Open AccessA 12b‐control ultra‐low‐power low‐noise SC‐VGA for medical ultrasound probes
Author(s) -
Wang Peng,
Halvorsrød Thomas M.,
Ytterdal Trond
Publication year - 2013
Publication title -
the journal of engineering
Language(s) - English
Resource type - Journals
ISSN - 2051-3305
DOI - 10.1049/joe.2013.0088
Subject(s) - variable gain amplifier , video graphics array , total harmonic distortion , amplifier , electrical engineering , materials science , noise (video) , capacitor , cmos , voltage , physics , electronic engineering , operational amplifier , optoelectronics , engineering , computer science , artificial intelligence , image (mathematics)
This Letter presents a 12b‐control ultra‐low‐power low‐noise two‐stage single‐ended to differential switched‐capacitor variable gain amplifier (SC‐VGA) for 2–6‐MHz second harmonic cardiac imaging ultrasound probes in 0.18 μm complementary metal oxide semiconductor. The proposed SC‐VGA consists of inverters and capacitor (CAP) arrays. By adopting inverters instead of operational trans‐conductance amplifiers (OTAs) in traditional SC‐amplifiers, both the power and noise are significantly improved. Each stage has a 6b binary‐weighted CAP array, and in total the 12b CAP arrays achieve the dB‐in‐linear gain range from − 21 to 21 dB. The CAP array is divided between the upper 3b and lower 3b by a CAP to decrease the capacitance spread. The total power consumption is 150 μA at 1 V supply voltage, and the input referred noise is 6.5 nV/√HZ at 4 MHz. The second harmonic distortion (HD2) has the mean value − 77 dB at the 460 mV peak‐to‐peak output swing for 50 samples of Monte Carlo mismatch simulation with a 30 MHz sampling frequency.