ON Semiconductor’s broadband advanced noise reduction SoC solution for applications such as smartphones and tablets

As users’ expectations for voice intelligibility and noise management of smartphones, laptops, tablets and other devices continue to increase, especially in the rapidly expanding VoIP market, designers are faced with extremely complex voice management design challenges. This article will highlight the key features, application benefits, and development support of ON semiconductor‘s BelaSigna® R262 voice capture and wideband noise reduction system-on-chip (SoC) solutions for these applications, helping them design designs that provide clarity wherever and how they communicate A very attractive device for voice.

BelaSigna® RFeatures of the series

ON Semiconductor’s BelaSigna® R-Series voice capture SoCs are specifically designed to address the acoustic design challenges of voice communications in noisy environments. The first product in the R series is the BelaSigna® R261, which supports dual microphones. It supports dual microphone direct input, the noise reduction algorithm is built into the integrated ROM memory, and the application controller based on the digital signal processor (DSP) structure provides high performance and Ultra-low power consumption, provides dual-channel analog output, and supports digital microphone output.

The latest BelaSigna® R262 is an upgrade from the BelaSigna® R261, offering higher performance and easier ease of use. The device also integrates DSP, voltage regulators, phase-locked loops, level shifters and memory in an extremely small WLCSP package with a footprint of less than 6 mm², requiring less board space than the additional external components normally required. A significantly larger competing scenario. This simplifies and speeds up the design process, helping engineers achieve the challenging goal of reducing design size.

ON Semiconductor’s broadband advanced noise reduction SoC solution for applications such as smartphones and tablets

figure 1: BelaSigna® R262 uses advanced real-time adaptive speech processing to provide up to 25 dB noise reduction

The BelaSigna® R262 uses an advanced dual-microphone real-time adaptive speech extraction algorithm that is capable of extracting speech signals without prior knowledge of the sound source or microphone location. This algorithm utilizes global optimization criteria, works in frequency domain, time domain and spatial domain at the same time, provides 25 dB noise suppression capability, can separate the required speech and environmental noise in real time, and at the same time can ensure natural sound quality, and can effectively cooperate with various quality Microphone works. The BelaSigna® R262 provides full 8 kHz bandwidth wideband voice capture for VoIP communications, eliminates reverberation, and supports 360° voice pickup for a variety of use cases.

BelaSigna® R262key advantage

The BelaSigna® R262 offers key advantages such as ease of integration, efficient voice capture, and design flexibility.

First, the device is an off-the-shelf solution that replaces a single microphone with two microphones connected directly to the audio input, and supports 5 mil (mil, thousandth of an inch) trace width on a printed circuit board ( PCB) and is pin compatible with BelaSigna® R261 for easy portability to existing products using BelaSigna® R261.

Second, the device supports a variety of use cases such as conferences, cell phone calls, and arm’s lengths, effectively capturing voice.

1) inconference modeNext, the BelaSigna® R262 can capture speech up to 6 meters away while attenuating noise and eliminating reverberation. This device supports users to move freely 360° in conference mode, providing great flexibility and convenience. This mode is suitable for notebooks, tablets and mobile phones in hands-free mode.

2) inphone call mode, BelaSigna® R262 supports the creation of virtual “bubbles” around the device, resulting in substantial noise reduction, and allows the phone to move freely around the mouth without performance degradation. This mode is suitable for mobile phone call mode.

3)arm’s length modeSuitable for laptops and tablets in private chat mode. This mode balances noise reduction with voice capture distance.

ON Semiconductor’s broadband advanced noise reduction SoC solution for applications such as smartphones and tablets

figure 2:BelaSigna® R262 is capable of effectively capturing speech in a variety of use cases.

The third key advantage of this device is design flexibility, which is mainly reflected in the fact that there are no restrictions on the industrial design or microphone model of the product. BelaSigna® R262 is not only compatible with a wide range of microphones, it also imposes no constraints on microphone layout or product industrial design. Not only does this device support dual-mic noise reduction, it also provides performance that is about as good when using one microphone as when using two. In addition, the device has broadband processing support and supports Skype VoIP calls.

ON Semiconductor’s broadband advanced noise reduction SoC solution for applications such as smartphones and tablets

image 3: BelaSigna® R262 can be used flexibly with a variety of voice capture devices.

In addition, BelaSigna® R262 has the advantage of extremely small size and low power consumption. This SoC uses a size of about 2.233 mm x 2.388 mm (about 5.34 mm2) in a very small WLCSP package (26-bump and 30-bump versions) for easy integration into the industrial design of the end application. Among them, the package version with full 30 bumps provides full functionality, including EEPROM read bypass, suitable for PCBs requiring 3 or 2 mil trace/line spacing; 26 bump package version reduces I/O selection, no hardware reset Pin, only provides 1 analog output, suitable for 5 mil trace/spacing PCB. The device supports operating voltages from 1.8 V to 3.6 V and offers very low power consumption, consuming only 17 mA under full load operation at 3.3 V and about 40 µA in standby mode. This low power consumption helps extend portable device battery life without sacrificing performance.

BelaSigna® R262Extensive hardware and software development support

The application schematic of BelaSigna® R262 is shown in Figure 4.

ON Semiconductor’s broadband advanced noise reduction SoC solution for applications such as smartphones and tablets

Figure 4: Application diagram of BelaSigna® R262.

To help customers develop, ON Semiconductor also provides a wealth of evaluation hardware, including customer prototype platforms (CPP), analog demo boards, prototype modules and communication accelerator adapters (CAA). Among them, the customer prototyping platform includes more functions, using the on-board MEMS microphone or plugging in the customer’s own microphone, self-powering with the on-board AAA battery or the designer’s own power supply, supporting the complete evaluation of the BelaSigna® R262.

Figure 5: ON Semiconductor provides BelaSigna® R262 with rich evaluation hardware to help customers develop.

The portable battery powered analog demo board measures 52 mm x 25 mm x 20 mm, the stereo output shows two simultaneous use cases, can be plugged into any standard microphone input, and is suitable for evaluating the performance of the BelaSigna® R262.

The prototyping module measures 22 mm x 6 mm, features an on-board 2.048 MHz oscillator, simply provides 3.3 V power and connects the output, provides analog and DMIC outputs, and is suitable for prototyping to evaluate the BelaSigna® R262. Also, connect to BelaSigna®The chip’s high-speed USB interface is used for development, debugging, and programming during production.

In addition, ON Semiconductor provides an intuitive, easy-to-use Windows application that supports all BelaSigna® R series chips, allowing designers to configure BelaSigna in the field® R262, supports running diagnostic tools during the design selection process, and can regenerate and retransmit customized EEPROM status parameters according to the designer’s configuration changes.


BelaSigna® R262 is a unique off-the-shelf solution for communication devices with the most complex voice management design challenges. As customer expectations for voice intelligibility and noise management continue to increase, especially in the rapidly expanding VoIP market, it is important for designers to have access to technologies like ON Semiconductor’s BelaSigna® R262 to help them design compelling Voice communication devices, no matter where and how you communicate, provide clear voice to help optimize the user experience.


1. BelaSigna® R262 product webpage, ON Semiconductor, www.onsemi.cn/PowerSolutions/product.do?id=BELASIGNA%20R262

2. BelaSigna® R262 data sheet, ON Semiconductor, www.onsemi.cn/pub/Collateral/BR262-D.PDF

3. “ON Semiconductor BelaSigna® R262 Audio DSP System” webinar presentation material, September 2012, http://seminar.21ic.com/detail.asp?meeting_id=109

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