8.1 Overview

The ISO224 is a precision, isolated amplifier with a high input impedance and wide input voltage range suitable for wide range of industrial applications. The input stage of the device drives a delta-sigma (ΔΣ) modulator. The modulator uses the internal voltage reference and clock generator to convert the analog input signal to a digital bitstream. The drivers (called TX in the Functional Block Diagram section) transfer the output of the modulator across the isolation barrier that separates the high-side and low-side voltage domains. The received bitstream and clock are synchronized and processed by a digital-to-analog conversion stage on the low-side and presented as a differential analog output.

The SiO₂-based, double-capacitive isolation barrier supports a high level of magnetic field immunity, as described in ISO72x Digital Isolator Magnetic-Field Immunity. The digital modulation used in the ISO224 and the isolation barrier characteristics result in high reliability and high common-mode transient immunity.