SLLA611 september 2023 TDP1204
2.4 Adjusting Termination
The transmitter termination can be adjusted as well for the TDP1204. However, when the termination register is set to 0x2h the termination setting automatically adjusts based on HDMI mode providing robustness to the end application. All other eye diagrams in this document have been using 0x2h to set the termination automatically. Furthermore, the register settings for EQ and VoD in this section are 0x8h and 0x3h, respectively.
In Figure 2-19 and Figure 2-20, the TDP1204 is configured in linear mode for the Worst Cable Model with a termination setting of 0 and 1, respectively.
Figure 2-19 Linear Mode for the Worst
Cable Model (TERM = 0)
Figure 2-20 Linear Mode for the Worst
Cable Model (TERM = 1)In Figure 2-21 and Figure 2-22, the TDP1204 is configured in limited mode for the Worst Cable Model with a termination setting of 0 and 1, respectively.
Figure 2-21 Limited Mode for the Worst
Cable Model (TERM = 0)
Figure 2-22 Limited Mode for the Worst
Cable Model (TERM = 1)Table 2-4 summarizes the performance of the TDP1204 when modifying the termination control between linear and limited redriver modes. The eye width and eye height both increase when using TERM = 1 or a 300 Ω termination rather than when TERM = 0 or no termination. When TERM = 2 and other register settings are unchanged, as shown inTable 2-4, the eye width is marginally smaller than when the termination setting is set to 1. However, the eye height increase continues the trend shown between the transition between TERM = 0 and TERM = 1.
| Termination Setting | Mode | Result |
|---|---|---|
| TERM = 0 or No Termination | Limited |
No Mask Failures Eye Width: 60.134 ps Eye Height: 188 mV |
| Linear |
No Mask Failures Eye Width: 51.986 ps Eye Height: 130 mV |
|
| TERM = 1 or 300 Ω Termination | Limited |
No Mask Failures Eye Width: 64.116 ps Eye Height: 274 mV |
| Linear |
No Mask Failures Eye Width: 55.060 ps Eye Height: 176 mV |