SCAS943 May   2015 CDCM6208V1F

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Simplified Schematics
  5. 5 Revision History
  6. 6 Description (continued)
  7. 7 Pin Configuration and Functions
  8. 8 Specifications
    1. 8.1  Absolute Maximum Ratings
    2. 8.2  ESD Ratings
    3. 8.3  Recommended Operating Conditions
    4. 8.4  Thermal Information, Airflow = 0 LFM
    5. 8.5  Thermal Information, Airflow = 150 LFM
    6. 8.6  Thermal Information, Airflow = 250 LFM
    7. 8.7  Thermal Information, Airflow = 500 LFM
    8. 8.8  Single Ended Input Characteristics
    9. 8.9  Single Ended Input Characteristics (PRI_REF, SEC_REF)
    10. 8.10 Differential Input Characteristics (PRI_REF, SEC_REF)
    11. 8.11 Crystal Input Characteristics (SEC_REF)
    12. 8.12 Single Ended Output Characteristics (STATUS1, STATUS0, SDO, SDA)
    13. 8.13 PLL Characteristics
    14. 8.14 LVCMOS Output Characteristics
    15. 8.15 LVPECL (High-Swing CML) Output Characteristics
    16. 8.16 CML Output Characteristics
    17. 8.17 LVDS (Low-Power CML) Output Characteristics
    18. 8.18 HCSL Output Characteristics
    19. 8.19 Output Skew and Sync to Output Propagation Delay Characteristics
    20. 8.20 Device Individual Block Current Consumption
    21. 8.21 Worst Case Current Consumption
    22. 8.22 I2C TIMING
    23. 8.23 SPI Timing Requirements
    24. 8.24 Typical Characteristics
      1. 8.24.1 Fractional Output Divider Jitter Performance
      2. 8.24.2 Power Supply Ripple Rejection (PSRR) versus Ripple Frequency
  9. 9 Parameter Measurement Information
    1. 9.1 Characterization Test Setup
  10. 10Detailed Description
    1. 10.1 Overview
    2. 10.2 Functional Block Diagram
    3. 10.3 Feature Description
    4. 10.4 Device Functional Modes
      1. 10.4.1 Control Pins Definition
      2. 10.4.2 Loop Filter Recommendations for Pin Modes
      3. 10.4.3 Status Pins Definition
      4. 10.4.4 PLL Lock Detect
      5. 10.4.5 Interface and Control
        1. 10.4.5.1 Register File Reference Convention
        2. 10.4.5.2 SPI - Serial Peripheral Interface
          1. 10.4.5.2.1 Configuring the PLL
    5. 10.5 Programming
      1. 10.5.1 Writing to the CDCM6208V1F
      2. 10.5.2 Reading from the CDCM6208V1F
      3. 10.5.3 Block Write/Read Operation
      4. 10.5.4 I2C Serial Interface
    6. 10.6 Register Maps
  11. 11Application and Implementation
    1. 11.1 Application Information
    2. 11.2 Typical Applications
      1. 11.2.1 Design Requirements
        1. 11.2.1.1  Device Block-level Description
        2. 11.2.1.2  Device Configuration Control
        3. 11.2.1.3  Configuring the RESETN Pin
        4. 11.2.1.4  Preventing False Output Frequencies in SPI/I2C Mode at Startup:
        5. 11.2.1.5  Power Down
        6. 11.2.1.6  Device Power Up Timing:
        7. 11.2.1.7  Input Mux and Smart Input Mux
        8. 11.2.1.8  Universal INPUT Buffer (PRI_REF, SEC_REF)
        9. 11.2.1.9  VCO Calibration
        10. 11.2.1.10 Reference Divider (R)
        11. 11.2.1.11 Input Divider (M)
        12. 11.2.1.12 Feedback Divider (N)
        13. 11.2.1.13 Prescaler Dividers (PS_A, PS_B)
        14. 11.2.1.14 Phase Frequency Detector (PFD)
        15. 11.2.1.15 Charge Pump (CP)
        16. 11.2.1.16 Programmable Loop Filter
          1. 11.2.1.16.1 Loop Filter Component Selection
          2. 11.2.1.16.2 Device Output Signaling
          3. 11.2.1.16.3 Integer Output Divider (IO)
          4. 11.2.1.16.4 Fractional Output Divider (FOD)
          5. 11.2.1.16.5 Output Synchronization
          6. 11.2.1.16.6 Output MUX on Y4 and Y5
          7. 11.2.1.16.7 Staggered CLK Output Powerup for Power Sequencing of a DSP
      2. 11.2.2 Detailed Design Procedure
        1. 11.2.2.1 Jitter Considerations in SERDES Systems
        2. 11.2.2.2 Jitter Considerations in ADC and DAC Systems
      3. 11.2.3 Application Performance Plots
        1. 11.2.3.1 Typical Device Jitter
  12. 12Power Supply Recommendations
    1. 12.1 Power Rail Sequencing, Power Supply Ramp Rate, and Mixing Supply Domains
      1. 12.1.1 Fast Power-up Supply Ramp
      2. 12.1.2 Delaying VDD_Yx_Yy to Protect DSP IOs
  13. 13Layout
    1. 13.1 Layout Guidelines
    2. 13.2 Layout Example
      1. 13.2.1 Reference Schematic
  14. 14Device and Documentation Support
    1. 14.1 Trademarks
    2. 14.2 Documentation Support
      1. 14.2.1 Related Documentation
    3. 14.3 Electrostatic Discharge Caution
    4. 14.4 Glossary
  15. 15Mechanical, Packaging, and Orderable Information

Package Options

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

13 Layout

13.1 Layout Guidelines

Employing the thermally enhanced printed circuit board layout shown in Figure 58 insures good thermal performance of the solution. Observing good thermal layout practices enables the thermal pad on the backside of the QFN-48 package to provide a good thermal path between the die contained within the package and the ambient air. This thermal pad also serves as the ground connection the device; therefore, a low inductance connection to the ground plane is essential.

13.2 Layout Example

Figure 58 shows a layout optimized for good thermal performance and a good power supply connection as well. The 7×7 filled via pattern facilitates both considerations.

CDCM6208V1F layout_recc_PCB_PNG_scas931.pngFigure 58. Recommended PCB layout of CDCM6208

Figure 59 shows two conceptual layouts detailing recommended placement of power supply bypass capacitors. If the capacitors are mounted on the back side, 0402 components can be employed; however, soldering to the Thermal Dissipation Pad can be difficult. For component side mounting, use 0201 body size capacitors to facilitate signal routing. Keep the connections between the bypass capacitors and the power supply on the device as short as possible. Ground the other side of the capacitor using a low impedance connection to the ground plane.

CDCM6208V1F layout_pwr_sup_bypass_PNG_scas931.pngFigure 59. PCB Conceptual Layouts

13.2.1 Reference Schematic

CDCM6208V1F Reference_Schematic_1_SCAS931.gifFigure 60. Schematic Page 1
CDCM6208V1F Reference_Schematic_2_SCAS931.gifFigure 61. Schematic Page 2
CDCM6208V1F Reference_Schematic_3_SCAS931.gifFigure 62. Schematic Page 3
CDCM6208V1F Reference_Schematic_4_SCAS931.gifFigure 63. Schematic Page 4