The TWS headset market is developing rapidly, and with it, consumers have higher and higher requirements for products. Ordinary TWS headset products are no longer enough to meet the needs of consumers, and customized special ones Products have become an important factor in whether manufacturers can take the lead in the TWS headset market. Goodix Technology also wants to bring meaningful solutions to everyone at such a critical moment.
This time, at the 2019 (Summer) China Intelligent Audio Industry Summit Forum, Feng Lin, product manager from Goodix Technology, shared about the "Goodix Technology Headphone Wear Detection and Human-Computer Interaction Two-in-One Solution" and Heart Rate Detection Solution” speech.
I found that the in-ear wear detection mentioned in this document is very different from the traditional implementation method, so I decided to conduct a detailed analysis of this new solution and share the learning with everyone.
The following is a transcript of the speech, edited and compiled by I Love Audio Network (www.52audio.com):
Regarding in-ear detection, the most common solution on the market is an optical solution, and some will use traditional Capacitance detection scheme.
Analysis of the pain points of the optical detection solution:
1. The volume is large, and the optical detection solution requires drilling holes on the surface of the earphones to let in light, which is not conducive to the waterproof design of the earphones.
2. Due to the limitation of structural space, it is difficult to stack PCBs in the headphone cavity, which is not conducive to the miniaturization design of the headset.
3. A large number of headphone products use a single-light path detection solution. This will cause the headset to be easily triggered by materials blocking the light path when the headset is not worn, and the headset will not work.
Capacitance detection solution, pain point analysis:
1. Temperature impact:
Capacitance detection solution is easily affected by temperature, especially in high latitude areas. For example, during the cold winter in Northeast China, the temperature ranges from minus 20 degrees outside to over ten degrees indoors.
2. Detection method:
The traditional solution only detects the capacitance change, which may be much greater than the headphone capacitance change. It is extremely easy to cause misjudgment and also leads to the failure of wearing detection.
It has a higher degree of integration and occupies very little space on the precious TWS headset PCB.
Taking into account the structural space limitations of the headset, we designed a two-in-one in-ear detection and touch control single chip solution. Among them, in-ear detection supports two channels, which can greatly reduce the false recognition rate and improve detection accuracy. Touch supports click, long press and sliding operations, and rich human-computer interaction functions can be realized without adding additional G-Sensor and separate touch IC control.
Therefore, our solution will be more integrated and the headset will take up less space.
Low power consumption, the power consumption in in-ear detection mode is 9.1 microamps
The headphone battery is dozens of milliamp hours, and the music playing is also milliamp level, 9.1 microamps is a difference By several orders of magnitude, it will not have any impact on the battery life of the headset.
When in-ear detection and human-computer interaction work at the same time, when the headphones are worn on the ears, the power consumption is only 16 microamps. When in TUCH, the power consumption is a little more, and when the finger is released, the Falling down again, the power consumption in the above two states is our most common power consumption.
The headphone occupancy is extremely small
This is reflected in the capacitive electrode used in our sensor. We can use the sensor of flexible PCB. The FPC industry is generally 0.1 mm, which can be attached Go to the inner surface of the earphone cavity or the bracket inside the earphone, so that it has a three-dimensional space on it, and it can be adapted to various types of earphones, especially miniaturized earphones, which may not even be able to accommodate optical devices. We The capacitor can be put down.
Our chip size is only 1.9 mm by 2.1 mm. We use CSP packaging. Such a small size can be placed directly on the sensorFPC or on the motherboard, so that it can adapt to different IDs. .
Temperature suppression, any temperature shock within the range from -20 degrees to 60 degrees will not be affected
From IC architecture and our software development to our application design We have made special designs on them. Our temperature suppression can be said to be absolute temperature suppression. Any temperature shock within the range from -20 degrees to 60 degrees will not have an impact.
When spraying with condensate, the curve will not change in any way and is only perceived by the human body. For mass production, we do not need to make holes on the surface of the earphones, which is more conducive to our waterproof design.
We are also a comprehensive solution provider for semiconductors. We will provide everything from chip applications to structural ID mass production and overall solutions.
Goodix Technology’s 2-in-1 in-ear detection and touch solution GH61x series adopts Goodix Technology’s latest patented human body capacitance detection technology. It is the multi-channel in-ear detection and human-computer interaction solution with the lowest power consumption and smallest headphone space occupation in the industry. It can assist true wireless headphones to achieve functions such as automatic sleep, automatic wake-up, master-slave switching, automatic start and stop of music, etc., improving user experience. It also supports rich human-computer interaction functions such as touch control and sliding volume adjustment. Compatible with a variety of headphone styles, such as wireless semi-in-ear, in-ear, head-mounted, etc.
Compared with the traditional optical-based wear detection solution, Goodix Technology’s in-ear detection plus touch two-in-one solution uses FPC sensor, which has a flexible design, does not occupy the three-dimensional space of the earphones, and does not require drilling holes on the surface of the earphones. There is no need to add additional G_sensor or touch IC for human-computer interaction. The use of dual-channel in-ear detection and the capacitance detection scheme only responds to electrodes, making it have a lower false recognition rate than traditional optical detection schemes. The chip integrates PMU and MCU, and the algorithm runs independently on the chip, reporting events directly to the main control without the need for the main control to do data processing.
The GH61x solution innovatively solves the weakness of traditional capacitor principles that are susceptible to temperature drift from the bottom of the chip. It can suppress the influence of temperature drift of more than 40dB in the range of -30 degrees to 60 degrees, and has extremely high performance. Strong ability to suppress temperature drift. This enables the solution to operate reliably in extreme cold, extreme heat, and scenarios with drastic temperature changes.
Goodix Technology provides a series of heart rate measurement products with high precision, low power consumption and high integration, which can bring unique advantages of high accuracy, long standby and easy processing to end customers' products.
This series of products includes a variety of optical sensor modules based on Photo Plethysmo Graphy (PPG), which can detect heart rate, blood oxygen and other physiological characteristics and can be widely used. It is used in wearable devices such as smart headphones, smart bracelets/watches, health armbands, heart rate patches, and other products that require PPG detection technology to provide end users with physiological information collection, exercise guidance, health monitoring, and emotional stress analysis. Function.
Goodix Technology also provides professional optical structure design specifications, dynamic heart rate algorithm libraries and supporting mass production testing services to help customers simplify the product development process and quickly realize product implementation.
GH300 is a heart rate sensor module that integrates 2 LEDs, an optical receiver (PD) and an analog front-end. It has the characteristics of ultra-small size and ultra-low power consumption, and is suitable for smart headphones, smart phones, etc. Rings and other products that have strict requirements on size and power consumption. For smart headphone applications, GH300 integrates a wearing detection function and supports access to an external photoreceiver (PD) and LED module to achieve higher-precision wearing detection requirements.
Compared with other products, GH300 has the characteristics of smallest size and lowest power consumption.
The size is about 1/3 of the volume of similar products on the market, and the power consumption is 1/10 of that of the products on the market.