TPS826X output capacitor?

Christopher Dunn

The data sheet says “The TPS8267x is designed as a Point-Of-Load (POL) regulator, to operate stand-alone without requiring any additional capacitance.” It then mentions “Adding a 2.2μF ceramic output capacitor (X7R or X5R dielectric) generally works from a converter stability point of view, but does not necessarily help to minimize the output ripple voltage.”

Under what conditions would we add an output capacitor to the TPS826X?

Thank you,

Chris

over 12 years ago

0 Florian Feckl over 12 years ago

TI__Expert 7110 points

Hi Chris,

as the mentioned Datasheet section says, the TPS8267x is designed as a POL regulator. If it needs to power a rail that has e.g. additional distributed capacitors, the device handles this as well.

Do you see the need to increase your output capacitance?

Regards,

Florian

0 Christopher Dunn over 12 years ago in reply to Florian Feckl

Prodigy 60 points

Florian

In several locations the datasheet says that no output capacitor is needed, except for the sentence “adding a 2.2μF ceramic output capacitor (X7R or X5R dielectric) generally works from a converter stability point of view”. I don't understand under what load conditions would I require the additional capacitor?

Thank you,
Chris

0 Florian Feckl over 12 years ago in reply to Christopher Dunn

TI__Expert 7110 points

Chris,

basically there is no need to add an additional C_OUT. However, the device can handle an additional capacitor as well. E.g. when powering a rail with additional capacitance (caused by the layout or by the need of distributed capacitors), the device is capable of dealing with this.

Regards,

Florian

0 Christopher Dunn over 12 years ago in reply to Florian Feckl

Prodigy 60 points

Florian

OK that makes sense now.

Thank you for your help,

Chris

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TPS826X output capacitor?