SBAS946C April   2021  – September 2022 ADS127L11

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and 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  Timing Requirements (1.65 V ≤ IOVDD ≤ 2 V)
    7. 6.7  Switching Characteristics (1.65 V ≤ IOVDD ≤ 2 V)
    8. 6.8  Timing Requirements (2 V < IOVDD ≤ 5.5 V)
    9. 6.9  Switching Characteristics (2 V < IOVDD ≤ 5.5 V)
    10. 6.10 Timing Diagrams
    11. 6.11 Typical Characteristics
  7. 7 Parameter Measurement Information
    1. 7.1  Offset Error Measurement
    2. 7.2  Offset Drift Measurement
    3. 7.3  Gain Error Measurement
    4. 7.4  Gain Drift Measurement
    5. 7.5  NMRR Measurement
    6. 7.6  CMRR Measurement
    7. 7.7  PSRR Measurement
    8. 7.8  SNR Measurement
    9. 7.9  INL Error Measurement
    10. 7.10 THD Measurement
    11. 7.11 SFDR Measurement
    12. 7.12 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 Analog Input (AINP, AINN)
        1. 8.3.1.1 Input Range
      2. 8.3.2 Reference Voltage (REFP, REFN)
        1. 8.3.2.1 Reference Voltage Range
      3. 8.3.3 Clock Operation
        1. 8.3.3.1 Internal Oscillator
        2. 8.3.3.2 External Clock
      4. 8.3.4 Modulator
      5. 8.3.5 Digital Filter
        1. 8.3.5.1 Wideband Filter
        2. 8.3.5.2 Low-Latency Filter (Sinc)
          1. 8.3.5.2.1 Sinc4 Filter
          2. 8.3.5.2.2 Sinc4 + Sinc1 Filter
          3. 8.3.5.2.3 Sinc3 Filter
          4. 8.3.5.2.4 Sinc3 + Sinc1 Filter
      6. 8.3.6 Power Supplies
        1. 8.3.6.1 AVDD1 and AVSS
        2. 8.3.6.2 AVDD2
        3. 8.3.6.3 IOVDD
        4. 8.3.6.4 Power-On Reset (POR)
        5. 8.3.6.5 CAPA and CAPD
      7. 8.3.7 VCM Output Voltage
    4. 8.4 Device Functional Modes
      1. 8.4.1 Power-Scalable Speed Modes
      2. 8.4.2 Idle Mode
      3. 8.4.3 Standby Mode
      4. 8.4.4 Power-Down Mode
      5. 8.4.5 Reset
        1. 8.4.5.1 RESET Pin
        2. 8.4.5.2 Reset by SPI Register Write
        3. 8.4.5.3 Reset by SPI Input Pattern
      6. 8.4.6 Synchronization
        1. 8.4.6.1 Synchronized Control Mode
        2. 8.4.6.2 Start/Stop Control Mode
        3. 8.4.6.3 One-Shot Control Mode
      7. 8.4.7 Conversion-Start Delay Time
      8. 8.4.8 Calibration
        1. 8.4.8.1 OFFSET2, OFFSET1, OFFSET0 Calibration Registers (Addresses 9h, Ah, Bh)
        2. 8.4.8.2 GAIN2, GAIN1, GAIN0 Calibration Registers (Addresses 0Ch, 0Dh, 0Eh)
        3. 8.4.8.3 Calibration Procedure
    5. 8.5 Programming
      1. 8.5.1 Serial Interface (SPI)
        1. 8.5.1.1 Chip Select (CS)
        2. 8.5.1.2 Serial Clock (SCLK)
        3. 8.5.1.3 Serial Data Input (SDI)
        4. 8.5.1.4 Serial Data Output/Data Ready (SDO/DRDY)
      2. 8.5.2 SPI Frame
      3. 8.5.3 SPI CRC
      4. 8.5.4 Register Map CRC
      5. 8.5.5 Full-Duplex Operation
      6. 8.5.6 Device Commands
        1. 8.5.6.1 No-Operation
        2. 8.5.6.2 Read Register Command
        3. 8.5.6.3 Write Register Command
      7. 8.5.7 Read Conversion Data
        1. 8.5.7.1 Conversion Data
        2. 8.5.7.2 Data Ready
          1. 8.5.7.2.1 DRDY
          2. 8.5.7.2.2 SDO/DRDY
          3. 8.5.7.2.3 DRDY Bit
          4. 8.5.7.2.4 Clock Counting
        3. 8.5.7.3 STATUS Header
      8. 8.5.8 Daisy-Chain Operation
      9. 8.5.9 3-Wire SPI Mode
        1. 8.5.9.1 3-Wire SPI Mode Frame Reset
    6. 8.6 Registers
      1. 8.6.1  DEV_ID Register (Address = 0h) [reset = 00h]
      2. 8.6.2  REV_ID Register (Address = 1h) [reset = xxh]
      3. 8.6.3  STATUS Register (Address = 2h) [reset = x1100xxxb]
      4. 8.6.4  CONTROL Register (Address = 3h) [reset = 00h]
      5. 8.6.5  MUX Register (Address = 4h) [reset = 00h]
      6. 8.6.6  CONFIG1 Register (Address = 5h) [reset = 00h]
      7. 8.6.7  CONFIG2 Register (Address = 6h) [reset = 00h]
      8. 8.6.8  CONFIG3 Register (Address = 7h) [reset = 00h]
      9. 8.6.9  CONFIG4 Register (Address = 8h) [reset = 00h]
      10. 8.6.10 OFFSET2, OFFSET1, OFFSET0 Registers (Addresses = 9h, Ah, Bh) [reset = 00h, 00h, 00h]
      11. 8.6.11 GAIN2, GAIN1, GAIN0 Registers (Addresses = Ch, Dh, Eh) [reset = 40h, 00h, 00h]
      12. 8.6.12 CRC Register (Address = Fh) [reset = 00h]
  9. 9 Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 SPI Operation
      2. 9.1.2 Input Driver
      3. 9.1.3 Antialias Filter
      4. 9.1.4 Reference Voltage
      5. 9.1.5 Simultaneous-Sampling Systems
    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
  10. 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
  11. 11Mechanical, Packaging, and Orderable Information

Package Options

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

8.4.6 Synchronization

Conversions are synchronized and controlled by the START pin or, optionally, through SPI operation. If controlling conversions through SPI operation, keep the START pin low to avoid contention with the pin. Writing to any register from 04h through 0Eh causes the conversion to restart, thus resulting in loss of synchronization. Resynchronization of the ADC may be necessary in this case.

The ADC has three modes to synchronize and control conversions: synchronized, start/stop, and one-shot modes, each with specific functionalities. Program the selected mode of synchronization by the START_MODE[1:0] bits of the CONFIG2 register. Only the start/stop and one-shot control modes can be controlled through SPI operation.

After the ADC is synchronized, the first conversion is fully settled data but incurs a delay (latency time) compared to the normal data period. This latency is needed to account for full settling of the digital filter. The latency time depends on the data rate and the filter mode (see the Section 8.3.5 section for filter latency details).