ZHCSFH1 September   2016 LMK04208

PRODUCTION DATA.  

  1. 特性
  2. 应用
  3. 说明
  4. 修订历史记录
  5. Pin Configuration and Functions
  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 Timing Requirements
    7. 6.7 Typical Characteristics
  7. Parameter Measurement Information
    1. 7.1 Charge Pump Current Specification Definitions
      1. 7.1.1 Charge Pump Output Current Magnitude Variation Vs. Charge Pump Output Voltage
      2. 7.1.2 Charge Pump Sink Current Vs. Charge Pump Output Source Current Mismatch
      3. 7.1.3 Charge Pump Output Current Magnitude Variation vs. Ambient Temperature
    2. 7.2 Differential Voltage Measurement Terminology
  8. Detailed Description
    1. 8.1 Overview
      1. 8.1.1  System Architecture
      2. 8.1.2  PLL1 Redundant Reference Inputs (CLKin0/CLKin0* and CLKin1/CLKin1*)
      3. 8.1.3  PLL1 Tunable Crystal Support
      4. 8.1.4  VCXO/Crystal Buffered Output
      5. 8.1.5  Frequency Holdover
      6. 8.1.6  Integrated Loop Filter Poles
      7. 8.1.7  Internal VCO
      8. 8.1.8  External VCO Mode
      9. 8.1.9  Clock Distribution
        1. 8.1.9.1 CLKout DIVIDER
        2. 8.1.9.2 CLKout Delay
        3. 8.1.9.3 Programmable Output Type
        4. 8.1.9.4 Clock Output Synchronization
      10. 8.1.10 0-Delay
      11. 8.1.11 Default Startup Clocks
      12. 8.1.12 Status Pins
      13. 8.1.13 Register Readback
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Inputs / Outputs
        1. 8.3.1.1 PLL1 Reference Inputs (CLKin0 and CLKin1)
        2. 8.3.1.2 PLL2 OSCin / OSCin* Port
        3. 8.3.1.3 Crystal Oscillator
      2. 8.3.2 Input Clock Switching
        1. 8.3.2.1 Input Clock Switching - Manual Mode
        2. 8.3.2.2 Input Clock Switching - Pin Select Mode
          1. 8.3.2.2.1 Pin Select Mode and Host
          2. 8.3.2.2.2 Switch Event without Holdover
          3. 8.3.2.2.3 Switch Event with Holdover
        3. 8.3.2.3 Input Clock Switching - Automatic Mode
          1. 8.3.2.3.1 Starting Active Clock
          2. 8.3.2.3.2 Clock Switch Event: PLL1 DLD
          3. 8.3.2.3.3 Clock Switch Event: PLL1 Vtune Rail
          4. 8.3.2.3.4 Clock Switch Event with Holdover
        4. 8.3.2.4 Input Clock Switching - Automatic Mode with Pin Select
          1. 8.3.2.4.1 Starting Active Clock
          2. 8.3.2.4.2 Clock Switch Event: PLL1 DLD
          3. 8.3.2.4.3 Clock Switch Event: PLL1 Vtune Rail
          4. 8.3.2.4.4 Clock Switch Event with Holdover
      3. 8.3.3 Holdover Mode
        1. 8.3.3.1 Enable Holdover
        2. 8.3.3.2 Entering Holdover
        3. 8.3.3.3 During Holdover
        4. 8.3.3.4 Exiting Holdover
        5. 8.3.3.5 Holdover Frequency Accuracy and DAC Performance
        6. 8.3.3.6 Holdover Mode - Automatic Exit of Holdover
      4. 8.3.4 PLLs
        1. 8.3.4.1 PLL1
        2. 8.3.4.2 PLL2
          1. 8.3.4.2.1 PLL2 Frequency Doubler
        3. 8.3.4.3 Digital Lock Detect
      5. 8.3.5 Status Pins
        1. 8.3.5.1 Logic Low
        2. 8.3.5.2 Digital Lock Detect
        3. 8.3.5.3 Holdover Status
        4. 8.3.5.4 DAC
