TPSM84209: Output Capacitor Selection

Koshi Ninomiya

Part Number: TPSM84209

Hi Team,

There is the "Table 4. Minimum Required Output Capacitance" on page 13 of TPSM84209 datasheet. When Vout range is 5V-to-6V, minimum requirement Cout is 47 μF (1 x 47 μF ceramic).
If the customer wants to comprise combination of ceramic and polymer-type capacitors, is it OK?
Is it OK of combination of the 1uF ceramic and the 47uF polymer-type capacitor?
What is the minimum requirement of ceramic capacitance for the TPSM84209 application?
Thank you.

Best Regards,

Koshi Ninomiya

over 6 years ago

0 J Arrigo over 6 years ago

TI__Mastermind 28020 points

Hi Koshi,

The minimum required capacitance must be ceramic type, so a 47uF ceramic is required. Any additional capacitance can be ceramic or poly-tantalum type.

0 Koshi Ninomiya over 6 years ago in reply to J Arrigo

TI__Expert 5435 points

Hi J Arrigo san,

Thank you for your reply. Please let me confirm the following thing.
If the customer uses combination of a 1uF ceramic (for noise rejection) and a 47uF polymer-type capacitor to the output capacitor at Vout=5V, what is concern on the TPSM84209 application?

Best Regards,

Koshi Ninomiya

0 Shawn Nie over 6 years ago in reply to Koshi Ninomiya

TI__Genius 10070 points

Hi,

Yes, a 47uF polymer capacitor adding a 1uF ceramic cap is feasible.
Why does the customer want to replace the ceramic cap with polymer cap? What is the application?

Shawn

0 Koshi Ninomiya over 6 years ago in reply to Shawn Nie

TI__Expert 5435 points

Hi Shawn-san,

Because the availability issue of large capacitance (large size) ceramic capacitor in the market, the customer is considering to use that combination to the output capacitor.
Thank you.

Best Regards,

Koshi Ninomiya

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TPSM84209: Output Capacitor Selection