LP87525-Q1: Rise time/ Fall time of SW pins

Cedrick

Part Number: LP87525-Q1

Hi,

Good day. I hope you are well.

Our customer want to know what is the acceptance criteria for the rise time and fall time for SW pins of LP87525BRNFRQ1. I'll copy below their exact inquiry so no words would be lost. I would appreciate your help on this matter.

"we need the Acceptance criteria for Rise time and Fall time at all SW pins for Testing purpose

I am doing functionality testing at SW pin , we will measure Rise,Fall, Switching frequency , Duty cycle amplitude
for Switching frequency data is found in datasheet , for Duty cycle and amplitude we can calculate
but rise time, fall time i don't know how to list the acceptance criteria."

I hope you could help us on providing this information. Thank you.

Regards,

Cedrick

over 3 years ago

0 Layne J over 3 years ago

TI__Genius 12735 points

Hi Cedrick,

I have assigned your thread to the expert for this part. They are located in Europe so please accept a delay in their response until tomorrow.

Best regards,

Layne J

0 Tomi Koskela over 3 years ago

TI__Genius 11020 points

Hello,

Rise/fall times depend on the PCB parasitics and whether they have snubbers on the board for SW nodes. So there is no definitive answer for min max values for this. Typically we see about 1...2ns rise/fall times in our EVM to give idea on the magnitude.

Thanks.

Regards,

Tomi Koskela

0 user4292095 over 3 years ago in reply to Tomi Koskela

Prodigy 50 points

ok, thanks for the information.

generally i had a doubt like why and what is the purpose to measure rise time and fall time at SW pin of regulator

0 Tomi Koskela over 3 years ago in reply to user4292095

TI__Genius 11020 points

Hello,

SW rise/fall times would show how much power is lost in SW transition. The slower the rise/fall times, the more switching losses there would be. Very high SW slew rates can cause EMI issues however.

Thanks.

Regards,

Tomi Koskela

Power management

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LP87525-Q1: Rise time/ Fall time of SW pins