        5. 8.3.5.5 PLL Divider Outputs
        6. 8.3.5.6 CLKinX_LOS
        7. 8.3.5.7 CLKinX Selected
        8. 8.3.5.8 MICROWIRE Readback
      6. 8.3.6 VCO
      7. 8.3.7 Clock Distribution
        1. 8.3.7.1 Fixed Digital Delay
        2. 8.3.7.2 Fixed Digital Delay - Example
        3. 8.3.7.3 Clock Output Synchronization (SYNC)
          1. 8.3.7.3.1 Effect of SYNC
          2. 8.3.7.3.2 Methods of Generating SYNC
          3. 8.3.7.3.3 Avoiding Clock Output Interruption Due to Sync
          4. 8.3.7.3.4 SYNC Timing
        4. 8.3.7.4 Dynamically Programming Digital Delay
          1. 8.3.7.4.1 Absolute vs. Relative Dynamic Digital Delay
          2. 8.3.7.4.2 Dynamic Digital Delay and 0-Delay Mode
          3. 8.3.7.4.3 SYNC and Minimum Step Size
          4. 8.3.7.4.4 Programming Overview
          5. 8.3.7.4.5 Internal Dynamic Digital Delay Timing
          6. 8.3.7.4.6 Other Timing Requirements
        5. 8.3.7.5 Absolute Dynamic Digital Delay
          1. 8.3.7.5.1 Absolute Dynamic Digital Delay - Example
        6. 8.3.7.6 Relative Dynamic Digital Delay
          1. 8.3.7.6.1 Relative Dynamic Digital Delay - Example
      8. 8.3.8 0-Delay Mode
    4. 8.4 Device Functional Modes
      1. 8.4.1 Mode Selection
      2. 8.4.2 Operating Modes
        1. 8.4.2.1 Dual PLL
        2. 8.4.2.2 0-Delay Dual PLL
        3. 8.4.2.3 Single PLL
        4. 8.4.2.4 0-Delay Single PLL
        5. 8.4.2.5 Clock Distribution
    5. 8.5 Programming
      1. 8.5.1 Special Programming Case for R0 to R5 for CLKoutX_DIV and CLKoutX_DDLY
        1. 8.5.1.1 Example
      2. 8.5.2 Recommended Programming Sequence
        1. 8.5.2.1 Programming Sequence Overview
      3. 8.5.3 Readback
        1. 8.5.3.1 Readback - Example
    6. 8.6 Register Maps
      1. 8.6.1 Register Map and Readback Register Map
      2. 8.6.2 Default Device Register Settings After Power On Reset
      3. 8.6.3 Register Descriptions
        1. 8.6.3.1  Registers R0 to R5
          1. 8.6.3.1.1 CLKoutX_PD, Powerdown CLKoutX Output Path
          2. 8.6.3.1.2 CLKoutX_OSCin_Sel, Clock Group Source
          3. 8.6.3.1.3 CLKoutX_ADLY_SEL, Select Analog Delay
          4. 8.6.3.1.4 CLKoutX_DDLY, Clock Channel Digital Delay
          5. 8.6.3.1.5 Reset
          6. 8.6.3.1.6 POWERDOWN
          7. 8.6.3.1.7 CLKoutX_HS, Digital Delay Half Shift
          8. 8.6.3.1.8 CLKoutX_DIV, Clock Output Divide
        2. 8.6.3.2  Registers R6 to R8
          1. 8.6.3.2.1 CLKoutX_TYPE
          2. 8.6.3.2.2 CLKoutX_ADLY
        3. 8.6.3.3  Register R10
          1. 8.6.3.3.1 OSCout_TYPE
          2. 8.6.3.3.2 EN_OSCout, OSCout Output Enable
          3. 8.6.3.3.3 OSCout_MUX, Clock Output Mux
          4. 8.6.3.3.4 PD_OSCin, OSCin Powerdown Control
          5. 8.6.3.3.5 OSCout_DIV, Oscillator Output Divide
          6. 8.6.3.3.6 VCO_MUX
          7. 8.6.3.3.7 EN_FEEDBACK_MUX
          8. 8.6.3.3.8 VCO_DIV, VCO Divider
          9. 8.6.3.3.9 FEEDBACK_MUX
        4. 8.6.3.4  Register R11
          1. 8.6.3.4.1 MODE: Device Mode
          2. 8.6.3.4.2 EN_SYNC, Enable Synchronization
