TPS53353: TPS53353 is question about switching frequency, output capacitor and VDD VREG VBST capacitor recommend value.

Bob Lee62837

Mastermind 7230 points

Part Number: TPS53353

Dear support member,

My customer used TPS53353.

I have question.

Q1.
When using resistors other than Table 1 on page 14 of the datasheet, how much switching frequency?

For example, when it is 200 kΩ, how much kHz is the switching frequency?

Q2
About Output capacitor.

Is it possible to use ceramics capacitor at all in parallel, when placing a conductive polymer capacitor at the output capacitor?

If you have something like design guidelines,
Could you teach me?

Q3.
Could you teach me know the capacitor recommended values for VDD, VREG, VBST respectively.

Best regard.
Bob Lee.

over 7 years ago

0 JohnTucker over 7 years ago

TI__Guru**** 191445 points

Bob,
1. You should use the exact values shown in the table. If you use a value in between, you may get either the higher or lower switching frequency of the adjacent resistor values. You will not know which one you will get.
2. Are you asking about polymer and ceramic capacitors combined in parallel? If so you can do that, but you need to examine the output ripple. Usually, there will be enough ripple reduction that you will need to use the ripple injection circuit as shown in the datasheet section 8.2.2 and treat the design a s a ceramic output design. But it will depend on the actual combination you choose.
3. There is nothing you need to know here. Just use the recommended values.

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TPS53353: TPS53353 is question about switching frequency, output capacitor and VDD VREG VBST capacitor recommend value.