OWS Market Overview
2023 was hailed as the "first year of Open Ear Headphones (OWS)". Open-ear headphones, characterized by their non-intrusive wearing design, entered a phase of rapid development, with major leading brands launching OWS products one after another. From January to August 2024, the total shipment volume of the Bluetooth headphone market reached 73.38 million units, achieving a 19.5% growth. Among them, OWS witnessed a booming trend: its shipment volume hit 16.36 million units, with a year-on-year growth rate of 271.5%. Additionally, as the computing power of main controllers increases and access to AI large models becomes feasible, more players are expected to enter the OWS track, promising a bright future for the market.
Figure 1: IDC Bluetooth Headphone Shipment Data (Jan-Aug 2024)
Advantages of OWS Headphones
OWS can be categorized based on different criteria:
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Wearing style: Behind-the-ear and earclip styles;
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Sound generation principle: Bone conduction and air conduction;
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Functionality: Basic functional type and AI intelligent type.
The surging popularity of the OWS market can be attributed to its distinct advantages:
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Stable wearing: Equipped with ear hooks or earclip designs, OWS headphones stay in place even during running, exercise, or sudden movements.
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Comfortable wearing: Ear hooks are made of soft, skin-friendly materials, and weight is evenly distributed on the auricle—after getting used to them, users barely feel their presence.
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Safe wearing: The non-intrusive design allows users to perceive ambient sounds without obstruction, making them safe to wear while crossing the road or driving.
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Excellent sound quality: The non-intrusive structure enables larger dynamic driver sizes, delivering richer low-frequency performance with greater amplitude. Technologies such as directional sound transmission and sound field phase control minimize sound leakage, effectively protecting user privacy.
Introduction to Shokz OpenFit Series Headphones
In the open-ear headphone track, Shokz pioneered the "non-intrusive" headphone category with its bone conduction sports headphones. In 2023, Shokz launched its first OpenFit open-ear headphone targeting fitness and hiking users, which quickly achieved impressive sales of 5.2 million units. In the spring of 2024, it released the second-generation product, OpenFit Air—lighter and more affordable, bringing surprises to new and existing users with its high cost-effectiveness. On February 10 this year, Shokz launched its new flagship model, OpenFit2, featuring a host of cutting-edge technologies that are sure to spark a new wave of market enthusiasm.
Awinic Inside the OpenFit Series
Figure 2: Shokz OpenFit Air Headphone Image
The continuous success of Shokz’s OpenFit series is supported by Awinic’s products. It is reported that the OpenFit series has integrated 3 types of Awinic products:
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On the headphone charging case:
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AW35X20ADNR: A power switch with integrated over-voltage (OVP) and over-current (OCP) dual protection, used for the charging port;
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AW8651XEBADNR: A HALL switch for detecting whether the headphone is inserted into or removed from the case;
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On the headphone itself:
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AW93X03CSR: A touch chip used for functions such as music play/pause and call answer/hang-up.
Detailed Introduction to the Three Chips
1. OVP+OCP Dual-Protection Chip – AW35X20ADNR
Figure 3: Typical Application Circuit Diagram of AW35X20A
AW35X20ADNR is a protection chip integrating over-current and over-voltage protection functions, serving as a critical safety barrier for the TYPE-C charging port. Its key features are as follows:
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Supports a wide input voltage range of 2.7~7V, with a DC withstand voltage of 24V;
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Low Rdson of 50mΩ, with a high power dissipation capacity of up to 1.5W;
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Flexible current limiting range of 250mA~3A (configurable as needed);
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OVP (Over-Voltage Protection) and UVP (Under-Voltage Protection) thresholds configurable via a front-end voltage divider resistor connected to ground;
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Equipped with a Css capacitor to adjust soft-start time, preventing inrush current from collapsing the front-end power supply;
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Self-recovery function after over-voltage/over-current protection;
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Over-temperature protection and short-circuit protection;
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3mm×2mm×0.75mm-8L package with a heat-dissipating pad at the bottom.
It is reported that AW35X20A is not only used in the OpenFit series but also in other Shokz product lines such as OpenRun, OpenSwim, and OpenComm.
