Zarlink Micro Technology: Targeting TWS Headphones, an innovative in-ear detection solution

The TWS headset market is developing rapidly. With the following, consumers are increasingly demanding products. Ordinary TWS headset products are insufficient to meet the needs of consumers. Customized special products have become an important factor for manufacturers to occupy the TWS headset market.Zarlink Micro Technology also wants to bring meaningful solutions to everyone at such a critical moment.

Optical detection program pain point analysis:

1, the volume is very large, the optical detection scheme needs to be perforated and lighted on the surface of the earphone, which is not conducive to the waterproof design of the earphone.

2. Due to the limitation of the structure space, it is difficult to make the PCB stacking of the earphone cavity, which is not conducive to the miniaturization design of the earphone.

3.A large number of earphone products adopt a single light path detection scheme, This will cause the material that blocks the light path to easily trigger detection when the earphone is not worn, and the earphone will not work.

Capacitance detection scheme, pain point analysis:

1, temperature impact:

Capacitance detection schemes are susceptible to temperature, especially at high latitudes.

For example, when the northeast winter is cold, the outdoor is minus 20 degrees to the indoor ten degrees.

2, detection method:

The traditional solution is only to detect the amount of capacitance change, which may be far greater than the change of the headphone capacitance, which is prone to misjudgment and also causes the failure of the wearing test.

Considering the space limitations of the earphone structure, we have designed a single-chip solution for in-ear detection + touch two-in-one. The in-ear detection supports two channels, which can greatly reduce the false recognition rate and improve the detection accuracy.

The footprint of the headset is very small

Reflected in our sensor, the capacitor electrode used, We can use the flexible PCB sensor, the FPC industry is generally 0.1 mm, It can be attached to the inner surface of the earphone cavity or to the bracket inside the earphone,So that it has a three-dimensional space on it, it can be adapted to a variety of, especially miniaturized headphones,It is possible that the optics can not be placed, and our capacitors can be put down.

Our chip size is only 1.9 mm by 2.1 mm. We use CSP package, so the small size can be placed directly on the sensorFPC or on the motherboard, so that it can adapt to different IDs.

JTW077 is a 2-channel touch-slip control and 1-channel in-ear detection control chip. It provides six touch gestures such as click, double click, triple click, long press and slide adjustment. It can apply touch detection circuit and environment self-correction technology. Adapt to a variety of environmental applications. The small package size makes it ideal for use in electronic products such as TWS headsets.

product description

Operating voltage range: 2.5 V ~ 5.5 V

Operating current: 500 uA@3.3V (normal mode); 3uA@3.3V (sleep mode)

Channel in-ear detection input, channel touch-slip input, application for six gestures

Simple application circuit, few peripheral components, easy processing and low cost

Continuously no button for 4 seconds, enter sleep mode

Integrated environmental self-correction mechanism with good anti-interference characteristics

Temperature suppression, no temperature impact from -20 degrees to +60 degrees

From IC architecture and our software development to our application design, we have made special designs. Our temperature suppression can be said to achieve absolute temperature suppression. Any temperature shock from -20 degrees to 60 degrees will not be affected.

When the paint is sprayed with the condensing agent, the curve will not be changed, aOnly have a perception of the human bodyIn mass production, we don't need to open the hole on the surface of the earphone, which is more conducive to our waterproof design.

We are also a comprehensive solution provider for semiconductors, and we offer everything from chip applications to fabric ID production and total solutions.