SBAS872B December   2020  – October 2022 ADC3681 , ADC3682 , ADC3683

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
  6. 6 Specifications
    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 - Power Consumption
    6. 6.6  Electrical Characteristics - DC Specifications
    7. 6.7  Electrical Characteristics - AC Specifications
    8. 6.8  Timing Requirements
    9. 6.9  Typical Characteristics - ADC3681
    10. 6.10 Typical Characteristics - ADC3682
    11. 6.11 Typical Characteristics - ADC3683
  7. 7 Parameter Measurement Information
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Analog Input
        1. 8.3.1.1 Analog Input Bandwidth
        2. 8.3.1.2 Analog Front End Design
          1. 8.3.1.2.1 Sampling Glitch Filter Design
          2. 8.3.1.2.2 Analog Input Termination and DC Bias
            1. 8.3.1.2.2.1 AC-Coupling
            2. 8.3.1.2.2.2 DC-Coupling
        3. 8.3.1.3 Auto-Zero Feature
      2. 8.3.2 Clock Input
        1. 8.3.2.1 Single Ended vs Differential Clock Input
        2. 8.3.2.2 Signal Acquisition Time Adjust
      3. 8.3.3 Voltage Reference
        1. 8.3.3.1 Internal voltage reference
        2. 8.3.3.2 External voltage reference (VREF)
        3. 8.3.3.3 External voltage reference with internal buffer (REFBUF)
      4. 8.3.4 Digital Down Converter
        1. 8.3.4.1 DDC MUX
        2. 8.3.4.2 Digital Filter Operation
        3. 8.3.4.3 FS/4 Mixing with Real Output
        4. 8.3.4.4 Numerically Controlled Oscillator (NCO) and Digital Mixer
        5. 8.3.4.5 Decimation Filter
        6. 8.3.4.6 SYNC
        7. 8.3.4.7 Output Formatting with Decimation
      5. 8.3.5 Digital Interface
        1. 8.3.5.1 Output Formatter
        2. 8.3.5.2 Output Scrambler
        3. 8.3.5.3 Output Bit Mapper
        4. 8.3.5.4 Output Interface/Mode Configuration
          1. 8.3.5.4.1 Configuration Example
        5. 8.3.5.5 Output Data Format
      6. 8.3.6 Test Pattern
    4. 8.4 Device Functional Modes
      1. 8.4.1 Normal Operation
      2. 8.4.2 Power Down Options
      3. 8.4.3 Digital Channel Averaging
    5. 8.5 Programming
      1. 8.5.1 Configuration using PINs only
      2. 8.5.2 Configuration using the SPI interface
        1. 8.5.2.1 Register Write
        2. 8.5.2.2 Register Read
    6. 8.6 Register Map
      1. 8.6.1 Detailed Register Description
  9. 9 Application Information Disclaimer
    1. 9.1 Typical Application
      1. 9.1.1 Design Requirements
      2. 9.1.2 Detailed Design Procedure
        1. 9.1.2.1 Input Signal Path
        2. 9.1.2.2 Sampling Clock
        3. 9.1.2.3 Voltage Reference
      3. 9.1.3 Application Curves
    2. 9.2 Initialization Set Up
      1. 9.2.1 Register Initialization During Operation
    3. 9.3 Power Supply Recommendations
    4. 9.4 Layout
      1. 9.4.1 Layout Guidelines
      2. 9.4.2 Layout Example
  10. 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
  11. 11Mechanical, Packaging, and Orderable Information

Package Options

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

8.3.4.7 Output Formatting with Decimation

When using decimation, the digital output data is formatted as shown in Figure 8-38 (complex decimation) and Figure 8-39 (real decimation).The output format is illustrated for 18-bit output resolution.

GUID-29BA1413-CE32-40DF-9319-D6E43616B1C2-low.gifFigure 8-38 Output Data Format in Complex Decimation (18-bit Output Resolution)

Table 8-4 illustrates the output interface data rate along with the corresponding DCLK/DCLKIN and FCLK frequencies based on output resolution (R), number of SLVDS lanes (L) and complex decimation setting (N).

Furthermore the table shows an actual lane rate example for the 2-, 1- and 1/2-wire interface, 18-bit output resolution and complex decimation by 4.

Table 8-4 Serial LVDS Lane Rate Examples with Complex Decimation and 18-bit Output Resolution
DECIMATION SETTINGADC SAMPLING RATEOUTPUT RESOLUTION# of WIRESFCLKDCLKIN, DCLKDA/B0,1
NFSRLFS / N[DA/B0,1] / 2FS x 2 x R / L / N
465 MSPS18216.25 MHz146.25 MHz292.5 MHz
1292.5 MHz585 MHz
55 MSPS1/213.75 MHz495 MHz990 MHz
GUID-7DF0CD18-671B-4FD7-950F-47E04A02F7BA-low.gif Figure 8-39 Output Data Format in Real Decimation (18-bit Output Resolution)

Table 8-5 illustrates the output interface data rate along with the corresponding DCLK/DCLKIN and FCLK frequencies based on output resolution (R), number of SLVDS lanes (L) and real decimation setting (M).

Furthermore the table shows an actual lane rate example for the 2-, 1- and 1/2-wire interface, 18-bit output resolution and real decimation by 4.

Table 8-5 Serial LVDS Lane Rate Examples with Real Decimation and 18-bit Output Resolution
DECIMATION SETTINGADC SAMPLING RATEOUTPUT RESOLUTION# of WIRESFCLKDCLKIN, DCLKDA/B0,1
MFSRLFS / M / 2 (L = 2)
FS / M (L = 1, 1/2)		[DA/B0,1] / 2FS x R / L / M
465 MSPS1828.125 MHz73.125 MHz146.25 MHz
116.25 MHz146.25 MHz292.5 MHz
1/2292.5 MHz585 MHz