SBAS427D February   2008  – June 2024 AMC1203

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5.   Device Comparison Table
  6. 4 Pin Configuration and Functions
  7. 5 Specifications
    1. 5.1  Absolute Maximum Ratings
    2. 5.2  ESD Ratings
    3. 5.3  Recommended Operating Conditions
    4. 5.4  Thermal Information
    5. 5.5  Power Ratings
    6. 5.6  Insulation Specifications
    7. 5.7  Safety-Related Certifications
    8. 5.8  Safety Limiting Values
    9. 5.9  Electrical Characteristics
    10. 5.10 Switching Characteristics
    11. 5.11 Timing Diagram
    12. 5.12 Typical Characteristics
  8. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1 Analog Input
      2. 6.3.2 Modulator
      3. 6.3.3 Digital Output
    4. 6.4 Device Functional Modes
  9. 7 Application and Implementation
    1. 7.1 Application Information
    2. 7.2 Typical Application
      1. 7.2.1 Design Requirements
      2. 7.2.2 Detailed Design Procedure
        1. 7.2.2.1 Shunt Resistor Sizing
        2. 7.2.2.2 Input Filter Design
        3. 7.2.2.3 Bitstream Filtering
      3. 7.2.3 Application Curve
    3. 7.3 Best Design Practices
    4. 7.4 Power Supply Recommendations
    5. 7.5 Layout
      1. 7.5.1 Layout Guidelines
      2. 7.5.2 Layout Example
  10. 8 Device and Documentation Support
    1. 8.1 Documentation Support
      1. 8.1.1 Related Documentation
    2. 8.2 Receiving Notification of Documentation Updates
    3. 8.3 Support Resources
    4. 8.4 Trademarks
    5. 8.5 Electrostatic Discharge Caution
    6. 8.6 Glossary
  11. 9 Revision History
  12. 10Mechanical, Packaging, and Orderable Information
    1. 10.1 Mechanical Data

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

6.1 Overview

The AMC1203 is a single-channel, second-order, CMOS delta-sigma (ΔΣ) modulator designed for high-resolution, analog-to-digital conversions of AC signals. The differential analog input of the AMC1203 is implemented with a switched-capacitor circuit. The isolated output of the converter (DOUT) provides a stream of digital ones and zeros. This bitstream is synchronous to the internally generated clock provided on the CLKOUT pin. The time average of this serial output is proportional to the analog input voltage.

The modulator shifts the quantization noise to high frequencies. Therefore, use a low-pass digital filter (such as a Sinc-filter) at the device output to increase the signal-to-noise ratio (SNR). The Sinc-filter also converts the 1-bit data stream at a high sampling rate into a higher-bit data word at a lower rate (decimation). Use a microcontroller (MCU) with integrated sigma-delta-filter-module (SDFM) or a field-programmable gate array (FPGA) to implement the filter.

The overall performance (speed and resolution) depends on the selection of an appropriate oversampling ratio (OSR) and filter type. A higher OSR results in higher resolution while operating at a lower refresh rate. A lower OSR results in lower resolution, but provides data at a higher refresh rate. This system allows flexibility with the digital filter design and is capable of analog-to-digital conversion results of 256 OSR and exceeding an 84dB dynamic range.

The silicon-dioxide (SiO2) based capacitive isolation barrier supports a high level of magnetic field immunity; see the ISO72x Digital Isolator Magnetic-Field Immunity application note. The AMC1203 uses digital modulation to transmit data across the isolation barrier. This modulation, and the isolation barrier characteristics, result in high reliability in noisy environments and high common-mode transient immunity.