SBASAS0 December   2025 AMC0300R-Q1

PRODUCTION DATA  

  1.   1
  2. Features
  3. Applications
  4. Description
  5. Device Comparison Table
  6. Pin Configuration and Functions
  7. Specifications
    1. 6.1  Absolute Maximum Ratings
    2. 6.2  ESD Ratings
    3. 6.3  Recommended Operating Conditions
    4. 6.4  Thermal Information (D Package)
    5. 6.5  Thermal Information (DWV Package)
    6. 6.6  Power Ratings 
    7. 6.7  Insulation Specifications (Basic Isolation)
    8. 6.8  Insulation Specifications (Reinforced Isolation)
    9. 6.9  Safety-Related Certifications (Basic Isolation)
    10. 6.10 Safety-Related Certifications (Reinforced Isolation)
    11. 6.11 Safety Limiting Values (D Package)
    12. 6.12 Safety Limiting Values (DWV Package)
    13. 6.13 Electrical Characteristics
    14. 6.14 Switching Characteristics
    15. 6.15 Timing Diagram
    16. 6.16 Insulation Characteristics Curves
    17. 6.17 Typical Characteristics
  8. 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 Isolation Channel Signal Transmission
      3. 7.3.3 Analog Output
    4. 7.4 Device Functional Modes
  9. Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 Input Filter Design
        2. 8.2.2.2 Connecting the REFIN Pin
      3. 8.2.3 Application Curves
    3. 8.3 Best Design Practices
    4. 8.4 Power Supply Recommendations
    5. 8.5 Layout
      1. 8.5.1 Layout Guidelines
      2. 8.5.2 Layout Example
  10. Device and Documentation Support
    1. 9.1 Documentation Support
      1. 9.1.1 Related Documentation
    2. 9.2 Receiving Notification of Documentation Updates
    3. 9.3 Support Resources
    4. 9.4 Trademarks
    5. 9.5 Electrostatic Discharge Caution
    6. 9.6 Glossary
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information
    1. 11.1 Mechanical Data

Input Filter Design

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

  • The cutoff frequency of the filter is at least one order of magnitude lower than the sampling frequency (20MHz) of the ΔΣ modulator
  • The input bias current does not generate significant voltage drop across the DC impedance of the input filter
  • The impedances measured from the analog inputs are equal

Place capacitors C6 and C7 to improve common-mode rejection at high frequencies (>1MHz) and to improve offset voltage performance. For best performance, verify C6 matches the value of C7 and that both capacitors are 10 to 20 times lower in value than C5. NP0-type capacitors offer low temperature drift and low voltage coefficients, and are preferred for common-mode filtering.

For most applications, the structure shown in Figure 8-2 achieves excellent performance.

AMC0300R-Q1 AMC0200R-Q1 Input Filter Figure 8-2 Input Filter