Title :
Tunable Square-Wave Generator for Integrated Sensor Applications
Author :
Kar, Sougata Kumar ; Sen, Siddhartha
Author_Institution :
Dept. of Electr. Eng., Indian Inst. of Technol., Kharagpur, India
Abstract :
An Operational Transconductance Amplifier (OTA) based square-wave and clock generator with independent control over amplitude and frequency has been presented in this paper. Two out of phase square-waves along with rail to rail clocks are generated which are suitable for integrated sensor applications. Both amplitude and frequency of the waveform generator can be controlled independently by tuning the bias currents of the OTAs. These bias currents are controlled by two highly linear tuning OTAs. The complete circuit is implemented fully on-chip in UMC 0.18 μm CMOS process technology making it possible for integration with micro-sensing devices. The measured results show wide sweep capability of amplitude from 280 mVpp to 1 Vpp and frequency from 120 kHz to 900 kHz approximately with good linearity. This generator is suitable for integrated capacitive and resistive sensors and other instrumentation applications.
Keywords :
CMOS analogue integrated circuits; capacitive sensors; circuit tuning; clocks; electric current control; microsensors; operational amplifiers; square-wave generators; system-on-chip; OTA; UMC CMOS process; amplitude control; bias current control; bias current tuning; clock generator; frequency control; integrated capacitive sensor; integrated resistive sensor; microsensing device; operational transconductance amplifier; size 0.18 mum; tunable square-wave generator; Capacitance; Clocks; Generators; Transconductance; Transistors; Tuning; Amplitude and frequency tuning; integrated sensors and instrumentation; linearity; operational transconductance amplifier; square-wave generator;
Journal_Title :
Instrumentation and Measurement, IEEE Transactions on
DOI :
10.1109/TIM.2011.2128490
