Wake up and listen: Vesper quiescent-sensing MEMS device innovation

-June 22, 2016

This product is featured in EDN's Hot 100 products of 2016. See all 100 here.
I have a strong belief that the most natural and efficient way to communicate with devices, in the coming of the Internet of Things (IoT), is the human voice. The primary element for this effort to be successful is the microphone and the primary features needed in such a system are low power, small size, rugged construction, and excellent signal-to-noise capability.

Designers, take heart! Your solution is here from Vesper, a privately held piezoelectric MEMS company from which we have heard before (See links at the end of this product review).

This company, which began at the University of Michigan, has improved the acoustic experience with a wide range of consumer products via a patented piezoelectric MEMS platform. These products include smartphones, smart speakers, Internet of Things (IoT) devices and connected automobiles.

Vesper has now demonstrated the first commercially available quiescent-sensing MEMS device, providing designers the possibility of acoustic event-detection devices at virtually zero power draw at just 3 µA of current while in listening mode. This piezoelectric MEMS microphone — VM1010 — will allow designers to advance voice and acoustic event monitoring in their systems. See Figure 1 for the pin out of this IC.

Figure 1: The pin out of the VM1010 (Image courtesy of Vesper)

Matt Crowley, Vesper CEO told me that this quiescent-sensing MEMS microphone is the only device that uses sound energy itself to wake a system from full power-down. It is known that even when fully powered-off, batteries in smartphones and smart speakers naturally dissipate 40-80uA, which is far more current than this device needs. So a design using this technology will see no difference in battery-life for a system using the VM1010 in listening mode and a fully powered-down conventional system. See Figure 2 for specifications.

Figure 2: Key specifications for the VM1010 (Image courtesy of Vesper)

Even in sleep mode, this microphone preserves its very high signal-to-noise ratio (SNR) — which is needed for a wider acoustic range. In fact, there is absolutely no SNR penalty from going into low power, extending the distance of far field voice control in battery-powered systems. Watch the following YouTube video which shows the actual performance and capabilities like wake-on-sound.

When a designer embeds this device into a voice-powered TV remote control or smart speaker, it could allow you to turn on your device from across the room without having to push a button and without diminishing battery life. See the block diagram of the VM1010 in Figure 3.

Figure 3:
Block diagram of the VM1010. (Image courtesy of Vesper)

This microphone employs a rugged piezoelectric transducer that is immune to dust, water, oils, humidity, particles and other environmental contaminants, making it ideal for deployments outdoors or in kitchens and automobiles.

Completely waterproof

This video shows the hydrophone capability of the VM1010. This opens up so many new markets and possibilities for designers. 

An ideal feature of any design that uses this quiescent sensor is that essentially no power will be consumed until the appropriate stimulus occurs. To date, Peter Cooney, principal analyst and director, SAR Insight & Consulting claims that no company has demonstrated this in an actual commercial device. Therefore, in an ‘always on’ case, this solution has the potential to advance quiescent sensing into the commercial realm, enabling a new era of ubiquitous ‘always on’ sensors that can run indefinitely on small batteries.  

A proof-of-concept board was used to test and evaluate performance (Figure 4).

Figure 4:
The VM1010 proof-of-concept board used to evaluate and test performance.
(Image courtesy of Vesper)

Engineering samples of VM1010 are available now to highly qualified customers developing technologically advanced systems. Production samples will be available in Q4 2016.

For more information visit Vesper’s website.    

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