A three-in-one sensor for in-ear headphones

Abstract

This invention discloses a three-in-one sensor for in-ear headphones, comprising: a substrate; a bare die disposed on the top of the substrate, the bare die including a differential delay chain, a microprocessor, and a power and clock management unit, the differential delay chain being electrically connected to the microprocessor, the microprocessor being electrically connected to the power and clock management unit, a pin frame disposed at the top edge of the substrate, and further including pins, the pins being disposed on the top of the substrate through the pin frame. This three-in-one sensor for in-ear headphones, through a highly stable internal reference discharge circuit, absoluteifies the relative diffusion time, thereby quantizing the discharge circuit composed of the external capacitor under test and the internal reference resistor, realizing high-speed, low-power multi-channel capacitance measurement.

Description

Technical Field

[0001] This invention relates to the field of in-ear headphone technology, specifically to a three-in-one sensor for in-ear headphones. Background Technology

[0002] The interaction methods for in-ear headphones mainly include swipe control and pressure-sensitive touch control.

[0003] Slide control primarily relies on the change in capacitance caused by the user's finger moving from plate A to plate B, or the movement in the opposite direction, such as... Figure 7 As shown in Figure a, capacitive sliding control is simple in principle, easy to implement, and has extremely low power consumption. However, it is highly susceptible to interference from external environmental factors, especially rainy or foggy weather, sweat, or malfunctions caused by other parts of the body. From a circuit perspective, capacitance measurement requires sampling via an analog-to-digital converter (ADC) and processing by a microprocessor. Its main functional modules are as follows: Figure 7 As shown in b.

[0004] Pressure-sensitive touch control primarily employs the principle of piezoresistive strain gauges. The front-end sensitive element C, typically a Wheatstone bridge, is implemented using flexible materials or MEMS technology. Sampling and digital processing are then completed by the back-end conditioning circuit D. Figure 8 As shown in Figure a, the principle of piezoresistive strain gauge pressure-sensitive touch control is very mature and has been used in the weighing field for decades. However, its disadvantages are also quite obvious: processing accuracy, including dimensional accuracy and uniformity, is highly dependent on the equipment, resulting in large inconsistencies; installation process, especially glue overflow during welding installation, can cause strain gauge failure; due to the characteristics of flexible materials, the temperature range is relatively narrow, and performance degrades significantly below zero degrees Celsius; due to the characteristics of MEMS technology, the product has poor drop resistance and cannot be ultrasonically cleaned; at least one sensitive front-end and one back-end conditioning chip are required, resulting in a large PCB size; the linearity regression coefficient of the solution is significantly affected by materials, structure, and installation, generally below 97%; the system power consumption of this solution is severely limited by the design of the analog-to-digital converter, typically in the milliampere (mA) range, using piezoresistive strain gauges, or typical Wheatstone bridge full-bridge structures such as... Figure 8 As shown in b, the functional modules of the pressure-sensitive touch system based on the Wheatstone bridge are as follows: Figure 8 As shown in c.

[0005] The principle of capacitive wear detection is similar to that of capacitive sliding control. However, it only requires a single capacitor plate to detect whether the headphones are being worn.

[0006] In summary, to implement capacitive wear detection, capacitive sliding control, and pressure-sensitive touch control in in-ear headphones, these functions are crucial for power consumption control and user experience. Current mainstream solutions require at least 3-4 components (chips): a multi-channel capacitance measurement chip for capacitive wear detection and capacitive sliding control; a piezoresistive strain gauge sensitive front-end for sensing user pressure input; a piezoresistive strain gauge back-end conditioning chip for sampling and processing pressure input; and an external or internal (capacitance measurement chip or piezoresistive strain gauge back-end conditioning chip integrated) microprocessor for signal processing. The chipset required for these three functions includes... Figure 9 As shown, the existing three-in-one sensor for in-ear headphones suffers from slow capacitance measurement speed and high power consumption. Summary of the Invention

[0007] The purpose of this invention is to provide a three-in-one sensor for in-ear headphones, so as to solve the problems of slow capacitance measurement speed and high power consumption of existing three-in-one sensors for in-ear headphones mentioned in the background art.

[0008] To achieve the above objectives, the present invention provides the following technical solution: a three-in-one sensor for in-ear headphones, comprising:

[0009] substrate;

[0010] A bare die is disposed on top of the substrate. The bare die includes a differential delay chain, a microprocessor, and a power and clock management unit. The differential delay chain is electrically connected to the microprocessor, and the microprocessor is electrically connected to the power and clock management unit.

[0011] Preferably, a pin frame is provided at the top edge of the substrate.

[0012] Preferably, it also includes pins, which are disposed on top of the substrate via the pin frame.

[0013] Preferably, a connecting key is evenly distributed at the top edge of the bare die, and a wire is provided on the top of the connecting key. The end of the wire away from the bare die is connected to the pin.

