7.1 Overview

The differential analog input (comprised of input signals AINP and AINN) of the AMC1336 is a chopper-stabilized instrumentation amplifier, followed by the switched-capacitor input of a second-order, delta-sigma (ΔΣ) modulator stage that digitizes the input signal into a 1-bit output stream. The 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 with a frequency in the range of 5 MHz to 21 MHz. The time average of this serial bitstream output is proportional to the analog input voltage. The Functional Block Diagram section shows a detailed block diagram of the AMC1336. The 1.6-GΩ differential input resistance of the analog input stage supports low gain-error signal sensing in high-voltage applications using resistive dividers. 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 report, available for download at www.ti.com.