SBAS807B January   2017  – December 2021 ADS58J64

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
    6. 6.6  AC Performance
    7. 6.7  Digital Characteristics
    8. 6.8  Timing Characteristics
    9. 6.9  Typical Characteristics: 14-Bit Burst Mode
    10. 6.10 Typical Characteristics: Mode 2
    11. 6.11 Typical Characteristics: Mode 0
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Analog Inputs
      2. 7.3.2 Recommended Input Circuit
      3. 7.3.3 Clock Input
    4. 7.4 Device Functional Modes
      1. 7.4.1 Digital Features
        1. 7.4.1.1  Numerically Controlled Oscillators (NCOs) and Mixers
        2. 7.4.1.2  Decimation Filter
          1. 7.4.1.2.1 Stage-1 Filter
          2. 7.4.1.2.2 Stage-2 Filter
        3. 7.4.1.3  Mode 0: Decimate-by-4 With IQ Outputs and fS / 4 Mixer
        4. 7.4.1.4  Mode 1: Decimate-by-4 With IQ Outputs and 16-Bit NCO
        5. 7.4.1.5  Mode 2: Decimate-by-4 With Real Output
        6. 7.4.1.6  Mode 3: Decimate-by-2 Real Output With Frequency Shift
        7. 7.4.1.7  Mode 4: Decimate-by-4 With Real Output
        8. 7.4.1.8  Mode 6: Decimate-by-4 With IQ Outputs for up to 110 MHz of IQ Bandwidth
        9. 7.4.1.9  Mode 7: Decimate-by-4 With Real Output and Zero Stuffing
        10. 7.4.1.10 Mode 8: Burst Mode
        11. 7.4.1.11 Trigger Input
        12. 7.4.1.12 Manual Trigger Mode
        13. 7.4.1.13 Auto Trigger Mode
        14. 7.4.1.14 Overrange Indication
    5. 7.5 Programming
      1. 7.5.1 JESD204B Interface
      2. 7.5.2 JESD204B Initial Lane Alignment (ILA)
      3. 7.5.3 JESD204B Frame Assembly
      4. 7.5.4 JESD Output Switch
        1. 7.5.4.1 SerDes Transmitter Interface
        2. 7.5.4.2 SYNCb Interface
        3. 7.5.4.3 Eye Diagram
      5. 7.5.5 Device Configuration
        1. 7.5.5.1 Details of the Serial Interface
          1. 7.5.5.1.1 Register Initialization
        2. 7.5.5.2 Serial Register Write
        3. 7.5.5.3 Serial Read
    6. 7.6 Register Maps
      1. 7.6.1 Register Map
        1. 7.6.1.1 Register Description
          1. 7.6.1.1.1 GLOBAL Page Register Description
            1. 7.6.1.1.1.1 Register 00h (address = 00h) [reset = 0h], GLOBAL Page
            2. 7.6.1.1.1.2 Register 04h (address = 04h) [reset = 0h], GLOBAL Page
            3. 7.6.1.1.1.3 Register 11h (address = 11h) [reset = 0h], GLOBAL Page
            4. 7.6.1.1.1.4 Register 12h (address = 12h) [reset = 0h], GLOBAL Page
            5. 7.6.1.1.1.5 Register 13h (address = 13h) [reset = 0h], GLOBAL Page
          2. 7.6.1.1.2 DIGTOP Page Register Description
            1. 7.6.1.1.2.1  Register 64h (address = 64h) [reset = 0h], DIGTOP Page
            2. 7.6.1.1.2.2  Register 8Dh (address = 8Dh) [reset = 0h], DIGTOP Page
            3. 7.6.1.1.2.3  Register 8Eh (address = 8Eh) [reset = 0h], DIGTOP Page
            4. 7.6.1.1.2.4  Register 8Fh (address = 8Fh) [reset = 0h], DIGTOP Page
            5. 7.6.1.1.2.5  Register 90h (address = 90h) [reset = 0h], DIGTOP Page
            6. 7.6.1.1.2.6  Register 91h (address = 91h) [reset = 0h], DIGTOP Page
            7. 7.6.1.1.2.7  Register ABh (address = ABh) [reset = 0h], DIGTOP Page
            8. 7.6.1.1.2.8  Register ACh (address = ACh) [reset = 0h], DIGTOP Page
            9. 7.6.1.1.2.9  Register ADh (address = ADh) [reset = 0h], DIGTOP Page
            10. 7.6.1.1.2.10 Register AEh (address = AEh) [reset = 0h], DIGTOP Page
            11. 7.6.1.1.2.11 Register B7h (address = B7h) [reset = 0h], DIGTOP Page
          3. 7.6.1.1.3 ANALOG Page Register Description
            1. 7.6.1.1.3.1  Register 6Ah (address = 6Ah) [reset = 0h], ANALOG Page
            2. 7.6.1.1.3.2  Register 6Fh (address = 6Fh) [reset = 0h], ANALOG Page
            3. 7.6.1.1.3.3  Register 71h (address = 71h) [reset = 0h], ANALOG Page
            4. 7.6.1.1.3.4  Register 72h (address = 72h) [reset = 0h], ANALOG Page
            5. 7.6.1.1.3.5  Register 93h (address = 93h) [reset = 0h], ANALOG Page
