Band-Gap

Reference

DOUT

CLKIN

DVDD

DGND

AINP

AINN

AMC1336

AVDD

Diagnostic

û Modulator

AGND

AVDD

Reinforced

Isolation

Barrier

Charge

Pump

11

AMC1336

www.ti.com

SBAS951 – AUGUST 2019

Product Folder Links: AMC1336

Submit Documentation Feedback

Copyright © 2019, Texas Instruments Incorporated

7 Detailed Description

7.1 Overview

The differential analog input (comprised of input signals AINP and AINN) of the AMC1336 is a chopper-stabilized

buffer, 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 9 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.

described in the ISO72x Digital Isolator Magnetic-Field Immunity application report, available for download at

www.ti.com.

7.2 Functional Block Diagram

7.3 Feature Description

7.3.1 Analog Input

The AMC1336 incorporates front-end circuitry that contains a buffered sampling stage, followed by a ΔΣ

modulator. To support a bipolar input range with a unipolar high-side supply AVDD, the device uses a charge

pump to simplify the overall system design and minimize circuit cost. For reduced offset and offset drift, the input

the switching frequency.