[0014] Preferably, the die further includes an internal discharge circuit, a storage area, and an interface circuit;

[0015] The internal discharge circuit is electrically connected to the differential delay chain;

[0016] The storage area is electrically connected to the microprocessor;

[0017] The interface circuit is electrically connected to the microprocessor.

[0018] Preferably, it further includes a packaging body disposed on top of the substrate, the packaging body covering the outside of the die and the pin.

[0019] Compared with the prior art, the beneficial effects of the present invention are: the three-in-one sensor of this in-ear headphone, through a highly stable internal reference discharge circuit, absolutizes the relative diffusion time, thereby quantifying the discharge circuit composed of the external capacitor under test and the internal reference resistor, and realizing high-speed, low-power multi-channel capacitance measurement. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of the present invention;

[0021] Figure 2 This is a side view of the present invention;

[0022] Figure 3 This is a block diagram of the absolute quantization processing system of the present invention;

[0023] Figure 4 This is a flowchart of the differential delay chain circuit relative to the quantized ion diffusion time of the present invention;

[0024] Figure 5 This is a schematic block diagram of the three-in-one device for wearing, sliding, and pressure-sensitive touch control of the present invention;

[0025] Figure 6 This is a schematic diagram of a single chain of the differential delay chain of the present invention;

[0026] Figure 7 This is a schematic diagram of the main functional modules of the capacitive sliding control and capacitance measurement circuit of the present invention;

[0027] Figure 8 This is a functional block diagram of the piezoresistive strain gauge type pressure-sensitive touch control, Wheatstone full-bridge piezoresistive strain gauge, and pressure-sensitive touch system of the present invention;

[0028] Figure 9 This is a schematic block diagram of the chipset for the present invention, which includes three functions: capacitive wear, sliding control, and pressure-sensitive touch control.

[0029] In the diagram: 100 substrate, 200 die, 210 connector, 220 wire, 300 pin, 400 package body. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] This invention provides a three-in-one sensor for in-ear headphones, integrating capacitive wearing, sliding control, and pressure-sensitive touch control into a single-chip solution. It measures the effect of stress and strain on the diffusion rate of N-type and P-type trench ions on a silicon substrate using a differential delay chain for relatively high-precision measurement (hundreds of picoseconds). The stress-strain-relative diffusion time is then linearized in the back-end processor to obtain the user-inputted stress value. Furthermore, a highly stable internal reference discharge circuit absolutizes the relative diffusion time, quantizing the discharge circuit composed of the external capacitor under test and the internal reference resistor. This enables high-speed, low-power multi-channel capacitance measurement. Compared to current mainstream solutions, the single-chip solution of this application has at least the following advantages:

[0032] Single-chip: PCB size reduced by 60-90%;

[0033] Low power consumption: Overall power consumption is reduced from milliamperes (mA) to tens of microamperes (μA), a reduction of more than 90%;

[0034] High reliability: Manufactured using standard CMOS technology, eliminating the need for coating processes required for flexible material piezoresistive strain gauges, resulting in higher reliability and stability;

[0035] High performance: Stable temperature characteristics and a wider temperature range (-40 to 85°C). Furthermore, the linearity regression coefficient can reach up to 99.91%.

[0036] Costs are more controllable;

[0037] Please see Figure 1 It includes: substrate 100, die 200, pins 300 and package body 400;

[0038] A pin frame is provided at the top edge of the substrate 100. A die 200 is disposed on the top of the substrate 100. The die 200 includes a differential delay chain, a microprocessor, and a power and clock management unit. The differential delay chain is electrically connected to the microprocessor, and the microprocessor is electrically connected to the power and clock management unit. Connecting keys 210 are uniformly disposed at the top edge of the die 200. A wire 220 is disposed on the top of the connecting key 210. The end of the wire 220 away from the die 200 is connected to the pin 300. The die 200 also includes an internal discharge circuit, a storage area, and an interface circuit. The internal discharge circuit is electrically connected to the differential delay chain, the storage area is electrically connected to the microprocessor, and the interface circuit is electrically connected to the microprocessor. The pin 300 is disposed on the top of the substrate 100 through the pin frame. A package 400 is disposed on the top of the substrate 100 and covers the outside of the die 200 and the pin 300.

[0039] The differential delay chain array in this application is as follows: Figure 6 As shown, this is used to relatively quantify the ion diffusion rates of N-type and P-type trenches in silicon substrates;

[0040] The stress input by the user is transmitted to the chip package through the pressure-sensitive touch area on the earphone stem. Regardless of whether a substrate or lead frame is used, the stress will be concentrated on the centrally located die, thereby causing strain on the silicon substrate. Figure 1 This is a schematic diagram of packaging using a substrate. Figure 2 This is a schematic diagram of a package using a metal lead frame.

