THVD9491-SEP: Clarification on THVD9491-SEP Operation at 50 Mbps Despite High Propagation Delay

Dhir Gandhi

Part Number: THVD9491-SEP

Tool/software:

Hello,
I would like to understand how the THVD9491-SEP is able to operate at 50 Mbps, considering its maximum receiver propagation delay is quite high (60 ns). Could you please clarify this?

6 months ago

+1 Clemens Ladisch 6 months ago

Guru 316780 points

(The pulse length of a 50 Mbps signal is 20 ns.)

This device is somewhat pipelined, i.e., you can apply a new signal at the inputs while the output is still switching for the old signal.

0 Dhir Gandhi 6 months ago in reply to Clemens Ladisch

Prodigy 190 points

Hello,
The IC does not seem to have any memory. Could you please elaborate on how buffering is possible in this case?

0 Clemens Ladisch 6 months ago in reply to Dhir Gandhi

Guru 316780 points

There is no deliberate buffering. But the internal stages each have a certain propagation delay.

0 BOBBY 5 months ago in reply to Dhir Gandhi

TI__Guru 72971 points

Clemens is correct, it just takes time for the device to recognize the input signal has changed and adjusts the output when it finally does. The prop delay doesn't really affect max data rate if both prop delays are the same/similar. The prop delay just means the signal will take additional time to travel to the end destination. This is also true as the signal travels through the cable (this adds an additional kind of travel prop delay).

-Bobby

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THVD9491-SEP: Clarification on THVD9491-SEP Operation at 50 Mbps Despite High Propagation Delay