TPS650330-Q1: TPS650330-Q1 Buck2 1.8V output stop at low load

Hi Rishabh,

   It's a very strange behavior! Let's debug together by checking followings:

1. How did you apply the 10 OHM as a load? 
2. Check the Buck2 inductor for possible cold soldering. Pushing the 10 OHM may make the cold soldering gone.
3. Do you have a board working well?
4. How many boards you have in total?
5. How many boards have the same issue? 

Thanks!

Phil

Hi Phil,

 Thank you for your response.

 1. we connect a TH 10 ohm resistance as load on Buck2(1.8V) output inductor to ground.

 2. We check all cold soldering points, all are perfect. ( we tested with 120 ohm same as load on buck2 but at that time it again not working, at no load (without image sensor and 10 ohm) output is stable 1.8V)

 As of now we have only one board others are in assembling process.

Thanks,

Rishabh 

Hi Rishabh,

 While we're waiting for more boards to check; would you please check the fault/interrupt registers? Also scope shots of the power up can help as well.

Thanks!

Phil

Hi Phil,

I apologize for the delayed response as we were waiting for the arrival of other boards.

Now we are able to stable 1.8V after removing Buck 2(1.8V) sequence dependencies with buck 3 (1.2V)  

'' SEQ_TRIG_BUCK2 Register (Address = Eh)''

Can you please assist me in understanding this?

Regards,

Rishabh

Hi Rishabh,

  TPS650330-Q1 is a GPN; what's the OPN you're using so I can check its NVM? 

Thanks!

Phil

Hi Phil,

The complete Part no. is TPS650330QRGEQ1.

Regards,

Rishabh 

Hi Rishabh,

  I'll try to have a bench test before answering your questions.

Thanks!

Phil