The input stage of the AMC1306M25E 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 externally provided clock source at the CLKIN pin. The time average of this serial bitstream output is proportional to the analog input voltage. The external clock input simplifies the synchronization of multiple current-sensing channels on the system level.

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 note. The digital modulation used in the AMC1306M25E to transmit data across the isolation barrier, and the isolation barrier characteristics, result in high reliability and common-mode transient immunity.