Description

This reference design provides solution for accurate measurement of 16-channel wide AC analog inputs (voltage and current) using precision 16-channel 16-bit 1-MSPS dual simultaneous-sampling ADC covering protection and measurement requirements (including sampling requirements as per IEC61850-9-2) simplifying system design, improving trip time performance and reliability. Coherent sampling of the analog inputs with configurable samples per cycles and programmable over sampling rate improves measurement performance. The reference design performance has been tested over wide temperature range with internal or external reference configured and no appreciable variation in error was observed. The alarm feature identifies the AC AIM faults on a sample basis for faster fault detection. ADS8688A ADC has an additional auxiliary channel to diagnose the output of the digital isolator supply or to compensate the measured analog inputs for temperature drift.