Single Power Supply, Compact, Self-Adaptive Dynamic Range Lock-In Amplifiers

To meet the high dynamic voltage or current range measuring in real-time in the modern electrical industry, ranging from the surface science to non-destructive testing, this paper reports two broad dynamic ranging, universal, and compact digital lock-in amplifier methods for the huge dynamic range signal, termed as the hybrid and all-digital amplifiers. Both have reduced the complex components required in the traditional amplifiers to only two or three components without sacrificing the measuring accuracy, even by less than 0.05% in some situations, which has been evaluated via simulations and experiments with the FPGA circuit. Additionally, benefiting from the single-power supply strategy, the proposed methods are suitable for portable devices, including the pocket spectrometer, mechanical resonator monitor, and powered on battery. Such results in this paper illustrate the phase coherent technology with a compact, universal, and integrated circuit with a promising future.