TL1451A: output issue

Hi Vicky,

Thanks for using the e2e forum.

As there is a public holiday in Germany today, responses may get delayed.
We will look into this issue and get back to you by the middle of this week.

Thank you very much for your patience.

Best regards,
Niklas

Hello Vicky,

Please explain the issues more in detail and add measurements of the input voltage, output voltages, gate signals and feedback signals.

How many boards show the same issue?

Best regards, 

Brigitte 

Hi Brigitte

We brought 2500 pcs of TL1451ACD,

• 1500pcs-->Datecode 1406+5
• 1000pcs-->Datecode 2008

Totally 198 boards were used and the issue all happened on the datecode 1406+5.

Because TL1451ACD wrong action, made the output voltage lower than 5V, it should be 5V!

We used the same board,but change orther part which datecode is 2008, it work and output wsa correct.

.

Hello Vicky, 

Thanks for your feedback. I would like to make sure we understood the issue correctly: the IC part number is the same as well as the board, the only one difference is the date code? How many boards with the date code 1406+5 failed out of the 198 total? 

Kind regards,
EM

Hi EM

the IC part number is the same as well as the board, the only one difference is the date code--> YES!

We total used 2000 pcs boards, 198 pcs boards failed with date code 1406+5.

Hello Vicky, 

Thank you for your feedback. Could you by chance share the info that my colleague Brigitte asked for in the above message? In addition, could we take a look at the layout? We're looking forward hearing from you soon and we will come back to you as soon as we have further updates. 

Kind regards,
EM 

Hi EM & Brigitte,

Please see below layout,thanks!

TL1451.pdf

Hello Vicky,

I am very sorry for the late reply.

Please explain the issues more in detail (what means output voltage is lower than 5V? How much lower?) and add measurements of the input voltage, output voltages, gate signals and feedback signals.

Please explain if you are seeing as well differences on the 23V output.

In parallel I am checking if there is a difference between the different date codes.

Best regards, 

Brigitte 

Hello Vicky,

Would it be possible to get pictures of the labels on the reels or boxes? If this is no longer possible, please send pictures of the text on the device.

Best regards,
Brigitte

Hi Brigitte,

Good day

Please see below label,thanks.

Hi Brigitte,

We input 5V but the output voltage was 2V or 0V.

Because many circuit boards have been burned, it is no longer possible to measure.

so we are unable to provide further information and measurements,thank you.

Hello Vicky,

Thank you for the picture. Do you have pictures of the ICs or the box of the ICs of the other date code you mentioned?

Do you still have some devices that are operating as expected for doing measurements on these?

Best regards,
Brigitte

Hi Brigitte,

Good day~

Please see below ,thanks.

The label and file is other date code(2008+5) which is functioning normally.

function normally.pdf

Hello Vicky,

Thank you for the pictures and the schematic. 

Please explain if you are seeing as well differences on the 23V output. The schematic shows an input voltage of 33V, so where do you input 5V?

Best regards,
Brigitte

Hi Brigitte,

Sorry!

The input voltage is 33V, Our customer gave us the wrong information. 

Please help to check the issues, thank you!

Hello Vicky,

What happens with the 23V? Are these working as expected?

Best regards,
Brigitte

Hi Brigitte,

The 23V is the power supply for the motor, and the ASIC will notify the TL1451 of the power supply when the motor needs to be activated.
 The 5V is the main power supply of other control ICs, so there is no 5V output  it will not be able to start up and operate normally.

Hello Vicky,

Thank you for this explanation. We are checking in the back if there is any difference between these devices, but we need to dig deeper than expected, so please expect some delay there.

Would you please order new devices and check if these work again?

Best regards,
Brigitte

Hi Brigitte,

Sorry! We won't reorder again.

Before We brought 2500 pcs of TL1451ACD, only the date code 14+ had problem,and the other date code 2008 was good.

So we wiil wait for the conclusion, thanks.

Hello Vicky,

You could request some samples for free from TI which most probable have a different date code. I would just be curious if these work.

Best regards,
Brigitte

Hi Brigitte,

Sorry for the late reply!
Other date code 2008 is works without any issues!
And we have discussed and provided the information before,so please analyze and compare the two date code 1406 & 2008.
Thanks!

Hi Vicky,

Have you confirmed this is a quality issue?

You can return the failure part to the distributor and finally to TI for further analysis. 

Or do you want to check with us about the phenomenon?

Best Regards,

Feng Ji

Hi Feng

We bought this part from Ti store and the customer support could not  handle this.

And let us to E2E,which is can help us to check this issue.

Please help to check the phenomenon, thank you!

Hi Vicky,

Please share some waveforms when 5V is lower than expected.

Maybe you can compare the waveforms to that of a normal device.

Best Regards,
Feng Ji