The input stage of the AMC1333M10 consists of a fully differential amplifier that feeds the switched-capacitor input of a second-order, delta-sigma (ΔΣ) modulator. The modulator converts the analog input signal into a digital bitstream that is transferred across the isolation barrier that separates the high-side from the low-side. The isolated data output DOUT of the converter provides a stream of digital ones and zeros that is synchronous to the internally generated clock source at the CLKOUT pin. The time average of this serial bitstream output is proportional to the analog input voltage.

The silicon-dioxide (SiO₂) based capacitive isolation barrier supports a high level of magnetic field immunity, as described in the ISO72x Digital Isolator Magnetic-Field Immunity application report. The digital modulation used in the AMC1333M10 to transmit data across the isolation barrier, and the isolation barrier characteristics itself, result in high reliability and common-mode transient immunity.