SBAS533E March   2011  – February 2023 ADS4222 , ADS4225 , ADS4226 , ADS4242 , ADS4245 , ADS4246

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Description (continued)
  6. 6 Pin Configuration and Functions
    1.     Pin Functions – LVDS Mode
    2.     Pin Functions – CMOS Mode
  7. 7 Specifications
    1. 7.1  Absolute Maximum Ratings
    2. 7.2  ESD Ratings
    3. 7.3  Recommended Operating Conditions
    4. 7.4  Thermal Information
    5. 7.5  Electrical Characteristics: ADS4246, ADS4245, ADS4242
    6. 7.6  Electrical Characteristics: ADS4226, ADS4225, ADS4222
    7. 7.7  Electrical Characteristics: General
    8. 7.8  Digital Characteristics
    9. 7.9  Timing Requirements: LVDS and CMOS Modes (1)
    10. 7.10 Serial Interface Timing Characteristics (1)
    11. 7.11 Reset Timing (Only When Serial Interface Is Used)
    12. 7.12 Typical Characteristics
      1. 7.12.1 ADS4246
      2. 7.12.2 ADS4245
      3. 7.12.3 ADS4242
      4. 7.12.4 ADS4226
      5. 7.12.5 ADS4225
      6. 7.12.6 ADS4222
      7. 7.12.7 General
      8. 7.12.8 Contour
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagrams
    3. 8.3 Feature Description
      1. 8.3.1 Analog Input
        1. 8.3.1.1 Drive Circuit Requirements
        2. 8.3.1.2 Driving Circuit
      2. 8.3.2 Clock Input
      3. 8.3.3 Digital Functions
      4. 8.3.4 Gain for SFDR/SNR Trade-off
      5. 8.3.5 Offset Correction
    4. 8.4 Device Functional Modes
      1. 8.4.1 Power-Down
        1. 8.4.1.1 Global Power-Down
        2. 8.4.1.2 Channel Standby
        3. 8.4.1.3 Input Clock Stop
    5. 8.5 Programming
      1. 8.5.1 47
      2. 8.5.2 Parallel Configuration Only
      3. 8.5.3 Serial Interface Configuration Only
      4. 8.5.4 Using Both Serial Interface and Parallel Controls
      5. 8.5.5 Parallel Configuration Details
      6. 8.5.6 Serial Interface Details
        1. 8.5.6.1 Register Initialization
        2. 8.5.6.2 Serial Register Readout
      7. 8.5.7 Digital Output Information
        1. 8.5.7.1 Output Interface
        2. 8.5.7.2 DDR LVDS Outputs
        3. 8.5.7.3 LVDS Buffer
        4. 8.5.7.4 Parallel CMOS Interface
        5. 8.5.7.5 CMOS Interface Power Dissipation
        6. 8.5.7.6 Multiplexed Mode of Operation
        7. 8.5.7.7 Output Data Format
    6. 8.6 Register Maps
      1. 8.6.1 64
      2. 8.6.2 Description Of Serial Registers
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Analog Input
        2. 9.2.2.2 Clock Driver
        3. 9.2.2.3 Digital Interface
        4. 9.2.2.4 SNR and Clock Jitter
      3. 9.2.3 Application Curves
    3. 9.3 Power Supply Recommendations
      1. 9.3.1 Sharing DRVDD and AVDD Supplies
      2. 9.3.2 Using DC/DC Power Supplies
      3. 9.3.3 Power Supply Bypassing
    4. 9.4 Layout
      1. 9.4.1 Layout Guidelines
        1. 9.4.1.1 Grounding
        2. 9.4.1.2 Supply Decoupling
        3. 9.4.1.3 Exposed Pad
        4. 9.4.1.4 Routing Analog Inputs
      2. 9.4.2 Layout Example
  10. 10Device and Documentation Support
    1. 10.1 Device Support
      1. 10.1.1 Device Nomenclature
    2. 10.2 Documentation Support
      1. 10.2.1 Related Documentation
    3. 10.3 Support Resources
    4. 10.4 Trademarks
    5. 10.5 Electrostatic Discharge Caution
    6. 10.6 Glossary
  11. 11Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

9.1 Application Information

The ADS424x/422x belong to TI's ultralow-power family of dual-channel 12-bit and 14-bit analog-to-digital converters (ADCs). At every rising edge of the input clock, the analog input signal of each channel is simultaneously sampled. The sampled signal in each channel is converted by a pipeline of low-resolution stages. In each stage, the sampled/held signal is converted by a high-speed, low-resolution, flash sub-ADC. The difference between the stage input and the quantized equivalent is gained and propagates to the next stage. At every clock, each succeeding stage resolves the sampled input with greater accuracy. The digital outputs from all stages are combined in a digital correction logic block and digitally processed to create the final code after a data latency of 16 clock cycles. The digital output is available as either DDR LVDS or parallel CMOS and coded in either straight offset binary or binary twos complement format. The dynamic offset of the first stage sub-ADC limits the maximum analog input frequency to approximately 400 MHz (with 2-VPP amplitude) or approximately 600 MHz (with 1 VPP amplitude).