SBAS500B june   2022  – august 2023 ADC32RF54 , ADC32RF55

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Revision History
  6. 5 Pin Configuration and Functions
  7. 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 - ADC32RF54 AC Specifications (Dither DISABLED)
    8. 6.8  Electrical Characteristics - ADC32RF54 AC Specifications (Dither ENABLED)
    9. 6.9  Electrical Characteristics - ADC32RF55 AC Specifications (Dither DISABLED)
    10. 6.10 Electrical Characteristics - ADC32RF55 AC Specifications (Dither ENABLED)
    11. 6.11 Timing Requirements
    12. 6.12 Typical Characteristics - ADC32RF54
    13. 6.13 Typical Characteristics - ADC32RF55
  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 and Full-Scale
        2. 7.3.1.2 Input Imbalance
        3. 7.3.1.3 Overrange Indication
        4. 7.3.1.4 Analog out-of-band dither
      2. 7.3.2 Sampling Clock Input
      3. 7.3.3 SYSREF
        1. 7.3.3.1 SYSREF Capture Detection
      4. 7.3.4 ADC Foreground Calibration
        1. 7.3.4.1 Calibration Control
        2. 7.3.4.2 ADC Switch
        3. 7.3.4.3 Calibration Configuration
      5. 7.3.5 Decimation Filter
        1. 7.3.5.1 Decimation Filter Response
        2. 7.3.5.2 Decimation Filter Configuration
        3. 7.3.5.3 20-bit Output Mode
        4. 7.3.5.4 Dynamic Switching
          1. 7.3.5.4.1 2 Lane Mode
          2. 7.3.5.4.2 1 Lane Mode
        5. 7.3.5.5 Numerically Controlled Oscillator (NCO)
        6. 7.3.5.6 NCO Frequency Programming
        7. 7.3.5.7 Fast Frequency Hopping
          1. 7.3.5.7.1 Fast frequency hopping Using the GPIO1/2 pins
          2. 7.3.5.7.2 Fast frequency hopping using GPIO1/2, SEN and SDIO pins
          3. 7.3.5.7.3 Fast Frequency Hopping Using the Fast SPI
      6. 7.3.6 JESD204B Interface
        1. 7.3.6.1 JESD204B Initial Lane Alignment (ILA)
          1. 7.3.6.1.1 SYNC Signal
        2. 7.3.6.2 JESD204B Frame Assembly
        3. 7.3.6.3 JESD204B Frame Assembly in Bypass Mode
        4. 7.3.6.4 JESD204B Frame Assembly with Complex Decimation - Single Band
        5. 7.3.6.5 JESD204B Frame Assembly with Real Decimation - Single Band
        6. 7.3.6.6 JESD204B Frame Assembly with Complex Decimation - Dual Band
        7. 7.3.6.7 JESD204B Frame Assembly with Complex Decimation - Quad Band
      7. 7.3.7 SERDES Output MUX
      8. 7.3.8 Test Pattern
        1. 7.3.8.1 Transport Layer
        2. 7.3.8.2 Link Layer
        3. 7.3.8.3 Internal Capture Memory Buffer
    4. 7.4 Device Functional Modes
      1. 7.4.1 Digital Averaging
    5. 7.5 Programming
      1. 7.5.1 GPIO Pin Control
      2. 7.5.2 Configuration Using the SPI Interface
        1. 7.5.2.1 Register Write
        2. 7.5.2.2 Register Read
    6. 7.6 Register Maps
      1. 7.6.1 Detailed Register Description
  9. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Applications
      1. 8.2.1 Wideband RF Sampling Receiver
        1. 8.2.1.1 Design Requirements
          1. 8.2.1.1.1 Input Signal Path
          2. 8.2.1.1.2 Clocking
        2. 8.2.1.2 Detailed Design Procedure
          1. 8.2.1.2.1 Sampling Clock
        3. 8.2.1.3 Application Curves
    3. 8.3 Initialization Set Up
      1. 8.3.1 Initial Device Configuration After Power-Up
        1. 8.3.1.1  STEP 1: RESET
        2. 8.3.1.2  STEP 2: Device Configuration
        3. 8.3.1.3  STEP 3: JESD Interface Configuration (1)
        4. 8.3.1.4  STEP 4: SYSREF Synchronization
        5. 8.3.1.5  STEP 5: JESD Interface Configuration (2)
        6. 8.3.1.6  STEP 6: Analog Trim Settings
        7. 8.3.1.7  STEP 7: Calibration Configuration
        8. 8.3.1.8  STEP 8: SYSREF Synchronization
        9. 8.3.1.9  STEP 9: Run Power up Calibration
        10. 8.3.1.10 STEP 10: JESD Interface Synchronization
    4. 8.4 Power Supply Recommendations
    5. 8.5 Layout
      1. 8.5.1 Layout Guidelines
      2. 8.5.2 Layout Example
  10. 9 Device and Documentation Support
    1. 9.1 Receiving Notification of Documentation Updates
    2. 9.2 Support Resources
    3. 9.3 Trademarks
    4. 9.4 Electrostatic Discharge Caution
    5. 9.5 Glossary
  11. 10Mechanical, Packaging, and Orderable Information

Package Options

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

7.3.2 Sampling Clock Input

The internal sampling clock path was designed for lowest residual phase noise contribution. The sampling clock circuitry requires a dedicated low noise power supply for best performance. The internal residual clock phase noise is also sensitive to clock amplitude. For best performance, the clock amplitude should be larger than 1 VPP. The phase noise ideally improves by 3 dB per 2x averaging, however at higher input frequencies the clock path contribution reduces the improvement.

Table 7-7 Internal Aperture Clock Phase Noise
(FS = 3 Gsps, VIN = 1 VPP)
Frequency Offset (MHz) Amplitude (dBc/Hz)
0.001 -117
0.01 -127
0.1 -137
1 -147
10 -154
250 -160

The clock input and ADC sampling circuitry also have an amplitude noise component which modulates on to the sampled input signal. Unlike phase noise, the amplitude noise does not scale with input frequency, it is only affected by the sampling reset switch as shown in Figure 7-10 and Figure 7-11. This noise component can dominate the close in noise performance at lower input frequencies.

GUID-20221209-SS0I-HPRR-52WD-G18TVRZCGR9J-low.svgFigure 7-10 Amplitude Noise vs Input Frequency
GUID-20221209-SS0I-NNFH-FV4R-5BWLZKHW07CJ-low.svgFigure 7-11 Amplitude and Phase noise at 10 kHz offset vs Input Frequency

The internal aperture jitter is also dependent on the amplitude of the external clock input signal. Figure 7-12 and Figure 7-13 show the expected SNR performance with dither on/off across clock amplitude (FS = 2.6 GSPS).

GUID-20211104-SS0I-QTP8-S6ZC-5THB3TWNGNQQ-low.svgFigure 7-12 SNR vs Clock Amplitude (Dither OFF)
GUID-20211104-SS0I-VCGV-N3RB-S90RDTPKV2JC-low.svgFigure 7-13 SNR vs Clock Amplitude (Dither ON)

The sampling clock input is internally terminated to 100 Ω differentially and provides a return loss better than 10 dB at 3 GHz (see Figure 7-14). The clock input consists of a single clock input buffer followed by a dedicated clock buffer for ADCA1/2 as well as ADCB1/2. When averaging multiple ADCs, there are some close in clock buffer noise which is correlated; and thus, does not improve with averaging.

GUID-08645406-B9B2-4CE9-A659-F496223D5C33-low.gif Figure 7-14 Internal Clock Input Routing