TUSB8020B: Length question

Dear JMMN
Thank you for your reply.
I want to confirm two questions with you.
1. If the Hub includes the Retime/Redriver function. How do I adjust the EQ?
2. Can I remove the Redriver on the architecture diagram? Is it only TUSB2080B?
CPU to TUSB8020B Less than 8 inch and Connector to TUSB8020B Less than 8 inch. Less than 16 inch in total. Is it?

Dear JMMN.

Thanks for your reply. We have a simulation question and would like to ask you.

Hub (TUSB8020B) IBIS model characteristic has qualm, simulation result were shown below

Use Hub IBIS TX => Hub IBIS RX (Fig.1), eye diagram was disorder (Fig.2)

Use Hub IBIS TX => 100ohm Termination (Fig.3), eye diagram was clear (Fig.4)

So it seem RX model has qualm, please help to check model characteristic

If the IBIS model couldn’t simulate for USB3.0 (5Gbps), are there other format models? (Ex. IBIS AMI)

Fig.1 Simulation Deck for Hub IBIS TX => Hub IBIS RX

 

Fig.2 Eye Diagram for Hub IBIS TX => Hub IBIS RX

 

Fig.3 Simulation Deck for Hub IBIS TX => 100ohm Termination

 

Fig.4 Eye Diagram for Hub IBIS TX => 100ohm Termination(TX model: usb3_WODE)

 

 

 

Hi AJ,

For USB 3.0 signalling there should be caps between the TX and RX which may impact the model. I'll check with the team.

Regards,
JMMN

Dear JMMN.

Thanks for kindly help. More information update on below for you reference. 

Fig.1 result was simulated with ADS USB3.0 default TX model, TUSB8020B IBIS model’s characteristic was bed.

Please help us to check IBIS characteristics was all right.

IBIS model is a buffer model that it couldn’t build up with EQ, so it always use IBIS AMI to exhibit EQ characteristics.

If the IBIS model can exhibit IC characteristics, please provide simulation deck. Thanks~

Fig.1 ADS USB3.0 default TX AMI model ó Hub IBIS RX

 

Dear JMMN.

Thanks for your reply.

We will check it after the holiday.

Do you have TUSB8020B IBIS_AMI model’s can share to us. Thanks~

Dear JMMN

USB3.0 considers the EQ characteristics to be observed after passing the component (Figure 1)

But with IBIS, the simulation can only be observed in front of the component (Figure 2), and the simulation results will be different from the actual one.

Can you please provide a simulation template (SPICE format or ADS deck)? Thanks for kindly help~

Figure 1

 

Figure 2

 

Hi AJ,

We do not have a simulation template available.

Regards,
JMMN

Dear JMMN.

Thanks for your reply.

Do you have TUSB8020B simulation result can provide to us?

New simulation result were update shown below

Fig.1 result was simulated from ADS USB3.0 default TX model to hub IBIS RX(TI_TUSB8020BPHPR) , the eye diagram in +-0.5V

Fig.2 add 90ohm between P/N, the eye diagram in +-0.3V

Adding 90ohm between P/N was unreasonable that it seems already have termination effect in IBIS model

Fig.1 ADS USB3.0 default TX AMI model to Hub IBIS RX

 

Fig.2 ADS USB3.0 default TX AMI model to Hub IBIS RX with 90ohm between P/N

 

 

 

 

 

Dear JMMN

Good day. Continue the previous question.

We need to know the TUSB8020B IBIS model are correct or not? Or need to be modify some thing?

Please also kindly provide the TUSB8020B simulation eye diagram result to us. Like our figures.

Fig.3 ADS USB3.0 default TX AMI model to termination differential-100ohm. Remove TUSB8020B IBIS model and use an ideal termination to exhibit receiver characteristics. the eye diagram are perfect.