SBASA22A september   2022  – july 2023 ADS131B26-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 Electrical Characteristics
    6. 6.6 Timing Requirements
    7. 6.7 Switching Characteristics
    8. 6.8 Timing Diagram
    9. 6.9 Typical Characteristics
  8. 7 Parameter Measurement Information
    1. 7.1 Offset Drift Measurement
    2. 7.2 Gain Drift Measurement
    3. 7.3 Noise Performance
  9. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Naming Conventions
      2. 8.3.2 Precision Voltage References (REFA, REFB)
      3. 8.3.3 Clocking (MCLK, OSCM, OSCD)
      4. 8.3.4 ADC1y
        1. 8.3.4.1 ADC1y Input Multiplexer
        2. 8.3.4.2 ADC1y Programmable Gain Amplifier (PGA)
        3. 8.3.4.3 ADC1y ΔΣ Modulator
        4. 8.3.4.4 ADC1y Digital Filter
        5. 8.3.4.5 ADC1y Offset and Gain Calibration
        6. 8.3.4.6 ADC1y Conversion Data
      5. 8.3.5 ADC2y
        1. 8.3.5.1 ADC2y Input Multiplexer
        2. 8.3.5.2 ADC2y Programmable Gain Amplifier (PGA)
        3. 8.3.5.3 ADC2y ΔΣ Modulator
        4. 8.3.5.4 ADC2y Digital Filter
        5. 8.3.5.5 ADC2y Offset and Gain Calibration
        6. 8.3.5.6 ADC2y Sequencer
        7. 8.3.5.7 VCMy Buffers
        8. 8.3.5.8 ADC2y Measurement Configurations
        9. 8.3.5.9 ADC2y Conversion Data
      6. 8.3.6 ADC3y
      7. 8.3.7 General-Purpose Digital Inputs and Outputs (GPIO0 to GPIO4)
        1. 8.3.7.1 GPIOx PWM Output Configuration
        2. 8.3.7.2 GPIOx PWM Input Readback
      8. 8.3.8 General-Purpose Digital Inputs and Outputs (GPIO0A, GPIO1A, GPIO0B, GPIO1B)
      9. 8.3.9 Monitors and Diagnostics
        1. 8.3.9.1  Supply Monitors
        2. 8.3.9.2  Clock Monitors
        3. 8.3.9.3  Digital Monitors
          1. 8.3.9.3.1 Register Map CRC
          2. 8.3.9.3.2 Memory Map CRC
          3. 8.3.9.3.3 GPIO Readback
        4. 8.3.9.4  Communication Monitors
        5. 8.3.9.5  Fault Flags and Fault Masking
        6. 8.3.9.6  FAULT Pin
        7. 8.3.9.7  Diagnostics and Diagnostic Procedure
        8. 8.3.9.8  Indicators
        9. 8.3.9.9  Conversion and Sequence Counters
        10. 8.3.9.10 Supply Voltage Readback
        11. 8.3.9.11 Temperature Sensors (TSA, TSB)
        12. 8.3.9.12 Test DACs (TDACA, TDACB)
        13. 8.3.9.13 Open-Wire Detection
        14. 8.3.9.14 Missing Host Detection and MHD Pin
        15. 8.3.9.15 Overcurrent Comparators (OCCA, OCCB)
          1. 8.3.9.15.1 OCCA and OCCB Pins
          2. 8.3.9.15.2 Overcurrent Indication Response Time
    4. 8.4 Device Functional Modes
      1. 8.4.1 Power-Up and Reset
        1. 8.4.1.1 Power-On Reset (POR)
        2. 8.4.1.2 RESETn Pin
        3. 8.4.1.3 RESET Command
      2. 8.4.2 Operating Modes
        1. 8.4.2.1 Active Mode
        2. 8.4.2.2 Standby Mode
        3. 8.4.2.3 Power-Down Mode
      3. 8.4.3 ADC Conversion Modes
        1. 8.4.3.1 ADC1y and ADC3y Conversion Modes
          1. 8.4.3.1.1 Continuous-Conversion Mode
          2. 8.4.3.1.2 Single-Shot Conversion Mode
          3. 8.4.3.1.3 Global-Chop Mode
            1. 8.4.3.1.3.1 Overcurrent Indication Response Time in Global-Chop Mode
        2. 8.4.3.2 ADC2y Sequencer Operation and Sequence Modes
          1. 8.4.3.2.1 Continuous Sequence Mode
          2. 8.4.3.2.2 Single-Shot Sequence Mode
          3. 8.4.3.2.3 Synchronized Single-Shot Sequence Mode Based on ADC1y Conversion Starts
    5. 8.5 Programming
      1. 8.5.1 Serial Interface
        1. 8.5.1.1 Serial Interface Signals
          1. 8.5.1.1.1 Chip Select (CSn)
          2. 8.5.1.1.2 Serial Data Clock (SCLK)
          3. 8.5.1.1.3 Serial Data Input (SDI)
          4. 8.5.1.1.4 Serial Data Output (SDO)
          5. 8.5.1.1.5 Data Ready (DRDYn)
        2. 8.5.1.2 Serial Interface Communication Structure
          1. 8.5.1.2.1 SPI Communication Frames
          2. 8.5.1.2.2 SPI Communication Words
          3. 8.5.1.2.3 STATUS Word
          4. 8.5.1.2.4 Communication Cyclic Redundancy Check (CRC)
          5. 8.5.1.2.5 Commands
            1. 8.5.1.2.5.1 NULL (0000 0000 0000 0000b)
            2. 8.5.1.2.5.2 RESET (0000 0000 0001 0001b)
            3. 8.5.1.2.5.3 LOCK (0000 0101 0101 0101b)
            4. 8.5.1.2.5.4 UNLOCK (0000 0110 0101 0101b)
            5. 8.5.1.2.5.5 WREG (011a aaaa aaa0 0nnnb)
            6. 8.5.1.2.5.6 RREG (101a aaaa aaan nnnnb)
          6. 8.5.1.2.6 SCLK Counter
          7. 8.5.1.2.7 SPI Timeout
          8. 8.5.1.2.8 Reading ADC1A, ADC1B, ADC2A, ADC2B, ADC3A, and ADC3B Conversion Data
          9. 8.5.1.2.9 DRDYn Pin Behavior
    6. 8.6 Register Map
      1. 8.6.1 Registers
  10. 9 Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 Unused Inputs and Outputs
      2. 9.1.2 Minimum Interface Connections
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Current-Shunt Measurement
        2. 9.2.2.2 Battery-Pack Voltage Measurement
        3. 9.2.2.3 Other Voltage Measurements
        4. 9.2.2.4 Shunt Temperature Measurement
        5. 9.2.2.5 Analog Output Temperature Sensor Measurement
      3. 9.2.3 Application Curves
    3. 9.3 Power Supply Recommendations
      1. 9.3.1 Power-Supply Options
        1. 9.3.1.1 Single Unregulated External 4-V to 16-V Supply (3.3-V Digital I/O Levels)
        2. 9.3.1.2 Single Regulated External 3.3-V Supply (3.3-V Digital IO Levels)
        3. 9.3.1.3 Single Regulated External 5-V Supply (5-V Digital I/O Levels)
      2. 9.3.2 Power-Supply Sequencing
      3. 9.3.3 Power-Supply Decoupling
    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

