proximity sensors for wearable applications - capacitive sensing, low power consumption

1. www.seltech-international.com
2017/4/13
ProxSense® solutions
for Wearable Applications

2. © 2014 SAS SELTECH - All rights reserved.
Wearable Market
page2
▪ The wearable market includes
– Smart Watches
– Fitness Trackers
– Wireless Headphones / Earphones
– BT Headsets
– Smart Glasses & VR Headsets
– Smart shoes and textiles
– Medical devices
▪ Typical Characteristics
– Limited space for user interface
– Avoid the use of mechanical buttons for ease
of assembly and reliability
– Small displays (LED or LCD)
– Low power requirements
– Low cost

3. © 2014 SAS SELTECH - All rights reserved.
ProxSense® Solutions
page3
▪ Wearable applications
– Detect if device is being worn (saves battery power)
– Elegant touch user interface
– Robust water-proof SwipeSwitch
– Small capacitive touch screen or pseudo touch screen (electrodes are
copper, but close to the touch screen so the user perceives it as a touch
screen)
– Proximity Alert or backlight trigger
– Combination of hard clicks and touch in the same estate
– Combination of HALL switch / rotation and touch function
▪ Azoteq’s ProxSense offers a range of capacitive proximity and
touch controllers as well as fusion sensors

4. © 2014 SAS SELTECH - All rights reserved.
Wear detection
page4
▪ Features
– Play/pause music as user wears/removes the device
– Can turn ON/OFF Bluetooth connection
▪ Advantages
– Makes usage easier
– No need for ON/OFF button
– Ultra low power solution
▪ Sensors
– IQS211A / IQS231A / IQS228 – single channel chipset
30s tip for wear-detect solutions

5. © 2014 SAS SELTECH - All rights reserved.
Touch key
page5
▪ Features
– Tap, Double Tap, Tap & Hold
– Turn on display, change modes
▪ Advantages
– Robust performance even in small designs
– Improved Battery Life
– Aesthetically Pleasing Design
– Easier implementation than mechanical keys
– Touch electrodes can be molded into the rubber
wristband
▪ Sensors
– IQS211A – single touch key (below 2uA in standby)

6. © 2014 SAS SELTECH - All rights reserved.
Swipe
page6
▪ Features
– Simple touch screen or pseudo touch screen
– Swipe on Strap
– Lock/unlock function
– Bi-directional Swipe
▪ Advantages
– Improved UI – swipes are intuitive to navigate
menus
– Aesthetically Pleasing Design
– Easier implementation than mechanical keys
– Touch keys can be molded into the rubber
wristband
▪ Sensors
– IQS213A, IQS263 – Swipe / 3 touch keys
Touch Electrodes (low cost, no ITO)
30 s tip for low cost touch screens in wearables
18x15mm module

7. © 2014 SAS SELTECH - All rights reserved.
Swipe implementation examples
page7
• ITO on screen/display
– Compensation circuit maintains good performance
in high parasitic capacitance environment
• Touch electrode next to active area
– UI has on screen touch experience
– Low cost implementation
– Small sizes still have enough resolution
• Ribbed Touch electrode between LEDs
– Low profile display
– UI to follow user finger tracking with LEDs

8. © 2014 SAS SELTECH - All rights reserved.
Slider and scroll wheel
page8
▪ Features
– Scroll wheel around bezel
– Slider or scroll wheel for volume adjustment
▪ Advantages
– Aesthetically Pleasing Design
– Easier implementation than mechanical keys
▪ Sensors
– IQS213A, IQS263 – Swipe / 3 touch keys
– IQS333 – slider/scroll wheel
Scroll wheel touch electrodes
(low cost, no ITO)

9. © 2014 SAS SELTECH - All rights reserved.
Trackpad solutions
page9
▪ Features
– Predefined set of gestures for tap, forward, backward,
upward, downward
– Configurable for additional gestures, power consumption
– Multi finger support
– Can be used for touchscreen controller
▪ Advantages
– Improved UI – control done on the headphone
– Aesthetics / Modern Design
– Ease of assembly
▪ Sensors
– IQS266, IQS360, IQS525, IQS572-
trackpad and touchscreen controllers
– TPR40/48/54, TPE48/60, TPS48 -
Standard module
Azoteq Standard Trackpad Modules for
BT Headphones and Remote Controls

10. © 2014 SAS SELTECH - All rights reserved.
Unique features
page10
▪ Features
– Avoid accidental activation of a critical function
– Can give another level of user interface for extra features
– Allow blind navigation by highlighting keys on touch before
press (see video)
– Using Azoteq patented technology
▪ Sensors
– IQS360 – low cost trackpad chipset
– IQS525/572/550 – trackpad chipsets
Combining mechanical keys and a trackpad area in the same real-estate
Azoteq 30 second tip for blind navigation

11. © 2014 SAS SELTECH - All rights reserved.
Unique features
page11
▪ Features
– Gestures on headphone cup
– Swipe and scroll wheel
– Tap, Tap & Hold
▪ Sensors
– IQS227 - 1 channel chipset
– IQS263 – 3 channel chipset
– IQS333 – 9 channel chipset
Touch on metal
30 second tip for implementing
scroll and swipe on metal
30 second tip for Touch on metal

12. © 2014 SAS SELTECH - All rights reserved.
Unique features
page12
▪ Features
– Use HALL rotation to control joystick or adjust focus on VR lenses
– Use capcitive key for prox detect (saves battery power)
▪ Sensors
– IQS624 – HALL rotation and 2 capacitive keys
Combination of HALL switch and touch keys in same chipset
▪ Features
– Use HALL switch to turn ON/OFF connectivity
– Use touch keys to play/pause music
▪ Sensors
– IQS620 – HALL switch and 2 capacitive keys
Combination of HALL rotation and touch keys in same chipset
IQS624 introduction

13. Thanks !