PGA300: PGA300 OWI can't active when I use the evaluation board PGA900EVM

Hello,

You should not have to make any changes to the EVM when using the PGA300 instead of the PGA900.

Are you using the PGA300 GUI or the PGA900 GUI? I would start by making sure to use the PGA300 GUI when communicating with the PGA300.

Can you please take a scope capture of the OWI signal at the VPWR pin when you activate OWI?

Regards,

Hi Scott,

Hello,

That waveform does not look normal. If you have multiple channels available on the scope can you please show the following signals on a single capture:

TP4: OWI activation control signal (trigger on this channel)

TP5: OWI_TX

TP20: VPWR/OWI

Could you also include a picture of your EVM that shows your jumper settings?

Regards,

Hello,

I have not received a reply for about 2 weeks, but is there any solution?

Best regards.

Hello,

The settings are correct, and the waveforms look normal, so you should be getting OWI communication. As another test, please decrease the OWI baud rate to 1200bps, and set the Rloop value to 0ohm. 

Does this problem persist with different PGA300 devices?

Regards,

I do think it is possible that the device may have some issues considering that the PGA900 you have tried works. What kind of current draw do you see on your power supply when you power on the PGA300?

Regards,

Hello,

When I power on the PGA300, the current is about 20mA.

I constantly monitor the current value of the PGA300.

Best regards,

Hello, 

That current draw is not out of the ordinary. Were you able to try another PGA300 device? Did the OWI work? If that is the case, I would suggest returning the first PGA300 through our support website here: http://www.ti.com/support-quality/resources/customer-returns.html

Regards,

Hello,

I tried with the new PGA300,but I couldn't connect with OWI.

The symptoms were the same as the previious PGA300.

Just in case, I comfirmed that I can connect with PGA900.

As a result, I couldn't connect with OWI with PGA900.

However, I could connect with SPI with PGA900.

Previously, when confirming connection with PGA900, I confirmed with the default setting (voltage mode using SPI).

From the above results, I guess that there is something wrong with the part related to OWI in PGA900-EVM.

Please let me know if you can advise.

Best regards,

Hello,

Based on those results there is a possibility that there is a problem with a component of the OWI circuitry on the EVM. The OWI activation output may be acting improperly. Can you please probe the positive input (pin 3) of U15, as well as the output (pin 1 or 4), and use TP4 as a trigger for your oscilloscope. There may be a problem with the buffer.

Regards, 

Hello,

The following figure shows the results of observing Pin3,Pin4 of U15 and TP4 with an oscilloscope.

There was almost no voltage at TP4, and Pin3,Pin4 of U15 had the same value.

I don't know what the correct waveform will look like, but it's probably not working properly when connected to OWI.

Hello,

The following figure shows the results of observing Pin3,Pin4 of U15 and TP4 with an oscilloscope when OWI ACTIVE in PGA300 GUI is clicked.

Is this the correct waveform?

Hello,

My apologies for the delay. There was a US holiday, and the responses have been delayed because of this. I will take a look at these waveforms and get back to you this week.

Thank you,

Hello,

Those waveforms look correct, however this is only the TX side of the OWI from the EVM to the PGA300. There may be an issue with the RX side, and it is not properly reading the response from the PGA300/PGA900.

Can you probe TP7, TP8, and the side of R35 or R24 that is connected to U6? These are the inputs and the output to the comparator that determines if there is a 1 or 0 being output from the PGA300 during OWI communication. If the threshold is off for some reason, the output may never change and communication will not work.

Regards,