CN211128113U

CN211128113U - Earphone in-ear detection chip circuit

Info

Publication number: CN211128113U
Application number: CN201921590307.6U
Authority: CN
Inventors: 阳志坚; 朱锌铧; 涂柏生
Original assignee: Changsha Boxin Microelectronics Technology Co ltd
Current assignee: Changsha Boxin Microelectronics Technology Co ltd
Priority date: 2019-09-24
Filing date: 2019-09-24
Publication date: 2020-07-28
Anticipated expiration: 2029-09-24

Abstract

The utility model discloses an earphone ear-entering detection chip circuit, which comprises a voltage comparator, wherein the output end of the voltage comparator is connected with a cpu processor, and the minus input end of the voltage comparator is connected with a reference voltage vref; the input end of the voltage comparator is connected with an electrode through a switch S2, the input end of the voltage comparator is connected with a cpu processor through a switch S1, and the input end of the voltage comparator is grounded through a connecting capacitor Cs; the motor is grounded through a capacitor Ct; the electrode is connected in series with VDD through a switch S3 to be grounded; the utility model can utilize the earphone equipment connected with the chip to judge whether the wireless earphone is worn or not or whether the touch key is effective or not; meanwhile, the detection is more stable and is not easy to be triggered by mistake.

Description

Earphone in-ear detection chip circuit

Technical Field

The utility model belongs to the technical field of earphone detection circuitry, specifically be an earphone pleasant detection chip circuit.

Background

The Bluetooth wireless earphone has the characteristics of small volume and light weight, efficiently utilizes a battery with limited capacity, and is particularly important in friendly human-computer interaction experience; the most common in the market is the optical in-ear detection scheme, which has the following disadvantages:

1. the volume is great, and the optical detection scheme needs to punch on the earphone surface and leads to the light, is unfavorable for the earphone to do waterproof design.

2. Limited by the structure space, the earphone cavity is difficult to stack when the PCB is made, so that the earphone is not beneficial to the miniaturization design.

3. A large number of earphone products adopt a single optical path detection scheme, which causes that when the earphone is not worn, detection is easily triggered when a material blocking the optical path is encountered, and the earphone cannot work.

The mechanical key switches adopted in the market have the following defects:

1. the mechanical switch has a service life, and poor contact or ineffectiveness can occur after the mechanical switch is used for a long time.

2. The mechanical switch needs to be provided with a hole on the shell, so that the product is difficult to realize water resistance and dust resistance.

SUMMERY OF THE UTILITY MODEL

The utility model aims at the above problems, and provides an earphone in-ear detection chip circuit, which can judge whether a wireless earphone is worn or not or whether a touch button is effective or not by using earphone equipment connected with the chip; detect simultaneously more stable, difficult spurious triggering, the utility model discloses the chip circuit does not have the decay, and lossless, longe-lived.

In order to realize the above purpose, the utility model adopts the technical scheme that: an earphone ear-entering detection chip circuit comprises a voltage comparator, wherein the output end of the voltage comparator is connected with a cpu processor, and the minus input end of the voltage comparator is connected with a reference voltage vref; the input end of the voltage comparator is connected with an electrode through a switch S2, the input end of the voltage comparator is connected with a cpu processor through a switch S1, and the input end of the voltage comparator is grounded through a connecting capacitor Cs; the motor is grounded through a capacitor Ct; the electrode is connected in series with VDD to ground through switch S3.

Further, the pin functions are respectively as follows: the 1-pin IOB4 touch switch signal output pin is normally high level, and outputs low level when the surface of the 5-pin electrode is touched by hands; 4-pin VSS is grounded; TCH0 touch key electrode 5; a 6-pin TCH1 in-ear detection electrode 2; the 7-pin IOB2 in-ear detection signal is output and is normally high level, and when the 6-pin IOB2 in-ear detection signal and the 8-pin IOB detection signal detect the ear wall simultaneously, the low level is output; the TCH2 in 8-pin is inserted into the ear to detect electrode 1.

Further, the ground of the 2-pin CMOD is connected with a capacitor Cs connected with 10000 Pf.

Furthermore, the 3-pin VDD is connected with a 2.2-5V power supply.

The utility model has the advantages that:

1. the chip BJTH8025A integrates two-in-one single-chip solution of in-ear detection and touch control, wherein the in-ear detection supports two channels, thereby greatly reducing the error recognition rate and improving the detection accuracy.

2. The utility model discloses go into the ear and detect the principle that utilizes the charge to shift, whether the change of electric charge judges the earphone to wear on the two way electrodes of sampling simultaneously, has lower misrecognition rate than traditional optical detection scheme. The inside of the BJTH8025A is integrated with PMU and MCU, the algorithm runs independently on the chip and reports to the master control directly through logic level change or other protocols, and the master control makes the earphone work in a low power consumption mode or a normal mode according to the reporting condition, thereby fully and effectively utilizing the energy of the battery.

3. The utility model discloses well BJTH8025A still takes the touch switch function, and relative mechanical key switch, touch button can pierce through the insulating material shell and need not punch on the shell, accomplish waterproof dustproof easily, and touch button does not have any mechanical parts, can not wear and tear, longe-lived.

