STM8T143 STMicroelectronics, STM8T143 Datasheet - Page 7

• Manufacturer Part Number: STM8T143
• Description: Single-channel capacitive sensor for touch and proximity detection
• Manufacturer: STMicroelectronics

STM8T143
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Description
The STM8T143 is a single channel, fully integrated, touch sensing capacitive sensor. It uses
a ProxSense™ charge transfer capacitive acquisition method that is capable of near range
proximity detection. The STM8T143 offers a state of the art capacitive sensing engine with
an embedded sampling capacitor and voltage regulator allowing the overall solution cost to
be reduced and improving system immunity in noisy environments. It can target a detection
range up to 20 cm thanks to the electrode parasistic capacitance compensation (EPCC)
feature. The EPCC automatically compensates ground parasitic capacitance sources (such
as ground planes, printed circuit board tacks, and large metal objects) which significantly
reduce the proximity detection range.
The application fields or typical functions with proximity features are various and include:
on/off switches, replacement/enhancement, home buttons, backlighting feature on proximity
for user interfaces, wakeup or control function on proximity, find-in-the-dark for lighting
equipment, and companion device for battery saving in portable equipment.
The device has been designed to be used in applications where proximity is required and
touch conditions can prevail for an extended period of time which may result in
uncompensated drift in conventional capacitive sensors. Therefore, a process called DYCAL
is implemented.
The STM8T143 is an ideal alternative, cost-effective, and extremely low power solution to
replace conventional infrared optical proximity sensors. Capacitive sensing technology is not
sensitive to sunlight or artifical light effects. The STM8T143 offers a much lower
consumption (12 µA range versus 100 µA range) and a small form factor (DFN8 2*3*0.65
mm). Lastly, there is no need for a clear opening on the bezel to let light pass through.
The STM8T143 is offered in 8-pin packages and features both touch and proximity sensing
outputs.
The STM8T143 touch pad can sense through almost any dielectric and thereby allows the
electronics to be contained in a sealed enclosure.
ProxSense™ is a trademark of Azoteq (Pty) Ltd.
Doc ID 18315 Rev 3
Description
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