SBASAL0A August   2025  – October 2025 ADC34RF72

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
  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 Inputs
        1. 7.3.1.1 Input Bandwidth
        2. 7.3.1.2 Background Calibration
      2. 7.3.2 Sampling Clock Input
      3. 7.3.3 SYSREF
        1. 7.3.3.1 SYSREF Monitor
      4. 7.3.4 ADC Power Down Modes
      5. 7.3.5 Digital Signal Processor (DSP) Features
        1. 7.3.5.1 DSP Input Mux
        2. 7.3.5.2 Fractional Delay
        3. 7.3.5.3 Programmable FIR Filter for Equalization
        4. 7.3.5.4 DSP Output Mux
        5. 7.3.5.5 Digital Down Converter (DDC)
          1. 7.3.5.5.1 Decimation Filter Input
          2. 7.3.5.5.2 Decimation Modes
          3. 7.3.5.5.3 Decimation Filter Response
          4. 7.3.5.5.4 Numerically Controlled Oscillator (NCO)
            1. 7.3.5.5.4.1 NCO Update
            2. 7.3.5.5.4.2 NCO RESET
      6. 7.3.6 Digital Output Interface
        1. 7.3.6.1 JESD204B/C Interface
          1. 7.3.6.1.1 JESD204B Initial Lane Alignment (ILA)
          2. 7.3.6.1.2 SYNC Signal
          3. 7.3.6.1.3 JESD204B/C Frame Assembly
          4. 7.3.6.1.4 JESD204B/C Frame Assembly in Bypass Mode
          5. 7.3.6.1.5 JESD204B/C Frame Assembly with Real Decimation
          6. 7.3.6.1.6 JESD204B,C Frame Assembly with Complex Decimation
        2. 7.3.6.2 JESD Output Reference Clock
    4. 7.4 Device Functional Modes
      1. 7.4.1 Device Operating Mode Comparison
    5. 7.5 Programming
      1. 7.5.1 GPIO Control
      2. 7.5.2 SPI Register Write
      3. 7.5.3 SPI Register Read
  9. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application: Spectrum Analyzer
      1. 8.2.1 Design Requirements
        1. 8.2.1.1 Input Signal Path: Wideband Receiver
        2. 8.2.1.2 Clocking
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 Sampling Clock Requirements
      3. 8.2.3 Application Performance Plots
    3. 8.3 Typical Application: Time Domain Digitizer
      1. 8.3.1 Design Requirements
        1. 8.3.1.1 Input Signal Path: Time Domain Digitizer
      2. 8.3.2 Application Performance Plots
    4. 8.4 Initialization Set Up
    5. 8.5 Power Supply Recommendations
    6. 8.6 Layout
      1. 8.6.1 Layout Guidelines
      2. 8.6.2 Layout Example
  10. 9 Device and Documentation Support
    1. 9.1 Documentation Support
      1. 9.1.1 Related Documentation
      2. 9.1.2 Third-Party Products Disclaimer
    2. 9.2 Receiving Notification of Documentation Updates
    3. 9.3 Support Resources
    4. 9.4 Trademarks
    5. 9.5 Electrostatic Discharge Caution
    6. 9.6 Glossary
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information

Package Options

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

7.3.3 SYSREF

The SYSREF input signal is used for multi-chip synchronization and resets the internal LMFC counter. The device must be armed in anticipation of a SYSREF signal; the device is sensitive to the first SYSREF edge after it is armed.

The internal SYSREF capture includes a programmable analog delay td, a SYSREF monitor as well as a programmable digital integer clock cycle delay z-n as shown in Figure 7-8.

ADC34RF72 SYSREF Input Internal PathFigure 7-8 SYSREF Input Internal Path

The SYSREF input signal can be AC or DC coupled (selected via SPI register option) as shown in Figure 7-9. The SYSREF input has internal 100Ω termination for DC coupling and internal biasing when using AC coupling.

ADC34RF72 SYSREF Input Circuitry and Edge Alignment (left side: DC coupling, right side: AC coupling)Figure 7-9 SYSREF Input Circuitry and Edge Alignment (left side: DC coupling, right side: AC coupling)

The following parameters can be programmed:

Table 7-4 SYSREF Configuration Programming

System Parameter

Name		SizeDefaultResetDescription
SYSREF_IN_TYPE_SEL20R/W

Select input SYSREF type:

0: DC coupled LVDS SYSREF input.

1: AC coupled SYSREF input.

2: not used.

3: Internally generated SYSREF using SPI write.

SYSREF_DIG_DEL80R/WDigital SYSREF internal delay (z-n) in clock cycles of CLK.

0...255: Number of device clock cycles delay that is applied to digital SYSREF before use.