          3. 8.6.3.4.3 NO_SYNC_CLKoutX
          4. 8.6.3.4.4 SYNC_MUX
          5. 8.6.3.4.5 SYNC_QUAL
          6. 8.6.3.4.6 SYNC_POL_INV
          7. 8.6.3.4.7 SYNC_EN_AUTO
          8. 8.6.3.4.8 SYNC_TYPE
          9. 8.6.3.4.9 EN_PLL2_XTAL
        5. 8.6.3.5  Register R12
          1. 8.6.3.5.1 LD_MUX
          2. 8.6.3.5.2 LD_TYPE
          3. 8.6.3.5.3 SYNC_PLLX_DLD
          4. 8.6.3.5.4 EN_TRACK
          5. 8.6.3.5.5 HOLDOVER_MODE
        6. 8.6.3.6  Register R13
          1. 8.6.3.6.1 HOLDOVER_MUX
          2. 8.6.3.6.2 HOLDOVER_TYPE
          3. 8.6.3.6.3 Status_CLKin1_MUX
          4. 8.6.3.6.4 Status_CLKin0_TYPE
          5. 8.6.3.6.5 DISABLE_DLD1_DET
          6. 8.6.3.6.6 Status_CLKin0_MUX
          7. 8.6.3.6.7 CLKin_SELECT_MODE
          8. 8.6.3.6.8 CLKin_Sel_INV
          9. 8.6.3.6.9 EN_CLKinX
        7. 8.6.3.7  Register 14
          1. 8.6.3.7.1 LOS_TIMEOUT
          2. 8.6.3.7.2 EN_LOS
          3. 8.6.3.7.3 Status_CLKin1_TYPE
          4. 8.6.3.7.4 CLKinX_BUF_TYPE, PLL1 CLKinX/CLKinX* Buffer Type
          5. 8.6.3.7.5 DAC_HIGH_TRIP
          6. 8.6.3.7.6 DAC_LOW_TRIP
          7. 8.6.3.7.7 EN_VTUNE_RAIL_DET
        8. 8.6.3.8  Register 15
          1. 8.6.3.8.1 MAN_DAC
          2. 8.6.3.8.2 EN_MAN_DAC
          3. 8.6.3.8.3 HOLDOVER_DLD_CNT
          4. 8.6.3.8.4 FORCE_HOLDOVER
        9. 8.6.3.9  Register 16
          1. 8.6.3.9.1 XTAL_LVL
        10. 8.6.3.10 Register 23
          1. 8.6.3.10.1 DAC_CNT
        11. 8.6.3.11 Register 24
          1. 8.6.3.11.1 PLL2_C4_LF, PLL2 Integrated Loop Filter Component
          2. 8.6.3.11.2 PLL2_C3_LF, PLL2 Integrated Loop Filter Component
          3. 8.6.3.11.3 PLL2_R4_LF, PLL2 Integrated Loop Filter Component
          4. 8.6.3.11.4 PLL2_R3_LF, PLL2 Integrated Loop Filter Component
          5. 8.6.3.11.5 PLL1_N_DLY
          6. 8.6.3.11.6 PLL1_R_DLY
          7. 8.6.3.11.7 PLL1_WND_SIZE
        12. 8.6.3.12 Register 25
          1. 8.6.3.12.1 DAC_CLK_DIV
          2. 8.6.3.12.2 PLL1_DLD_CNT
        13. 8.6.3.13 Register 26
          1. 8.6.3.13.1 PLL2_WND_SIZE
          2. 8.6.3.13.2 EN_PLL2_REF_2X, PLL2 Reference Frequency Doubler
          3. 8.6.3.13.3 PLL2_CP_POL, PLL2 Charge Pump Polarity
          4. 8.6.3.13.4 PLL2_CP_GAIN, PLL2 Charge Pump Current
          5. 8.6.3.13.5 PLL2_DLD_CNT
          6. 8.6.3.13.6 PLL2_CP_TRI, PLL2 Charge Pump TRI-STATE
        14. 8.6.3.14 Register 27
          1. 8.6.3.14.1 PLL1_CP_POL, PLL1 Charge Pump Polarity
          2. 8.6.3.14.2 PLL1_CP_GAIN, PLL1 Charge Pump Current
          3. 8.6.3.14.3 CLKinX_PreR_DIV
          4. 8.6.3.14.4 PLL1_R, PLL1 R Divider
          5. 8.6.3.14.5 PLL1_CP_TRI, PLL1 Charge Pump TRI-STATE
        15. 8.6.3.15 Register 28
          1. 8.6.3.15.1 PLL2_R, PLL2 R Divider
          2. 8.6.3.15.2 PLL1_N, PLL1 N Divider
        16. 8.6.3.16 Register 29
          1. 8.6.3.16.1 OSCin_FREQ, PLL2 Oscillator Input Frequency Register
          2. 8.6.3.16.2 PLL2_FAST_PDF, High PLL2 Phase Detector Frequency
          3. 8.6.3.16.3 PLL2_N_CAL, PLL2 N Calibration Divider
