AMC22C11 datasheet(12/33 Pages) TI

12 / 33 page

7 Detailed Description

7.1 Overview

When the voltage on the REF pin is greater than VMSEL, the device operates in positive-comparator mode. This

mode is particularly useful for monitoring positive voltages. The negative comparator (Cmp1) is disabled and

only the positive comparator (Cmp0) is functional. The reference voltage in this mode can be as high as 2.7 V.

The AMC22C11 is an isolated comparator with an open-drain output and optional latch function. The comparator

compares the input voltage (VIN) against the VIT+ threshold that is adjustable from 20 mV to 3 V through an

internally generated 100-μA reference current and a single external resistor. The open-drain output is actively

pulled low when the input voltage (VIN) is higher than the reference value VREF. The behavior when VIN drops

below the trip threshold is determined by the LATCH pin, as described in the Open-Drain Digital Output section.

Galvanic isolation between the high- and low-voltage side of the device is achieved by transmitting the

comparator states across a SiO2-based, capacitive isolation barrier. This 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 scheme used in the AMC22C11 to transmit data across the isolation barrier, and the

isolation barrier characteristics itself, result in high reliability and common-mode transient immunity.

7.2 Functional Block Diagram

GND2

OUT

LATCH

VDD2

GND1

REF

VDD1

AMC22C11

LDO

100 μA

AMC22C11

SBASAJ6 – APRIL 2022

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AMC22C11 Datasheet(PDF) 12 Page - Texas Instruments