Inquiry Regarding Teseo-LIV3 Ant-off Signal Behavior

[Kento]

I have a question regarding the Teseo-LIV3.

My understanding is that when power is supplied to the IC,

the Ant-off signal should go high (H) after a certain period.

 

However, in my case, the Ant-off signal remains low (L) even after powering the IC.

Aside from a possible antenna short circuit, what other factors could cause this behavior?

[GalaxyQuest]

Hi,

Maybe the first thing to check is to see if the module is running.

Are you getting PPS output?

Have you checked if you are getting any UART/I2C data even thought it might be blank data for satellites?

[Kento]

Hi,

Thank you for your suggestions.

I am not receiving any PPS output.
The UART terminal remains high after powering on (I am not using the I2C terminal).

To provide more context, we are currently facing defects in some of the products that utilize this IC, and we have confirmed that the IC is not functioning correctly. We are in the process of isolating which part of the circuit is causing the issue.

 

Based on these observations, do you have any further advice?

[GalaxyQuest]

Hi Kento,

Having no PPS output and not seeing any NMEA data is indication that device is not powering up.

Have you checked your power supply ? Is it constant and not a lot of noise on the lines?

Are you applying power to VBAT?

Are you designing with Teseo LIV3F or Teseo LIV3FL?

If you are designing with Teseo LIV3F, refer to this hardware manual below,

https://www.st.com/resource/en/user_manual/um2231-teseoliv3-gnss-module--hardware-manual-stmicroelectronics.pdf

If it is Teseo-LIV3FL, refer to this manual below

https://www.st.com/resource/en/user_manual/um2980-hardware-specifications-for-teseoliv3fl-stmicroelectronics.pdf

You can private message me your schematic.

I notice you are from JPN, have you gotten in touch with local ST sales and marketing to see if it can be addressed from the JPN region itself?

 

Thank you.

[GalaxyQuest]

Hi Kento,

I wanted to follow-up on troubleshooting the problem you had mentioned.

From your post I understand you might be working on a production design hence the suggestion to reach out JPN ST sales and marketing.

Therefore, could you please let me know if you have made progress on identifying the problem?

[Kento]

I wanted to share our findings regarding the recent issue.

It appears that the problem was caused by the temperature settings of the reflow oven.

It seems the heat damaged an oscillator inside the TESEO-LIV3FL.

 

Thank you for your support.

[GalaxyQuest]

Thank you for letting me know that the problem is resolved.