing accuracy and flexibility of capacitance sensing equipment.

For this reason, the embodiment of the present invention provides following technical scheme:

A sensing sensitivity test device for capacitive sensing equipment, the device comprising: a sensing sensitivity capacitance array, and a sensing sensor coupled between a sensing channel to be tested and the sensing sensitivity capacitance array Channel selection switch group;

The sensing sensor channel selection switch group is used to select the sensing channel to be tested;

The sensing sensitivity capacitance array includes one or more sensitivity capacitances and a capacitance selection switch group, and the capacitance selection switch group is used to control the size of the sensitivity capacitance connected to the sensing channel.

Optionally, the capacitor selection switch group is coupled between the sensitivity capacitor and the sensing channel switch group.

Optionally, the capacitance selection switch group includes one or more capacitance selection switches, and each capacitance selection switch is connected to one of the sensitivity capacitances.

Optionally, the sensing sensor channel selection switch group includes one or more channel selection switches, and each channel selection switch connects or disconnects a sensing channel to be tested.

Optionally, both the sensing sensor channel selection switch group and the sensing sensitivity capacitive array are integrated in the capacitive sensing device.

Optionally, the device further includes a parasitic capacitance of the sensing channel itself.

A capacitive sensing device, the device includes a capacitive sensing circuit, a switch circuit respectively coupled to the capacitive sensing circuit and a sensing channel to be tested, and the sensing sensitivity testing device as described above.

A sensing sensitivity testing method, said method comprising:

Select the sensing channels to be tested in turn, and start the capacitive sensing device for capacitive sensing;

Set the size of the sensitivity capacitor connected to the sensing channel, and obtain the capacitance sensing value through the capacitance sensing process;

Sequentially changing the size of the sensitivity capacitors connected to the sensing channel, and obtaining capacitance sensing values through the capacitance sensing process, until all the sensitivity capacitors to be tested have been connected and the test is completed.

Optionally, the selection of the sensing channel to be tested includes:

Select the sensing channel to be tested through the configured sensing sensor channel selection switch group.

Optionally, the changing the size of the sensitivity capacitor connected to the sensing channel includes:

The size of the sensitivity capacitance connected to the sensing channel is changed by configuring a sensing sensitivity capacitance array including a capacitance selection switch group and a sensitivity capacitance.

The sensing sensitivity testing device and method provided by the embodiments of the present invention utilize a sensing sensitivity capacitor array and a sensing sensor channel selection switch group to realize a more flexible and refined sensitivity test for sensing sensitivity testing. Among them, the size of each sensitivity capacitor in the sensing sensitivity capacitor array can be set according to the sensitivity requirements of the capacitance sensing device. By controlling the state of the capacitor selection switch in the sensitivity capacitor array, multi-level sensitivity capacitor access can be realized, so that Sensitivity testing is more flexible. In addition, capacitive components of different sizes can be flexibly coupled to the outside of the capacitive sensing device according to the test requirements, which facilitates the sensing channel to access different external capacitors without the need to couple capacitive sensors of a specific size, so the test is more flexible and convenient .

The capacitance sensing device provided by the embodiment of the present invention integrates the sensing sensor channel selection switch group and the sensing sensitivity capacitance array of the sensing sensitivity test device into the device, and can be used in the capacitance sensing device according to the test requirements The external flexible coupling of capacitive components of different sizes facilitates the sensing channel to access different external capacitors to achieve sensing sensitivity tests under different "background capacitances", without the need to couple capacitive sensors of specific sizes, so the test is more convenient Flexible and convenient.

Description of drawings

FIG. 1 is a schematic structural diagram of a capacitive sensing device in the prior art.

Fig. 2 is a schematic structural diagram of a sensing sensitivity testing device according to an embodiment of the present invention.

Fig. 3 is a schematic diagram of testing a sensing channel with a sensing sensitivity testing device according to an embodiment of the present invention.

