PS25454
EPIC Ultra High Impedance Movement Sensor
Advance Information
Data Sheet 291966 issue 1
FEATURES Ordering Information
Ultra high effective input resistance, typically 20G.
PS25454
Effective input capacitance as low as 15pF. Custom package
Upper 3dB point typically 20kHz.
-25C to +75C
Operates with bipolar power supply from 2.4V to 5.5V.
Sensors supplied in a custom package with exposed pins for
surface mount assembly.
Plessey Semiconductors Electric Potential
Integrated Circuit (EPIC) product line targets a
range of applications.
APPLICATIONS
The PS25454 is an ultra high impedance non-
Proximity switching of lighting and similar electric circuits
contact solid state electric potential sensor. It
Remote control of TVs and other domestic appliances can be used to detect field disturbance due to
the movement of a near-by object. This
Presence detection for security / alarm systems
functionality can be employed in a range of
Room occupancy detection for rescue services
applications including security motion sensors
Simple gesture recognition to control childrens toys
and non-contact electric switches for lighting,
Controller-less computer gaming systems
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
realise a sensor with a frequency response
suitable for remote sensing applications.
Fig. 1 The PS25454 Sensor Top and Bottom Fig. 2 Internal circuit of EPIC Movement Sensor
Data Sheet 291966 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 Web: www.plesseysemi.com
1 PS25454
ELECTRICAL CHARACTERISTICS
T = -25C to +75C,Vdd/Vss 2.4V to 5..5V. The electrical characteristics are guaranteed by either production
amb
test or by design and characterisation. They apply within the specified ambient temperature and supply voltage
unless otherwise stated.
Value
Units
Characteristics Conditions
Min. Typ. Max.
Supply voltage 2.4 5.5 V Bipolar supply, Gnd=0V
Supply current 1.5 2.5 3.5 mA
Effective input resistance 20 G
Effective input capacitance 15 pF As measured at the sensor electrode
Voltage Gain (Av) 10
Set by internal DC signal rejection
Lower -3dB point 0.20 Hz
network coupling capacitor 250pF
Upper -3dB point 20.0 kHz
Noise tbd
--33ddBB
00..22HHzz 2200..00kkHHzz
Fig. 3 Typical Bode Plot for PS25454 Sensor with Coupling through 250pF Capacitor
Data Sheet 291966 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 Web: www.plesseysemi.com
2