Reliable Methodology to FPGA Design Verification and Noise Analysis for Digital Lock-In Amplifiers

The lock-in amplifier (LIA) instruments are designed to provide signal conditioning for precision measurement systems to extract signals from extremely noisy environments. The digital LIAs design often requires a verification process to ensure hardware performance. Thus, hardware description language (HDL) with functional verification strategies offers a powerful tool to provide an field-programmable gate array (FPGA) integrated solution. In this letter, we propose a methodology of design and verification of all-digital LIA and an additive white Gaussian noise (AWGN) module able to measure extremely lower levels of signal-to-noise ratio (SNR) of $\approx $ ${10}^{-{15}}$ or down to −37 dB while a wide reserve of spurious-free dynamic range (SFDR) up to 90 dB on FPGA is ensured. To this end, the designed and implemented FPGA framework for quick, accurate, and comprehensive characterization of a given digital LIA is used to leverage the capabilities of the design under controllable AWGN noise patterns stimulus.