Title :
A CMOS frequency-mixing transimpedance amplifier with 5nArms input noise for frequency-domain near-infrared spectroscopy
Author :
Yun, Ruida ; Joyner, Valencia M.
Author_Institution :
Dept. of Electr. & Comput. Eng., Tufts Univ., Medford, MA, USA
Abstract :
A novel frequency mixing transimpedance amplifier (FM-TIA) is proposed and implemented in 0.18μm CMOS for low-noise detection of sinusoidally-modulated optical signals in frequency-domain near infrared (NIR) spectroscopy instrumentation. The FM-TIA topology employs a T-feedback resistor network incorporating gate-controlled transistors for resistance modulation, enabling operation in both wideband and frequency-mixing mode. In wideband mode, the TIA achieves a transimpedance gain of 110 dBΩ, 263 MHz bandwidth, 230 nArms total integrated input current noise and 1 dB compression point of 1.65 μA for 4pF photodiode capacitance. In frequency-mixing mode, the amplifier is capable of directly downconverting and amplifying photocurrent signals generated by near-infrared excitation light modulated at 100 MHz. The FM-TIA obtains 5 nArms input noise, current-to-voltage conversion gain of 93 dBQ, and 1 dB compression point of 1.1 μA with up to 47 dB dynamic range. The amplifier consumes only 22 mW of power from a 1.8 V supply.
Keywords :
CMOS analogue integrated circuits; biomedical equipment; infrared spectroscopy; integrated circuit noise; low-power electronics; operational amplifiers; optical signal detection; photoconductivity; resistors; CMOS frequency mixing transimpedance amplifier; FM-TIA topology; T-feedback resistor network; bandwidth 263 MHz; capacitance 4 pF; compression point; current 1.1 muA; current 1.65 muA; current-to-voltage conversion gain; frequency 100 MHz; frequency-domain near infrared spectroscopy; gate-controlled transistors; near-infrared excitation light; photocurrent; power 22 mW; sinusoidally-modulated optical signal low-noise detection; size 0.18 mum; voltage 1.8 V; Frequency modulation; Gain; Noise; Radio frequency; Topology; Transistors; Wideband;
Conference_Titel :
Biomedical Circuits and Systems Conference (BioCAS), 2010 IEEE
Conference_Location :
Paphos
Print_ISBN :
978-1-4244-7269-7
Electronic_ISBN :
978-1-4244-7268-0
DOI :
10.1109/BIOCAS.2010.5709615
