SBASAJ4B June   2022  – October 2024 ADC12QJ1600-EP

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
    8. 5.8  Switching Characteristics
    9. 5.9  Timing Requirements
    10. 5.10 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 Analog Input
        1. 6.3.1.1 Analog Input Protection
        2. 6.3.1.2 Full-Scale Voltage (VFS) Adjustment
        3. 6.3.1.3 Analog Input Offset Adjust
        4. 6.3.1.4 ADC Core
          1. 6.3.1.4.1 ADC Theory of Operation
          2. 6.3.1.4.2 ADC Core Calibration
          3. 6.3.1.4.3 Analog Reference Voltage
          4. 6.3.1.4.4 ADC Over-range Detection
          5. 6.3.1.4.5 Code Error Rate (CER)
      2. 6.3.2 Temperature Monitoring Diode
      3. 6.3.3 Timestamp
      4. 6.3.4 Clocking
        1. 6.3.4.1 Converter PLL (C-PLL) for Sampling Clock Generation
        2. 6.3.4.2 LVDS Clock Outputs (PLLREFO±, TRIGOUT±)
        3. 6.3.4.3 Optional CMOS Clock Outputs (ORC, ORD)
        4. 6.3.4.4 SYSREF for JESD204C Subclass-1 Deterministic Latency
          1. 6.3.4.4.1 SYSREF Capture for Multi-Device Synchronization and Deterministic Latency
          2. 6.3.4.4.2 SYSREF Position Detector and Sampling Position Selection (SYSREF Windowing)
      5. 6.3.5 JESD204C Interface
        1. 6.3.5.1  Transport Layer
        2. 6.3.5.2  Scrambler
        3. 6.3.5.3  Link Layer
        4. 6.3.5.4  8B or 10B Link Layer
          1. 6.3.5.4.1 Data Encoding (8B or 10B)
          2. 6.3.5.4.2 Multiiframes and the Local Multiframe Clock (LMFC)
          3. 6.3.5.4.3 Code Group Synchronization (CGS)
          4. 6.3.5.4.4 Initial Lane Alignment Sequence (ILAS)
          5. 6.3.5.4.5 Frame and Multiframe Monitoring
        5. 6.3.5.5  64B or 66B Link Layer
          1. 6.3.5.5.1 64B or 66B Encoding
          2. 6.3.5.5.2 Multiblocks, Extended Multiblocks and the Local Extended Multiblock Clock (LEMC)
            1. 6.3.5.5.2.1 Block, Multiblock and Extended Multiblock Alignment using Sync Header
              1. 6.3.5.5.2.1.1 Cyclic Redundancy Check (CRC) Mode
              2. 6.3.5.5.2.1.2 Forward Error Correction (FEC) Mode
          3. 6.3.5.5.3 Initial Lane Alignment
          4. 6.3.5.5.4 Block, Multiblock and Extended Multiblock Alignment Monitoring
        6. 6.3.5.6  Physical Layer
          1. 6.3.5.6.1 SerDes Pre-Emphasis
        7. 6.3.5.7  JESD204C Enable
        8. 6.3.5.8  Multi-Device Synchronization and Deterministic Latency
        9. 6.3.5.9  Operation in Subclass 0 Systems
        10. 6.3.5.10 Alarm Monitoring
          1. 6.3.5.10.1 Clock Upset Detection
          2. 6.3.5.10.2 FIFO Upset Detection
    4. 6.4 Device Functional Modes
      1. 6.4.1 Low Power Mode and High Performance Mode
      2. 6.4.2 JESD204C Modes
        1. 6.4.2.1 JESD204C Transport Layer Data Formats
        2. 6.4.2.2 64B or 66B Sync Header Stream Configuration
        3. 6.4.2.3 Redundant Data Mode (Alternate Lanes)
      3. 6.4.3 Power-Down Modes
      4. 6.4.4 Test Modes
        1. 6.4.4.1 Serializer Test-Mode Details
        2. 6.4.4.2 PRBS Test Modes
        3. 6.4.4.3 Clock Pattern Mode
        4. 6.4.4.4 Ramp Test Mode
        5. 6.4.4.5 Short and Long Transport Test Mode
          1. 6.4.4.5.1 Short Transport Test Pattern
        6. 6.4.4.6 D21.5 Test Mode
        7. 6.4.4.7 K28.5 Test Mode
        8. 6.4.4.8 Repeated ILA Test Mode
        9. 6.4.4.9 Modified RPAT Test Mode
      5. 6.4.5 Calibration Modes and Trimming
        1. 6.4.5.1 Foreground Calibration Mode
        2. 6.4.5.2 Background Calibration Mode
        3. 6.4.5.3 Low-Power Background Calibration (LPBG) Mode
      6. 6.4.6 Offset Calibration
      7. 6.4.7 Trimming
    5. 6.5 Programming
      1. 6.5.1 Using the Serial Interface
      2. 6.5.2 SCS
      3. 6.5.3 SCLK
      4. 6.5.4 SDI
      5. 6.5.5 SDO
      6. 6.5.6 Streaming Mode
      7. 6.5.7 SPI_Register_Map Registers
  8. 7 Application and Implementation
    1. 7.1 Application Information
    2. 7.2 Typical Applications
      1. 7.2.1 Light Detection and Ranging (LiDAR) Digitizer
        1. 7.2.1.1 Design Requirements
        2. 7.2.1.2 Detailed Design Procedure
          1. 7.2.1.2.1 Analog Front-End Requirements
          2. 7.2.1.2.2 Calculating Clock and SerDes Frequencies
        3. 7.2.1.3 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
    2. 8.2 Receiving Notification of Documentation Updates
    3. 8.3 Support Resources
    4. 8.4 Trademarks
    5. 8.5 Electrostatic Discharge Caution
    6. 8.6 Glossary
  10. 9 Revision History
  11. 10Mechanical, Packaging, and Orderable Information

