SBASAO3A May   2023  – September 2023 AMC131M03-Q1

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 Temperature Sensor
        1. 8.3.15.1 Internal Temperature Sensor
        2. 8.3.15.2 External Temperature Sensor
        3. 8.3.15.3 Clock Selection for Temperature Sensor Operation
      16. 8.3.16 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 AMC131M03-Q1 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
      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

8.3.15.2 External Temperature Sensor

Set the TS_EN bit in the CH2_CFG register to 1b, and the TS_SEL bit in the CH2_CFG register to 1b to select the external temperature sensor mode. Set the PGAGAIN2[2:0] bits in the GAIN register to 000b (gain of 1) when using the external temperature sensor. In this mode, the ADC for channel 2 measures the voltage between the AIN2P and AIN12N pins (channel 2 input), as shown in Figure 8-16, for sensing an external temperature sensor (such as a PTC or NTC element).

The PTC or NTC element is powered from the secondary (high-side) supply that is generated by the onboard DC/DC converter and therefore exhibits supply variations. As shown in Figure 8-16, to eliminate supply variations and enable a ratiometric measurement, the ADC reference input for channel 2 in external temperature sensor mode is connected to a voltage Vref_R derived from the secondary (high-side) supply HLDO_OUT using a resistor divider R1 and R2. This reference selection is different from the internal temperature sensor mode and the normal ADC conversion mode, because in both modes the ADC is measured with respect to the internal reference VREF of 1.2 V. R1 and R2 are selected so that Vref_R is also typically 1.2 V.

GUID-20220211-SS0I-JH8C-DWJF-5P2WSWJCHPVQ-low.svg Figure 8-16 External Temperature Sensor Measurement Block Diagram

Equation 9 and Equation 10 determine the external temperature by measuring the temperature-dependent resistance of the NTC or PTC element, assuming a gain of 1.

Equation 9. C o n v e r s i o n R e s u l t   = V s e n s V r e f _ R =   R N T C R N T C + R L D O   ∙   R 1 + R 2 R 2    
Equation 10. R 1 = 320   k Ω ,     R 2 = 240   k Ω ,       R 1 + R 2 R 2   = 2.33  

In Equation 9, ConversionResult is expressed in units ranging from 0 (zero-scale) to 1.0 (full-scale). To obtain ConversionResult from the decimal ADC code, divide the ADC code by 223.

Equation 11. ConversionResult = ADC_CODE / 223

Equation 9 can be transformed into Equation 12, which calculates the temperature-dependent resistance of the NTC or PTC element from the ADC conversion result on channel 2.

Equation 12.   R N T C = R L D O   ∙   C o n v e r s i o n R e s u l t R 1 + R 2 R 2   -     C o n v e r s i o n R e s u l t     =     R L D O   ∙   C o n v e r s i o n R e s u l t 2.33     -     C o n v e r s i o n R e s u l t    

Equation 12 illustrates that the measurement of the NTC or PTC resistance is independent from the secondary (high-side) supply voltage and is therefore ratiometric, eliminating any errors from variation of the supply voltage.