SLVSDR2B November   2018  – March 2021 ADC12DJ3200QML-SP

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: DC Specifications
    6. 6.6  Electrical Characteristics: Power Consumption
    7. 6.7  Electrical Characteristics: AC Specifications (Dual-Channel Mode)
    8. 6.8  Electrical Characteristics: AC Specifications (Single-Channel Mode)
    9. 6.9  Timing Requirements
    10. 6.10 Switching Characteristics
    11. 6.11 Timing Diagrams
    12. 6.12 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Analog Inputs
        1. 7.3.1.1 Analog Input Protection
        2. 7.3.1.2 Full-Scale Voltage (VFS) Adjustment
        3. 7.3.1.3 Analog Input Offset Adjust
      2. 7.3.2 ADC Core
        1. 7.3.2.1 ADC Theory of Operation
        2. 7.3.2.2 ADC Core Calibration
        3. 7.3.2.3 ADC Overrange Detection
        4. 7.3.2.4 Code Error Rate (CER)
      3. 7.3.3 Timestamp
      4. 7.3.4 Clocking
        1. 7.3.4.1 Noiseless Aperture Delay Adjustment (tAD Adjust)
        2. 7.3.4.2 Aperture Delay Ramp Control (TAD_RAMP)
        3. 7.3.4.3 SYSREF Capture for Multi-Device Synchronization and Deterministic Latency
          1. 7.3.4.3.1 SYSREF Position Detector and Sampling Position Selection (SYSREF Windowing)
          2. 7.3.4.3.2 Automatic SYSREF Calibration
      5. 7.3.5 Digital Down Converters (Dual-Channel Mode Only)
        1. 7.3.5.1 Numerically-Controlled Oscillator and Complex Mixer
          1. 7.3.5.1.1 NCO Fast Frequency Hopping (FFH)
          2. 7.3.5.1.2 NCO Selection
          3. 7.3.5.1.3 Basic NCO Frequency Setting Mode
          4. 7.3.5.1.4 Rational NCO Frequency Setting Mode
          5. 7.3.5.1.5 NCO Phase Offset Setting
          6. 7.3.5.1.6 NCO Phase Synchronization
        2. 7.3.5.2 Decimation Filters
        3. 7.3.5.3 Output Data Format
        4. 7.3.5.4 Decimation Settings
          1. 7.3.5.4.1 Decimation Factor
          2. 7.3.5.4.2 DDC Gain Boost
      6. 7.3.6 JESD204B Interface
        1. 7.3.6.1 Transport Layer
        2. 7.3.6.2 Scrambler
        3. 7.3.6.3 Link Layer
          1. 7.3.6.3.1 Code Group Synchronization (CGS)
          2. 7.3.6.3.2 Initial Lane Alignment Sequence (ILAS)
          3. 7.3.6.3.3 8b, 10b Encoding
          4. 7.3.6.3.4 Frame and Multiframe Monitoring
        4. 7.3.6.4 Physical Layer
          1. 7.3.6.4.1 SerDes Pre-Emphasis
        5. 7.3.6.5 JESD204B Enable
        6. 7.3.6.6 Multi-Device Synchronization and Deterministic Latency
        7. 7.3.6.7 Operation in Subclass 0 Systems
      7. 7.3.7 Alarm Monitoring
        1. 7.3.7.1 NCO Upset Detection
        2. 7.3.7.2 Clock Upset Detection
      8. 7.3.8 Temperature Monitoring Diode
      9. 7.3.9 Analog Reference Voltage
    4. 7.4 Device Functional Modes
      1. 7.4.1 Dual-Channel Mode
      2. 7.4.2 Single-Channel Mode (DES Mode)
      3. 7.4.3 JESD204B Modes
        1. 7.4.3.1 JESD204B Output Data Formats
        2. 7.4.3.2 Dual DDC and Redundant Data Mode
      4. 7.4.4 Power-Down Modes
      5. 7.4.5 Test Modes
        1. 7.4.5.1 Serializer Test-Mode Details
        2. 7.4.5.2 PRBS Test Modes
        3. 7.4.5.3 Ramp Test Mode
        4. 7.4.5.4 Short and Long Transport Test Mode
          1. 7.4.5.4.1 Short Transport Test Pattern
          2. 7.4.5.4.2 Long Transport Test Pattern
        5. 7.4.5.5 D21.5 Test Mode
        6. 7.4.5.6 K28.5 Test Mode
        7. 7.4.5.7 Repeated ILA Test Mode
        8. 7.4.5.8 Modified RPAT Test Mode
      6. 7.4.6 Calibration Modes and Trimming
        1. 7.4.6.1 Foreground Calibration Mode
        2. 7.4.6.2 Background Calibration Mode
        3. 7.4.6.3 Low-Power Background Calibration (LPBG) Mode
      7. 7.4.7 Offset Calibration
      8. 7.4.8 Trimming
      9. 7.4.9 Offset Filtering
    5. 7.5 Programming
      1. 7.5.1 Using the Serial Interface
        1. 7.5.1.1 SCS
        2. 7.5.1.2 SCLK
        3. 7.5.1.3 SDI
        4. 7.5.1.4 SDO
        5. 7.5.1.5 Streaming Mode
    6. 7.6 Register Maps
      1. 7.6.1 Register Descriptions
      2. 7.6.2 SYSREF Calibration Registers (0x2B0 to 0x2BF)
      3. 7.6.3 Alarm Registers (0x2C0 to 0x2C2)
  8. 8 Application Information Disclaimer
    1. 8.1 Application Information
      1. 8.1.1 Analog Inputs
      2. 8.1.2 Analog Input Bandwidth
      3. 8.1.3 Clocking
      4. 8.1.4 Radiation Environment Recommendations
        1. 8.1.4.1 Single Event Latch-Up (SEL)
        2. 8.1.4.2 Single Event Functional Interrupt (SEFI)
        3. 8.1.4.3 Single Event Upset (SEU)
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 RF Input Signal Path
        2. 8.2.2.2 Calculating Values of AC-Coupling Capacitors
      3. 8.2.3 Application Curves
    3. 8.3 Initialization Set Up
  9. 9 Layout
    1. 9.1 Layout Guidelines
    2. 9.2 Layout Example
  10. 10Device and Documentation Support
    1. 10.1 Device Support
      1. 10.1.1 Development Support
    2. 10.2 Documentation Support
      1. 10.2.1 Related Documentation
    3. 10.3 Receiving Notification of Documentation Updates
    4. 10.4 Community Resources
    5. 10.5 Trademarks

