How to Design Reliable Noise Filtering and Transient Protection for Precision Analog Power Supplies in OCT Devices?

Noise in precision analog power supplies can directly degrade image signal-to-noise ratio. Protection requires a hierarchical strategy. At the board-level power entry point, TVS diodes such as the SMCJ series should be deployed to clamp high-amplitude surges and EFT interference from the power network. Subsequently, an independent local decoupling network should be configured for each power pin of sensitive analog chips (e.g., ADC, op-amp), consisting of a bulk capacitor, a ceramic decoupling capacitor, and a ferrite bead. The ferrite bead must be selected based on the power supply noise spectrum to provide high impedance in specific frequency bands, blocking digital noise crosstalk. All filtering components must be placed as close as possible to the chip pins to minimize coupling paths formed by parasitic inductance.