SLVSGH5B March   2023  – June 2024 ADC12DJ5200SE

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
  6. 5 Specifications
    1. 5.1  Absolute Maximum Ratings
    2. 5.2  ESD Ratings
    3. 5.3  Recommended Operating Conditions
    4. 5.4  Thermal Information
    5. 5.5  Electrical Characteristics: DC Specifications
    6. 5.6  Electrical Characteristics: Power Consumption
    7. 5.7  Electrical Characteristics: AC Specifications (Dual-Channel Mode)
    8. 5.8  Electrical Characteristics: AC Specifications (Single-Channel Mode)
    9. 5.9  Timing Requirements
    10. 5.10 Switching Characteristics
    11. 5.11 Typical Characteristics
  7. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1  Device Comparison
      2. 6.3.2  Analog Inputs
        1. 6.3.2.1 Analog Input Protection
        2. 6.3.2.2 Full-Scale Voltage (VFS) Adjustment
        3. 6.3.2.3 Analog Input Offset Adjust
      3. 6.3.3  ADC Core
        1. 6.3.3.1 ADC Theory of Operation
        2. 6.3.3.2 ADC Core Calibration
        3. 6.3.3.3 Analog Reference Voltage
        4. 6.3.3.4 ADC Overrange Detection
        5. 6.3.3.5 Code Error Rate (CER)
      4. 6.3.4  Temperature Monitoring Diode
      5. 6.3.5  Timestamp
      6. 6.3.6  Clocking
        1. 6.3.6.1 Noiseless Aperture Delay Adjustment (tAD Adjust)
        2. 6.3.6.2 Aperture Delay Ramp Control (TAD_RAMP)
        3. 6.3.6.3 SYSREF Capture for Multi-Device Synchronization and Deterministic Latency
          1. 6.3.6.3.1 SYSREF Position Detector and Sampling Position Selection (SYSREF Windowing)
          2. 6.3.6.3.2 Automatic SYSREF Calibration
      7. 6.3.7  Programmable FIR Filter (PFIR)
        1. 6.3.7.1 Dual Channel Equalization
        2. 6.3.7.2 Single Channel Equalization
        3. 6.3.7.3 Time Varying Filter
      8. 6.3.8  Digital Down Converters (DDC)
        1. 6.3.8.1 Numerically-Controlled Oscillator and Complex Mixer
          1. 6.3.8.1.1 NCO Fast Frequency Hopping (FFH)
          2. 6.3.8.1.2 NCO Selection
          3. 6.3.8.1.3 Basic NCO Frequency Setting Mode
          4. 6.3.8.1.4 Rational NCO Frequency Setting Mode
          5. 6.3.8.1.5 NCO Phase Offset Setting
          6. 6.3.8.1.6 52
          7. 6.3.8.1.7 NCO Phase Synchronization
        2. 6.3.8.2 Decimation Filters
        3. 6.3.8.3 Output Data Format
        4. 6.3.8.4 Decimation Settings
          1. 6.3.8.4.1 Decimation Factor
          2. 6.3.8.4.2 DDC Gain Boost
      9. 6.3.9  JESD204C Interface
        1. 6.3.9.1 Transport Layer
        2. 6.3.9.2 Scrambler
        3. 6.3.9.3 Link Layer
        4. 6.3.9.4 8B/10B Link Layer
          1. 6.3.9.4.1 Data Encoding (8B/10B)
          2. 6.3.9.4.2 Multiframes and the Local Multiframe Clock (LMFC)
          3. 6.3.9.4.3 Code Group Synchronization (CGS)
          4. 6.3.9.4.4 Initial Lane Alignment Sequence (ILAS)
          5. 6.3.9.4.5 Frame and Multiframe Monitoring
        5. 6.3.9.5 64B/66B Link Layer
          1. 6.3.9.5.1 64B/66B Encoding
          2. 6.3.9.5.2 Multiblocks, Extended Multiblocks and the Local Extended Multiblock Clock (LEMC)
          3. 6.3.9.5.3 Block, Multiblock and Extended Multiblock Alignment using Sync Header
            1. 6.3.9.5.3.1 Cyclic Redundancy Check (CRC) Mode
            2. 6.3.9.5.3.2 Forward Error Correction (FEC) Mode
          4. 6.3.9.5.4 Initial Lane Alignment
          5. 6.3.9.5.5 Block, Multiblock and Extended Multiblock Alignment Monitoring
        6. 6.3.9.6 Physical Layer
          1. 6.3.9.6.1 SerDes Pre-Emphasis
        7. 6.3.9.7 JESD204C Enable
        8. 6.3.9.8 Multi-Device Synchronization and Deterministic Latency
        9. 6.3.9.9 Operation in Subclass 0 Systems
      10. 6.3.10 Alarm Monitoring
        1. 6.3.10.1 NCO Upset Detection
        2. 6.3.10.2 Clock Upset Detection