        17. 8.6.3.17 Register 30
          1. 8.6.3.17.1 PLL2_P, PLL2 N Prescaler Divider
          2. 8.6.3.17.2 PLL2_N, PLL2 N Divider
        18. 8.6.3.18 Register 31
          1. 8.6.3.18.1 READBACK_LE
          2. 8.6.3.18.2 READBACK_ADDR
          3. 8.6.3.18.3 uWire_LOCK
  9. Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 Loop Filter
        1. 9.1.1.1 PLL1
        2. 9.1.1.2 PLL2
      2. 9.1.2 Driving CLKin and OSCin Inputs
        1. 9.1.2.1 Driving CLKin Pins with a Differential Source
        2. 9.1.2.2 Driving CLKin Pins with a Single-Ended Source
      3. 9.1.3 Termination and Use of Clock Output (Drivers)
        1. 9.1.3.1 Termination for DC Coupled Differential Operation
        2. 9.1.3.2 Termination for AC Coupled Differential Operation
        3. 9.1.3.3 Termination for Single-Ended Operation
      4. 9.1.4 Frequency Planning with the LMK04208
      5. 9.1.5 PLL Programming
        1. 9.1.5.1 Example PLL2 N Divider Programming
      6. 9.1.6 Digital Lock Detect Frequency Accuracy
        1. 9.1.6.1 Minimum Lock Time Calculation Example
      7. 9.1.7 Calculating Dynamic Digital Delay Values for Any Divide
        1. 9.1.7.1 Example
      8. 9.1.8 Optional Crystal Oscillator Implementation (OSCin/OSCin*)
        1. 9.1.8.1 Examples of Phase Noise and Jitter Performance
    2. 9.2 Typical Applications
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Device Selection
          1. 9.2.2.1.1 Clock Architect
          2. 9.2.2.1.2 Calculation Using LCM
        2. 9.2.2.2 Device Configuration
          1. 9.2.2.2.1 PLL LO Reference
          2. 9.2.2.2.2 POR Clock
        3. 9.2.2.3 PLL Loop Filter Design
          1. 9.2.2.3.1 PLL1 Loop Filter Design
          2. 9.2.2.3.2 PLL2 Loop Filter Design
        4. 9.2.2.4 Clock Output Assignment
        5. 9.2.2.5 Other Device Specific Configuration
          1. 9.2.2.5.1 Digital Lock Detect
          2. 9.2.2.5.2 Holdover
        6. 9.2.2.6 Device Programming
      3. 9.2.3 Application Curve
    3. 9.3 System Examples
      1. 9.3.1 System Level Diagram
    4. 9.4 Do's and Don'ts
      1. 9.4.1 LVCMOS Complementary vs. Non-Complementary Operation
      2. 9.4.2 LVPECL Outputs
      3. 9.4.3 Sharing MICROWIRE (SPI) Lines
  10. 10Power Supply Recommendations
    1. 10.1 Pin Connection Recommendations
      1. 10.1.1 Vcc Pins and Decoupling
        1. 10.1.1.1 Vcc2, Vcc3, Vcc10, Vcc11, Vcc12, Vcc13 (CLKout Vccs)
        2. 10.1.1.2 Vcc1 (VCO), Vcc4 (Digital), and Vcc9 (PLL2)
        3. 10.1.1.3 Vcc6 (PLL1 Charge Pump) and Vcc8 (PLL2 Charge Pump)
        4. 10.1.1.4 Vcc5 (CLKin), Vcc7 (OSCin and OSCout)
      2. 10.1.2 LVPECL Outputs
      3. 10.1.3 Unused Clock Outputs
      4. 10.1.4 Unused Clock Inputs
      5. 10.1.5 LDO Bypass
    2. 10.2 Current Consumption and Power Dissipation Calculations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12器件和文档支持
    1. 12.1 器件支持
      1. 12.1.1 开发支持
    2. 12.2 文档支持
      1. 12.2.1 相关文档
    3. 12.3 接收文档更新通知
    4. 12.4 社区资源
    5. 12.5 商标
    6. 12.6 静电放电警告
    7. 12.7 Glossary
  13. 13机械、封装和可订购信息

