TPS22916: Customer has issue with these parts "not switching"

Hey Dan, 

Thanks for reaching out on E2E!

Can the customer elaborate on when the device is failing? Is it during startup or a DC condition? Is the EN/ON pin high or low? Can you share any oscilloscope shots of the behavior?

Also, is this a prototype build or a final production build. We've seen issues in the past regarding the handling of the device and the pick/place force. 

Thanks,

Arthur Huang

To TI Support Team:

Hi Arthur,

The customer responded to your queries with the below answers.
Can you help us resolve this issue?

[Sean Miner, our Engineer, has answered your listed questions. Please let me know if you need further information.]
-------------------------------------------------------------------------------------------------------------------
1. Can you elaborate on when the device is failing? For example, is it during startup or a DC condition?
      (1.The device failure is during initial checkout or startup. The devices that failed, when EN/ON pin is high, it did not switch its
      input voltage to the output voltage to the load (input of 3v and output of 0v). Another failure is when the EN/On pin is high, the
      device partially switched the input voltage to the output pin of the device, about 1.8V output voltage from an input voltage of 3.3v.)

2. When the device fails, is the EN/ON pin high or low?
      (2.The EN/on pin is high during the failure.)
     

3. Can you share any oscilloscope images(s) of the behavior?
      (3. I can provide images of the behavior if needed.)
     

4. Is this a prototype build or a final production build?
      (4.This is a prototype build but will be moving into a production build quickly after the proof of concept is finished.)

Thx
DT

Hi DT, 

A few additional questions based on the information they provided:

• How are they placing the units? Is there any top-side damage or chipping due to placement?
• Have they tried removing the upstream DC/DC and running the on/off test?
• If they could provide oscilloscope shots, that would be appreciated.

At first glance, my guess would be a pick/place issue. Since the failure appears different on both devices, there could have been chipping that caused damage to the TSC.

Thanks,

Arthur

To TI Support Team:

Hi Arthur,

Please see the customer's below responses to your additional queries on this p/n  PS22916CYFPT.

Can you help us with this?  What would be the next step?

-------------------------------------------------------------------------------------------------------------------------------------

"I got the reply below from our EE, Sean Miner, in regards to your request for more info on his issues

with TI part TPS22916CYFPT. Please let me know if you need further information. Thanks,

David"

1. How are they placing the units? Is there any top-side damage or

chipping due to placement?

(I would assume using a pick and place machine, I do not see any visible damage to the load switch on the failed unit)SM

2. Have they tried removing the upstream DC/DC and running the on/off test?

(I have not tried removing the DC/DC convertor, I will give that a try) SM

3. If they could provide oscilloscope shots, that would be appreciated.

( I have attached a picture using an oscope of the failure) SM

-------------------------------------------------------------------------------------------------------------------------------------

Thanks,
Dan Rapp
Technical Support
Mouser Electronics
(800) 346-6873

(817) 804-3800
www.mouser.com

Mouser Service Order# 489723

Hey Dan, 

Sorry, I was one timebank last week. Have you been able to resolve the issue?

Since you mentioned that the device fails during the initial startup, the failure could be potentially due to an initial voltage/current spike. What is the downstream loading conditions? What is your load capacitance? If you could also share an oscilloscope of a working unit, this will help us compare the results. 

Have you tried repeating the test by removing the DC/DC converter? Does the behavior still occur?

Thanks,

Arthur

To TI Support Team:

Hi Arthur,

We are trying to get answers and information to your questions from the customer; please bear in mind the coming holiday and keep this post open.

BTW, this would be faster if you could communicate direct with the customer over the phone on their issue, which seems to be moving toward a FA.

Thanks,
Dan Rapp
Technical Support
Mouser Electronics
(800) 346-6873

(817) 804-3800
www.mouser.com

Service Orders:  S489723, S495258

To TI Support Team:

Hi Arthur,

Again, we have tried pinging the customer for answers to your latest questions, but we have not yet heard back (!).

We will keep trying a little more and get back with you as soon as that happens; perhaps -- and hopefully, they were

able to resolve their issue by investigating your questions. However, please keep this post open until we can find out.

Thanks, 
Dan Rapp
Technical Support
Mouser Electronics
(817) 804-3800

www.mouser.com

Service Orders:  S489723, S495258