TPS54540: TPS54540, equation difference between datasheet and TPS54360-361FAMILY_CALC_TOOL_REVE

Stephan Schade

Part Number: TPS54540

In the Datasheet the equations 7 and 8 maybe incorrect, in the Excel-Sheet "TPS54360-361FAMILY_CALC_TOOL_REVE" the RT and f_sw are swapped (calculating the Resistor that determine the Clock frequency).

My Question: Wich equation is correct? in datasheet or in the Excel-Sheet?

over 6 years ago

0 Katelyn Wiggenhorn over 6 years ago

TI__Genius 11040 points

I understand and see the discrepancy that you are describing. I will forward your question to the product expert, and we will provide feedback.

Best Regards,
Katelyn Wiggenhorn

0 Robert Blattner over 6 years ago in reply to Katelyn Wiggenhorn

TI__Expert 6245 points

Hello Stephan,

The equations in the data sheet and the spreadsheet are derived from the curves shown in the “Typical Characteristics” section of the datasheet. Any calculation should be checked using these plots.

Regards, Robert

0 Stephan Schade over 6 years ago in reply to Robert Blattner

Prodigy 150 points

Hello Robert

Sorry but that don´t answered my Question.

My concern is the discrepance between the Datasheet and the Spreadsheet.

The Formula in the Datasheet (to calculate the Resistor for the Switching Frequency) is different to the Formula in the Spreadsheet!

Regards Stephan.

0 Robert Blattner over 6 years ago in reply to Stephan Schade

TI__Expert 6245 points

Hello Stephan,

The calculator needs to be updated; the datasheet is correct.

Regards, Robert

0 Stephan Schade over 6 years ago in reply to Robert Blattner

Prodigy 150 points

Hello Robert
OK, Thank you.
I have one more Question.
Is the Calculating of the Resistors in the Webbench correct, the Values of the calculator Spreadsheet (the non updated) are the same like in the Webbench.

0 Robert Blattner over 6 years ago in reply to Stephan Schade

TI__Expert 6245 points

Hello Stephan,

Webench agrees with the datasheet equation and plots. Only the calculator spreadsheet is wrong.

Regards, Robert

Power management

Power management forum

TPS54540: TPS54540, equation difference between datasheet and TPS54360-361FAMILY_CALC_TOOL_REVE