封装选项

机械数据 (封装 | 引脚)
散热焊盘机械数据 (封装 | 引脚)
订购信息

10 Power Supply Recommendations

10.1 Pin Connection Recommendations

10.1.1 Vcc Pins and Decoupling

All Vcc pins must always be connected.

Integrated capacitance on the LMK04208 makes external high frequency decoupling capacitors (≤ 1 nF) unnecessary. The internal capacitance is more effective at filtering high frequency noise than off device bypass capacitance because there is no bond wire inductance between the LMK04208 circuit and the bypass capacitor.

10.1.1.1 Vcc2, Vcc3, Vcc10, Vcc11, Vcc12, Vcc13 (CLKout Vccs)

Each of these pins has an internal 200 pF of capacitance.

Ferrite beads may be used to reduce crosstalk between different clock output frequencies on the same LMK04208 device. Ferrite beads placed between the power supply and a clock Vcc pin will reduce noise between the Vcc pin and the power supply. When several output clocks share the same frequency a single ferrite bead can be used between the power supply and each same frequency CLKout Vcc pin.

When using ferrite beads on CLKout Vcc pins, consider the following guidelines to ensure the power supply will source the needed switching current:

  • In most cases a ferrite bead may be placed and the internal capacitance is sufficient.
  • If a ferrite bead is used with a low frequency output (typically ≤ 30 MHz) and a high current switching clock output format such as non-complementary LVCMOS or high swing LVPECL is used, then:
    • The ferrite bead can be removed to the lower impedance to the main power supply and bypass capacitors, or
    • Localized capacitance can be placed between the ferrite bead and Vcc pin to support the switching current.
      • Note: the decoupling capacitors used between the ferrite bead and a CLKout Vcc pin can permit high frequency switching noise to couple through the capacitors into the ground plane and onto other CLKout Vcc pins with decoupling capacitors. This can degrade crosstalk performance.
    • TI recommends using a complementary LVCMOS output format such as LVCMOS (Norm/Inv) to reduce switching noise and crosstalk when using LVCMOS. If only a single LVCMOS output is required, the complementary LVCMOS output format can still be used by leaving the unused LVCMOS output floating.

10.1.1.2 Vcc1 (VCO), Vcc4 (Digital), and Vcc9 (PLL2)

Each of these pins has internal bypass capacitance.

Ferrite beads should not be used between these pins and the power supply/large bypass capacitors because these Vcc pins don’t produce much noise and a ferrite bead can cause phase noise disturbances and resonances.

The typical application diagram in Figure 41 shows all these Vccs connected to together to Vcc without a ferrite bead.

10.1.1.3 Vcc6 (PLL1 Charge Pump) and Vcc8 (PLL2 Charge Pump)

Each of these pins has an internal bypass capacitor.

Use of a ferrite bead between the power supply/large bypass capacitors and PLL1 is optional. PLL1 charge pump can be connected directly to Vcc along with Vcc1, Vcc4, and Vcc9. Depending on the application, a 0.1 µF capacitor may be placed close to PLL1 charge pump Vcc pin.

