Title :
A fully differential amplifier with CMOS feedback biasing for sensing CMUT signals
Author :
Bose, Soumya ; Mandal, Pradip
Author_Institution :
India Design Center, Rambus Inc., Bangalore, India
fDate :
Feb. 28 2014-March 2 2014
Abstract :
The paper illustrates design of a fully differential amplifier to sense current signals generated by CMUT for ultrasound imaging. Detection of reflected ultrasonic waves from body tissues requires low noise amplifier with wide input dynamic range. The transducer, being capacitive, isolates dc voltage from the input of the amplifier necessitating additional biasing circuit. In this work, a differential amplifier topology is chosen for its ability to reject common mode interference. Biasing is done by low frequency feedback using CMOS transistors which do not add significant noise to the system. The amplifier is designed in 0.18 μm CMOS process. Its input referred noise is 24.3 μV rms in the band 1-15 MHz. At 10 MHz it provides a gain of 25.5 dB with an input dynamic range of 62.5 dB. The amplifier consumes 314 μW of power with 1.8V-GND supply.
Keywords :
CMOS analogue integrated circuits; biological tissues; biomedical electronics; biomedical imaging; capacitive sensors; circuit feedback; differential amplifiers; low noise amplifiers; microsensors; ultrasonic imaging; ultrasonic transducers; CMOS feedback biasing circuit; CMOS transistors; body tissues; capacitive micromachined ultrasonic transducer; common mode interference rejection; differential amplifier topology; frequency 1 MHz to 15 MHz; fully differential amplifier; gain 25.5 dB; isolates dc voltage; low frequency feedback; low noise amplifier; power 314 muW; reflected ultrasonic wave detection; sensing CMUT signals; size 0.18 mum; ultrasound imaging; voltage 1.8 V; voltage 24.3 muV; wide input dynamic range; Acoustics; CMOS integrated circuits; Gain; Logic gates; Noise; Sensors; Transistors;
Conference_Titel :
Students' Technology Symposium (TechSym), 2014 IEEE
Conference_Location :
Kharagpur
Print_ISBN :
978-1-4799-2607-7
DOI :
10.1109/TechSym.2014.6807933