Drawings

Fig. 1 is a schematic diagram of a system circuit according to the present invention.

Fig. 2 is a functional diagram of the pin of the middle chip BJTH8025A according to the present invention.

Detailed Description

In order to make the technical solution of the present invention better understood, the present invention is described in detail below with reference to the accompanying drawings, and the description of the present invention is only exemplary and explanatory, and should not be construed as limiting the scope of the present invention.

As shown in fig. 1-2, the specific structure of the present invention is: an earphone ear-entering detection chip circuit comprises a voltage comparator, wherein the output end of the voltage comparator is connected with a cpu processor, and the minus input end of the voltage comparator is connected with a reference voltage vref; the input end of the voltage comparator is connected with an electrode through a switch S2, the input end of the voltage comparator is connected with a cpu processor through a switch S1, and the input end of the voltage comparator is grounded through a connecting capacitor Cs; the motor is grounded through a capacitor Ct; the electrode is connected in series with VDD to ground through switch S3.

Preferably, the pin functions are respectively as follows: the 1-pin IOB4 touch switch signal output pin is normally high level, and outputs low level when the surface of the 5-pin electrode is touched by hands; 4-pin VSS is grounded; TCH0 touch key electrode 5; a 6-pin TCH1 in-ear detection electrode 2; the 7-pin IOB2 in-ear detection signal is output and is normally high level, and when the 6-pin IOB2 in-ear detection signal and the 8-pin IOB detection signal detect the ear wall simultaneously, the low level is output; the TCH2 in 8-pin is inserted into the ear to detect electrode 1.

Preferably, the 2-pin CMOD is grounded by a capacitor Cs connected to 10000 Pf.

Preferably, the 3-pin VDD is connected with a 2.2-5V power supply.

The specific working process is as follows:

the CPU of BJTH8025A charges the Ct capacitor (parasitic capacitor of the electrode itself) by an electronic switch, and switches the charge to transfer to the capacitor Cs by the electronic switch, so that the voltage of the capacitor Cs reaches Vref. Generally, the Cs capacitance is more than 10000pF, Ct generally only has 5-10pF, so that the Cs voltage reaches Vref only by circularly transferring Ct to Cs charge for many times, and the change of Ct can be judged by the CPU through the change of the times. The specific judging steps are as follows:

1. s1 short circuit, S2 open circuit, S3 open circuit, release the charge on Cs;

2. s1 is open, S2 is open, S3 is short, and VDD charges the capacitor Ct;

3. s1 is open, S2 is short, S3 is open, and Ct capacitor charges Cs;

repeatedly executing the

steps

2 and 3 to enable the voltage of the Cs to reach Vref, and meanwhile, accumulating the times by the counter;

when the hand or the ear wall approaches the electrode, the capacitance Cx is connected in parallel with the capacitance Ct, so that the capacity of the Ct is increased.

The change in Ct capacity results in a change in the number of times Cs is fully charged. For example, when the Ct capacity is large, the number of times of transfer required to fully charge Cs becomes small, which corresponds to a large amount of charge transferred to Cs per time. The CPU judges whether the wireless earphone is worn or whether the touch key is effective or not through internal algorithm processing according to the change.

It should be noted that, in this document, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.

The principles and embodiments of the present invention have been explained herein using specific examples, which are presented only to assist in understanding the methods and their core concepts. The foregoing is only a preferred embodiment of the present invention, and it should be noted that there are objectively infinite specific structures due to the limited character expressions, and it will be apparent to those skilled in the art that a plurality of modifications, decorations or changes can be made without departing from the principle of the present invention, and the above technical features can be combined in a proper manner; the application of these modifications, variations or combinations, or the application of the concepts and solutions of the present invention in other contexts without modification, is not intended to be considered as a limitation of the present invention.

Claims

1. The circuit is characterized by comprising a voltage comparator, wherein the output end of the voltage comparator is connected with a cpu processor, and the minus input end of the voltage comparator is connected with a reference voltage vref; the input end of the voltage comparator is connected with an electrode through a switch S2, the input end of the voltage comparator is connected with a cpu processor through a switch S1, and the input end of the voltage comparator is grounded through a connecting capacitor Cs; the motor is grounded through a capacitor Ct; the electrode is connected in series with VDD to ground through switch S3.

2. The earphone in-ear detection chip circuit according to claim 1, characterized in that its pin functions are respectively: the 1-pin IOB4 touch switch signal output pin is normally high level, and outputs low level when the surface of the 5-pin electrode is touched by hands; 4-pin VSS is grounded; TCH0 touch key electrode 5; a 6-pin TCH1 in-ear detection electrode 2; the 7-pin IOB2 in-ear detection signal is output and is normally high level, and when the 6-pin IOB2 in-ear detection signal and the 8-pin IOB detection signal detect the ear wall simultaneously, the low level is output; the TCH2 in 8-pin is inserted into the ear to detect electrode 1.

3. The headset in-ear detection chip circuit of claim 2, wherein the 2-pin CMOD is connected to the ground by a capacitor Cs connected to 10000 Pf.

4. The headset in-ear detection chip circuit of claim 2, wherein the 3-pin VDD is connected to a 2.2-5V power supply.