SBAS960B February   2020  – October 2024 ADC12DJ1600-Q1 , ADC12QJ1600-Q1 , ADC12SJ1600-Q1

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  ADC12xJ1600-Q1: Electrical Characteristics: Power Consumption
    7. 5.7  ADC12xJ1600-Q1: Electrical Characteristics: AC Specifications
    8. 5.8  Timing Requirements
    9. 5.9  Switching Characteristics
    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 Device Comparison
      2. 6.3.2 Analog Input
        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
        4. 6.3.2.4 ADC Core
          1. 6.3.2.4.1 ADC Theory of Operation
          2. 6.3.2.4.2 ADC Core Calibration
          3. 6.3.2.4.3 Analog Reference Voltage
          4. 6.3.2.4.4 ADC Over-range Detection
          5. 6.3.2.4.5 Code Error Rate (CER)
      3. 6.3.3 Temperature Monitoring Diode
      4. 6.3.4 Timestamp
      5. 6.3.5 Clocking
        1. 6.3.5.1 Converter PLL (C-PLL) for Sampling Clock Generation
        2. 6.3.5.2 LVDS Clock Outputs (PLLREFO±, TRIGOUT±)
        3. 6.3.5.3 Optional CMOS Clock Outputs (ORC, ORD)
        4. 6.3.5.4 SYSREF for JESD204C Subclass-1 Deterministic Latency
          1. 6.3.5.4.1 SYSREF Capture for Multi-Device Synchronization and Deterministic Latency
          2. 6.3.5.4.2 SYSREF Position Detector and Sampling Position Selection (SYSREF Windowing)
      6. 6.3.6 JESD204C Interface
        1. 6.3.6.1  Transport Layer
        2. 6.3.6.2  Scrambler
        3. 6.3.6.3  Link Layer
        4. 6.3.6.4  8B/10B Link Layer
          1. 6.3.6.4.1 Data Encoding (8B/10B)
          2. 6.3.6.4.2 Multiframes and the Local Multiframe Clock (LMFC)
          3. 6.3.6.4.3 Code Group Synchronization (CGS)
          4. 6.3.6.4.4 Initial Lane Alignment Sequence (ILAS)
          5. 6.3.6.4.5 Frame and Multiframe Monitoring
        5. 6.3.6.5  64B/66B Link Layer
          1. 6.3.6.5.1 64B/66B Encoding
          2. 6.3.6.5.2 Multiblocks, Extended Multiblocks and the Local Extended Multiblock Clock (LEMC)
            1. 6.3.6.5.2.1 Block, Multiblock and Extended Multiblock Alignment using Sync Header
              1. 6.3.6.5.2.1.1 Cyclic Redundancy Check (CRC) Mode
              2. 6.3.6.5.2.1.2 Forward Error Correction (FEC) Mode
          3. 6.3.6.5.3 Initial Lane Alignment
          4. 6.3.6.5.4 Block, Multiblock and Extended Multiblock Alignment Monitoring
        6. 6.3.6.6  Physical Layer
          1. 6.3.6.6.1 SerDes Pre-Emphasis
        7. 6.3.6.7  JESD204C Enable
        8. 6.3.6.8  Multi-Device Synchronization and Deterministic Latency
        9. 6.3.6.9  Operation in Subclass 0 Systems
        10. 6.3.6.10 Alarm Monitoring
          1. 6.3.6.10.1 Clock Upset Detection
          2. 6.3.6.10.2 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/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
6.3.2.4.4 ADC Over-range Detection

For the system gain management to have the best possible response time, a low-latency configurable over-range function is included. The over-range function works by monitoring the converted 12-bit samples at the ADC to quickly detect if the ADC is near saturation or already in an over-range condition. The absolute value of the upper 8 bits of the ADC data are checked against a programmable threshold, OVR_TH. The threshold programmed into OVR_TH is used for all analog inputs.Table 6-2 lists how an ADC sample is converted to an absolute value for a comparison of the thresholds.

Table 6-2 Conversion of ADC Sample for Over-range Comparison
ADC SAMPLE
(Offset Binary)		ADC SAMPLE
(2's Complement)		ABSOLUTE VALUEUPPER 8 BITS USED FOR COMPARISON
1111 1111 1111 (4095) 0111 1111 1111 (+2047) 111 1111 1111 (2047) 1111 1111 (255)
1111 1111 0000 (4080) 0111 1111 0000 (+2032) 111 1111 0000 (2032) 1111 1110 (254)
1000 0000 0000 (2048) 0000 0000 0000 (0) 000 0000 0000 (0) 0000 0000 (0)
0000 0001 0000 (16) 1000 0001 0000 (–2032) 111 1111 0000 (2032) 1111 1110 (254)
0000 0000 0000 (0) 1000 0000 0000 (–2048) 111 1111 1111 (2047) 1111 1111 (255)

Over-range detection is enabled by setting OVR_EN to 1. If the upper 8 bits of the absolute value equal or exceed the OVR_TH threshold during the monitoring period, then the over-range bit associated with the over-ranged ADC channel is set to 1, otherwise the over-range bit is 0. For the Quad channel device, the over-range status can be monitored on the ORA, ORB, ORC or ORD output pins for ADC channels A, B, C and D, respectively. For the dual channel device, the over-range status can be monitored on the ORA or ORB output pins for ADC channels A and B, respectively. For the single channel device, the over-range status can be monitored on the ORA output pins. OVR_N can be used to set the output pulse duration from the last over-range event. Table 6-3 lists the over-range pulse lengths for the various OVR_N settings.

Table 6-3 Over-range Monitoring Period
OVR_Nover-range PULSE LENGTH SINCE LAST over-range EVENT (DEVCLK Cycles)
08
116
232
364
4128
5256
6512
71024

Typically, the OVR_TH threshold is set near the 8-bit full-scale value (228 for example). When the threshold is triggered, a typical system turns down the system gain to avoid clipping. The downstream logic device then monitors the output samples to determine when the over-range condition no longer exists and then increases the system gain as desired.