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

6.3.2 Modulator

Figure 6-2 conceptualizes the second-order, switched-capacitor, ΔΣ modulator implemented in the AMC1203. The output V6 of the 1-bit, digital-to-analog converter (DAC) is subtracted from the input voltage VIN = (VINN – VINP). This subtraction provides an analog voltage V2 at the input of the first integrator stage. V6 is again subtracted from the output of the first integrator, resulting in a voltage V3 that feeds the input of the second integrator stage. The output of the second integrator stage, V4, is compared against an internal reference voltage VREF. Depending on the value of V4, the output of the comparator potentially changes. In this case, the 1-bit DAC responds on the next clock pulse by changing the associated analog output voltage V6. This change causes the integrators to progress in the opposite direction and forces the integrator output value to track the average input value.

AMC1203 Block Diagram of a Second-Order Modulator Figure 6-2 Block Diagram of a Second-Order Modulator

The modulator shifts the quantization noise to high frequencies. In a typical application, the sigma-delta output bitstream is filtered by a digital low-pass filter to increase the resolution of the analog-to-digital conversion. This filter also converts the 1-bit data stream at a high sampling rate into a higher-bit data word at a lower rate (decimation). TI's C2000™ and Sitara™ microcontroller families offer a programmable, hardwired filter structure, termed a sigma-delta filter module (SDFM), optimized for use with the AMC1203. Alternatively, use a field-programmable gate array (FPGA) or complex programmable logic device (CPLD) to implement the filter.