        3. 6.3.10.3 FIFO Upset Detection
    4. 6.4 Device Functional Modes
      1. 6.4.1 Dual-Channel Mode
      2. 6.4.2 Single-Channel Mode (DES Mode)
      3. 6.4.3 Dual-Input Single-Channel Mode (DUAL DES Mode)
      4. 6.4.4 JESD204C Modes
        1. 6.4.4.1 JESD204C Operating Modes Table
        2. 6.4.4.2 JESD204C Modes cont.
        3. 6.4.4.3 JESD204C Transport Layer Data Formats
        4. 6.4.4.4 64B/66B Sync Header Stream Configuration
        5. 6.4.4.5 Dual DDC and Redundant Data Mode
      5. 6.4.5 Power-Down Modes
      6. 6.4.6 Test Modes
        1. 6.4.6.1 Serializer Test-Mode Details
        2. 6.4.6.2 PRBS Test Modes
        3. 6.4.6.3 Clock Pattern Mode
        4. 6.4.6.4 Ramp Test Mode
        5. 6.4.6.5 Short and Long Transport Test Mode
          1. 6.4.6.5.1 Short Transport Test Pattern
          2. 6.4.6.5.2 Long Transport Test Pattern
        6. 6.4.6.6 D21.5 Test Mode
        7. 6.4.6.7 K28.5 Test Mode
        8. 6.4.6.8 Repeated ILA Test Mode
        9. 6.4.6.9 Modified RPAT Test Mode
      7. 6.4.7 Calibration Modes and Trimming
        1. 6.4.7.1 Foreground Calibration Mode
        2. 6.4.7.2 Background Calibration Mode
        3. 6.4.7.3 Low-Power Background Calibration (LPBG) Mode
      8. 6.4.8 Offset Calibration
      9. 6.4.9 Trimming
    5. 6.5 Programming
      1. 6.5.1 Using the Serial Interface
        1. 6.5.1.1 SCS
        2. 6.5.1.2 SCLK
        3. 6.5.1.3 SDI
        4. 6.5.1.4 SDO
        5. 6.5.1.5 Streaming Mode
    6. 6.6 SPI Register Map
  8. 7 Application Information Disclaimer
    1. 7.1 Application Information
    2. 7.2 Typical Applications
      1. 7.2.1 Wideband RF Sampling Receiver
        1. 7.2.1.1 Design Requirements
          1. 7.2.1.1.1 Input Signal Path
          2. 7.2.1.1.2 Clocking
        2. 7.2.1.2 Application Curves
    3. 7.3 Initialization Set Up
    4. 7.4 Power Supply Recommendations
      1. 7.4.1 Power Sequencing
    5. 7.5 Layout
      1. 7.5.1 Layout Guidelines
      2. 7.5.2 Layout Example
  9. 8 Device and Documentation Support
    1. 8.1 Device Support
      1. 8.1.1 Development Support
    2. 8.2 Documentation Support
      1. 8.2.1 Related Documentation
    3. 8.3 Receiving Notification of Documentation Updates
    4. 8.4 Support Resources
    5. 8.5 Trademarks
  10. 9 Revision History
  11. 10Mechanical, Packaging, and Orderable Information

6.4.8 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). 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 to properly calibration the offsets. Requiring the system to be sure of the condition during normal operation, or have the ability to mute the input signal during calibration. The lower bandwidth of the balun will signficantly suppress signals near DC, but care must the taken to avoid AC signals near the sample rate from aliasing near DC. Foreground offset calibration is enabled via 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 be sure there are no DC or near DC signals or aliased signals that fall at or near DC during normal operation. When background offset calibration is used the analog to digital conversion is disturbed by a bandwidth difference. The calibration time is relatively long becuase the offset calibration engine requires a lot of averaging. A preferred method for offset calibration is to use foreground calibration as a one-time operation so the timing of the disturbing glitch can be controlled. A one time foreground calibration can be performed by setting CAL_OS to 1 before setting CAL_EN. However, this will not correct for variations as operating conditions change.

The offset calibration correction uses the input offset voltage trim registers (see Table 6-66) to correct the offset; 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).