2. HALL Switch – AW8651XEBADNR
Figure 4: Typical Application Circuit Diagram of AW8651X
AW8651XEBADNR is an omnipolar Hall switch. Its key features are as follows:
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Supports a supply voltage range of 1.6~5.5V;
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Trigger thresholds: Bop=±60Gs, Brp=±50Gs;
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Push-pull output;
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Ultra-low quiescent current: 0.8μA (typical);
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Compact WBDFN 1.6mm×1.2mm×0.37mm-4L package.
Awinic offers a comprehensive product lineup of HALL switches, including unipolar/omnipolar types, low/medium/high sensitivity options, and various packages such as SOT and DFN. To facilitate customer use, Awinic provides HALL simulation support based on structural design data during the initial design phase.
3. 3-Channel Touch Chip – AW93X03CSR
Figure 5: Typical Application Circuit Diagram of AW93X03
AW93X03 is a 3-channel touch chip with an I2C control interface, capable of detecting functions such as single-click, double-click, long-press, and one-dimensional sliding. The touch solution enables an integrated housing structure, effectively preventing dust and sweat erosion. Its key features are as follows:
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Supports a supply voltage range of 1.7~3V;
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3-channel touch key control:
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Independent recognition of 3 touch keys;
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Pseudo-differential design with 2 channels for wear detection;
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3 channels configurable via PCB design for one-dimensional sliding recognition;
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High capacitance resolution accuracy of up to 1fF;
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I2C address configurable via the CS2 pin level;
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Ultra-low power consumption: 8.7μA (idle state), 3.3μA (deep sleep mode);
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Compact 1.75mm×0.96mm×0.57mm-8B WLCSP package.
Awinic’s touch chips have mature applications and a wide range of uses in the wearable device market. They have been adopted in wearable products (such as smartwatches, headphones, and smart glasses) by multiple customers including Coros, Anker, and Amazfit.
Awinic’s Applications in OWS
In addition to the 3 aforementioned products, Awinic offers other chips applicable to OWS products, as shown in the following block diagrams:
Figure 6: Typical Application Block Diagram of OWS (Charging Case)
Figure 7: Typical Application Block Diagram of OWS (Headphone Side)
Detailed Introduction to Additional Chips in the Block Diagrams
1. Force Sensor
AW8687X:
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Controlled via I2C, with 2 independent ASIC pressure key channels;
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Supports 1.2V/1.8V voltage domain I/O;
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Flexible gain adjustment (1~256 levels);
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14-bit ADC sampling rate of 150Ksps;
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Ultra-compact 1.41mm×1.41mm×0.34mm-16B WLCSP package;
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Ultra-low power consumption: 10μA @ 10Hz (2 channels).
The force sensor solution effectively prevents false touches and interference from water/sweat, enhancing user experience.
Figure 8: Typical Application Circuit Diagram of Force Sensor
2. Linear Charging IC
AW3201X:
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High DC input withstand voltage of up to 28V;
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Flexible configurable charging current (2~500mA);
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High charging accuracy of ±0.5%;
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Equipped with Powerpath and shipping mode functions;
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Ultra-compact 1.4mm×1.4mm×0.63mm WLCSP package;
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Industry-leading low quiescent current of 5μA at the VBAT terminal (greatly extending standby time);
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Configurable charging termination current (1~31mA) to ensure full battery charging and significantly extend working battery life.

Figure 9: Typical Application Circuit Diagram of Linear Charging IC
3. RGB LED Driver
AW202X:
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Drives 3 independent LEDs or a single RGB LED;
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4 levels of configurable global maximum current (5~30mA);
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Enables 4096-level color mixing and 256-level PWM dimming per channel;
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Supports autonomous breathing mode;
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Low standby current of 2μA;
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Intuitively indicates communication connection status and charging status through colors or flashing effects.
Figure 10: Typical Application Circuit Diagram of RGB LED Driver
Conclusion
As an important companion to smartphones, OWS boasts broad market prospects thanks to its excellent wearing stability, safety, and the added AI edge assistant functionality. Its market scale is expected to continue expanding. Awinic will continue to deepen its efforts in various product lines, committed to creating high-quality analog and digital-analog hybrid chips. Through continuous innovation and technological upgrading, Awinic aims to bring OWS users a more outstanding sound quality experience, more intelligent interaction, and more stable connectivity.
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