STMicroelectronics EVALST-3PHISOSD Evaluation board

     The STMicroelectronics EVALST-3PHISOSD evaluation board features a complete three-phase ammeter with a low cost shunt current sensor. The solution is based on ISOSD61, a single-channel, electrically isolated, second-order Σ-Δ modulator that measures current in each phase through a shunt current sensor. The sensor circuit and PCB layout are optimized to maximize the signal-to-noise ratio and achieve optimal accuracy.

     The STMicroelectronics ISOSD61 outputs a delta-Sigma bit stream of current through a microcontroller synchronized clock (up to 15MHz) and oversamples the signal. The firmware embedded in the solution utilizes the STM32F413RH's DFSDM filter to convert three bit streams into 24-bit current data at an optional sampling rate. The firmware also uses a virtual COM port for communication, allowing easy access to internal parameters to read data and calibrate the board.