TPS40210 Messy syntax in a formula on TI datasheet

Hi Jose,

I checked the formula and did not see any issue. Following the standard order of operations the equation works out as it should. This equation is generated from curve fitting which results in the relatively large equation. There's also not any way to simplify the equation further.

If you're having issues with the equation, please check the units used. Since RT is in kOhm the result would be 100 not 100000 for 100 kOhm. Same for fsw where 300 kHz should be 300 and not 300000 when used in the equation. Lastly 100 pF would be 100 and not 100 * 10^-12.

Best Regards,
Anthony

Thanks Anthony

I was thinking that they missed some parenthesis, because there are repeated terms, some of them which can be grouped, others appears many times while others could just be add the powers...

Sorry I understand that you say it's correct that way, could you just please tell me if it it this way?

RT = 1/(5.8E-8 * FSW * (CT + 8E-10) *((FSW^2)+1.4E-7)*(FSW-(1.5E-4)+(1.7E-6))*(CT-4E-9)*(CT^2));

or this way

RT = 1/(5.8E-8 * FSW * CT * (FSW^2) * FSW * CT * (CT^2) + (8E-10 + 1.4E-7 -1.5E-4 + 1.7E-6 -4E-9));

Thanks and my best regards

Oh man you're right! Thanks a lot, my apologies

No worries. Good to see it's worked out now.