Question: External loop compensation of MAX17502. The value of RZ calculated for the design in figure 9 of the datasheet comes out to 36kohm (6000 x 50000 x 10uF x 12V). But in the datasheet RZ=20kohm. Kindly explain the discrepancy in calculations
Answer : Rz is indeed set according to the formula. However the value used for CSEL in the equation should be the actual value of that O/P capacitor when the voltage across the O/P capacitance is 12V (the capacitance value of a ceramic capacitor decreases with increasing voltage across it - this decrease can be established from the capacitor manufacturers datasheet)