SCAS931G May   2012  – January 2018 CDCM6208

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Simplified Schematic
      2.      Simplified Schematic
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
    1.     Pin 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, Airflow = 0 LFM
    5. 6.5  Thermal Information, Airflow = 150 LFM
    6. 6.6  Thermal Information, Airflow = 250 LFM
    7. 6.7  Thermal Information, Airflow = 500 LFM
    8. 6.8  Single-Ended Input Characteristics (SI_MODE[1:0], SDI/SDA/PIN1, SCL/PIN4, SDO/ADD0/PIN2, SCS/ADD1/PIN3, STATUS1/PIN0, RESETN/PWR, PDN, SYNCN, REF_SEL)
    9. 6.9  Single-Ended Input Characteristics (PRI_REF, SEC_REF)
    10. 6.10 Differential Input Characteristics (PRI_REF, SEC_REF)
    11. 6.11 Crystal Input Characteristics (SEC_REF)
    12. 6.12 Single-Ended Output Characteristics (STATUS1, STATUS0, SDO, SDA)
    13. 6.13 PLL Characteristics
    14. 6.14 LVCMOS Output Characteristics
    15. 6.15 LVPECL (High-Swing CML) Output Characteristics
    16. 6.16 CML Output Characteristics
    17. 6.17 LVDS (Low-Power CML) Output Characteristics
    18. 6.18 HCSL Output Characteristics
    19. 6.19 Output Skew and Sync to Output Propagation Delay Characteristics
    20. 6.20 Device Individual Block Current Consumption
    21. 6.21 Worst Case Current Consumption
    22. 6.22 Timing Requirements, I2C Timing
    23. 6.23 Typical Characteristics
  7. 7 Parameter Measurement Information
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1  Typical Device Jitter
      2. 8.3.2  Universal Input Buffer (PRI_REF, SEC_REF)
      3. 8.3.3  VCO Calibration
      4. 8.3.4  Reference Divider (R)
      5. 8.3.5  Input Divider (M)
      6. 8.3.6  Feedback Divider (N)
      7. 8.3.7  Prescaler Dividers (PS_A, PS_B)
      8. 8.3.8  Phase Frequency Detector (PFD)
      9. 8.3.9  Charge Pump (CP)
      10. 8.3.10 Fractional Output Divider Jitter Performance
      11. 8.3.11 Device Block-Level Description
      12. 8.3.12 Device Configuration Control
      13. 8.3.13 Configuring the RESETN Pin
      14. 8.3.14 Preventing False Output Frequencies in SPI/I2C Mode at Start-Up
      15. 8.3.15 Input MUX and Smart Input MUX
    4. 8.4 Device Functional Modes
      1. 8.4.1 Control Pins Definition
      2. 8.4.2 Loop Filter Recommendations for Pin Modes
      3. 8.4.3 Status Pins Definition
      4. 8.4.4 PLL Lock Detect
      5. 8.4.5 Interface and Control
        1. 8.4.5.1 Register File Reference Convention
        2. 8.4.5.2 SPI - Serial Peripheral Interface
          1. 8.4.5.2.1 Writing to the CDCM6208
          2. 8.4.5.2.2 Reading From the CDCM6208
          3. 8.4.5.2.3 Block Write/Read Operation
          4. 8.4.5.2.4 I2C Serial Interface
    5. 8.5 Programming
    6. 8.6 Register Maps
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Applications
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedures
        1. 9.2.2.1  Jitter Considerations in SERDES Systems
        2. 9.2.2.2  Jitter Considerations in ADC and DAC Systems
        3. 9.2.2.3  Configuring the PLL
        4. 9.2.2.4  Programmable Loop Filter
        5. 9.2.2.5  Loop filter Component Selection
        6. 9.2.2.6  Device Output Signaling
        7. 9.2.2.7  Integer Output Divider (IO)
        8. 9.2.2.8  Fractional Output Divider (FOD)
        9. 9.2.2.9  Output Synchronization
        10. 9.2.2.10 Output Mux on Y4 and Y5
        11. 9.2.2.11 Staggered CLK Output Power Up for Power Sequencing of a DSP
  10. 10Power Supply Recommendations
    1. 10.1 Power Rail Sequencing, Power Supply Ramp Rate, and Mixing Supply Domains
      1. 10.1.1 Mixing Supplies
      2. 10.1.2 Power-On Reset
      3. 10.1.3 Slow Power-Up Supply Ramp
      4. 10.1.4 Fast Power-Up Supply Ramp
      5. 10.1.5 Delaying VDD_Yx_Yy to Protect DSP IOs
    2. 10.2 Device Power-Up Timing
    3. 10.3 Power Down
    4. 10.4 Power Supply Ripple Rejection (PSRR) versus Ripple Frequency
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Reference Schematics
  12. 12Device and Documentation Support
    1. 12.1 Documentation Support
      1. 12.1.1 Related Documentation
    2. 12.2 Receiving Notification of Documentation Updates
    3. 12.3 Community Resources
    4. 12.4 Trademarks
    5. 12.5 Electrostatic Discharge Caution
    6. 12.6 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

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

8.3 Feature Description

Supply Voltage: The CDCM6208 supply is internally regulated. Therefore, each core and I/O supply can be mixed and matched in any order according to the application needs. The device jitter performance is independent of supply voltage.