4 is a schematic structural diagram of a capacitive sensing device according to an embodiment of the present invention;

FIG. 5 is a schematic flowchart of a sensing sensitivity testing method according to another embodiment of the present invention.

FIG. 6 is a schematic diagram of a sensing sensitivity curve according to another embodiment of the present invention.

FIG. 7 is a schematic diagram of a sensing sensitivity curve according to another embodiment of the present invention.

detailed description

In order to make the above objects, features and beneficial effects of the present invention more comprehensible, specific embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings.

The following description sets forth numerous specific details, such as examples of particular systems, components, methods, etc., in order to provide a better understanding of several embodiments of the invention. It will be apparent, however, to one skilled in the art that at least some embodiments of the invention may be practiced without these specific details. In other instances, well-known components or methods have not been described in detail or presented in simple block diagram format in order to avoid unnecessarily obscuring the present invention. Accordingly, the specific details set forth are exemplary only. Particular implementations may vary from these exemplary details and still be contemplated within the scope of the invention.

Embodiments of the present invention provide a sensing sensitivity testing device for capacitance sensing equipment, which can accurately measure the sensing sensitivity of the sensing equipment, and effectively improve the testing accuracy and flexibility of the capacitance sensing equipment.

As shown in FIG. 2, in one embodiment of the present invention, the sensing sensitivity testing device 100 includes: a sensing sensitivity capacitor array 120, and a sensor coupled between the sensing channel to be tested and the sensing sensitivity capacitor array 120. Sensing sensor channel selection switch group 110 . in:

The sensing sensor channel selection switch group 110 is used to select the sensing channel to be tested, and specifically may include one or more channel selection switches, and each channel selection switch connects or disconnects a sensing channel to be tested.

The sensing sensitivity capacitor array 120 includes one or more sensitivity capacitors and a capacitor selection switch group, and the capacitor selection switch group is used to control the size of the sensitivity capacitor connected to the sensing channel. As shown in Figure 2, the capacitance selection switch group is coupled between the sensitivity capacitor and the sensing channel switch group, and may include one or more capacitance selection switches, and each capacitance selection switch is connected to one of the sensitivity capacitance.

Further, the sensing sensitivity capacitor array 120 also includes the parasitic capacitance of the sensing channel itself, such as capacitors C _p1 , C _p2 , . . . , C _pn in FIG. 2 .

When testing the sensing sensitivity of the sensing channel, it is necessary to couple the sensing channel of the capacitive sensing device to a capacitive sensor or capacitive element of a certain size, such as the capacitive element 140 coupled to different sensing channels as shown in FIG. 3 , 150, ..., 160. The parasitic capacitance of the capacitive sensor or capacitive element, as well as the sensing channel itself, corresponds to the "background capacitance". The sensing sensor channel selection switch group 110 is used to select the sensing channel to be tested, for example, when testing the sensing sensitivity of the sensing channel 0, the channel selection switch coupled with the sensing channel 0 in the switch group 110 is closed , while the other channel selection switches in the sensing sensor channel selection switch group 110 are all turned off. The sensing sensitivity capacitor array 120 includes one or more sensitivity capacitors, and a capacitor selection switch group connected to the sensitivity capacitors. When testing the sensitivity, the size of the sensitivity capacitor connected to the sensing channel is changed by controlling the state of the capacitor selection switch group of the sensitivity capacitor array 120 , so as to obtain the magnitude of the sensing signal. For example, the sensing sensitivity capacitor array 120 includes 16 sensitivity capacitors and 16 capacitor selection switches, and each sensitivity capacitor is 0.1 pF. If one of the capacitance selection switches is closed, the sensitivity capacitance connected to the sensing channel is 0.1pF; if two of the capacitance selection switches are closed, the sensitivity capacitance connected to the sensing channel is 0.2pF; and so on. The external capacitances 140 , 150 , 160 coupled to each sensing sensor channel and the parasitic capacitance of each sensing channel constitute the background capacitance of each sensing channel.

