A complete low voltage analog lock-in amplifier to recover sensor signals buried in noise for embedded applications

This paper presents a low-voltage 3V single supply analog lock-in amplifier (LIA) for processing small AC sensor signals buried in noise, including those presenting a relative phase with respect to the reference signal. Reference and bias sensor signals are provided by a quadrature oscillator. Experimental results confirm the capability of the proposed lock-in amplifier to effectively recover information from signal to noise ratios below 0.025, with an error below 9%.