ISOUSB211DPEVM: Jumper settings of the EVM

Hi Takumi,

Thanks for reaching out. Before coming to ISOUSB211EVM Jumpers I have some observation below:

Takumi Suzuki1 said:

AMP(analog signal out) --- ADS131M04EVM --- ISOUSB211DPEVM --- PC

This Signal chain does not seem compatible with USB protocol, hence ISOUSB device can not be used to interface with ADS131M04EVM.

Please Note that ISOUSB is an Isolated USB Repeater which is compliant with USB protocol. It does not respond to or transmit any random digital signals on it's UD+/- or DD+/- pins.

Do Let me know if I'm interpreting the chain correctly.

Regards
Varun

Hi Varun-san,

Thank you for your reply !

I understood.

Do you have any other solution to connect ADS131M04EVM with isolation?

Thanks and Regards,

Takumi

Hi Varun-san,

Thank you for your advise.

Let me explain my situation again.

The interface between ADS131M04EVM and PC is USB, not SPI.

About ADS131M04EVM kit, it has a USB interface with PC.

ADS131M04EVM Evaluation board | TI.com

The ADS131M04EVM kit includes the ADS131M04EVM board and a precision host interface (PHI) controller board that enables the accompanying computer software.

As the EVM kit consists of EVM board + PHI board, we can connect the EVM with PC via USB.

So I thought I could use ISOUSB211DPEVM to isolate ADS131M04EVM and PC.

Is my understanding not correct ??

Regards,

Takumi

Hi Takumi-San,

Thanks for the further details. I misunderstood the ADS131M04EVM kit.

As long as the EVM kit gives a USB Protocol Output, ISOUSB211 can be used. Answering your first question:

Takumi Suzuki1 said:

should we prepare external power supply for ISOUSB211

 The Supply used for ADS131M04EVM can be used for the Side interfacing with it. We have on board LDO on ISOUSB211EVM  or if you want you can use direct 5V or 3.3V supply based on what is available for the ADC EVM. 

Regards
Varun

Hi Varun-san,

Thank you for your reply.

I'm sorry that as I'm not familiar with ISOUSB211 and USB specificationss,

please let me know the jumper settings on the ISOUSB211DPEVM to connect with ADS131M04EVM.

The initial jumper conditions of the ISOUSB211DPEVM(J3 - J10) are all "open".

Will you tell me the setting of these jumpers?

I tried to connect ADS131M04EVM with PC via ISOUSB211DPEVM under the initial conditions, but the connection did not work, to my regret.

Of course, in case ADS131M04EVM is connected with PC directly, the connection is working well.

I appreciate your advise very much

Best Regards,

Takumi

Hi Takumi-san,

Thanks for the details. Helps to understand the requirement and issue better.

The Jumpers J3-J10 are EQ Settings and are used to improve Eye Diagram of the USB Differential Signal for Cable Losses. Please refer Page12(Section 6.9 Contd.) and Section 8.3.9 for more details about the Equalization and Pre-Emphasis. There's also an Appnote from TI explaining cables losses in USB transmission : https://www.ti.com/lit/an/slla579/slla579.pdf?ts=1742978649419

So coming to issue, I don't see how Jumper J3-J10 can affect the USB communication between ISOUSB and ADS131M04 until you have very long wires > 5m in length...

Few Questions to eliminate any confusion:

1. How did you supply power to the USB side which is connected to ADS131M04EVM?
2. How are the datelines D+/D- connected between ISOUSB211EVM and ADS131M04EVM?
   1. The Length should be be matched for D+ and D- line.
3. It would also be helpful if you can share a picture of the setup showing both sides connection of ISOUSB211EVM

Regards
Varun

Hi Varun-san,

Thank you for your kind reply !

About the power supply to ADS131M04EVM, there is no external power supply for the EVM.

Just using USB bus power.

And the connection between both EVM, I am using  "commercially available USB cables".

PC ----- "A" plug/"B" plug(150cm) ----- ISOUSB ----- "A" plug/"Micro B" plug (80cm) ---- ADS131

I will show you the setup picture later.

Regards,

Takumi

Hi,

Let me show you the connection as attached.

Thanks and Regards,

Takumi

ISOUSB Connection.pdf

HI Takumi-San,

Thank you for the setup pictures. Number One Question:

1. The USB Interface Adapter attached to ADS131M04EVM generates VBUS of 5V that cab be given to VBUS2 Pin of ISOUSB211 on the EVM?

To check what is the VBUS2 and proper powering up ISOUSB211 on Right Side, can you probe TP13 . Probing TP14, TP15 and TP17 will give us voltage on VCC2 and V1P8V2. Also Probing TP10(V2OK) will tell us whether Side2 is powered or not. Do let me know the Voltage Readings on these Test Points on your EVM.

Also let me know the Jumper Connection on J11 and J12? This will tell us if transformer is delivering power to Side or not.

Looking Forward to your inputs.

Regards
Varun

Hi Varun-san,

Thank you for your support !

Let me check and wait a moment please.

Best Regards,

Takumi

Thanks Takumi-san. Will wait for your inputs.

Regards
Varun

Hi Varun-san,

Thank you for your waiting.

I checked the voltage of your mentioned as below.

TP13 : 3.27V

TP14: : 3.27V

TP15 : 1.773V

TP17 : 1.773V

TP10 : 3.411V

TP5: 5.125V

And about J11 and J12, both jumper settings are "open".

I suppose there seems to be shown correct operation of the ISO EVM.

Maybe there is something problem on the ADS131EVM...

Thank you for your support.

Regards,

Takumi

Hi Takumi-San,

Thank you for your inputs.

All the Voltages mentioned above indicates right voltages at Right Side for ISOUSB211 Operation.

Now the Question is, whether the main 5V Supply at TP5 is coming from on board transformer or ADS131EVM..... Reason this is important is the current limits that can be on ADS131EVM. which can be insufficient for ISOUSB211EVM Functionality.

As per below snapshot from EVM user guide can you check J15 jumper position and TP3 Voltage?

Regards
Varun

Hi Varun-san,

Thanks for your reply.

Let me inform you the voltage of TP3, TP3 : 5.15V.

And about J15 setting, please check the picture as attached.

JP setting ISOUSB211DPEVM.pdf

Thank you for your support.

Regards,

Takumi 

Hi Takumi-san,

Thanks for all the inputs provided. The ISOUSB211EVM seems to work fine from all the Voltage Values provided by you.

The only question unanswered is whether  ADS131EVM provides VBUS, if yes then please depopulate L2 and check for functionality and let us know.

Also, The output of  ADS131EVM is USB2.0 and not 3.0, right? Can you please confirm? ISOUSB211 only supports USB2.0.

Regards
Varun

Hi Varun-san,

Thank you for your reply,

Let me answer your questions as below.

 - ADS131EVM does not provide VBUS

 - The USB is USB2.0

Thanks for your kind support.

Best Regards,

Takumi

Hi Takumi-san,

The Second bullet point infers that VBUS is indeed getting generated through ADS131EVM  since no external supply is required.

Can you please do the following and see if the solution works. We need to disconnect VBUS of ADS131EVM  and 5V getting generated on the ISOUSBEVM.

Varun Kumar said:

if yes then please depopulate L2 and check for functionality and let us know.

Regards
Varun

Hi Varun-san,

Thank you for your reply.

I tried your instruction but the EVM did not work, to my regret.

I doubt the power-on timing of PHI board of ADS131M04EVM... 

Regards,

Takumi

Hi Varun-san,

I appreciate your kind support very much !

Regards,

Takumi