Abstract
A low voltage low power operational transconductance amplifier (OTA) based on a bulk driven cell and its application to implement a tunable Gm-C filter is presented. The linearity of the OTA is improved by attenuation and source degeneration techniques. The attenuation technique is implemented by bulk driven cell which is used for low supply voltage circuits. The OTA is designed to operate with a 0.9 V supply voltage and consumes 58.8 μW power. A 600 mVppd sine wave input signal at 1 MHz frequency shows total harmonic distortion (THD) better than -40 dB over the tuning range of the transconductance. The OTA has been used to realize a tunable Gm-C low-pass filter with gain tuning from 5 dB to 21 dB with 4 dB gain steps, which results in power consumptions of 411.6 to 646.8 μW. This low voltage filter can operate as channel select filter and variable gain amplifier (VGA) for wireless sensor network (WSN) applications. The proposed OTA and filter have been simulated in 0.18 μm CMOS technology. Corner case and temperature simulation results are also included to forecast process and temperature variation affects after fabrication.
Highlights
Due to the spreading market of portable electronic equipments, low power low voltage circuit design has become an important goal of electronic circuits industry
The operational transconductance amplifier (OTA) has been used to realize a tunable Gm-C low-pass filter with gain tuning from 5 dB to 21 dB with 4 dB gain steps, which results in power consumptions of 411.6 to 646.8 μW
Like wireless sensor networks (WSNs), need low supply voltage circuits for proper operation which results in reducing their weight and increasing their battery life time
Summary
Due to the spreading market of portable electronic equipments, low power low voltage circuit design has become an important goal of electronic circuits industry. Like wireless sensor networks (WSNs), need low supply voltage circuits for proper operation which results in reducing their weight and increasing their battery life time. Operational transconductor amplifier (OTA) is an important building block of many analog circuits like filters, data converters, etc. This block converts input voltage to output current with a linear transformation factor. The linearity of the OTA is an important issue because the linearity of the overall system would be determined by this block This issue becomes very challenging under the low supply voltage and limited power consumption. Novel circuit design techniques should be considered to improve linearity performances of the OTA and overcome the deterioration of its specifications
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call