7.2.1.1 Design Requirements

An example list of LiDAR system requirements and the resulting digitizer requirements is given in Table 7-1. The example system requirements are for a mechanically rotating LiDAR system using a spinning mirror to cover the horizontal (azimuth) field-of-view and parallel receivers (photodiodes) to cover the vertical (elevation) field-of-view. The scan time requirement dictates that four vertical points are captured in parallel which requires four ADC channels and therefore a 16:1 photodiode to ADC mux ratio. The long 200 meter range for a 10% reflectivity target requires high performance and therefore a 12-bit ADC is chosen. The minimum pulse width of 5 ns, for high spatial resolution, requires a sampling rate of 1 GSPS in order to get 5 samples of each returning pulse. Low cost and small size are important to enable high volume production and a quad channel ADC with integrated clocking features help drive down these important metrics. Other considerations include the maximum SerDes rate supported by the FPGA and number of lanes. Assume the FPGA has 4 SerDes lanes that support up to 12.5 Gbps. For this reason, JMODE 8 is chosen.

Table 7-1 LiDAR System and Digitizer Requirements
System ParameterExample System RequirementExample Digitizer Requirement
Maximum Target Range 200 meters at 10% reflectivity 12-bit ADC
Minimum Laser Pulse Width5 ns1 GSPS (5 samples per pulse)
Horizontal FOV360°See Full Scan Time
Vertical FOV20°See Vertical Scanning Method
Horizontal Resolution0.1°See Full Scan Time
Vertical Resolution0.3125°See Vertical Scanning Method
Horizontal Scanning MethodSpinning mirrorSee Full Scan Time
Vertical Scanning MethodParallel photodiodes64 photodiodes
Full Scan Time76.8 ms16:1 mux ratio (4 ADC channels)
System CostLow costClock features integrated in ADC
System Form FactorSmall form factorQuad channel ADC with integrated clocking