SBASAL2 November   2025 ADC32RF72

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 ADC Channel Selection and Power Down Modes
      3. 7.3.3 Sampling Clock Input
      4. 7.3.4 SYSREF
        1. 7.3.4.1 SYSREF Monitor
      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

7.3.3 Sampling Clock Input

The clock input has internal 100Ω differential termination with self biasing to VCM = 0.7V, enabling external AC coupling (see Figure 7-7).

ADC32RF72 Internal Sampling Clock Circuitry Figure 7-7 Internal Sampling Clock Circuitry

The internal sampling clock path is designed for ultra-low residual phase noise contribution. The sampling clock circuitry requires a dedicated low noise power supply for best performance. The internal aperture clock phase noise is also sensitive to clock amplitude. For best performance, the clock amplitude must be larger than 1Vpp.

Table 7-4 Internal Aperture Clock Noise at 1GHz
Frequency Offset (MHz) Phase Noise (dBc/Hz) Amplitude Noise (dBc/Hz)
0.001 −130 −139
0.01 −140 −149
0.1 −150 −155
1 −155 −159

The following parameters can be programmed:

Table 7-5 Clock Register Programming

System Parameter

Name		 Size Default Reset Description
ADC_CLK_FREQ_HZ 33 0 R/W 33-bit unsigned number that represent the sampling clock frequency in Hz.