Frequency Range: The PLL includes dual reference inputs with input multiplexer, charge pump, loop filter, and VCO that operates from 2.39 GHz to 2.55 GHz (CDCM6208V1) and 2.94 GHz to 3.13 GHz (CDCM6208V2).

Reference inputs: The primary and secondary reference inputs support differential and single ended signals from 8 kHz to 250 MHz. The secondary reference input also supports crystals from 10 MHz to 50 MHz. There is a 4-bit reference divider available on the primary reference input. The input mux between the two references supports simply switching or can be configured as Smart MUX and supports glitchless input switching.

Divider and Prescaler: In addition to the 4-bit input divider of the primary reference a 14-b input divider at the output of input MUX and a cascaded 8-b and 10-b continuous feedback dividers are available. Two independent prescaler dividers offer divide by /4, /5 and /6 options of the VCO frequency of which any combination can then be chosen for a bank of 4 outputs (2 with fractional dividers and 2 that share an integer divider) through an output MUX. A total of 2 output MUXes are available.

Phase Frequency Detector and Charge Pump: The PFD input frequency can range from 8 kHz to 100 MHz. The charge pump gain is programmable and the loop filter consists of internal + partially external passive components and supports bandwidths from a few Hz up to 400 kHz.

Phase Noise: The Phase Noise performance of the device can be summarized to:

Table 2. Synthesizer Mode (Loop Filter BW >250 kHz)

RANDOM JITTER (ALL OUTPUTS)TOTAL JITTER
TYPICALMAXIMUMMAXIMUM
10k-20MHz 12k-20MHz 10k-100MHz Integer divider
DJ-unbound
RJ 10k-20MHz		 Fractional divider
DJ 10k-40MHz
RJ 10k-20MHz
0.27 ps-rms (Integer division)
0.7ps-rms (fractional div)		 0.3 ps-rms (int div)(2) 0.625 ps-rms (int div) 20 ps-pp (1) 50-220 ps-pp,
see Figure 30
(1) TJ = 20 pspp applies for LVPECL, CML, and LVDS signaling. TJ lab characterization measured 8 pspp, (typical) and 12 pspp (max) over PVT.
(2) Integrated Phase Noise (12kHz - 20 MHz) for 156.25 MHz output clock measured at room temperature using a 25 MHz Low Noise reference source

Table 3. Jitter Cleaner Mode (Loop Filter BW < 1 kHz)

RANDOM JITTER (ALL OUTPUTS)TOTAL JITTER
TYPICALMAXIMUMMAXIMUM
10k-20MHz 10k-20MHz 10k-100MHz Integer divider
DJ unbound
RJ 10k-20MHz		 Fractional divider
DJ 10k-40MHz
RJ 10k-20MHz
1.6 ps-rms (Integer division)
2.3 ps-rms (fractional div) 10k-20MHz		 2.1 ps-rms (int div) 2.14 ps-rms (int div) 40 ps-pp 70-240 ps-pp,
see Figure 30

Spurious Performance: The spurious performance is as follows:

  • Less than -80 dBc spurious from PFD/reference clocks at 122.88 MHz output frequency in the Nyquist range.
  • Less than -68 dBc spurious from output channel-to-channel coupling on the victim output at differential signaling level operated at 122.88 MHz output frequency in the Nyquist range.

Device outputs:

The Device outputs offer multiple signaling formats: high-swing CML (LVPECL like), normal-swing CML (CML), low-swing CML (LVDS like), HCSL, and LVCMOS signaling.

Table 4. Supported Output Formats and Frequency Ranges

OutputsLVPECLCMLLVDSHCSLLVCMOSOUTPUT DIVIDERFREQUENCY RANGE
Y[3:0] X X X Integer only 1.55 - 800 MHz
Y[7:4] X X X Integer 1.55 - 800 MHz
Fractional 1.00 - 400 MHz

Outputs [Y0:Y3] are driven by 8-b continuous integer dividers per pair. Outputs [Y4:Y7] are each driven by 20-b fractional dividers that can achieve any frequency with better than 1ppm frequency accuracy. The output skew is typically less than 40 ps for differential outputs. The LVCMOS outputs support adjustable slew rate control to control EMI. Pairs of 2 outputs can be operated at 1.8 V, 2.5 V or 3.3 V power supply voltage.

Device Configuration: 32 distinct pin modes are available that cover many common use cases without the need for any serial programming of the device. For maximum flexibility the device also supports SPI and I2C programming. I2C offers 4 distinct addresses to support up to 4 devices on the same programming lines.

CDCM6208 Typical_use_case_SCAS931.gifFigure 26. Typical Use Case: CDCM6208 Example in Wireless Infrastructure Baseband Application