SBAS790C October   2018  – June 2019 ADS125H02

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Functional Block Diagram
  4. 4 Revision History
  5. 5 Device Comparison Table
  6. 6 Pin Configuration and Functions
    1.     Pin Functions
  7. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
    6. 7.6 Timing Requirements
    7. 7.7 Switching Characteristics
    8. 7.8 Typical Characteristics
  8. 8 Parameter Measurement Information
    1. 8.1 Noise Performance
  9. 9 Detailed Description
    1. 9.1 Overview
    2. 9.2 Functional Block Diagram
    3. 9.3 Feature Description
      1. 9.3.1 Input Range
      2. 9.3.2 Analog Inputs
        1. 9.3.2.1 ESD Diodes
        2. 9.3.2.2 Input Multiplexer
          1. 9.3.2.2.1 Analog Inputs (AIN0, AIN1, AINCOM)
          2. 9.3.2.2.2 High-Voltage Power Supply Readback
          3. 9.3.2.2.3 Internal VCOM Connection (Default)
          4. 9.3.2.2.4 Temperature Sensor
      3. 9.3.3 Programmable Gain Amplifier (PGA)
        1. 9.3.3.1 PGA Operating Range
        2. 9.3.3.2 PGA Monitor
      4. 9.3.4 Reference Voltage
        1. 9.3.4.1 Internal Reference
        2. 9.3.4.2 External Reference
        3. 9.3.4.3 AVDD Power-Supply Reference
        4. 9.3.4.4 Reference Monitor
      5. 9.3.5 Current Sources (IDAC1 and IDAC2)
      6. 9.3.6 General-Purpose Inputs and Outputs (GPIOs)
      7. 9.3.7 ADC Modulator
      8. 9.3.8 Digital Filter
        1. 9.3.8.1 Sinc Filter Mode
          1. 9.3.8.1.1 Sinc Filter Frequency Response
        2. 9.3.8.2 FIR Filter
        3. 9.3.8.3 50-Hz and 60-Hz Normal Mode Rejection
    4. 9.4 Device Functional Modes
      1. 9.4.1 Conversion Control
        1. 9.4.1.1 Continuous-Conversion Mode
        2. 9.4.1.2 Pulse-Conversion Mode
        3. 9.4.1.3 Conversion Latency
        4. 9.4.1.4 Start-Conversion Delay
      2. 9.4.2 Auto-Zero Mode
      3. 9.4.3 Clock Mode
      4. 9.4.4 Reset
        1. 9.4.4.1 Power-On Reset
        2. 9.4.4.2 Reset by Pin
        3. 9.4.4.3 Reset by Command
      5. 9.4.5 Calibration
        1. 9.4.5.1 Offset and Full-Scale Calibration
          1. 9.4.5.1.1 Offset Calibration Registers
          2. 9.4.5.1.2 Full-Scale Calibration Registers
        2. 9.4.5.2 Offset Calibration (OFSCAL)
        3. 9.4.5.3 Full-Scale Calibration (GANCAL)
        4. 9.4.5.4 Calibration Command Procedure
        5. 9.4.5.5 User Calibration Procedure
    5. 9.5 Programming
      1. 9.5.1 Serial Interface
        1. 9.5.1.1 Chip-Select Pins (CS1 and CS2)
        2. 9.5.1.2 Serial Clock (SCLK)
        3. 9.5.1.3 Data Input (DIN)
        4. 9.5.1.4 Data Output/Data Ready (DOUT/DRDY)
      2. 9.5.2 Data Ready (DRDY)
        1. 9.5.2.1 DRDY in Continuous-Conversion Mode
        2. 9.5.2.2 DRDY in Pulse-Conversion Mode
        3. 9.5.2.3 Data Ready by Software Polling
      3. 9.5.3 Conversion Data
        1. 9.5.3.1 Status Byte (STATUS0)
        2. 9.5.3.2 Conversion Data Format
      4. 9.5.4 Cyclic Redundancy Check (CRC)
      5. 9.5.5 Commands
        1. 9.5.5.1  General Command Format
        2. 9.5.5.2  NOP Command
        3. 9.5.5.3  RESET Command
        4. 9.5.5.4  START Command
        5. 9.5.5.5  STOP Command
        6. 9.5.5.6  RDATA Command
        7. 9.5.5.7  OFSCAL Command
        8. 9.5.5.8  GANCAL Command
        9. 9.5.5.9  RREG Command
        10. 9.5.5.10 WREG Command
        11. 9.5.5.11 LOCK Command
        12. 9.5.5.12 UNLOCK Command
    6. 9.6 Register Map
      1. 9.6.1  Device Identification (ID) Register (address = 00h) [reset = 6xh]
        1. Table 30. ID Register Field Descriptions
      2. 9.6.2  Main Status (STATUS0) Register (address = 01h) [reset = 01h]
        1. Table 31. STATUS0 Register Field Descriptions
      3. 9.6.3  Mode 0 (MODE0) Register (address = 02h) [reset = 24h]
        1. Table 32. MODE0 Register Field Descriptions
      4. 9.6.4  Mode 1 (MODE1) Register (address = 03h) [reset = 01h]
        1. Table 33. MODE1 Register Field Descriptions
      5. 9.6.5  Mode 2 (MODE2) Register (address = 04h) [reset = 00h]
        1. Table 34. MODE2 Register Field Descriptions
      6. 9.6.6  Mode 3 (MODE3) Register (address = 05h) [reset = 00h]
        1. Table 35. MODE3 Register Field Descriptions
      7. 9.6.7  Reference Configuration (REF) Register (address = 06h) [reset = 05h]
        1. Table 36. REF Register Field Descriptions
      8. 9.6.8  Offset Calibration (OFCALx) Registers (address = 07h, 08h, 09h) [reset = 00h, 00h, 00h]
        1. Table 37. OFCAL0, OFCAL1, OFCAL2 Registers Field Description
      9. 9.6.9  Full-Scale Calibration (FSCALx) Registers (address = 0Ah, 0Bh, 0Ch) [reset = 00h, 00h, 40h]
        1. Table 38. FSCAL0, FSCAL1, FSCAL2 Registers Field Description
      10. 9.6.10 Current Source Multiplexer (I_MUX) Register (address = 0Dh) [reset = FFh]
        1. Table 39. I_MUX Register Field Descriptions
      11. 9.6.11 Current Source Magnitude (I_MAG) Register (address = 0Eh) [reset = 00h]
        1. Table 40. I_MAG Register Field Descriptions
      12. 9.6.12 Reserved (RESERVED) Register (address = 0Fh) [reset = 00h]
        1. Table 41. RESERVED Register Field Descriptions
      13. 9.6.13 MODE4 (MODE4) Register (address = 10h) [reset = 50h]
        1. Table 42. MODE4 Register Field Descriptions
      14. 9.6.14 PGA Alarm (STATUS1) Register (address = 11h) [reset = xxh]
        1. Table 43. STATUS1 Register Field Descriptions
      15. 9.6.15 Status 2 (STATUS2) Register (address = 12h) [reset = 0xh]
        1. Table 44. STATUS2 Register Field Descriptions
  10. 10Application and Implementation
    1. 10.1 Application Information
      1. 10.1.1 Input Range
      2. 10.1.2 Input Overload
        1. 10.1.2.1 Input Signal Rate of Change (dV/dt)
      3. 10.1.3 Unused Inputs and Outputs
    2. 10.2 Typical Applications
      1. 10.2.1 ±10-V Analog Input Module
        1. 10.2.1.1 Design Requirements
        2. 10.2.1.2 Detailed Design Procedure
        3. 10.2.1.3 Application Curves
      2. 10.2.2 Thermocouple Input With High Common-Mode Voltage
    3. 10.3 Initialization Setup
  11. 11Power Supply Recommendations
    1. 11.1 Power-Supply Decoupling
    2. 11.2 Analog Power-Supply Clamp
    3. 11.3 Power-Supply Sequencing
    4. 11.4 5-V to ±15-V DC-DC Converter
  12. 12Layout
    1. 12.1 Layout Guidelines
    2. 12.2 Layout Example
  13. 13Device and Documentation Support
    1. 13.1 Documentation Support
      1. 13.1.1 Related Documentation
    2. 13.2 Receiving Notification of Documentation Updates
    3. 13.3 Community Resources
    4. 13.4 Trademarks
    5. 13.5 Electrostatic Discharge Caution
    6. 13.6 Glossary
  14. 14Mechanical, Packaging, and Orderable Information

