TPS25830A-Q1: Calculation of Buck Average Current Limit

Yuta Kurimoto

Part Number: TPS25830A-Q1

Hello Team,

I have 2 questions as below. Can you please answer?

Q. For the Equation 7, is there any deviation about the "0.5" and "0.0007"?

Q. For the VCSP-VCSN/OUT spec, the datasheet show the 2 examples when RLIMIT=13k or 26.1k. In case customer want to use other RLIMIT value, they want to the VCSP-VCSN/OUT. Do you have the "RLIMIT" vs "VCSP-VCSN/OUT" graph?

Thanks,

Yuta Kurimoto

over 4 years ago

0 Bob Ma over 4 years ago

TI__Expert 8980 points

Hi, Yuta-san,

Q1. This equation is calibrated by test data. What do you mean of deviation about the "0.5" and "0.0007".

Q2. Sorry we don't have "RLIMIT" vs "VCSP-VCSN/OUT" graph, what for do you think customer need CSP-CSN of other RILIMT.

Regards,

Bob

0 Yuta Kurimoto over 4 years ago in reply to Bob Ma

TI__Genius 10630 points

Hello Bob,

Thanks for your answer.

For Q1 customer want to know each variation like 0.5 ± _% or 0.0007 ± _%. They also want to know the mathematical meaning of each value.

Regards,

Yuta Kurimoto

+1 Bob Ma over 4 years ago in reply to Yuta Kurimoto

TI__Expert 8980 points

Hi, Yuta-san,

0.5 means Iset is divided equally into IMON and IILIMT as below diagram shows. 0.0007 is to calibrate the calculate result to match the test result. The variation will be small and can be reflected at CSP-CSN data variation.

Regards,
Bob

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TPS25830A-Q1: Calculation of Buck Average Current Limit