Low noise, low power variable gain amplifier for ultrasounds

This paper presents the simulation of a variable gain amplifier from three perspectives: functional, using LTspice circuit simulator; signal-to-noise-ratio, computed with Excel and power consumption, estimated with ACEplorer power simulator. The architectural decisions are taken based on these simulations to meet the following requirements: a dynamic range greater than 60 dB, the frequency domain from 0.1 to 3 MHz, the signal to noise ratio greater than 12 dB (for an input sensitivity better than 50 microvolts), and power consumption lower than 20 mW. The proposed circuit is realized with current feedback amplifiers.