            6. 7.6.1.1.3.6  Register 94h (address = 94h) [reset = 0h], ANALOG Page
            7. 7.6.1.1.3.7  Register 9Bh (address = 9Bh) [reset = 0h], ANALOG Page
            8. 7.6.1.1.3.8  Register 9Dh (address = 9Dh) [reset = 0h], ANALOG Page
            9. 7.6.1.1.3.9  Register 9Eh (address = 9Eh) [reset = 0h], ANALOG Page
            10. 7.6.1.1.3.10 Register 9Fh (address = 9Fh) [reset = 0h], ANALOG Page
            11. 7.6.1.1.3.11 Register AFh (address = AFh) [reset = 0h], ANALOG Page
          4. 7.6.1.1.4 SERDES_XX Page Register Description
            1. 7.6.1.1.4.1  Register 20h (address = 20h) [reset = 0h], SERDES_XX Page
            2. 7.6.1.1.4.2  Register 21h (address = 21h) [reset = 0h], SERDES_XX Page
            3. 7.6.1.1.4.3  Register 22h (address = 22h) [reset = 0h], SERDES_XX Page
            4. 7.6.1.1.4.4  Register 23h (address = 23h) [reset = 0h], SERDES_XX Page
            5. 7.6.1.1.4.5  Register 25h (address = 25h) [reset = 0h], SERDES_XX Page
            6. 7.6.1.1.4.6  Register 26h (address = 26h) [reset = 0h], SERDES_XX Page
            7. 7.6.1.1.4.7  Register 28h (address = 28h) [reset = 0h], SERDES_XX Page
            8. 7.6.1.1.4.8  Register 2Dh (address = 2Dh) [reset = 0h], SERDES_XX Page
            9. 7.6.1.1.4.9  Register 36h (address = 36h) [reset = 0h], SERDES_XX Page
            10. 7.6.1.1.4.10 Register 37h (address = 37h) [reset = 0h], SERDES_XX Page
            11. 7.6.1.1.4.11 Register 39h (address = 39h) [reset = 0h], SERDES_XX Page
            12. 7.6.1.1.4.12 Register 3Ah (address = 3Ah) [reset = 0h], SERDES_XX Page
            13. 7.6.1.1.4.13 Register 3Bh (address = 3Bh) [reset = 0h], SERDES_XX Page
            14. 7.6.1.1.4.14 Register 3Ch (address = 3Ch) [reset = 0h], SERDES_XX Page
            15. 7.6.1.1.4.15 Register 3Dh (address = 3Dh) [reset = 0h], SERDES_XX Page
            16. 7.6.1.1.4.16 Register 3Eh (address = 3Eh) [reset = 0h], SERDES_XX Page
            17. 7.6.1.1.4.17 Register 3Fh (address = 3Fh) [reset = 0h], SERDES_XX Page
            18. 7.6.1.1.4.18 Register 40h (address = 40h) [reset = 0h], SERDES_XX Page
            19. 7.6.1.1.4.19 Register 41h (address = 41h) [reset = 0h], SERDES_XX Page
            20. 7.6.1.1.4.20 Register 42h (address = 42h) [reset = 0h], SERDES_XX Page
          5. 7.6.1.1.5 CHX Page Register Description
            1. 7.6.1.1.5.1 Register 26h (address = 26h) [reset = 0h], CHX Page
            2. 7.6.1.1.5.2 Register 27h (address = 27h) [reset = 0h], CHX Page
            3. 7.6.1.1.5.3 Register 2Dh (address = 2Dh) [reset = 0h], CHX Page
            4. 7.6.1.1.5.4 Register 78h (address = 78h) [reset = 0h], CHX Page
            5. 7.6.1.1.5.5 Register 7Ah (address = 7Ah) [reset = 0h], CHX Page
            6. 7.6.1.1.5.6 Register 7Bh (address = 7Bh) [reset = 0h], CHX Page
            7. 7.6.1.1.5.7 Register 7Eh (address = 7Eh) [reset = 3h], CHX Page
          6. 7.6.1.1.6 ADCXX Page Register Description
            1. 7.6.1.1.6.1 Register 07h (address = 07h) [reset = FFh], ADCXX Page
            2. 7.6.1.1.6.2 Register 08h (address = 08h) [reset = 0h], ADCXX Page
            3. 7.6.1.1.6.3 Register D5h (address = D5h) [reset = 0h], ADCXX Page
  8. 8 Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 Start-Up Sequence
      2. 8.1.2 Hardware Reset
      3. 8.1.3 Frequency Planning
      4. 8.1.4 SNR and Clock Jitter
      5. 8.1.5 ADC Test Pattern
        1. 8.1.5.1 ADC Section
        2. 8.1.5.2 Transport Layer Pattern
        3. 8.1.5.3 Link Layer Pattern
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
      3. 8.2.3 Application Curves
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Receiving Notification of Documentation Updates
    2. 11.2 Support Resources
    3. 11.3 Trademarks
    4. 11.4 Electrostatic Discharge Caution
    5. 11.5 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