The size of each sensitivity capacitor in the sensing sensitivity capacitor array 120 can be set according to the sensitivity requirements of the sensing device, so the sensing sensitivity testing device proposed by the present invention can realize more detailed sensitivity testing. By controlling the state of the capacitor selection switch in the sensitivity capacitor array 120, multi-level sensitivity capacitor access can be realized, making the sensitivity test more flexible. In addition, capacitive components of different sizes can be flexibly coupled to the outside of the capacitive sensing device according to the test requirements, which facilitates the sensing channel to access different external capacitors without the need to couple capacitive sensors of a specific size, so the test is more flexible and convenient .

It should be noted that, in practical applications, the above-mentioned sensing sensitivity test device can be independent of the capacitance sensing device, or the sensing sensor channel selection switch group 110 and the sensing sensitivity capacitance array 120 can be integrated in a capacitance sensing device. The inside of the sensing device is not limited in this embodiment of the present invention.

By adopting the above method of integrating the sensing sensor channel selection switch group 110 and the sensing sensitivity capacitor array 120 inside the capacitive sensing device, there are less requirements for external components of the capacitive sensing device , can reduce the test cost.

Correspondingly, the embodiment of the present invention also provides a capacitive sensing device. As shown in FIG. The sensing channel is coupled to the switch circuit 170 and the aforementioned sensing sensitivity testing device.

Using the capacitive sensing device can realize a more refined sensitivity test, and by controlling the state of the capacitor selection switch in the sensitivity capacitor array 120 , multi-level sensitivity capacitor access can be realized, making the sensitivity test more flexible. In addition, capacitive components of different sizes can be flexibly coupled to the outside of the capacitive sensing device according to test requirements, so that the sensing channel can be connected to different external capacitors, so as to realize the sensing sensitivity test under different background capacitances without coupling A capacitive sensor of a specific size, so it is more flexible and convenient to test.

FIG. 5 is a schematic flowchart of a sensing sensitivity testing method according to another embodiment of the present invention. Sensing sensitivity test method comprises the steps:

Step S1, selecting the sensing channel to be tested, and starting the capacitive sensing device for capacitive sensing;

Step S2, setting the size of the sensitivity capacitor connected to the sensing channel;

Step S3, acquiring a capacitive sensing value through a capacitive sensing process;

Step S4, judging whether all the sensitivity capacitors to be tested have been connected and completed the test; if yes, execute step S5; otherwise, execute step S2;

Repeat the above step S2 to step S3 until all the sensitivity capacitors to be tested have been connected and the test is completed.

Step S5, judging whether all the sensing channels have been tested. If not, execute step S1 to select a new sensing channel for testing; if yes, then end the testing.

In the above step S1, the sensing channel to be tested can be selected through the configured sensing sensor channel selection switch group; The sensitivity capacitance connected to the sensing channel. For specific configuration and selection methods, refer to the description in the foregoing embodiments of the sensing sensitivity testing device of the present invention, and details are not repeated here.

It should be noted that the "capacitance sensing value" described in the embodiments of the present application is a broad concept, not limited to refer to the specific value of the capacitance of the sensing channel, but also includes the capacitance sensing device will sense the channel Capacitors convert digital or analog signals.

FIG. 6 is a schematic diagram of a sensing sensitivity curve according to another embodiment of the present invention. In the sensing sensitivity curve 300, the abscissa represents the sensitivity capacitance connected to the sensing channel by configuring the switch state in the sensing sensitivity capacitor array 120, and the ordinate represents the capacitance value sensed by the sensing channel size. For example, when the sensitivity capacitance connected to the sensing channel is 0, the capacitive sensing value of the channel is C0 (this value represents the background capacitance of the sensing channel); when the sensitivity capacitance connected to the sensing channel When it is 0.1pF, the capacitive sensing value of the channel is C1 (this value represents the sum of background capacitance and sensitivity capacitance of the sensing channel), and so on. That is, when the capacitance of the channel increases by 0.1 pF, the capacitance sensing value sensed by the capacitance sensing device in the channel increases (C1-C0). In a specific implementation, the size of each sensitivity capacitor in the sensing sensitivity capacitor array 120 , the number of capacitors, and the change range of the sensitivity capacitor in each step can be adjusted according to the test requirements, which are not limited in the present invention.