7.3 Noise Performance

Adjust the data rate and gain to optimize the noise performance of the individual ADCs. When reducing the data rate by increasing the oversampling ratio (OSR), averaging is increased and results in lower noise. Table 7-1 to Table 7-3 summarize the noise performance of ADC1y, ADC2y, and ADC3y. The data are representative of typical noise performance at TA = 25°C using fMCLK = 8.192 MHz. The data shown are typical input-referred noise results in units of μVRMS with the analog inputs shorted together and averaging data across a 1-ms period. Use Equation 3 to calculate effective resolution from the provided μVRMS numbers.

Equation 18. Effective Resolution = ln[(2 × VREFy / Gain) / VRMS-Noise] / ln(2)

The noise performance of ADC1y and ADC3y improves by a factor of √2 in global-chop mode.

Table 7-1 ADC1y Noise Performance (μVRMS) at TA = 25°C
OSR1y DATA RATE,
fMCLK = 8.192 MHz		 GAIN
4 8 16 32
64 64 kSPS 20.7 10.8 10.8 10.8
128 32 kSPS 6.19 3.96 3.96 3.96
256 16 kSPS 3.70 2.51 2.51 2.51
512 8 kSPS 2.61 1.78 1.78 1.78
1024 4 kSPS 1.88 1.28 1.28 1.28
2048 2 kSPS 1.46 0.91 0.91 0.91
4096 1 kSPS 1.15 0.65 0.65 0.65
8192 0.5 kSPS 0.88 0.44 0.44 0.44
Table 7-2 ADC2y Noise Performance (μVRMS) at TA = 25°C
OSR2y CONVERSION TIME,
fMCLK = 8.192 MHz		 GAIN
1 2 4
64 46.87 μs 93.4 48.3 48.3
128 62.50 μs 48.4 26.5 26.5
256 93.75 μs 31.9 17.5 17.5
512 156.25 μs 22.4 12.1 12.1
Table 7-3 ADC3y Noise Performance (μVRMS) at TA = 25°C
OSR3y DATA RATE,
fMCLK = 8.192 MHz		 GAIN
1 2 4
64 64 kSPS 93.4 48.3 48.3
128 32 kSPS 35.1 19.8 19.8
256 16 kSPS 21.2 12.6 12.6
512 8 kSPS 14.4 8.73 8.73
1024 4 kSPS 10.3 6.21 6.21
2048 2 kSPS 7.37 4.29 4.29
4096 1 kSPS 5.39 3.01 3.01
8192 0.5 kSPS 3.52 2.05 2.05