Synaptics’ FlexSense Sensor Fusion Processor Cuts Board Space and Power

By Rich Nass

Executive Vice President

Embedded Computing Design

June 07, 2022


Synaptics’ FlexSense Sensor Fusion Processor Cuts Board Space and Power

Sensor Fusion—it sounds like something out of Star Trek, like some super-futuristic technology. In reality, it’s simply combining sensors in one device. While it sounds simple, it’s actually fairly difficult to do, as different sensor types often employ different technology and have different outputs, and obviously different input types.

However, if you are designing an IoT device and want to perform your calculations at the Edge of the IoT, Sensor Fusion could be a boon to your end product. And it’s that technology that was recently announced by Synaptics in its FlexSense family of fusion processors. These devices have the ability to capture and intelligently process input from up to four sensors, all at the same time. While significantly reducing the size of the board due to a reduced number of components, it also reduces the power consumption. Synaptics claims that the form factor is 80% smaller than existing solutions (2.62 by 2.62 mm) and the part consumes 240 µW (typical) and 10 µW in sleep mode.

The FlexSense devices integrate combinations of capacitive, inductive, Hall effect, and ambient sensing modalities onto one processor. These are generally the type of sensors needed for reliable, low-latency, and context-aware force, proximity, and touch sensing. End applications that would apply include IoT devices such as true wireless stereo (TWS) earbuds, gaming controllers, augmented reality (AR) and virtual reality (VR) headsets, and wearables.

Using the software supplied by Synaptics, FlexSense can access multiple sensors to ensure reliable performance across moisture and temperature variations and to eliminate false or unintentional sensor stimuli. It also enables more nuanced detection of user intent for gesture, swipe, force, squeeze, docking, or the rotation of a knob. Accurate detection of increasingly advanced inputs is critical to create a seamless and intuitive interactive experience for IoT devices.

A simple, out-of-the box solution helps to accelerate time to market. That solution consists of a processor and up to eight analog input channels that can be user configured to mix and match up to four different sensors. Note that processor versions are available that can include a magnetic field sensor to enable Hall effect sensing integrated directly on the chip. This can be used for dock detection, contactless buttons, and other applications.

Once set up, configured, and calibrated, the FlexSense processor makes contextual sense of all sensor data to measure force (push, intent), touch (tap, hold, slide), proximity (in-ear detection, body presence), and dock detection. Real-time analysis of the incoming data, as well as ambient conditions such as temperature, ensures the optimum response to match user expectations, a key element of an intuitive and seamless user experience. 

FlexSense is sampling now and an evaluation kit is available with core functions, such as slider, touch, flick slider gestures, inductive, and Hall effect sensing programmable through Synaptics’ Configuration Tool.

Richard Nass’ key responsibilities include setting the direction for all aspects of OSM’s ECD portfolio, including digital, print, and live events. Previously, Nass was the Brand Director for Design News. Prior, he led the content team for UBM’s Medical Devices Group, and all custom properties and events. Nass has been in the engineering OEM industry for more than 30 years. In prior stints, he led the Content Team at EE Times,, and TechOnLine. Nass holds a BSEE degree from NJIT.

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