Chip enables voice-activated wake-up, always-on operation

October 01, 2015 // By Graham Prophet
ON Semiconductor’s BelaSigna R281 is designed to provide voice activation in portable devices, acting as an ultra-low-power, always-listening voice trigger.

Using an audio pattern-matching algorithm developed by ON Semiconductor, BelaSigna R281 can detect a single, user-trained trigger phrase. This phrase can be any series of sounds, and is neither speech nor language dependent. Upon recognising this trigger phrase, BelaSigna R281 will assert a wake-up signal which, when connected to a host controller, alleviates the need for users to touch their device to wake it prior to use.

Based on ultra-low-power technology developed for advanced hearing aid solutions, BelaSigna R281 has virtually no impact on standby battery life. Unlike some standalone solutions which are only compatible with digital microphones, BelaSigna R281’s mixed-signal architecture works with both analogue and digital microphone signals. The device provides a configurable, regulated microphone supply to facilitate simple integration. Other features of BelaSigna R281 include an I²C interface for configuration and control, a configurable GPIO wake-up signal, and an internal oscillator.

BelaSigna R281 is available in a 5 x 5 mm QFN32 package and (planned) in an ultra-miniature 2.42 x 2.74 mm WLCSP. Both packages can be designed onto a single-sided PCB with 4 mil ( 0.004 in., 0.1 mm) routing and a minimal number of external components, providing one of the simplest solutions available for always-on, always-listening voice trigger.

ON Semiconductor;