TPS62827: Output capacitance requirements

Daniel De Sousa

Part Number: TPS62827
Other Parts Discussed in Thread: TPS62826,

Hi there, we use the TPS62826 in our design but due to supply chain issues are fitting in the TPS62827 instead. Do we have to change anything in our design?

Looking at the EVM, it looks like the TPS62827 adds an additional 10uF of capacitance on the output. Is this to support to additional current capability of the device (4A) ? To my knowledge, there is practically no difference between the TPS62827 and TPS62826 besides the current limit.

Our applications max output current requirement is 2A peak.

over 4 years ago

0 Febin over 4 years ago

TI__Mastermind 28020 points

Hi Daniel,

Yes, the TPS62826/7 has the same die and only the current limit differs.

If the same inductor is used in both the designs, then I don't see a problem if the additional 10uF Cout is not used.

However, I advise to confirm that the loop stability, transient performance and output ripple are still in accordance with the application requirements.

The additional 10uF Cout is recommended to ensure the guaranteed loop stability, transient performance and output ripple at 4A load.

Regards,

Febin

0 Daniel De Sousa over 4 years ago in reply to Febin

Intellectual 580 points

Do we need to perform this additional analysis if we are staying under 3A?

0 Febin over 4 years ago in reply to Daniel De Sousa

TI__Mastermind 28020 points

Hi Daniel,

I would suggest to at least check the loop stability.

Regards,

Febin

0 Daniel De Sousa over 4 years ago in reply to Febin

Intellectual 580 points

Please correct me if I am wrong but if it's the same die and we are using the same output current, how would the stability characteristics change?

Webench says that it is not needed:

0 Febin over 4 years ago in reply to Daniel De Sousa

TI__Mastermind 28020 points

Hi Daniel,

In the Webench model for TPS62827, the additional 10uF will not be populated by default even for full load. We need to add this manually.

And as I said earlier, I do not expect any problem when the minimum Cout is 22uF. It was a suggestion to confirm loop stability on the customer's board. But the customer is free to make a decision here.

Regards,

Febin

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TPS62827: Output capacitance requirements