TPSM84624: Calculating RTT

user6004480

Part Number: TPSM84624

Tool/software:

Hi expert,

When we calculate RTT using Equation 3 in D/S, should we also consider the deviation of VOUT and CO(eff)?
If we should consider the deviation, Should we adopt the MAX values of VOUT and CO(eff) so that the RTT value is larger?

6 months ago

0 Amod Vaze 6 months ago

TI__Mastermind 26780 points

Please use the steady state DC VOUT you are designing for. For effective Cout, check DC bias characteristics from manufacturer and use that value for the DC VOUT you’re designing for.

Thanks,

Amod

0 user6004480 6 months ago in reply to Amod Vaze

Intellectual 630 points

Hi Amod,

Thank you for reply!

Please let us confirm just to be sure.

Don't we also need to consider COUT capacitance tolerance to calculate the RTT value?
Is it okay to adopt the typical value of Cout and calculate the effective Cout by considering the DC bias characteristics for the typical value of COUT?

0 Calan Elaya 6 months ago in reply to user6004480

TI__Genius 11325 points

Hello,

Amod will respond to this in couple days.

Thanks,

Calan

0 Amod Vaze 6 months ago in reply to user6004480

TI__Mastermind 26780 points

Yes, typical value of Cout with DC bias based effective value is good for this eqn. The variation in Cout value will slightly change the crossover frequency as expected. As long as the phase margin is sufficient in +/-10% region of the typical crossover frequency, this will work.

Thanks,

Amod

+1 user6004480 6 months ago in reply to Amod Vaze

Intellectual 630 points

Hi Amod,

Thank you for reply !

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TPSM84624: Calculating RTT