SBAS751B October   2017  – October 2018 ADS122C04

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      K-Type Thermocouple Measurement
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
    1.     Pin Functions
  6. 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 I2C Timing Requirements
    7. 6.7 I2C Switching Characteristics
    8. 6.8 Typical Characteristics
  7. 7 Parameter Measurement Information
    1. 7.1 Noise Performance
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1  Multiplexer
      2. 8.3.2  Low-Noise Programmable Gain Stage
        1. 8.3.2.1 PGA Input Voltage Requirements
        2. 8.3.2.2 Bypassing the PGA
      3. 8.3.3  Voltage Reference
      4. 8.3.4  Modulator and Internal Oscillator
      5. 8.3.5  Digital Filter
      6. 8.3.6  Conversion Times
      7. 8.3.7  Excitation Current Sources
      8. 8.3.8  Sensor Detection
      9. 8.3.9  System Monitor
      10. 8.3.10 Temperature Sensor
        1. 8.3.10.1 Converting From Temperature to Digital Codes
          1. 8.3.10.1.1 For Positive Temperatures (For Example, 50°C):
          2. 8.3.10.1.2 For Negative Temperatures (For Example, –25°C):
        2. 8.3.10.2 Converting From Digital Codes to Temperature
      11. 8.3.11 Offset Calibration
      12. 8.3.12 Conversion Data Counter
      13. 8.3.13 Data Integrity Features
    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 RESET Pin
        3. 8.4.1.3 Reset by Command
      2. 8.4.2 Conversion Modes
        1. 8.4.2.1 Single-Shot Conversion Mode
        2. 8.4.2.2 Continuous Conversion Mode
      3. 8.4.3 Operating Modes
        1. 8.4.3.1 Normal Mode
        2. 8.4.3.2 Turbo Mode
        3. 8.4.3.3 Power-Down Mode
    5. 8.5 Programming
      1. 8.5.1 I2C Interface
        1. 8.5.1.1 I2C Address
        2. 8.5.1.2 Serial Clock (SCL) and Serial Data (SDA)
        3. 8.5.1.3 Data Ready (DRDY)
        4. 8.5.1.4 Interface Speed
        5. 8.5.1.5 Data Transfer Protocol
        6. 8.5.1.6 I2C General Call (Software Reset)
        7. 8.5.1.7 Timeout
      2. 8.5.2 Data Format
      3. 8.5.3 Commands
        1. 8.5.3.1 Command Latching
        2. 8.5.3.2 RESET (0000 011x)
        3. 8.5.3.3 START/SYNC (0000 100x)
        4. 8.5.3.4 POWERDOWN (0000 001x)
        5. 8.5.3.5 RDATA (0001 xxxx)
        6. 8.5.3.6 RREG (0010 rrxx)
        7. 8.5.3.7 WREG (0100 rrxx dddd dddd)
      4. 8.5.4 Reading Data and Monitoring for New Conversion Results
      5. 8.5.5 Data Integrity
    6. 8.6 Register Map
      1. 8.6.1 Configuration Registers
      2. 8.6.2 Register Descriptions
        1. 8.6.2.1 Configuration Register 0 (address = 00h) [reset = 00h]
          1. Table 19. Configuration Register 0 Field Descriptions
        2. 8.6.2.2 Configuration Register 1 (address = 01h) [reset = 00h]
          1. Table 20. Configuration Register 1 Field Descriptions
        3. 8.6.2.3 Configuration Register 2 (address = 02h) [reset = 00h]
          1. Table 22. Configuration Register 2 Field Descriptions
        4. 8.6.2.4 Configuration Register 3 (address = 03h) [reset = 00h]
          1. Table 23. Configuration Register 3 Field Descriptions
  9. 9 Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 Interface Connections
      2. 9.1.2 Connecting Multiple Devices on the Same I2C Bus
      3. 9.1.3 Unused Inputs and Outputs
      4. 9.1.4 Analog Input Filtering
      5. 9.1.5 External Reference and Ratiometric Measurements
      6. 9.1.6 Establishing Proper Limits on the Absolute Input Voltage
      7. 9.1.7 Pseudo Code Example
    2. 9.2 Typical Applications
      1. 9.2.1 K-Type Thermocouple Measurement (–200°C to +1250°C)
        1. 9.2.1.1 Design Requirements
        2. 9.2.1.2 Detailed Design Procedure
        3. 9.2.1.3 Application Curves
      2. 9.2.2 3-Wire RTD Measurement (–200°C to +850°C)
        1. 9.2.2.1 Design Requirements
        2. 9.2.2.2 Detailed Design Procedure
          1. 9.2.2.2.1 Design Variations for 2-Wire and 4-Wire RTD Measurements
        3. 9.2.2.3 Application Curves
      3. 9.2.3 Resistive Bridge Measurement
        1. 9.2.3.1 Design Requirements
        2. 9.2.3.2 Detailed Design Procedure
  10. 10Power Supply Recommendations
    1. 10.1 Power-Supply Sequencing
    2. 10.2 Power-Supply Decoupling
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Device Support
      1. 12.1.1 Third-Party Products Disclaimer
    2. 12.2 Documentation Support
      1. 12.2.1 Related Documentation
    3. 12.3 Receiving Notification of Documentation Updates
    4. 12.4 Community Resources
    5. 12.5 Trademarks
    6. 12.6 Electrostatic Discharge Caution
    7. 12.7 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

