SLVSDR3C may   2018  – may 2023 ADC12DL3200

PRODUCTION DATA  

  1.   1
  2. 1Features
  3. 2Applications
  4. 3Description
  5. 4Revision History
  6. 5Pin Configuration and Functions
  7. 6Specifications
    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 Typical Characteristics
  8. 7Detailed 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)
        5. 7.3.2.5 Internal Dither
      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 LVDS Digital Interface
        1. 7.3.5.1 Multi-Device Synchronization and Deterministic Latency Using Strobes
          1. 7.3.5.1.1 Dedicated Strobe Pins
          2. 7.3.5.1.2 Reduced Width Interface With Dedicated Strobe Pins
          3. 7.3.5.1.3 LSB Replacement With a Strobe
          4. 7.3.5.1.4 Strobe Over All Data Pairs
      6. 7.3.6 Alarm Monitoring
        1. 7.3.6.1 Clock Upset Detection
      7. 7.3.7 Temperature Monitoring Diode
      8. 7.3.8 Analog Reference Voltage
    4. 7.4 Device Functional Modes
      1. 7.4.1 Dual-Channel Mode (Non-DES Mode)
      2. 7.4.2 Internal Dither Modes
      3. 7.4.3 Single-Channel Mode (DES Mode)
      4. 7.4.4 LVDS Output Driver Modes
      5. 7.4.5 LVDS Output Modes
        1. 7.4.5.1 Staggered Output Mode
        2. 7.4.5.2 Aligned Output Mode
        3. 7.4.5.3 Reducing the Number of Strobes
        4. 7.4.5.4 Reducing the Number of Data Clocks
        5. 7.4.5.5 Scrambling
        6. 7.4.5.6 Digital Interface Test Patterns and LVSD SYNC Functionality
          1. 7.4.5.6.1 Active Pattern
          2. 7.4.5.6.2 Synchronization Pattern
          3. 7.4.5.6.3 User-Defined Test Pattern
      6. 7.4.6 Power-Down Modes
      7. 7.4.7 Calibration Modes and Trimming
        1. 7.4.7.1 Foreground Calibration Mode
        2. 7.4.7.2 Background Calibration Mode
        3. 7.4.7.3 Low-Power Background Calibration (LPBG) Mode
      8. 7.4.8 Offset Calibration
      9. 7.4.9 Trimming
    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 78
        6. 7.5.1.6 Streaming Mode
        7. 7.5.1.7 80
    6. 7.6 Register Maps
      1. 7.6.1 SPI_REGISTER_MAP Registers
  9.   Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Applications
      1. 8.2.1 Wideband RF Sampling Receiver
        1. 8.2.1.1 Design Requirements
          1. 8.2.1.1.1 Input Signal Path
          2. 8.2.1.1.2 Clocking
        2. 8.2.1.2 Detailed Design Procedure
          1. 8.2.1.2.1 Calculating Values of AC-Coupling Capacitors
        3. 8.2.1.3 Application Curves
      2. 8.2.2 Reconfigurable Dual-Channel, 2.5-GSPS or Single-Channel, 5.0-GSPS Oscilloscope
        1. 8.2.2.1 Design Requirements
          1. 8.2.2.1.1 Input Signal Path
          2. 8.2.2.1.2 Clocking
          3. 8.2.2.1.3 The ADC12DL3200
        2. 8.2.2.2 Application Curves
    3. 8.3 Initialization Set Up
    4. 8.4 Power Supply Recommendations
      1. 8.4.1 Power Sequencing
    5. 8.5 Layout
      1. 8.5.1 Layout Guidelines
      2. 8.5.2 Layout Example
  10. 8Device and Documentation Support
    1. 8.1 Device Support
      1. 8.1.1 Development 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
  11. 9Mechanical, Packaging, and Orderable Information

7.3.2.3 ADC Overrange Detection

To ensure that system gain management has the quickest possible response time, a low-latency configurable overrange function is included. The overrange 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 overrange condition. The absolute value of the upper eight bits of the ADC data are checked against two programmable thresholds, OVR_T0 and OVR_T1. These thresholds apply to both channel A and channel B in dual-channel mode. Table 7-1 lists how an ADC sample is converted to an absolute value for a comparison of the thresholds.

Table 7-1 Conversion of ADC Sample for Overrange 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)

If the upper eight bits of the absolute value equal or exceed the OVR_T0 or OVR_T1 thresholds during the monitoring period, then the overrange bit associated with the threshold is set to 1, otherwise the overrange bit is 0. In dual-channel mode, the overrange status can be monitored on the ORA0 and ORA1 pins for channel A and the ORB0 and ORB1 pins for channel B, where ORx0 corresponds to the OVR_T0 threshold and ORx1 corresponds to the OVR_T1 threshold. In single-channel mode, the overrange status for the OVR_T0 threshold is determined by monitoring both the ORA0 and ORB0 outputs and the OVR_T1 threshold is determined by monitoring both ORA1 and ORB1 outputs. In single-channel mode, the two outputs for each threshold must be OR'd together to determine whether an over-range condition occurred. OVR_N can be used to set the output pulse duration from the last overrange event. Table 7-2 lists the overrange pulse durations for the various OVR_N settings (see the overrange configuration register).

Table 7-2 Overrange Monitoring Period for the ORA0, ORA1, ORB0, and ORB1 Outputs
OVR_NOVERRANGE PULSE DURATION FROM LAST OVERRANGE EVENT (DEVCLK Cycles)
08
116
232
364
4128
5256
6512
71024

Typically, the OVR_T0 threshold can be set near the full-scale value (228 for example). When the threshold is triggered, a typical system can turn down the system gain to avoid clipping. The OVR_T1 threshold can be set much lower. For example, the OVR_T1 threshold can be set to 64 (peak input voltage of −12 dBFS). If the input signal is strong, the OVR_T1 threshold is tripped occasionally. If the input is quite weak, the threshold is never tripped. The downstream logic device monitors the OVR_T1 bit. If OVR_T1 stays low for an extended period of time, then the system gain can be increased until the threshold is occasionally tripped (meaning the peak level of the signal is above −12 dBFS).