ZHCSB29I September 2009 – October 2019 DS90UR905Q-Q1 , DS90UR906Q-Q1
PRODUCTION DATA.
The De-Emph pin controls the amount of de-emphasis beginning one full bit time after a logic transition that the serializer drives. This is useful to counteract loading effects of long or lossy cables. This pin should be left open for standard switching currents (no de-emphasis) or if controlled by register. De-emphasis is selected by connecting a resistor on this pin to ground, with R value between 0.5 kΩ to 1 MΩ, or by register setting. When using De-Emphasis, TI recommends to set VODSEL = H.
| RESISTOR VALUE (KΩ) | DE-EMPHASIS SETTING |
|---|---|
| Open | Disabled |
| 0.6 | –12 dB |
| 1.0 | –9 dB |
| 2.0 | –6 dB |
| 5.0 | –3 dB |
Figure 25. De-Emph vs. R value