A ferrite bead should be placed between the power supply/large bypass capacitors and Vcc8. Most applications have high PLL2 phase detector frequencies and (> 50 MHz) such that the internal bypassing is sufficient and a ferrite bead can be used to isolate this switching noise from other circuits. For lower phase detector frequencies a ferrite bead is optional and depending on application a 0.1 µF capacitor may be added on Vcc8.

10.1.1.4 Vcc5 (CLKin), Vcc7 (OSCin and OSCout)

Each of these pins has an internal 100 pF of capacitance. No ferrite bead should be placed between the power supply/large bypass capacitors and Vcc5 or Vcc7.

These pins are unique since they supply an output clock and other circuitry.

Vcc5 supplies CLKin.

Vcc7 supplies OSCin, OSCout, and PLL2 circuitry.

Impacts of excessive noise on PLL2 circuitry may impact PLL2 DLD operation.

TI recommends using a complementary LVCMOS output format such as LVCMOS (Norm/Inv) to reduce switching noise and crosstalk when using LVCMOS. If only a single LVCMOS output is required, the complementary LVCMOS output format can still be used by leaving the unused LVCMOS output floating.

10.1.2 LVPECL Outputs

When using an LVPECL output it is not recommended to place a capacitor to ground on the output as might be done when using a capacitor input LC lowpass filter. The capacitor will appear as a short to the LVPECL output drivers which are able to supply large amounts of switching current. The effect of the LVPECL sourcing large switching currents can result in:

  1. Large switching currents through the Vcc pin of the LVPECL power supply resulting in more Vcc noise and possible Vcc spikes.
  2. Large switching currents injected into the ground plane through the capacitor which could couple onto other Vcc pins with bypass capacitors to ground resulting in more Vcc noise and possible Vcc spikes.

10.1.3 Unused Clock Outputs

Leave unused clock outputs floating and powered down.

10.1.4 Unused Clock Inputs

Unused clock inputs can be left floating.

10.1.5 LDO Bypass

The LDObyp1 and LDObyp2 pins should be connected to GND through external capacitors, as shown in Figure 41.

10.2 Current Consumption and Power Dissipation Calculations

From Table 118 the current consumption can be calculated for any configuration.

For example, the current for the entire device with 1 LVDS (CLKout0) and 1 LVPECL 1.6 Vpp w/ 240-Ω emitter resistors (CLKout1) output active with a clock output divide = 1, and no other features enabled can be calculated by adding up the following blocks: core current, clock buffer, one LVDS output buffer current, and one LVPECL output buffer current. There will also be one LVPECL output drawing emitter current, which means some of the power from the current draw of the device is dissipated in the external emitter resistors which doesn't add to the power dissipation budget for the device but is important for LDO ICC calculations.

For total current consumption of the device, add up the significant functional blocks. In this example, 228.1 mA equals the sum of the following:

  • 140 mA (core current)
  • 17.3 mA (base clock distribution)
  • 25.5 mA (CLKout0 divider)
  • 25.5 mA (CLKout1 divider)
  • 14.3 mA (LVDS buffer)
  • 31 mA (LVPECL 1.6 Vpp buffer w/ 240-Ω emitter resistors)

Once total current consumption has been calculated, power dissipated by the device can be calculated. The power dissipation of the device is equation to the total current entering the device multiplied by the voltage at the device minus the power dissipated in any emitter resistors connected to any of the LVPECL outputs. If no emitter resistors are connected to the LVPECL outputs, this power will be 0 watts. Continuing the above example which has 253.6 mA total Icc and one output with 240-Ω emitter resistors. Total IC power = 801.88 mW = 3.3 V * 253.6 mA - 35 mW.