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

8.1.3 Frequency Planning

The ADS58J64 uses an architecture where the ADCs are 2x interleaved followed by a digital decimation by 2. The 2x interleaved and decimation architecture comes with a unique advantage of improved linearity resulting from frequency planning. Frequency planning refers to choosing the clock frequency and signal band appropriately such that the harmonic distortion components, resulting from the analog front-end (LNA, PGA), can be made to fall outside the decimation filter pass band. In absence of the 2x interleave and decimation architecture, these components alias back in band and limit the performance of the signal chain. For example, for fCLK = 983.04 MHz and fIN = 184.32 MHz:

Second-order harmonic distortion (HD2) = 2 × 184.32 = 368.64 MHz

Pass band of the 2x decimation filter = 0 MHz to 245.76 MHz (0 to fCLK / 4)

The second-order harmonic performance improves by the stop-band attenuation of the filter (approximately 40 dBc) because the second-order harmonic frequency is outside the pass band of the decimation filter.

Figure 8-2 shows the harmonic components (HD2–HD5) that fall in the decimation pass band for the input clock rate (fCLK) of the 983.04-MHz and 100-MHz signal band around the center frequency of 184.32 MHz.

GUID-68960243-8581-4553-9952-4190734C1ABD-low.gif
fCLK = 983.04 MHz, signal band = 134.32 MHz to 234.32 MHz
Figure 8-2 In-Band Harmonics for a Frequency Planned System

As shown in Figure 8-2, both HD2 and HD3 are completely out of band. HD4 and HD5 fall in the decimation pass band for some frequencies of the input signal band.

Through proper frequency planning, the specifications of the ADC antialias filter can be relaxed.