6 Detailed Description

6.1 Overview

The AMC0380D is a precision, galvanically isolated amplifier with a high-voltage AC, high impedance input, and

fixed-gain differential output. The input stage of the device drives 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.

On the low-side, the received bitstream is processed by a fourth-order analog filter that outputs a differential

signal at the OUTP and OUTN pins. This differential output signal is proportional to the input signal.

The 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 AMC0380D

transmits data across the isolation barrier. This modulation, and the isolation barrier characteristics, result in high

reliability and high common-mode transient immunity.

6.2 Functional Block Diagram

VDD2

OUTP

OUTN

GND2

ΔΣ Modulator

Reference

10 MHz Oscillator

SNSP

GND1

SNSN

VDD1

R1

HVIN

1

5

4

6

2

R2

14

11

10

9

Analog Filter

6.3 Feature Description

6.3.1 Analog Input

The resistive divider at the input of the AMC0380D scales down the voltage applied to the HVIN pin to a ±1V

linear full-scale level. This signal is available on the SNSP pin, which is also the input of the analog signal chain.

The high-impedance input buffer on the SNSP pin feeds a second-order, switched-capacitor, feed-forward ΔΣ

modulator. The modulator converts the analog signal into a bitstream that is transferred across the isolation

barrier, as described in the Isolation Channel Signal Transmission section.

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AMC0380D

SBASAT0 – SEPTEMBER 2025

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