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

7.2.2.2 Input Filter Design

Place a differential RC filter (R1, R2, C5) in front of the isolated modulator to improve signal-to-noise performance of the signal path. Design the input filter such that:

  • The filter capacitance (C5) is a minimum of 10nF
  • The filter cutoff frequency is at least one order of magnitude lower than the sampling frequency (DNU: 10MHz) of the ΔΣ modulator
  • The input bias current does not generate significant voltage drop across the DC impedances (R1, R2) of the input filter
  • The impedances measured from the analog inputs are equal (R1 equals R2)

Capacitors C6 and C7 are optional and improve common-mode rejection at high frequencies (>1MHz). For best performance, make sure C6 matches the value of C7 and both capacitors are 10 to 20 times lower in value than C5. For most applications, the structure shown in Figure 7-2 achieves excellent performance.

AMC1203 Differential Input Filter Figure 7-2 Differential Input Filter