SNLS534D April   2016  – June 2018 LMH1226

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Simplified Block Diagram
  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
    5. 6.5 Electrical Characteristics
    6. 6.6 Recommended SMBus Interface AC Timing Specifications
    7. 6.7 Serial Parallel Interface (SPI) AC Timing Specifications
    8. 6.8 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 4-Level Input Configuration Pins
      2. 7.3.2 Input Carrier Detect
      3. 7.3.3 Continuous Time Linear Equalizer (CTLE)
        1. 7.3.3.1 Adaptive PCB Trace Equalizer (IN1±)
      4. 7.3.4 Input-Output Mux Selection
      5. 7.3.5 Clock and Data Recovery (CDR) Reclocker
      6. 7.3.6 Internal Eye Opening Monitor (EOM)
      7. 7.3.7 Output Function Control
      8. 7.3.8 Output Driver Amplitude and De-Emphasis Control
      9. 7.3.9 Status Indicators and Interrupts
        1. 7.3.9.1 LOCK_N (Lock Indicator)
        2. 7.3.9.2 CD_N (Carrier Detect)
        3. 7.3.9.3 INT_N (Interrupt)
    4. 7.4 Device Functional Modes
      1. 7.4.1 System Management Bus (SMBus) Mode
        1. 7.4.1.1 SMBus Read and Write Transactions
          1. 7.4.1.1.1 SMBus Write Operation Format
          2. 7.4.1.1.2 SMBus Read Operation Format
      2. 7.4.2 Serial Peripheral Interface (SPI) Mode
        1. 7.4.2.1 SPI Read and Write Transactions
          1. 7.4.2.1.1 SPI Write Transaction Format
          2. 7.4.2.1.2 SPI Read Transaction Format
        2. 7.4.2.2 SPI Daisy Chain
    5. 7.5 LMH1226 Register Map
      1. 7.5.1 Share Register Page
      2. 7.5.2 CTLE/CDR Register Page
      3. 7.5.3 Drivers Register Page
  8. 8 Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 General Guidance for SMPTE and 10 GbE Applications
      2. 8.1.2 LMH1219 and LMH1226 Compatibility
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
      3. 8.2.3 Recommended VOD and DEM Register Settings
      4. 8.2.4 Application Performance Plots
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 PCB Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Receiving Notification of Documentation Updates
    2. 11.2 Community Resources
    3. 11.3 Trademarks
    4. 11.4 Electrostatic Discharge Caution
    5. 11.5 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

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

7.3.5 Clock and Data Recovery (CDR) Reclocker

After the input signal passes through the CTLE, the equalized data is fed into the clock and data recovery (CDR) block. Using an internal PLL, the CDR locks to the incoming equalized data and recovers a clean internal clock to re-sample the equalized data. The LMH1226 CDR is able to tolerate high input jitter, tracking low frequency input jitter below the PLL bandwidth while reducing high frequency input jitter above the PLL bandwidth.

The supported data rates are listed in Table 3. IN1 locks to either SMPTE or 10 GbE data rates according to the IN_OUT_SEL pin logic shown previously in Table 2. When locked to SMPTE data rates according to IN_OUT_SEL pin logic, IN1 can be programmed to lock to the 10 GbE data rate, and vice versa, via register control by applying the appropriate override bit values. For more information, refer to the LMH1226 Register Map.

Table 3. Supported Data Rates

IN_OUT_SEL
LEVEL		 DATA RATE RECLOCKER MODE
H, F 11.88 Gbps, 5.94 Gbps, 2.97 Gbps, 1.485 Gbps, 270 Mbps(1) Reclocker Enabled
125 Mbps Reclocker Disabled (CDR Bypassed)
R, L 10.3125 Gbps Reclocker Enabled
1.25 Gbps Reclocker Disabled (CDR Bypassed)
(1) Divide-by-1.001 lock rates available only for 11.88 Gbps, 5.94 Gbps, 2.97 Gbps, and 1.485 Gbps.

NOTE

If the selected data rate (SMPTE or 10 GbE) is changed while the device is operating with active data, a CDR reset and release is required for the CDR to re-acquire lock. If the input data signal is toggled off and on after the selected data rate is changed, the Carrier Detect circuit will reset the CDR. In this case, no register write is needed for the CDR to re-acquire lock.