Title :
Synchronous Demodulator for Autonomous Sensors
Author :
Casanella, Ramon ; Casas, Óscar ; Ferrari, Marco ; Ferrari, Vittorio ; Pallàs-Areny, Ramon
Author_Institution :
Castelldefels Sch. of Technol., Catalonia Tech. Univ., Barcelona
Abstract :
A novel differential synchronous demodulator is presented that uses the on-off switching characteristic of the power supply in autonomous systems as control signal for demodulation. The proposed circuit, which uses a single op amp and SPDT switch, can be useful in sensors networks or distributed data acquisition systems involving ac sensors or impedance measurements. A prototype demodulator yields a nonlinearity of 0.8% FSR and CMRR = 47 dB at 15 kHz for unity gain. The feasibility of the circuit when supplied by a piezoelectric energy converter is also verified
Keywords :
data acquisition; demodulators; electric impedance measurement; operational amplifiers; power supply circuits; wireless sensor networks; 15 kHz; SPDT switch; ac sensors; autonomous sensors; differential synchronous demodulator; distributed data acquisition systems; impedance measurements; piezoelectric energy converter; power supply; single operational amplifiers; wireless sensor networks; Control systems; Data acquisition; Demodulation; Impedance measurement; Operational amplifiers; Power supplies; Sensor phenomena and characterization; Sensor systems; Switches; Switching circuits; autonomous sensor; impedance measurement; synchronous demodulator;
Conference_Titel :
Instrumentation and Measurement Technology Conference, 2006. IMTC 2006. Proceedings of the IEEE
Conference_Location :
Sorrento
Print_ISBN :
0-7803-9359-7
Electronic_ISBN :
1091-5281
DOI :
10.1109/IMTC.2006.328191
