Chip senses gesture through electric fields


The PS25401A is an ultra high impedance non-contact solid state electric potential sensor. It can be used to detect field disturbance due to the movement of a near-by object. This functionality can be employed in a range of applications including security motion sensors and non-contact electric switches for lighting, door opening, toys etc

The device uses active feedback techniques to both lower the effective input capacitance of the sensing element (Cin) and boost the input resistance (Rin). These techniques are used to realize a sensor with a frequency response suitable for remote sensing applications.

Also known as PS25401A EPIC Sensor.


  • Ultra high effective input resistance, typically 20GΩ.
  • Effective input capacitance as low as 15pF.
  • Upper 3dB point typically 10kHz.
  • Operates with bipolar power supply from ±2.4V to ±4.0V.
  • Sensors supplied in a custom package with exposed pins for surface mount assembly

Chip senses gesture through electric fields

Plessey has released an electrostatic field sensing chip for security, switching and gaming applications.

It is the second member of the firm’s EPIC (electric potential IC) range, the first of which was a non-contact EEG (heart waveform) monitor.

“We have optimised the base layout of the EPIC sensor chip such that discrete movements of the human body can be detected with a range of up to several metres,” said Plessey CTO Dr Keith Strickland. “For example, the sensor can be configured to detect the proximity of a hand or to detect specific hand motions depending on the chip variant and the appropriate selection of circuit components external to the sensor.”

Called PS25401, the new chip can detect movement through walls, said Plessey, and can drive a relay “to act as a simple non-touch electric switch. It can also be used to replace, or as an adjunct to, a passive infra-red (PIR) sensor.”


For more read: Chip senses gesture through electric fields

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Ibrar Ayyub

I am an experienced technical writer holding a Master's degree in computer science from BZU Multan, Pakistan University. With a background spanning various industries, particularly in home automation and engineering, I have honed my skills in crafting clear and concise content. Proficient in leveraging infographics and diagrams, I strive to simplify complex concepts for readers. My strength lies in thorough research and presenting information in a structured and logical format.

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