TUSB211A: r End Eye Measurement

Hi Takemura-san,

Taito Takemura said:

(1) I understand the following in each figure of TUSB211A data sheet 8.2.3. Figure 8-3 shows the case without TUSB211A, Figure 8-4 shows the case when TUSB211A is connected to a pre-channel cable of the same length, and Figures 8-5 and 8-6 are the same. Is this my understanding correct?

Figures 8-3 shows what the eye looks like with 2 meter pre-channel without the redriver, and figure 8-4 shows what the eye looks like with a 2 meter pre-channel with the redriver active at an EQ setting of 1.

Figures 8-5 and 8-6 are the same, just with a 5 meter pre-channel.

Taito Takemura said:

(2) It is my understanding that data sheet 8.2.3 of TUSB211 was also measured using the same setup as (1). Comparing this with each figure in 8.2.3 of the TUSB211A data sheet, if (1) is correct, the TUSB211A appears to have improved the rise/fall speed variation or jitter that existed in the original signal. Is such an understanding correct?

The TUSB211A incorporates additional forms of signal compensation, such as DC Boost, and has improved driving capability, so yes, it would be a correct understanding to say that the TUSB211A has an improved performance versus the TUSB211.

Please let me know if you have any more questions!

Thanks,

Ryan