STMicroelectronics EVALSTPM-3PHISO Evaluation Board

STMicroelectronics EVALSTPM-3PHISO Evaluation Board features a complete three-phase energy meter with cost-effective shunt current sensors. The solution is based on the STPMS2 double-channel, 24-bit second-order sigma-delta modulator, measuring current and voltage for each phase through a voltage divider and a shunt current sensor. The sensing circuitry and PCB layout are optimized to maximize the signal-to-noise ratio for accuracy. The STMicroelectronics STPMS2 oversamples the signal using a 4MHz clock synchronized by the microcontroller and outputs voltage and current sigma-delta bitstreams multiplexed on the same pin. The two-wire communication between the STPMS2 modulator and the MCU is isolated by STISO621W, a 6kV galvanic isolated interface, allowing up to 100Mbps rate and low pulse distortion (< 3ns) for fast and safe data transfer between isolated domains.