SBASAP6 February   2025 ADC3683-EP , ADC3683-SEP

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 - Power Consumption
    6. 5.6 Electrical Characteristics - DC Specifications
    7. 5.7 Electrical Characteristics - AC Specifications
    8. 5.8 Timing Requirements
    9. 5.9 Typical Characteristics - ADC3683
  7. 6 Parameter Measurement Information
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Analog Input
        1. 7.3.1.1 Analog Input Bandwidth
        2. 7.3.1.2 Analog Front End Design
          1. 7.3.1.2.1 Sampling Glitch Filter Design
          2. 7.3.1.2.2 Analog Input Termination and DC Bias
            1. 7.3.1.2.2.1 AC-Coupling
            2. 7.3.1.2.2.2 DC-Coupling
        3. 7.3.1.3 Auto-Zero Feature
      2. 7.3.2 Clock Input
        1. 7.3.2.1 Single Ended vs Differential Clock Input
        2. 7.3.2.2 Signal Acquisition Time Adjust
      3. 7.3.3 Voltage Reference
        1. 7.3.3.1 Internal voltage reference
        2. 7.3.3.2 External voltage reference (VREF)
        3. 7.3.3.3 External voltage reference with internal buffer (REFBUF/CTRL)
      4. 7.3.4 Digital Down Converter
        1. 7.3.4.1 DDC MUX
        2. 7.3.4.2 Digital Filter Operation
        3. 7.3.4.3 FS/4 Mixing with Real Output
        4. 7.3.4.4 Numerically Controlled Oscillator (NCO) and Digital Mixer
        5. 7.3.4.5 Decimation Filter
        6. 7.3.4.6 SYNC
        7. 7.3.4.7 Output Formatting with Decimation
      5. 7.3.5 Digital Data Path and Interface
        1. 7.3.5.1 Data Path Overview
        2. 7.3.5.2 Output Scrambler
        3. 7.3.5.3 Output Bit Mapper
          1. 7.3.5.3.1 2-Wire Mode
          2. 7.3.5.3.2 1-Wire Mode
          3. 7.3.5.3.3 ½-Wire Mode
        4. 7.3.5.4 Device Configuration Steps
          1. 7.3.5.4.1 Configuration Example
        5. 7.3.5.5 Output Data Format
      6. 7.3.6 Test Pattern
    4. 7.4 Device Functional Modes
      1. 7.4.1 Normal Operation
      2. 7.4.2 Power Down Options
      3. 7.4.3 Digital Channel Averaging
    5. 7.5 Programming
      1. 7.5.1 Configuration using PINs only
      2. 7.5.2 Configuration using the SPI interface
        1. 7.5.2.1 Register Write
        2. 7.5.2.2 Register Read
  9. 8 Application Information Disclaimer
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 Input Signal Path
        2. 8.2.2.2 Sampling Clock
        3. 8.2.2.3 Voltage Reference
      3. 8.2.3 Application Curves
    3. 8.3 Initialization Set Up
      1. 8.3.1 Register Initialization During Operation
    4. 8.4 Power Supply Recommendations
    5. 8.5 Layout
      1. 8.5.1 Layout Guidelines
      2. 8.5.2 Layout Example
  10. 9 Register Map
    1. 9.1 Detailed Register Description
  11. 10Device and Documentation Support
    1. 10.1 Receiving Notification of Documentation Updates
    2. 10.2 Support Resources
    3. 10.3 Trademarks
    4. 10.4 Electrostatic Discharge Caution
    5. 10.5 Glossary
  12. 11Revision History
  13. 12Mechanical, Packaging, and Orderable Information
    1. 12.1 Mechanical Data

7.3.3.2 External voltage reference (VREF)

For highest accuracy and lowest temperature drift, the VREF input is connected directly to an external 1.6V reference. A 10μF and a 0.1μF ceramic bypass capacitor (CVREF) connected between the VREF and REFGND pins and placed as close to the pins as possible is recommended. The load current from the external reference is about 1mA.

Note: The internal reference is also used for other functions inside the device; therefore, the reference amplifier should only be powered down in power down state but not during normal operation.
ADC3683-SEP ADC3683-EP External 1.6V referenceFigure 7-19 External 1.6V reference