Data Sheet 291501 issue 1

Plessey Semiconductors Ltd.

Design & Technology Centre, Delta 500, Delta Business Park, Great Western Way, Swindon, UK SN5 7XE

Tel: +44 1793 518000

Fax: +44 1793 518030

1

PS25012A1, PS25012B1

Application Boards for EPIC sensor PS25201A

Figure 1

Description

The PS25012A1 and PS25012B1 are single and

dual

channel

application

boards

for

the

demonstration of the Plessey PS25201A electric

potential sensor.

The PS25201A electric potential sensors on these

boards allow the measurement of a wide range of

electric potential sources from electrophysiological

signals through to spatial electric field. The sensors

incorporate a DC block feature that allows the DC

component of an applied signal to be rejected while

maintaining good low frequency response.

The

electrode surface of the detector is passivated with a

thin dielectric that allows the direct application to a

test surface. In the case of contact with skin there is

no need for electrically conductive gel.

The PS25201A sensor demonstrated on these

boards is an integrated assembly designed for

surface mount assembly on a motherboard.

The application boards provide the regulated +2.5V

and generated -2.5V supplies that are used to

operate the sensor.

This allows the boards to

demonstrate the sensors from a wide, single sided,

power supply voltage while the output of the sensor

can cover the range ±2.1V.

The boards are

connected by a high reliability five pin connector.

Two single channel PS25012A1 boards or a dual

channel PS25012B1 board may be used to generate

a differential signal. A typical example is shown in

Figure 3 below:

Figure 3: Differential signal from two sensors in

contact with the skin showing ECG type

characteristics

Features

•

Ultra high input resistance, typically 5x10

10

.

•

Frequency response (3dB) 200mHz to 4.0kHz.

•

Wide operating voltage from 4.0 to 8.0V.

•

Operating temperature range 0 to 50ºC.

•

200pF load drive capability.

•

Ground referenced output.

•

DC signal rejection.

•

Dual sensor board allows differential operation.

Applications

•

Electrophysiological signal detection.

• ECG/EOG/EMG/EEG

•

Electric field and potential sensing.

• Movement sensing

Figure 1: PS25012A1 single channel board carrying a

single PS25201A sensor

Figure 2: PS25012B1 dual channel board carrying

two PS25201A sensors