High Gain and Wide Dynamic Range Front-end Receiver for Weak Signal Acoustic Detector

The novel acoustic analog front-end receiver chip basing all-CMOS technology was designed to amplify the weak signal depressed the harmonic distortion and interference of adjacent channels for multi-channel acoustic imaging system. The 48 channel variable gain amplifiers (VGA) with the exponential gain control, multi-channel output data strobe, output buffer and continuous-time and anti-aliasing fourth-order Butterworth low pass filter for high signal-noise-ration (SNR) of analog-to-digital convertor (ADC), and integrated a vertical shift register. By the simulation verification, processing and test, the system shown linearity gain dynamic range 52dB, the equivalent input noise 5.2nV /Hz1/2@ 1.5MHz, and - 3dB bandwidth on 15MHz~92MHz. When the gain was less than 55dB, the second-order harmonic distortion was less than - 40dB, the receiving sensitivity 50μV while signal to noise ration (SNR) 30dB, the power consumption of each channel 6mW at 5V power supply.