SNAS811 July   2020  – May  CDCE6214

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Application Example CDCE6214
  4. 4 Revision History
  5. 5 Description (cont.)
  6. 6 Pin Configuration and Functions
    1.     Pin Functions G = Ground, P = Power I = Input, I/O = Input/Output, O = Output I, RPUPD = Input with Resistive Pull-up and Pull-down I, RPU = Input with Resistive Pull=up I/O, RPU = Input/Output with resistive pull-up
  7. 7 Specifications
    1. 7.1  Absolute Maximum Ratings
    2. 7.2  ESD Ratings
    3. 7.3  Recommended Operating Conditions
    4. 7.4  Thermal Information
    5. 7.5  EEPROM Characteristics
    6. 7.6  Reference Input, Single-Ended Characteristics
    7. 7.7  Reference Input, Differential Characteristics
    8. 7.8  Reference Input, Crystal Mode Characteristics
    9. 7.9  General-Purpose Input Characteristics
    10. 7.10 Triple Level Input Characteristics
    11. 7.11 Logic Output Characteristics
    12. 7.12 Phase Locked Loop Characteristics
    13. 7.13 Closed-Loop Output Jitter Characteristics
    14. 7.14 Input and Output Isolation
    15. 7.15 Buffer Mode Characteristics
    16. 7.16 PCIe Spread Spectrum Generator
    17. 7.17 LVCMOS Output Characteristics
    18. 7.18 LP-HCSL Output Characteristics
    19. 7.19 LVDS Output Characteristics
    20. 7.20 Output Synchronization Characteristics
    21. 7.21 Power-On Reset Characteristics
    22. 7.22 I2C-Compatible Serial Interface Characteristics
    23. 7.23 Timing Requirements, I2C-Compatible Serial Interface
    24. 7.24 Power Supply Characteristics
    25. 7.25 Typical Characteristics
  8. 8 Parameter Measurement Information
    1. 8.1 Reference Inputs
    2. 8.2 Outputs
    3. 8.3 Serial Interface
    4. 8.4 PSNR Test
    5. 8.5 Clock Interfacing and Termination
      1. 8.5.1 Reference Input
      2. 8.5.2 Outputs
  9. 9 Detailed Description
    1. 9.1 Overview
    2. 9.2 Functional Block Diagram
    3. 9.3 Feature Description
      1. 9.3.1 Reference Block
        1. 9.3.1.1 Zero Delay Mode, Internal and External Path
      2. 9.3.2 Phase-Locked Loop (PLL)
        1. 9.3.2.1 PLL Configuration and Divider Settings
        2. 9.3.2.2 Spread Spectrum Clocking
        3. 9.3.2.3 Digitally-Controlled Oscillator/ Frequency Increment and Decrement - Serial Interface Mode and GPIO Mode
      3. 9.3.3 Clock Distribution
        1. 9.3.3.1 Glitchless Operation
        2. 9.3.3.2 Divider Synchronization
        3. 9.3.3.3 Global and Individual Output Enable
      4. 9.3.4 Power Supplies and Power Management
      5. 9.3.5 Control Pins
    4. 9.4 Device Functional Modes
      1. 9.4.1 Operation Modes
        1. 9.4.1.1 Fall-Back Mode
        2. 9.4.1.2 Pin Mode
        3. 9.4.1.3 Serial Interface Mode
    5. 9.5 Programming
      1. 9.5.1 I2C Serial Interface
      2. 9.5.2 EEPROM
        1. 9.5.2.1 EEPROM - Cyclic Redundancy Check
        2. 9.5.2.2 Recommended Programming Procedure
        3. 9.5.2.3 EEPROM Access
          1. 9.5.2.3.1 Register Commit Flow
          2. 9.5.2.3.2 Direct Access Flow
        4. 9.5.2.4 Register Bits to EEPROM Mapping
  10. 10Application and Implementation
    1. 10.1 Application Information
    2. 10.2 Typical Application
      1. 10.2.1 Design Requirements
      2. 10.2.2 Detailed Design Procedure
      3. 10.2.3 Application Curves
  11. 11Power Supply Recommendations
    1. 11.1 Power-Up Sequence
    2. 11.2 Decoupling
  12. 12Layout
    1. 12.1 Layout Guidelines
    2. 12.2 Layout Examples
  13. 13Device and Documentation Support
    1. 13.1 Device Support
      1. 13.1.1 Development Support
      2. 13.1.2 Device Nomenclature
    2. 13.2 Receiving Notification of Documentation Updates
    3. 13.3 Support Resources
    4. 13.4 Trademarks
    5. 13.5 Electrostatic Discharge Caution
    6. 13.6 Glossary
  14. 14Mechanical, Packaging, and Orderable Information

パッケージ・オプション

メカニカル・データ（パッケージ｜ピン）
サーマルパッド・メカニカル・データ
発注情報

9.3.2.3 Digitally-Controlled Oscillator/ Frequency Increment and Decrement - Serial Interface Mode and GPIO Mode

In this mode, the output clock frequency can be incremented or decremented by a fixed frequency step. The frequency step size is determined by the register R43[15:0]. This value is added or subtracted to the numerator of the sigma-delta modulator. Various bit fields as shown in can be used to exercise this functionality. Every rising edge of FREQ_INC signal increases the output frequency, while every rising edge of FREQ_DEC signal decreases the output frequency. There are two ways to trigger the increment or decrement:

  1. Appropriate configuration of the GPIOs and sending FREQ_INC/FREQ_DEC signal through an external microcontroller or ASIC.
  2. Using register bit fields controlled through serial interface.

Table 7. Register Settings for Frequency Increment/Decrement Functionality

REGISTER BIT ADDRESS REGISTER BIT FIELD NAME DESCRIPTION
R3[3] FREQ_INC_DEC_EN Enables/Disables DCO mode
R3[4] FREQ_INC_DEC_REG_MODE Selects DCO trigger through GPIOs or Serial Interface.
R3[6:5] FREQ_DEC_REG, FREQ_INC_REG Generates FREQ_INC/FREQ_DEC signal through serial Interface
R43[15:0] FREQ_INC_DEC_DELTA Frequency Increment/Decrement step size

Table 8. Computing Divider Settings in DCO Mode

PARAMETERS VALUE (EXAMPLE) DESCRIPTION
Input PFD Frequency (FPFD) 25 MHz Set according to FPFD.
Expected VCO Frequency (FVCO) 2457.6 MHz FVCO is set within the operating VCO range of 2335 MHz - 2625 MHz. FVCO is selected such that PSA/PSB/Output Divider is Integer.
Expected Output Frequency (FOUT) 24.576 MHz PSA = 4, IOD = 25. FVCO = PSA × IOD × FOUT.
Expected step size (in ppm) (Fstep) 0.1 Every rising edge of FREQ_INC/FREQ_DEC would change the output by this step size.
N-divider Value (N) 98 INT(FVCO/FPFD)
Minimum Numerator value to meet 0ppb accuracy (Num) 76 These values are computed to meet accuracy requirement at output. Should be less than 224.
Minimum Denominator to meet 0ppb accuracy (Den) 250
Minimum Denominator value to meet ppm step size (FDEN,min) 101725.26 1/(Fstep × 1e6) / (FVCO/FPFD)
Final Denominator value (FDEN,final) 500000 FDEN,final should be greater than FDEN,min and less than 224. FDEN,final and FNUM,final should be integer multiple of Den and Num respectively. FDEN,final/Den = FNUM,final/Num
Final Numerator value (FNUM,final) 152000
Increment/ Decrement step size 5 This value should be less than 216-1. FDEN,final should be closest integer multiple of FDEN,min.