6.8 Typical Characteristics

at TA = 25°C, AVDD = 3.3 V, and AVSS = 0 V using internal VREF = 2.048 V (unless otherwise noted)
ADS122C04 D019_sbas752.gif
Normal mode, PGA disabled, VIN = 0 V
Figure 4. Absolute Input current vs Absolute Input Voltage
ADS122C04 D023_sbas752.gif
Turbo mode, PGA disabled, VIN = 0 V
Figure 6. Absolute Input Current vs Absolute Input Voltage
ADS122C04 D027_sbas752.gif
Normal mode, PGA disabled, VCM = 1.65 V
Figure 8. Differential Input Current vs
Differential Input Voltage
ADS122C04 D031_sbas752.gif
Turbo mode, PGA disabled, VCM = 1.65 V
Figure 10. Differential Input Current vs
Differential Input Voltage
ADS122C04 D002_sbas752.gif
PGA enabled, external reference, best fit
Figure 12. INL vs Differential Input Voltage
ADS122C04 D036_sbas752.gif
PGA enabled, gain = 1, 620 samples
Figure 14. Offset Voltage Histogram
ADS122C04 D043_sbas752.gif
PGA enabled
Figure 16. Input Offset Voltage vs Temperature
ADS122C04 D011_sbas752.gif
PGA enabled, gain = 1, 620 samples
Figure 18. Gain Error Histogram
ADS122C04 D041_sbas752.gif
PGA disabled
Figure 20. Gain Error vs Temperature
ADS122C04 D051_sbas752.gif
PGA disabled
Figure 22. DC CMRR vs Temperature
ADS122C04 D062_sbas752.gif
5940 samples, TSSOP package
Figure 24. Internal Reference Voltage Histogram
ADS122C04 D035_sbas752.gif
Figure 26. Internal Reference Voltage vs AVDD
ADS122C04 D053_sbas752.gif
Normal mode
Figure 28. Internal Oscillator Frequency Histogram
ADS122C04 D061_sbas752.gif
Normal mode
Figure 30. Internal Oscillator Frequency vs DVDD
ADS122C04 D064_sbas752.gif
Figure 32. IDAC Accuracy vs Temperature
ADS122C04 D066_sbas752.gif
Figure 34. Internal Temperature Sensor Accuracy vs Temperature
ADS122C04 D044_sbas752.gif
Power-down mode
Figure 36. Analog Supply Current vs Temperature
ADS122C04 D046_sbas752.gif
Normal mode
Figure 38. Analog Supply Current vs AVDD
ADS122C04 D040_sbas752.gif
Normal mode
Figure 40. Digital Supply Current vs Temperature
ADS122C04 D021_sbas752.gif
Normal mode, PGA enabled, VIN = 0 V
Figure 5. Absolute Input Current vs Absolute Input Voltage
ADS122C04 D025_sbas752.gif
Turbo mode, PGA enabled, VIN = 0 V
Figure 7. Absolute Input Current vs Absolute Input Voltage
ADS122C04 D029_sbas752.gif
Normal mode, PGA enabled, VCM = 1.65 V
Figure 9. Differential Input Current vs
Differential Input Voltage
ADS122C04 D033_sbas752.gif
Turbo mode, PGA enabled, VCM = 1.65 V
Figure 11. Differential Input Current vs
Differential Input Voltage
ADS122C04 D003_sbas752.gif
PGA enabled, internal reference, best fit
Figure 13. INL vs Differential Input Voltage
ADS122C04 D001_sbas752.gif
PGA disabled
Figure 15. Input Offset Voltage vs Temperature
ADS122C04 D008_sbas752.gif
PGA disabled, gain = 1, 620 samples
Figure 17. Gain Error Histogram
ADS122C04 D018_sbas752.gif
PGA enabled, gain = 128, 620 samples
Figure 19. Gain Error Histogram
ADS122C04 D042_sbas752.gif
PGA enabled
Figure 21. Gain Error vs Temperature
ADS122C04 D052_sbas752.gif
PGA enabled
Figure 23. DC CMRR vs Temperature
ADS122C04 D063_sbas752.gif
Figure 25. Internal Reference Voltage vs Temperature
ADS122C04 D059_sbas752.gif
Figure 27. External Reference Input Current vs Temperature
ADS122C04 D060_sbas752.gif
Normal mode
Figure 29. Internal Oscillator Frequency vs Temperature
ADS122C04 C006_bas501.png
Figure 31. IDAC Accuracy vs Compliance Voltage
ADS122C04 D065_sbas752.gif
Figure 33. IDAC Matching vs Temperature
ADS122C04 vol_vs_iol_bas751.gif
DVDD = 3.3 V
Figure 35. Digital Pin Output Voltage vs Sinking Current
ADS122C04 D045_sbas752.gif
Normal mode
Figure 37. Analog Supply Current vs Temperature
ADS122C04 D039_sbas752.gif
Power-down mode
Figure 39. Digital Supply Current vs Temperature
ADS122C04 D038_sbas752.gif
Normal mode
Figure 41. Digital Supply Current vs DVDD