7.4.7 Offset Calibration

Foreground calibration and background calibration modes inherently calibrate the offsets of the ADC cores; however, the input buffers sit outside of the calibration loop and therefore their offsets are not calibrated by the standard calibration process. In both dual-channel mode and single-channel mode, uncalibrated input buffer offsets result in a shift in the mid-code output (dc offset) with no input. Further, in single-channel mode uncalibrated input buffer offsets can result in a fixed spur at fS / 2. A separate calibration is provided to correct the input buffer offsets.

There must be no signals at or near dc, or aliased signals that fall at or near dc, in order to properly calibrate the offsets. These input signals must not exist during normal operation, or the system must be designed to mute the input signal during calibration. Foreground offset calibration is enabled using CAL_OS and only performs the calibration one time as part of the foreground calibration procedure. Background offset calibration is enabled via CAL_BGOS and continues to correct the offset as part of the background calibration routine to account for operating condition changes. When CAL_BGOS is set, the system must make sure that there are no dc or near-dc signals or aliased signals that fall at or near dc during normal operation. Offset calibration can be performed as a foreground operation when using background calibration by setting CAL_OS to 1 before setting CAL_EN, but does not correct for variations as operating conditions change.

The offset calibration correction uses the input offset voltage trim registers (see Table 7-43) to correct the offset and therefore must not be written by the user when offset calibration is used. The user can read the calibrated values by reading the OADJ_x_VINy registers, where x is the ADC core and y is the input (INA± or INB±), after calibration is completed. Only read the values when FG_DONE is read as 1 when using foreground offset calibration (CAL_OS = 1) and do not read the values when using background offset calibration (CAL_BGOS = 1).