TPS6594-Q1: LDO Total capacitance at output higher than recommended

Peter Fritzenschaft

Part Number: TPS6594-Q1

Hello,

TPS6594-Q1 data sheet SLVSEA7B recommends a maximum total capacitance of 20uF at LDO3 Output (COUT_TOTAL (LDOn)).
TI Evaluation Board PROC078 001 J721EXSOMG01EVM has approximately 100uF at LDO3 Output.
AM6x/DRA8x/TDA4x Schematic Checklist Tool recommends to follow EVM decoupling strategy, which means the total capacitance at LDO3 output is significantly greater than recommended in the PMIC datasheet.

Can you confirm that the used values on the Eval Board are ok?

Regards, Peter

over 1 year ago

0 Nicholas McNamara over 1 year ago

TI__Mastermind 20257 points

Hello Peter,

due to the amount of traffic on E2E, please expect a delay in the response for this question.

BR,

Nicholas

+1 Nicholas McNamara over 1 year ago in reply to Nicholas McNamara

TI__Mastermind 20257 points

Hello Peter,

So very sorry for the late reply.

In short, yes, explanation below.

This capacitance is based upon is based all conditions the LDO and to maintain the stability.

Now the 20uF figure is after derating of the capacitors and to include the no current situation.

So this is fine, but after derating 50uF can be had (hence the 100uF), but there needs to be a load.

What we recommend is placing a small bleed resistor to achieve a pull of 1mA.

BR,

Nicholas

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TPS6594-Q1: LDO Total capacitance at output higher than recommended