TPS63031: tps63030 in power save mode with cc1350 launchpad

Davide Giovanelli

Part Number: TPS63031
Other Parts Discussed in Thread: CC1350, TPS63030

Hello,

I have a wireless sensor network based on cc1350 (subGHz). The system is build using the cc1350 launchpads equipped with a shield that does the power supply. The energy for the system comes from a standard li-poly battery and it is regulated to 3.3v by a tps63031 buck-boost regulator. The board is then powered through the expansion headers of the launchpads.

I had several issues in making the network to work and today finally I found the source of the problems which is the noise produced by the tps63030 when put in power save mode. In fact by disabling the tps63031 power save mode the nodes works perfectly, the same if the node is powered with other non-noisy regulator.

Of course disabling the PS is just a workaround, not the solution (the tps have about 2mA of idle current in this condition), so I'm trying to decide what to do. By checking the values of the passives I see that the inductor is 47uH while on the datasheet the suggested value is 1.5uH, can this cause problems such as excessive noise? Or did we choose the wrong dcdc for a sub-GHz application?

Thank you,

Davide.

over 6 years ago

0 Brigitte over 6 years ago

TI__Guru 65470 points

Hello Davide,

Yes, increasing the inductor by such a high factor will increase the noise in power save mode. Please check if the problems are gone when exchanging the inductor.

0 Milos over 6 years ago

TI__Expert 7925 points

Hi Davide,

We haven’t heard back so we're assuming this resolves your issue. If not, just post a reply below, or create a new thread if the thread has locked due to time-out.

Thanks and regards,
Milos

0 Davide Giovanelli over 6 years ago in reply to Milos

Expert 1275 points

Hi,

actually I haven't solved the problem, I ordered the correct inductors however I haven't received them yet.

For now I still with the 47uH inductor and the power save mode disabled, this setting does not affect the communication range compared to the plain launchpad (i.e. without the tps regulator).

As soon I receive the correct inductors I'll try with them and the PS mode enabled and I'll let you know. However, I'm still confused and I'm not sure whether the problem is the dcdc or in the software, or most likely both, for sure the correct component value will help.

I'll try to report progresses here.

0 Milos over 6 years ago in reply to Davide Giovanelli

TI__Expert 7925 points

Hi Davide,

Is there any update with a proper inductance value?

Best regards,
Milos

0 Davide Giovanelli over 6 years ago in reply to Milos

Expert 1275 points

Not yet. I've requested the order but you now, it has to pass through the purchase office and all the bureaucratic stuff of the company and this can take some time.

0 Davide Giovanelli over 6 years ago in reply to Davide Giovanelli

Expert 1275 points

So, 5 minutes after the last message I received the notification that the inductors had arrived at my company.

Everything seems to work, then the issue can be closed.

For other people reading this thread, I want to specify that in this project we had issues also on the software side, and I'm not 100% sure that the problem was hardware. To avoid problems just pick up the proper components!

0 Julian Hagedorn over 6 years ago in reply to Davide Giovanelli

TI__Mastermind 20900 points

Hi Davide,

thanks for the update. I will close this thread.

Regards,

Julian

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TPS63031: tps63030 in power save mode with cc1350 launchpad