TPS548A20: VDD and VREG capacitor

K. Sasaki14

Part Number: TPS548A20

On TPS548A20 datasheet typical application circuit, VREG and VDD capacitor is 1uF.
However two parallel 1uF is set on EVM.

Does this mean VREG and VDD capacitor require greater than 1uF as a effective capacitance?

Best Regards,
Kohei Sasaki

over 7 years ago

0 JohnTucker over 7 years ago

TI__Guru**** 191445 points

We are looking into your request. We will get back to you soon.

0 JohnTucker over 7 years ago in reply to JohnTucker

TI__Guru**** 191445 points

No, It was there when we first design the EVM as a place holder but we only need one.

0 K. Sasaki14 over 7 years ago in reply to JohnTucker

Guru 10200 points

John-san,

What effective capacitance is required on VREG and VDD.
Is 0.5uF enough?

Best Regards,
Kohei Sasaki

0 JohnTucker over 7 years ago in reply to K. Sasaki14

TI__Guru**** 191445 points

Based on the system engineer, 1uF is enough for these 2 pins. The part number listed below is good. We’ve always recommended 1uF X7R when doing the schematic review and never had an issue unless the customer place these capacitors so for from the pin. As you already know, the location is important. I believe the place holder never got removed from the E1 to A version of the EVM.

GRM188R71C105KA12J C = .76 uF at 5 V and .28 uF at 14 V.

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TPS548A20: VDD and VREG capacitor