DS90UB933-Q1EVM: POC configuration on DS90UB934-Q1EVM deserializer

Tamir Meoded

Prodigy 100 points

Part Number: DS90UB933-Q1EVM
Other Parts Discussed in Thread: DS90UB934-Q1EVM, LM53601-Q1, LM2941

Hi,

Lately, I received from TI :

DS90UB933-Q1EVM and DS90UB934-Q1EVM for evaluation.

DS90UB933-Q1EVM user manual states that POC from DS90UB934-Q1EVM deserializer board should be (5V<=VPoC<=9V) .

Pls. see doc "SNLU210B–July 2016–Revised December 2017 " page 2.

DS90UB934-Q1EVM is has arrived from TI with jumpers that set POC_voltage to 9V.

However, when powering up DS90UB934-Q1EVM with external 12V , it delivers on POC voltage of 12V.

My question :

Is it safe to connect the two boards by coax although DS90UB934-Q1EVM delivers to DS90UB933-Q1EVM on POC 12V and not 9V ?

Thanks

DS90UB934-Q1EVM deserializer board for connection

over 5 years ago

0 Zoe Nuyens over 5 years ago

TI__Expert 3055 points

Hi Tamir,

Can you share a picture of the EVM so we can confirm what the jumper settings are?

We would recommend using 9V since this is the intended voltage level.

Regards,

Zoe

0 Tamir Meoded over 5 years ago in reply to Zoe Nuyens

Prodigy 100 points

Dear Zoe,

Pls see attached files ,

BTW, on DS90UB933-Q1EVM poc_voltage goes to LM53601-Q1 input which has Wide Operating Input Voltage: 3.55 V to 36 V.

Thanks

Tamir

0 Zoe Nuyens over 5 years ago in reply to Tamir Meoded

TI__Expert 3055 points

Hi Tamir,

Using the same jumper settings as you, I am seeing the expected 9V. Can you share how/where you are measuring the 12V?

Regards,
Zoe

0 Tamir Meoded over 5 years ago in reply to Zoe Nuyens

Prodigy 100 points

on Fakra CN1 and CN2.
I checked resistors on LM2941 that set voltage level of VFEED_LDO1/2 .
Pls see resistors (R111/R115) and (R100/R102) in DS90UB934-Q1EVM schematics.
It seems that actual resistance of (R111/R115) and (R100/R102) is (120k/5.6k) which is not as appears in schematics (29.4k,5.5k)
Is It possible that there is a newer assembly version for that EVBs ?
TNX

0 Zoe Nuyens over 5 years ago in reply to Tamir Meoded

TI__Expert 3055 points

Thanks for the additional information. I would have expected these resistors to match the schematic given that you are using a Rev A board.

I will look into this more to see if there has been any change to this board, but it may take me a few days to verify this information.

In the mean time, I would suggest replacing R111/R115 and R100/R102 with the values listed in the schematic, if you have these resistors available.

0 Zoe Nuyens over 5 years ago in reply to Zoe Nuyens

TI__Expert 3055 points

Hello,

I have double checked and there is no change to the BoM for Rev A of the EVM. The (R111/R115) and (R100/R102) should be (29.4k,5.5k) as in the schematic.

Is this a shared board? Is it possible someone modified these resistors without notifying you?

Regards,
Zoe

0 Tamir Meoded over 5 years ago in reply to Zoe Nuyens

Prodigy 100 points

Hi Zoe,

Thanks.

I replaced the resistors according to your mail.

It works fine.

Regards,

Tamir

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DS90UB933-Q1EVM: POC configuration on DS90UB934-Q1EVM deserializer