High-precision oxygen dissolving instrument system and special SoC

The invention belongs to the technical field of sensing measuring instruments, and particularly relates to a dissolved oxygen meter system and a special SoC. The dissolved oxygen meter system comprises a transmitting module (RDO, FIR and current domain DAC), a sensing module (a fluorescent film, an optical filter and a dissolved oxygen solution), a receiving module (PD, TIA, PGA and an analog phase-locked amplification module) and a signal processing and control module. According to the system, RDO, FIR and DAC are used for generating sinusoidal current signals to drive red light and blue light LEDs, generated fluorescence is received by PD and converted into current signals, the current signals are converted into voltage signals through TIA, and the voltage signals are converted into differential signals through PGA; after an output signal passes through the PGA and the filter through the analog phase-locked amplification module, harmonic waves are eliminated, and the maximum-range input of the ADC is achiev