SBAS988 November   2023 ADC34RF55

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 (Dither DISABLED)
    8. 5.8  Electrical Characteristics - AC Specifications (Dither ENABLED)
    9. 5.9  Timing Requirements
    10. 5.10 Typical Characteristics
  7. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1 Analog Inputs
        1. 6.3.1.1 Input Bandwidth and Full-Scale
        2. 6.3.1.2 Input Imbalance
        3. 6.3.1.3 Over Range Indication
        4. 6.3.1.4 Analog out-of-band dither
      2. 6.3.2 Sampling Clock Input
      3. 6.3.3 ADC Foreground Calibration
        1. 6.3.3.1 Calibration Control
        2. 6.3.3.2 ADC Switch
        3. 6.3.3.3 Calibration Configuration
      4. 6.3.4 SYSREF
        1. 6.3.4.1 SYSREF Capture Detection
      5. 6.3.5 Decimation Filter
        1. 6.3.5.1 Decimation Filter Response
        2. 6.3.5.2 Decimation Filter Configuration
        3. 6.3.5.3 20-bit Output Mode
        4. 6.3.5.4 Numerically Controlled Oscillator (NCO)
        5. 6.3.5.5 NCO Frequency Programming Using the SPI Interface
        6. 6.3.5.6 Fast Frequency Hopping
          1. 6.3.5.6.1 Fast frequency hopping using the GPIO1/2 pins
          2. 6.3.5.6.2 Fast frequency hopping using GPIO1/2, SEN and SDATA pins
          3. 6.3.5.6.3 Fast frequency hopping using the fast SPI
      6. 6.3.6 JESD204B Interface
        1. 6.3.6.1 JESD204B Initial Lane Alignment (ILA)
          1. 6.3.6.1.1 SYNC Signal
        2. 6.3.6.2 JESD204B Frame Assembly
          1. 6.3.6.2.1 JESD204B Frame Assembly in Bypass Mode
          2. 6.3.6.2.2 JESD204B Frame Assembly with Real Decimation - Single Band
          3. 6.3.6.2.3 JESD204B Frame Assembly with Complex Decimation - Single Band
          4. 6.3.6.2.4 JESD204B Frame Assembly with Decimation - Dual Band
        3. 6.3.6.3 SERDES Output MUX
      7. 6.3.7 Test Pattern
        1. 6.3.7.1 Transport Layer
        2. 6.3.7.2 Link Layer
        3. 6.3.7.3 Internal Capture Memory Buffer
    4. 6.4 Device Functional Modes
      1. 6.4.1 Bypass Mode
      2. 6.4.2 Digital Averaging
    5. 6.5 Programming
      1. 6.5.1 GPIO Pin Control
      2. 6.5.2 Configuration using the SPI interface
        1. 6.5.2.1 Register Write
        2. 6.5.2.2 Register Read
    6. 6.6 Register Maps
      1. 6.6.1 Detailed Register Description
  8. 7 Application Information Disclaimer
    1. 7.1 Application Information
    2. 7.2 Typical Application
      1. 7.2.1 Wideband RF Sampling Receiver
      2. 7.2.2 Design Requirements
        1. 7.2.2.1 Input Signal Path
        2. 7.2.2.2 Clocking
      3. 7.2.3 Detailed Design Procedure
        1. 7.2.3.1 Sampling Clock
      4. 7.2.4 Application Curves
    3. 7.3 Initialization Set Up
      1. 7.3.1 Initial Device Configuration After Power-Up
        1. 7.3.1.1  STEP 1: RESET
        2. 7.3.1.2  STEP 2: Device Configuration
        3. 7.3.1.3  STEP 3: JESD Interface Configuration (1)
        4. 7.3.1.4  STEP 4: SYSREF Synchronization
        5. 7.3.1.5  STEP 5: JESD Interface Configuration (2)
        6. 7.3.1.6  STEP 6: Analog Trim Settings
        7. 7.3.1.7  STEP 7: Calibration Configuration
        8. 7.3.1.8  STEP 8: SYSREF Synchronization
        9. 7.3.1.9  STEP 9: Run Power up Calibration
        10. 7.3.1.10 Step 10: JESD Interface Synchronization
        11. 7.3.1.11 Step 11: NCO Configuration
    4. 7.4 Power Supply Recommendations
    5. 7.5 Layout
      1. 7.5.1 Layout Guidelines
      2. 7.5.2 Layout Example
  9. 8 Device and Documentation Support
    1. 8.1 Device Support
      1. 8.1.1 Third-Party Products Disclaimer
    2. 8.2 Receiving Notification of Documentation Updates
    3. 8.3 Support Resources
    4. 8.4 Trademarks
    5. 8.5 Electrostatic Discharge Caution
    6. 8.6 Glossary
  10. 9 Revision History
  11. 10Mechanical, Packaging, and Orderable Information

Package Options

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

6.3.4.1 SYSREF Capture Detection

The SYSREF input signal rising edge should be edge aligned with the rising edge of the sampling clock to maximize the setup and hold times. The ADC34RF5x includes an internal SYSREF monitoring circuitry to detect possible metastability resulting in a clock cycle slip and thus misalignment across devices.

The sampling clock gets delayed by approximately 160 ps and then captures the SYSREF signal. The SYSREF monitoring circuitry provides insights into SYSREF/clock misalignment by detecting whether SYSREF is leading the clock by up to 50 ps or lagging by up to 48 ps. This circuitry will detect and raise one of the SYSREF XOR flags corresponding to the matching SYSREF window below:

  • Window XOR1: SYSREF leading sample clock by 25 to 50 ps
  • Window XOR2: SYSREF leading sample clock by up to 25 ps
  • Window XOR3: SYSREF lagging sample clock by up to 16 ps
  • Window XOR4: SYSREF lagging sample clock by 16 to 32 ps
  • Window XOR5: SYSREF lagging sample clock by 32 to 48 ps

The SYSREF monitor registers are not sticky registers. They get updated at every rising edge of SYSREF.

GUID-76E89D64-EA9D-440F-8DF9-48C0EFE592CC-low.gifFigure 6-21 SYSREF Detection Circuitry

The example in Figure 6-22 shows a misaligned SYSREF signal where the SYSREF signal arrives much later than the sampling clock rising edge. The SYSREF window feature checks if the SYSREF transition is within ±50 ps of the instant when the SYSREF signal gets captured by the sampling clock. In this example, the delayed SYSREF signal transitions between the "B" and "C" reverse which raises the XOR2 flag. The XOR flags is reported in register 0x22F in the digital page. Register 0x22F then reads back 0x8B, as shown in Table 6-14.

GUID-54B74627-C468-4419-8F76-A2AA26B030E9-low.gif Figure 6-22 Detection of SYSREF Transition within Capture Window
Table 6-14 SYSREF Window Register Example (0x22F)
ADDRD7D6D5D4D3D2D1D0
0x22F1SYSREF X5SYSREF X4SYSREF X3SYSREF X2SYSREF X1SYSREF OR1
10001011