SBAS951B August   2019  – April 2020 AMC1336

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Simplified Schematic
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
    1.     Pin Functions
  6. 6 Specifications
    1. Table 1.  Absolute Maximum Ratings
    2. Table 2.  ESD Ratings
    3. Table 3.  Recommended Operating Conditions
    4. Table 4.  Thermal Information
    5. Table 5.  Power Ratings
    6. Table 6.  Insulation Specifications
    7. Table 7.  Safety-Related Certifications
    8. Table 8.  Safety Limiting Values
    9. Table 9.  Electrical Characteristics
    10. Table 10. Switching Characteristics
    11. 6.1       Insulation Characteristics Curves
    12. 6.2       Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Analog Input
      2. 7.3.2 Modulator
      3. 7.3.3 Isolation Channel Signal Transmission
      4. 7.3.4 Clock Input
      5. 7.3.5 Digital Output
    4. 7.4 Device Functional Modes
      1. 7.4.1 Output Behavior in Case of a Full-Scale Input
      2. 7.4.2 AVDD Diagnostics and Fail-Safe Output
  8. 8 Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 Digital Filter Usage
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
      3. 8.2.3 Application Curve
      4. 8.2.4 What to Do and What Not to Do
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Device Support
      1. 11.1.1 Device Nomenclature
        1. 11.1.1.1 Isolation Glossary
    2. 11.2 Documentation Support
      1. 11.2.1 Related Documentation
    3. 11.3 Receiving Notification of Documentation Updates
    4. 11.4 Community Resources
    5. 11.5 Trademarks
    6. 11.6 Electrostatic Discharge Caution
    7. 11.7 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

8.1.1 Digital Filter Usage

The modulator generates a bitstream that is processed by a digital filter to obtain a digital word similar to a conversion result of a conventional analog-to-digital converter (ADC). Equation 2 shows a sinc3-type filter, which is a very simple filter that is built with minimal effort and hardware:

Equation 2. AMC1336 q_hz_sbas734.gif

This filter provides the best output performance at the lowest hardware size (count of digital gates) for a second-order modulator. All the characterization in this document is also done with a sinc3 filter with an oversampling ratio (OSR) of 256 and an output word width of 16 bits.

An example code for implementing a sinc3 filter in an FPGA is discussed in the Combining the ADS1202 with an FPGA Digital Filter for Current Measurement in Motor Control Applications application note, available for download at www.ti.com.