ON Semi's latest solutions enable state-of-the-art wireless and recharging in hearing aids



Ezairo 7150 SL wireless-enabled audio processor

ON Semiconductor, driving energy efficient innovations, further underlines its leadership position in assisting next-generation hearing aid development with the introduction of two new products: HPM10, a Power Management Integrated Circuit (PMIC); and Ezairo 7150 SL, a wireless-enabled audio processor.


Ezairo 7150 SL uses the company’s widely-implemented proprietary digital signal processing (DSP) technology and brings wireless connectivity to hearing aids and cochlear implants. The compact hybrid module is based on the powerful Ezairo 7100 open-programmable 24 bit mixed-signal DSP platform. This System in Package (SiP) solution provides wireless multi-protocol operation and is optimised for 2.4 gigahertz (GHz) band applications, including Bluetooth® Low-Energy (BLE). Ezairo® 7150 SL integrates EA2M, a low power 2 Mb serial CMOS EEPROM used for storing hearing aid firmware and important parameters.


To simplify and accelerate the development process of an Ezairo 7150 SL-based product, ON Semiconductor has provided a complete reference design of a behind-the-ear (BTE) hearing aid. The reference design includes software, hardware, and firmware which enable advanced wireless features. The control over BLE (CoBLE) function allows hearing aid users to control an array of parameters from their smartphone. The user can adjust the hearing aid’s volume, make program changes, check the battery status, and receive phone alerts (such as incoming calls or text messages).

It also features a valuable ‘Find Me’ function to help users quickly locate a misplaced hearing aid. The stereo audio streaming proprietary protocol enables music to be streamed from any external audio source (smartphones, tablet computers, televisions, etc.) through a remote dongle. The connectivity range can reach up to 10 meters in good surrounding conditions.


HPM10 is a Power Management IC (PMIC) that provides a high−performance solution for rechargeable batteries in hearing aids and hearing implant devices. The PMIC generates the voltage needed by the hearing aid and it also manages the charging algorithms such that the battery autonomy and the number of charging cycles are optimised. The rechargeable chemistries supported include silver−zinc (AgZn), and lithium−ion (Li−ion). HPM10 also detects zinc−air (Zn−Air) and nickel metal hydride (Ni-Mh) batteries but doesn’t charge them.


During operation, HPM10’s high efficiency power regulators help minimize lost power from the battery to the hearing aid. HPM10’s built-in charger communication interface (CCIF) can pass data to the hearing aid charger during the charging process. Battery parameters such as voltage levels, current levels, temperature and different forms of battery failures can also be communicated. Different charging parameters, representative of battery size and type, can be stored in the HPM10’s on-chip one-time programmable (OTP) memory.


“Our new solutions are set to have real impact on hearing aid design and the end-user experience. Ezairo® 7150 SL allows much improved user control over their device directly from any BLE-enabled smartphone. It also allows users to listen to audio from any source, like televisions or HiFi audio systems,” states Michel De Mey, senior director at ON Semiconductor. “By enabling rechargeable technology in hearing aids, HPM10 helps answer the need of our customers and the market to provide rechargeable hearing aids, which is another great step towards increased user friendliness.”


ON Semiconductor