Hi I want to design a step up converter using lm2577with the following requirements: VinMin = 3.7 VinMax= 4.6V Vout = 5.5 V Iout=1A; Following the datasheet I made the following calculations: Ioutmax = 2.1 x 3.7 /5.5V =1.41 A wich is more than my 1A D= (5.5 + 0.5 - 3.7) /(5.5+0.5-0.6) = 0.41 = (0.19 * 47 uh * 2568 * 1.41)/ (3.7*5,5)= 1496 uF =1557uF and Cout >= 3.7 * 2000* 21.09 /(487,8 * 5 * 5 *5 )= about 2.5F to big in my opinion so If I choose the max (as datasheet suggest ) I should use 2.5F for Cout in order to have it working. What I'm doing wrong? Could you suggest the value of the external components in order to design this kind of boost DC-DC? Awaitng your kind reply Thanks a lot nico
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