DS90UB954-Q1: Cable Specifications Required

Carlos Rodriguez1

Part Number: DS90UB954-Q1

Dear TI team,

I would like to ask you about one requirement which I think is not written in the datasheet.

You can find requirements of S11 and S21 measurements regarding the PCB, but nothing related to the cables/interconnections. There is a maximum level of attenuation which is required for the cable?.

You recommended to use Leoni Dacar 302 and 462 too, but what about the limit of the attenuation in the system related to the cable? In case we have several interconnections which also add some losses, which is the recommended limit of this completely attenuation?

Thanks and regards!!

over 5 years ago

0 Hamzeh Jaradat over 5 years ago

TI__Guru** 107860 points

Hello Carlos,

Can you tell me which SER/DES pair are you using?

0 Carlos Rodriguez1 over 5 years ago in reply to Hamzeh Jaradat

Intellectual 345 points

Hi Hamzeh,

We are using 954/953, in Coax Mode

Thanks!

0 Hamzeh Jaradat over 5 years ago in reply to Carlos Rodriguez1

TI__Guru** 107860 points

Carlos,

We do have the following Total channel requirements:

Total Transmission Channel = SER PCB (with PoC) + Cable and Connectors + DES PCB (with PoC)

Frequency --- max. IL

1MHz -------- 1.4dB
5MHz --------- 2.3dB
10MHz ------- 2.5dB
50MHz ------- 3.5dB
100MHz ----- 4.5dB
500MHz ----- 9.5dB
1GHz -------- 14.0dB
2.1GHz ------ 21.6dB

0 Carlos Rodriguez1 over 5 years ago in reply to Hamzeh Jaradat

Intellectual 345 points

Thanks Hamzeh,

I would like to ask you other question, because to measure the S11 parameter of the PCB track in the FPDLink is needed to remove the 954 and place termination resistor. As far as I understand, to measure the S21 parameter, we need to remove the termination resistor, and measure between the FAKRA connector and the + PAD of the FPDLink right? In the 954 footprint. Without termination.

I will be very thankful if you could give me a confirmation.

Thanks and best regards!

0 Hamzeh Jaradat over 5 years ago in reply to Carlos Rodriguez1

TI__Guru** 107860 points

Hello Carlos,

yes, your understanding is correct.

0 Carlos Rodriguez1 over 5 years ago in reply to Hamzeh Jaradat

Intellectual 345 points

Thanks! And my last questions, in the limits you sent me

1MHz -------- 1.4dB
5MHz --------- 2.3dB
10MHz ------- 2.5dB
50MHz ------- 3.5dB
100MHz ----- 4.5dB
500MHz ----- 9.5dB
1GHz -------- 14.0dB
2.1GHz ------ 21.6dB

Shall I assume a linear evolution between values? Or is just steps?

Thanks!!

0 Hamzeh Jaradat over 5 years ago in reply to Carlos Rodriguez1

TI__Guru** 107860 points

Hello Carlos,

yes, linear.

Interface

Interface forum

DS90UB954-Q1: Cable Specifications Required