A 12b‐control ultra‐low‐power low‐noise SC‐VGA for medical ultrasound probes. Issue 10 (30th October 2013)

• Record Type: Journal Article
• Authors: Wang, Peng; Halvorsrød, Thomas M.; Ytterdal, Trond
• Is Part Of: Journal of engineering. Volume 2013:Issue 10(2013)
• Page Start: 55
• Page End: 57
• Publication Date: 2013-10-30
• Subjects: biomedical ultrasonics -- capacitance -- capacitors -- CMOS analogue integrated circuits -- differential amplifiers -- invertors -- low noise amplifiers -- low‐power electronics -- Monte Carlo methods -- switched capacitor networks; ultralow‐power low‐noise SC‐VGA -- medical ultrasound probes -- ultralow‐power low‐noise two‐stage single‐ended‐to‐differential switched‐capacitor variable gain amplifier -- harmonic cardiac imaging ultrasound probes -- inverters -- capacitor arrays -- SC‐amplifiers -- binary‐weighted CAP array -- power consumption -- second harmonic distortion -- HD2 -- Monte Carlo mismatch simulation -- sampling frequency -- complementary metal oxide semiconductor -- frequency 2 MHz to 6 MHz -- gain ‐21 dB to 21 dB -- voltage 1 V; Engineering -- Periodicals; Engineering; Electronic journals; Periodicals; 620.005
• DOI: 10.1049/joe.2013.0088
• Languages: English
• ISSNs: 2051-3305

Abstract

Abstract : 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.