SLLSF57A August   2022  – April 2024 TMDS1204

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
  6. 5 Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 ESD and Latch-Up Ratings
    3. 5.3 Recommended Operating Conditions
    4. 5.4 Thermal Information
    5. 5.5 Electrical Characteristics
    6. 5.6 Timing Requirements
    7. 5.7 Switching Characteristics
    8. 5.8 Typical Characteristics
  7. 6 Parameter Measurement Information
  8. 7 Detailed Description
    1. 7.1 Functional Block Diagram
    2. 7.2 Feature Description
      1. 7.2.1  4-Level Inputs
      2. 7.2.2  I/O Voltage Level Selection
      3. 7.2.3  HPD_OUT
      4. 7.2.4  Lane Control
      5. 7.2.5  Swap
      6. 7.2.6  Linear and Limited Redriver
      7. 7.2.7  Main Link Inputs
      8. 7.2.8  Receiver Equalizer
      9. 7.2.9  CTLE Bypass
      10. 7.2.10 Adaptive Equalization in HDMI 2.1 FRL
        1. 7.2.10.1 HDMI 2.1 TX Compliance Testing with AEQ Enabled
      11. 7.2.11 HDMI 2.1 Link Training Compatible Rx EQ
      12. 7.2.12 Input Signal Detect
        1. 7.2.12.1 SIGDET_OUT Indicator
      13. 7.2.13 Main Link Outputs
        1. 7.2.13.1 Transmitter Bias
        2. 7.2.13.2 Transmitter Impedance Control
        3. 7.2.13.3 TX Slew Rate Control
        4. 7.2.13.4 TX Pre-Emphasis and De-Emphasis Control
        5. 7.2.13.5 TX Swing Control
        6. 7.2.13.6 Fan-out Buffer
      14. 7.2.14 HDMI DDC Capacitance
      15. 7.2.15 DisplayPort
    3. 7.3 Device Functional Modes
      1. 7.3.1 MODE Control
        1. 7.3.1.1 I2C Mode (MODE = "F")
        2. 7.3.1.2 Pin Strap Modes
          1. 7.3.1.2.1 Pin-Strap: HDMI 1.4 and HDMI 2.0 Functional Description
          2. 7.3.1.2.2 Pin-Strap HDMI 2.1 Function (MODE = "0"): Fixed Rx EQ)
          3. 7.3.1.2.3 Pin-Strap HDMI 2.1 Function (Mode = "1"): Flexible Rx EQ
          4. 7.3.1.2.4 Pin-Strap HDMI 2.1 Function (Mode = "R"): Flexible Rx EQ and Fan-Out Buffer
      2. 7.3.2 DDC Snoop Feature
        1. 7.3.2.1 HDMI Type
        2. 7.3.2.2 HDMI 2.1 FRL Snoop
      3. 7.3.3 Low Power States
    4. 7.4 Programming
      1. 7.4.1 Pseudocode Examples
        1. 7.4.1.1 HDMI 2.1 Source Example with DDC Snoop Disabled and DDC Buffer Disabled
        2. 7.4.1.2 Sink Example
      2. 7.4.2 TMDS1204 I2C Address Options
      3. 7.4.3 I2C Target Behavior
    5. 7.5 Register Maps
      1. 7.5.1 TMDS1204 Registers
  9. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Source-Side Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 Pre-Channel (LAB)
        2. 8.2.2.2 Post-Channel (LCD)
        3. 8.2.2.3 Common Mode Choke
        4. 8.2.2.4 ESD Protection
      3. 8.2.3 Application Curves
    3. 8.3 Typical Sink-Side Application
      1. 8.3.1 Design Requirements
      2. 8.3.2 Detailed Design Procedures
    4. 8.4 Power Supply Recommendations
      1. 8.4.1 Supply Decoupling
    5. 8.5 Layout
      1. 8.5.1 Layout Guidelines
      2. 8.5.2 Layout Example
  10. 9 Device and Documentation Support
    1. 9.1 Documentation Support
      1. 9.1.1 Related Documentation
    2. 9.2 Receiving Notification of Documentation Updates
    3. 9.3 Support Resources
    4. 9.4 Trademarks
    5. 9.5 Electrostatic Discharge Caution
    6. 9.6 Glossary
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information

Package Options

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

7.2.13.4 TX Pre-Emphasis and De-Emphasis Control

The TMDS1204 provides pre-emphasis and de-emphasis on the data lanes allowing the output signal pre-conditioning to offset interconnect losses between the TMDS1204 outputs and a TMDS receiver. Pre-emphasis and de-emphasis is not implemented on the clock lane unless the TMDS1204 is in HDMI 2.1 FRL mode and at which time the clock lane becomes a data lane. There are two methods to implement pre-emphasis, pin strapping or through I2C programming. TX pre-emphasis and de-emphasis control is only supported in limited mode.

When using pin strap mode, the TXPRE pin controls four different global pre-emphasis and de-emphasis values for all data lanes when TMDS1204 is operating in HDMI 1.4 or HDMI 2.0. Table 7-15 lists these pre-emphasis and de-emphasis values. In HDMI 2.1 FRL mode, the de-emphasis value used is based on the DDC TXFFE snooped value. Table 7-16 lists how the TMDS1204 uses the de-emphasis level for each TX FFE level.

Table 7-15 Pin-Strap TXPRE Pin Function
LINEAR_EN pin = "0" LINEAR_EN pin = "F" or "1" LINEAR_EN pin = "R"
TXPRE pin HDMI 1.4 or HDMI 2.0 HDMI 2.1 FRL
TXFF0 Level		 AEQ ADJUSTMENT AEQ ADJUSTMENT AEQ ADJUSTMENT
0 3.5dB pre-emphasis

Refer to Table 7-16.

0

+1

0
R -2.5dB de-emphasis

Refer to Table 7-16.

0

+4

0
F 0dB

Refer to Table 7-16.

0

0

0
1 6.0dB pre-emphasis

Refer to Table 7-16

0

+2

0
Table 7-16 HDMI 2.1 FRL TX FFE Levels
FRL TX FFE Snooped Level De-Emphasis
(dB)
TXFFE0 -2.5
TXFFE1 -3.5
TXFFE2 -3.7
TXFFE3 -4.6