Band-Gap

Reference

DOUT

CLKIN

DVDD

DGND

AINP

AINN

AMC1306x

VCM, AVDD

Diagnostic

û Modulator

AGND

AVDD

Reinforced

Isolation

Barrier

21

AMC1306E05, AMC1306E25, AMC1306M05, AMC1306M25

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SBAS734C – MARCH 2017 – REVISED JANAURY 2020

Product Folder Links: AMC1306E05 AMC1306E25 AMC1306M05 AMC1306M25

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8 Detailed Description

8.1 Overview

The differential analog input (comprised of input signals AINP and AINN) of the AMC1306 is a fully-differential

amplifier feeding 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 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 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 AMC1306. The analog input range

is tailored to directly accommodate a voltage drop across a shunt resistor used for current sensing. 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. The

external clock input simplifies the synchronization of multiple current-sensing channels on the system level. The

extended frequency range of up to 21 MHz supports higher performance levels compared to the other solutions

available on the market.

8.2 Functional Block Diagram