Spreadsheet for calculation of Buck Converter Parameters

[vilela]

Hi, everyone!

Based on the article "Buck-Converter Design Demystified", Danilo, an undergraduate student that works with me, has created a spreadsheet that does most of the math (to edit the input parameters, please download a copy).

We are now looking for opinions and tips on how to improve the worksheet.

Also, we hope the spreadsheet helps some of you. For further details on the topic, please read <**broken link removed**>.

 

[treez]

bst thing is to remember thaan in a buck , like virtually all hard switched smps you only have two shapes of current waveform to worry about.....
1..triangle = the buck inductor current
2 = trapezoid = the diode and fet currnt shapes.

so just get the standard formula for their rms and average, and you are done.

As with any converter, dangerous to rely on one fixed sheet...do separate sheet for every design...then you do not miss anything......

start with pout vout and iout

then get est efficiency

then get pin

then get I(in) average = pin/vin

(do this at vin min

then you know input current is trapezoid....

and you know average of trapezoid is D(IPK+IPED)/2

ETC ETC

YOU MAKE THE SHeet out every time...you do not just throw sheet in there, if you do you miss something and mistake is there.

 

[BradtheRad]

Excellent!

Comments:

* 'Resistance' is spelled correctly in some places, incorrectly in other places.

* 'Reverse transfer capacitance'. Its pop-up information is in a different language than the spreadsheet is in.

* Your Farad values show several zeroes after the decimal point. It will be easier on your readers if you automatically multiply by 10^6 and state the units in uF.

* 'Capacitor output voltage' is not explained. (Cell E23) Is it the same as ripple voltage? It has the value 0.0006341295755 V (cell E27), which is less than a mV. This looks like an insignificant amount.

* ESR on the other hand (0.01874565258 Ohm, in cell K27), by itself will cause a greater voltage rise, as much as several hundredths of a volt, during each cycle when several amperes go through it.