FIG. 7 is a schematic diagram of a sensing sensitivity curve according to another embodiment of the present invention. In the sensing sensitivity curve 400, the abscissa represents the sensitivity capacitance connected to the sensing channel by configuring the switch state in the sensing sensitivity capacitor array 120, and the ordinate represents the capacitance value sensed by the sensing channel size. For example, when the sensitivity capacitance connected to the sensing channel is 0, the capacitive sensing value of the channel is C0 (this value represents the background capacitance of the sensing channel); when the sensitivity capacitance connected to the sensing channel When it is 0.1pF, the capacitive sensing value of the channel is C1 (this value represents the sum of background capacitance and sensitivity capacitance of the sensing channel), and so on. That is, when the capacitance of the channel increases by 0.1 pF, the capacitance sensing value sensed by the capacitance sensing device in the channel decreases (C0-C1). In a specific implementation, the size of each sensitivity capacitor in the sensing sensitivity capacitor array 120 , the number of capacitors, and the change range of the sensitivity capacitor in each step can be adjusted according to the test requirements, which are not limited in the present invention.

Although the present invention is disclosed above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, so the protection scope of the present invention should be based on the scope defined in the claims.

Claims (10)

1. A sensing sensitivity testing apparatus for a capacitive sensing device, the apparatus comprising: a sensing sensitivity capacitive array, and a sensing sensor channel selection switch set coupled between a sensing channel to be tested and the sensing sensitivity capacitive array;

the sensing sensor channel selection switch group is used for selecting the sensing channel to be tested;

the sensing sensitivity capacitor array comprises one or more sensitivity capacitors and a capacitance selection switch group, wherein the capacitance selection switch group is used for controlling the size of the sensitivity capacitor connected to the sensing channel.

2. The apparatus of claim 1, wherein the bank of capacitance selection switches is coupled between the sensitivity capacitance and the bank of sense channel switches.

3. The apparatus of claim 2, wherein the bank of capacitance selection switches comprises one or more capacitance selection switches, each capacitance selection switch coupled to one of the sensitivity capacitors.

4. The apparatus of claim 1, wherein the sensing sensor channel selection switch set comprises one or more channel selection switches, each channel selection switch connecting or disconnecting one sensing channel to be tested.

5. The apparatus of claim 1, wherein the sensing sensor channel selection switch bank and the sensing sensitivity capacitance array are both integrated within the capacitance sensing device.

6. The apparatus of any of claims 1 to 5, further comprising a parasitic capacitance of the sensing channel itself.

7. A capacitive sensing apparatus, comprising a capacitive sensing circuit, a switching circuit coupled to the capacitive sensing circuit and a sensing channel to be tested, respectively, and a sensing sensitivity test device according to any one of claims 1 to 6.

8. A method of sensing sensitivity testing, the method comprising:

sequentially selecting a sensing channel to be detected, and starting capacitance sensing equipment to sense capacitance;

setting the size of a sensitivity capacitor accessed to the sensing channel, and acquiring a capacitance sensing value through a capacitance sensing process;

and sequentially changing the size of the sensitivity capacitor accessed to the sensing channel, and acquiring a capacitance sensing value through a capacitance sensing process until all the sensitivity capacitors to be tested are accessed and the test is completed.

9. The method of claim 8, wherein selecting the sensing channel to be tested comprises:

and selecting the sensing channel to be tested by the configured sensing sensor channel selection switch group.

10. The method of claim 8 or 9, wherein the varying the magnitude of the sensitivity capacitance coupled into the sensing channel comprises:

and changing the size of the sensitivity capacitance accessed to the sensing channel by a configured sensing sensitivity capacitance array comprising a capacitance selection switch group and the sensitivity capacitance.

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