Table 118. Typical Current Consumption for Selected Functional Blocks
(TA = 25 °C, VCC = 3.3 V)

BLOCK CONDITION TYPICAL ICC
(mA)
POWER DISSIPATED in DEVICE
(mW)
POWER DISSIPATED EXTERNALLY(1)(2)(3)
(mW)
CORE and FUNCTIONAL BLOCKS
Core MODE = 0: Dual Loop, Internal VCO PLL1 and PLL2 locked 140 462 -
MODE = 2: Dual Loop, Internal VCO, 0-Delay PLL1 and PLL2 locked; Includes EN_FEEDBACK_MUX = 1 155 512 -
MODE = 3: Dual Loop, External VCO PLL1 and PLL2 locked 127 419 -
MODE = 5: Dual PLL, 0-DELAY, External VCO PLL1 and PLL2 locked; Includes EN_FEEDBACK_MUX = 1 142 469 -
MODE = 6: Single Loop (PLL2), Internal VCO PLL2 locked 116 383 -
MODE = 11: Single Loop (PLL2), External VCO PLL2 locked 103 340 -
MODE = 16: Clock Distribution PD_OSCin = 0 42 139 -
PD_OSCin = 1 34.5 114 -
EN_TRACK Tracking is enabled (EN_TRACK = 1) 2 6.6 -
Base Clock Distribution At least 1 CLKoutX_PD = 0 17.3 57.1 -
CLKout Group Each CLKout group (CLKout0 and 5, CLKout1 and 2, CLKout 3 and 4) 2.8 9.2 -
Clock Divider/
Digital Delay
When a clock output is enabled, this contributes the divider/delay block 25.5 84.1 -
Divider / digital delay in extended mode 29.6 97.7 -
VCO Divider VCO Divider current 7.7 25.4 -
HOLDOVER mode When in holdover mode 2.2 7.2 -
Feedback Mux Feedback mux must be enabled for 0-delay modes and digital delay mode (SYNC_QUAL = 1) 4.9 16.1 -
SYNC Asserted While SYNC is asserted, this extra current is drawn 1.7 5.6 -
EN_SYNC = 1 Required for SYNC functionality. May be turned off once SYNC is complete to save power. 6 19.8 -
SYNC_QUAL = 1 Delay enabled, delay > 7 (CLKout_MUX = 2, 3) 8.7 28.7 -
Crystal Mode Enabling the Crystal Oscillator XTAL_LVL = 0 1.8 5.9 -
XTAL_LVL = 1 2.7 9 -
XTAL_LVL = 2 3.6 12 -
XTAL_LVL = 3 4.5 15 -
OSCin Doubler EN_PLL2_REF_2X = 1 2.8 9.2 -
Analog Delay Analog Delay Value CLKoutX_ANLG_DLY = 0 to 3 3.4 11.2 -
CLKoutX_ANLG_DLY = 4 to 7 3.8 12.5 -
CLKoutX_ANLG_DLY = 8 to 11 4.2 13.9 -
CLKoutX_ANLG_DLY = 12 to 15 4.7 15.5 -
CLKoutX_ANLG_DLY = 16 to 23 5.2 17.2 -
CLOCK OUTPUT BUFFERS
LVDS 100-Ω differential termination 14.3 47.2 -
LVPECL LVPECL 2.0 Vpp, AC coupled using 240-Ω emitter resistors 32 70.6 35
LVPECL 1.6 Vpp, AC coupled using 240-Ω emitter resistors 31 67.3 35
LVPECL 1.6 Vpp, AC coupled using 120-Ω emitter resistors 46 91.8 60
LVPECL 1.2 Vpp, AC coupled using 240-Ω emitter resistors 30 59 40
LVPECL 0.7 Vpp, AC coupled using 240-Ω emitter resistors 29 55.7 40
LVCMOS LVCMOS Pair (CLKoutX_TYPE
= 6 to 9)
CL = 5 pF
3 MHz 24 79.2 -
30 MHz 26.5 87.5 -
150 MHz 36.5 120.5 -
LVCMOS Single (CLKoutX_TYPE
= 10 to 13)
CL = 5 pF
3 MHz 15 49.5 -
30 MHz 16 52.8 -
150 MHz 21.5 71 -
(1) Power is dissipated externally in LVPECL emitter resistors. The externally dissipated power is calculated as twice the DC voltage level of one LVPECL clock output pin squared over the emitter resistance. That is to say power dissipated in emitter resistors = 2 * Vem2 / Rem.
(2) Assuming R θJA = 15 °C/W, the total power dissipated on chip must be less than (125 °C – 85 °C) / 16 °C/W = 2.5 W to ensure a junction temperature is less than 125 °C.
(3) Worst case power dissipation can be estimated by multiplying typical power dissipation with a factor of 1.15.