SBASA56 September   2023 AMC131M02

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Revision History
  6. 5 Pin Configuration and Functions
  7. 6 Specifications
    1. 6.1  Absolute Maximum Ratings
    2. 6.2  ESD Ratings
    3. 6.3  Recommended Operating Conditions
    4. 6.4  Thermal Information
    5. 6.5  Insulation Specifications
    6. 6.6  Safety-Related Certifications
    7. 6.7  Safety Limiting Values
    8. 6.8  Electrical Characteristics
    9. 6.9  Timing Requirements
    10. 6.10 Switching Characteristics
    11. 6.11 Timing Diagrams
    12. 6.12 Typical Characteristics
  8. 7 Parameter Measurement Information
    1. 7.1 Noise Measurements
  9. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1  Isolated DC/DC Converter
        1. 8.3.1.1 DC/DC Converter Failure Detection
      2. 8.3.2  High-Side Current Drive Capability
      3. 8.3.3  Isolation Channel Signal Transmission
      4. 8.3.4  Input ESD Protection Circuitry
      5. 8.3.5  Input Multiplexer
      6. 8.3.6  Programmable Gain Amplifier (PGA)
      7. 8.3.7  Voltage Reference
      8. 8.3.8  Internal Test Signals
      9. 8.3.9  Clocking and Power Modes
      10. 8.3.10 ΔΣ Modulator
      11. 8.3.11 Digital Filter
        1. 8.3.11.1 Digital Filter Implementation
          1. 8.3.11.1.1 Fast-Settling Filter
          2. 8.3.11.1.2 SINC3 and SINC3 + SINC1 Filter
        2. 8.3.11.2 Digital Filter Characteristic
      12. 8.3.12 Channel Phase Calibration
      13. 8.3.13 Calibration Registers
      14. 8.3.14 Register Map CRC
      15. 8.3.15 General-Purpose Digital Output (GPO)
    4. 8.4 Device Functional Modes
      1. 8.4.1 Power-Up and Reset
        1. 8.4.1.1 Power-On Reset
        2. 8.4.1.2 SYNC/RESET Pin
        3. 8.4.1.3 RESET Command
      2. 8.4.2 Start-Up Behavior After Power-Up
      3. 8.4.3 Start-Up Behavior After a Pin Reset or RESET Command
      4. 8.4.4 Start-Up Behavior After a Pause in CLKIN
      5. 8.4.5 Synchronization
      6. 8.4.6 Conversion Modes
        1. 8.4.6.1 Continuous-Conversion Mode
        2. 8.4.6.2 Global-Chop Mode
      7. 8.4.7 Power Modes
      8. 8.4.8 Standby Mode
    5. 8.5 Programming
      1. 8.5.1 Serial Interface
        1. 8.5.1.1  Chip Select (CS)
        2. 8.5.1.2  Serial Data Clock (SCLK)
        3. 8.5.1.3  Serial Data Input (DIN)
        4. 8.5.1.4  Serial Data Output (DOUT)
        5. 8.5.1.5  Data Ready (DRDY)
        6. 8.5.1.6  Conversion Synchronization or System Reset (SYNC/RESET)
        7. 8.5.1.7  SPI Communication Frames
        8. 8.5.1.8  SPI Communication Words
        9. 8.5.1.9  Short SPI Frames
        10. 8.5.1.10 Communication Cyclic Redundancy Check (CRC)
        11. 8.5.1.11 SPI Timeout
      2. 8.5.2 ADC Conversion Data
      3. 8.5.3 Commands
        1. 8.5.3.1 NULL (0000 0000 0000 0000)
        2. 8.5.3.2 RESET (0000 0000 0001 0001)
        3. 8.5.3.3 STANDBY (0000 0000 0010 0010)
        4. 8.5.3.4 WAKEUP (0000 0000 0011 0011)
        5. 8.5.3.5 LOCK (0000 0101 0101 0101)
        6. 8.5.3.6 UNLOCK (0000 0110 0101 0101)
        7. 8.5.3.7 RREG (101a aaaa annn nnnn)
          1. 8.5.3.7.1 Reading a Single Register
          2. 8.5.3.7.2 Reading Multiple Registers
        8. 8.5.3.8 WREG (011a aaaa annn nnnn)
      4. 8.5.4 ADC Output Buffer and FIFO Buffer
      5. 8.5.5 Collecting Data for the First Time or After a Pause in Data Collection
    6. 8.6 AMC131M02 Registers
  10. 9 Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 Unused Inputs and Outputs
      2. 9.1.2 Antialiasing
      3. 9.1.3 Minimum Interface Connections
      4. 9.1.4 Multiple Device Configuration
      5. 9.1.5 Calibration
      6. 9.1.6 Troubleshooting
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Voltage Measurement
        2. 9.2.2.2 Current Shunt Measurement
      3. 9.2.3 Application Curves
    3. 9.3 Power Supply Recommendations
    4. 9.4 Layout
      1. 9.4.1 Layout Guidelines
      2. 9.4.2 Layout Example
  11. 10Device and Documentation Support
    1. 10.1 Documentation Support
      1. 10.1.1 Related Documentation
    2. 10.2 Receiving Notification of Documentation Updates
    3. 10.3 Support Resources
    4. 10.4 Trademarks
    5. 10.5 Electrostatic Discharge Caution
    6. 10.6 Glossary
  12. 11Mechanical, Packaging, and Orderable Information

Package Options

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

9.2.2.2 Current Shunt Measurement

The analog front-end for current measurement is different from the analog front-end for voltage measurement. Figure 9-5 shows the analog front-end used for current measurement at the ADC channel 0, which consists of the shunt resistor RSHUNT and an RC low-pass antialiasing filter (RFILT and CFILT).

For a shunt value of 200 μΩ and a maximum current of IMAX = 100 A, the maximum voltage drop across the shunt is VSHUNT = RSHUNT × IMAX = 200 μΩ × ±100 A = ±20 mV.

To measure this shunt voltage, configure channel 0 of the AMC131M02 for gain = 32, which allows differential voltage measurements of VIN1 = VAIN1P – VAIN1N = ±VREF / 8 = ±1.2 V / 32 = ±37.5 mV. The integrated charge pump in the device allows voltage measurements 1.3 V below HGND while using a unipolar analog power supply. This bipolar voltage measurement capability is important because one side of the shunt is connected to the same ISO_GND potential as the HGND pin of the AMC131M02, which means that the absolute voltage that the device must measure during the current measurement is up to 37.5 mV below HGND.