Package Options

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

10.1.3 Unused Inputs and Outputs

  • Analog Inputs

    • To minimize input current leakage, connect unused analog inputs to AGND when operating the device with bipolar supplies, or connect unused inputs to AVDD when operating the device with a unipolar supply.

  • Analog Outputs

    • A capacitor is not required for REFOUT if the internal reference or the IDAC current sources are not used. Otherwise, connect a 10-µF capacitor between REFOUT and AGND.

  • Digital I/O

    • ADC operation is possible using only a subset of the digital I/O. Tie any unused digital inputs high or low (DVDD or DGND, as appropriate). Do not float (tri-state) the digital inputs or unpredictable operation can result. The following is a summary of digital I/O with optional connections:

    • CLKIN: Tie CLKIN to DGND to operate the ADC using the internal oscillator. The internal oscillator stops operation if CLKIN is connected to DVDD, resulting in loss of ADC functionality. Connect CLKIN to an external clock source to operate with an external clock.
    • START: Tie START low in order to control conversions entirely by command. Tie START high to free-run conversions when programmed to the continuous-conversion mode. Connect START to the host controller to control conversions directly by the pin.
    • RESET: Tie RESET high if desired. An external RC reset on the RESET input pin is not necessary because the ADC resets at power on. The ADC can also be reset by the RESET command. Connect the RESET pin to the host controller to reset the ADC by hardware.
    • DRDY: Indication of data ready is also provided by the DOUT/DRDY pin. CS1 must be low to use DOUT/DRDY in the data-ready function. The indication of data ready is also achieved by polling the DRDY bit of the STATUS0 byte. For these methods, the connection of DRDY to the host controller is not necessary and the pin can be unconnected.

  • GPIO

    • Program unused GPIOs as outputs (default setting). If any GPIOs are programmed as inputs, the GPIO must not be allowed to float (unconnected), otherwise AVDD power-supply leakage current may result.