[0041] Strain on the silicon substrate causes a change in the ion diffusion rate. The built-in microprocessor provides start and stop signals, and the interval between the start and stop signals is controlled by the internal clock frequency division. At the same time, the number of differential delay chain units through which the signal passes is accumulated. By comparing the accumulated number under different stress and strain conditions, the stress-ion diffusion time can be relatively quantified.

[0042] The specific workflow is as follows: Figure 4 As shown,

[0043] Assuming the preset time after clock division is T, in picoseconds, and the cumulative delay chain unit number under no external stress or strain is N, in units;

[0044] The cumulative number of delay chain elements under external stress and strain is N', in units of ;

[0045] By linearizing the relationship function between external stress F and ΔT, the numerical value of the external stress can be obtained from ΔT, where ΔT is as follows:

[0046]

[0047] Assuming that external stresses F1 and F2 affect the measured ion diffusion time differences ΔT1 and ΔT2 as follows:

[0048] F1→ΔT1

[0049] F2→ΔT2

[0050] The functional relationship between external stress F and ΔT can be obtained through two-point calibration as follows:

[0051]

[0052]

[0053] Where k is the slope of the first-order function, which is dimensionless.

[0054] The above process relatively quantifies the ion diffusion time of the N-channel and P-channel in the silicon substrate caused by stress and strain. If the relatively quantized time can be absoluteized, the external capacitance under test can be measured. The system block diagram is as follows. Figure 3 As shown;

[0055] Assuming the internal reference discharge circuits are Rref and Cref, the absolute discharge time constant is:

[0056] T a =R ref xC ref

[0057] The measured relative ion diffusion time can be absoluteized as follows:

[0058] T = kT a =kx(R) ref ×C ref )

[0059] Figure 3 The on-chip system shown can measure both the stress and strain transmitted to the package, as well as the capacitance of the external capacitor under test. Therefore, through this core solution—differential delay chain technology combined with an internal discharge circuit—it can be used for capacitive wear detection, capacitive sliding control, and pressure-sensitive touch control in in-ear headphones, such as... Figure 5 As shown, for in-ear headphones where space and system power consumption resources are becoming increasingly scarce, the stress and capacitance fusion sensor on-chip system based on differential delay chain involved in this application meets the functions of wearing, sliding control detection and pressure-sensitive touch control of headphones with a maximum size of 2mm x 3mm x 0.9mm, while the power consumption is only 10%-20% of the competing solutions.

[0060] Although the invention has been described above with reference to embodiments, various modifications can be made and components can be replaced with equivalents without departing from the scope of the invention. In particular, features in the embodiments disclosed herein can be combined in any way, provided there is no structural conflict. The lack of an exhaustive description of these combinations in this specification is merely for brevity and resource conservation. Therefore, the invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A three-in-one sensor for in-ear headphones, characterized in that: include: substrate(100); A die (200) is disposed on top of the substrate (100). The die (200) includes a differential delay chain, a microprocessor, and a power and clock management unit. The differential delay chain is electrically connected to the microprocessor, and the microprocessor is electrically connected to the power and clock management unit. The bare die (200) also includes an internal discharge circuit, a storage area, and an interface circuit; The internal discharge circuit is electrically connected to the differential delay chain; The storage area is electrically connected to the microprocessor; The interface circuit is electrically connected to the microprocessor; The stress input by the user is transmitted to the chip package through the pressure-sensitive touch area of ​​the earphone stem, and the stress is concentrated on the bare die in the center of the package, which in turn causes strain on the silicon substrate. Based on the strain of the silicon substrate, the ion diffusion rate changes. The built-in microprocessor provides start and stop signals, and the interval between the start and stop signals is controlled by the internal clock frequency division. At the same time, the number of differential delay chain units through which the signal passes is accumulated. By comparing the accumulated number under different stress and strain conditions, the relative quantification of stress-ion diffusion time is achieved. Furthermore, by using an internal reference discharge circuit, the relative diffusion time is made absolute, thereby quantifying the discharge circuit composed of the external capacitor under test and the internal reference resistor, and realizing multi-channel capacitance measurement.

2. The three-in-one sensor for an in-ear headphone according to claim 1, characterized in that: A pin frame is provided at the top edge of the substrate (100).

3. The three-in-one sensor for an in-ear headphone according to claim 2, characterized in that: It also includes pins (300) which are disposed on top of the substrate (100) via the pin frame.

4. The three-in-one sensor for an in-ear headphone according to claim 3, characterized in that: The die (200) has a connecting key (210) evenly distributed at its top edge. The connecting key (210) has a wire (220) on its top. The end of the wire (220) away from the die (200) is connected to the pin (300).

5. The three-in-one sensor for an in-ear headphone according to claim 3, characterized in that: It also includes a package body (400) disposed on top of the substrate (100) and covering the outside of the die (200) and the pins (300).

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