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

Package Options

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

9.3.3 Clock Distribution

The VCO output connects to two individually configurable pre-scalar dividers sourcing the on-chip clock distribution – PSA and PSB. PSA and PSB can be configured as division value of /4, /5 or /6 independently.

The clock distribution consists of four output channels. Each output channel contains an integer divider (IOD) with glitchless switching and synchronization capabilities.

IOD can be sourced from either the PSA, the PSB, or the Reference Clock. IOD can be bypassed to provide a Reference clock at the output.

There are five output channels – OUT0, OUT1, OUT2, OUT3, and OUT4.

The OUT0 is a slew-rate controllable LVCMOS output. Either the reference clock or PFD clock can be routed to this output through the clock distribution network.

The OUT1 and OUT4 are identical output channels. The output buffers in this channel are compatible with various signaling standards – LVCMOS, LP-HCSL, and LVDS-like.

The OUT2 and OUT3 are identical output channels. The output buffers in this channel are compatible with various signaling standards – LP-HCSL and LVDS-like.

  • The LP-HCSL output buffer can be directly connected to the receiver without any termination resistor to GND. The output impedance of LP-HCSL is trimmed to 50 Ω ± 10%. A series resistor can be used to adapt to the trace impedance.
  • The LVDS-like requires a differential termination connected between the positive and negative polarity output pins. The termination can be connected directly or through an AC-coupling capacitor. For a 50-Ω system, a 100-Ω differential termination is appropriate.
  • LVCMOS outputs are designed for capacitive loads only. The polarity of the positive and negative output pins can be configured individually.
The differential buffers support wide range of output frequencies up to 328.125 MHz. LVCMOS supports up to 200 MHz.

Table 9. Configuring Input Reference/PFD/PLL Clock to Output (7)

REGISTER BIT ADDRESS REGISTER BIT FIELD NAME DESCRIPTION
R25[10] IP_BYP_OUT0_EN Enables Reference Clock/PFD Clock to OUT0.
R25[9] REF_CH_MUX Selects between PFD Clock or Input Reference Clock
R25[14:11] IP_REF_TO_OUT4_EN, IP_REF_TO_OUT3_EN, IP_REF_TO_OUT2_EN, IP_REF_TO_OUT1_EN Selects reference clock to OUT1-OUT4
R56[15:14] CH1_MUX Clock selection MUX control for OUT1
R62[15:14] CH2_MUX Clock selection MUX control for OUT2
R67[15:14] CH3_MUX Clock selection MUX control for OUT3
R72[15:14] CH4_MUX Clock selection MUX control for OUT4
7. It is recommended to disable any clock when not in use to reduce crosstalk

Table 10. Configuring Clock Distribution Network

REGISTER BIT ADDRESS REGISTER BIT FIELD NAME DESCRIPTION
R47[6:5] PLL_PSB Programmable Pre-scalar divider PSB
R47[4:3] PLL_PSA Programmable Pre-scalar divider PSA
R56[13:0] CH1_DIV OUT1 Integer Divider value
R62[13:0] CH2_DIV OUT2 Integer Divider value
R67[13:0] CH3_DIV OUT3 Integer Divider value
R72[13:0] CH4_DIV OUT4 Integer Divider value

Table 11. Configuring LVCMOS Output Buffer (8)(9)

REGISTER BIT ADDRESS REGISTER BIT FIELD NAME DESCRIPTION
R78[12] CH0_EN Enables OUT0 LVCMOS Buffer
R79[3:0] CH0_CMOS_SLEW_RATE_CTRL Controls output slew rate of OUT0 LVCMOS Buffer
R59[14], R75[14] CH1_CMOSN_EN, CH4_CMOSP_EN Enables OUT1N/OUT4P LVCMOS Buffer
R59[13], R75[13] CH1_CMOSP_EN, CH4_CMOSN_EN Enables OUT1P/OUT4N LVCMOS Buffer
R59[12], R75[12] CH1_CMOSN_POL, CH4_CMOSP_POL Sets output polarity of OUT1N/OUT4P LVCMOS Buffer
R59[11], R75[11] CH1_CMOSP_POL, CH4_CMOSN_POL Sets output polarity of OUT1P/OUT4N LVCMOS Buffer
R60[3:0], R76[3:0] CH1_CMOS_SLEW_RATE_CTRL, CH4_CMOS_SLEW_RATE_CTRL Controls output slew rate of OUT1/OUT4 LVCMOS Buffer
8. Multiple output buffers should not be enabled at the same time
9. Based on the VDDO levels, ch1_1p8vdet, ch2_1p8vdet, ch3_1p8vdet, ch4_1p8vdet should be set accordingly. When setting for 1.8V, safety_1p8v_mode should be set.

Table 12. Configuring LP-HCSL Output Buffer (10)(11)(12)

REGISTER BIT ADDRESS REGISTER BIT FIELD NAME DESCRIPTION
R57[14] , R63[13], R68[13], R73[13] CH1_HCSL_EN, CH2_HCSL_EN, CH3_HCSL_EN, CH4_HCSL_EN Enables LP-HCSL buffer on OUT1/OUT2/OUT3/OUT4
10. Multiple output buffers should not be enabled at the same time
11. External termination not needed. Voltage mode driver.
12. Based on the VDDO levels, ch1_1p8vdet, ch2_1p8vdet, ch3_1p8vdet, ch4_1p8vdet should be set accordingly. When setting for 1.8V, safety_1p8v_mode should be set.

Table 13. Configuring LVDS-Like Output Buffer (13)(14)(15)

REGISTER BIT ADDRESS REGISTER BIT FIELD NAME DESCRIPTION
R59[15], R65[11], R70[11], R75[15] CH1_LVDS_EN, CH2_LVDS_EN, CH3_LVDS_EN, CH4_LVDS_EN Enables LVDS-like buffer on OUT1/OUT2/OUT3/OUT4
R60[15:12], R66[3:0], R71[3:0], R76[9:6] CH1_DIFFBUF_IBIAS_TRIM, CH2_DIFFBUF_IBIAS_TRIM, CH3_DIFFBUF_IBIAS_TRIM, CH4_DIFFBUF_IBIAS_TRIM Sets the output swing and output common mode of OUT1/OUT2/OUT3/OUT4
R60[11:10], R66[5:4], R71[5:4], R76[5:4] CH1_LVDS_CMTRIM_INC, CH2_LVDS_CMTRIM_INC, CH3_LVDS_CMTRIM_INC, CH4_LVDS_CMTRIM_INC Increases the output common mode of OUT1/OUT2/OUT3/OUT4. 2.5 V/3.3 V mode only.
R60[5:4], R65[14:13], R71[10:9], R77[1:0] CH1_LVDS_CMTRIM_DEC, CH2_LVDS_CMTRIM_DEC, CH3_LVDS_CMTRIM_DEC, CH4_LVDS_CMTRIM_DEC Decreases the output common mode of OUT1/OUT2/OUT3/OUT4. 2.5 V/3.3 V mode only.
13. Multiple output buffers should not be enabled at the same time.
14. 100 Ω differential termination needed in DC-coupled mode. 50 Ω single ended or 100 Ω differential termination needed in AC-coupled mode
15. Based on the VDDO levels, ch1_1p8vdet, ch2_1p8vdet, ch3_1p8vdet, ch4_1p8vdet should be set accordingly. When setting for 1.8V, safety_1p8v_mode should be set.