We follow the datasheet's equation and below conditions, we can get the result of the Cin that is 0.34uF by datasheet 8.2.2.8
Iout(max)=0.26A,D=0.5,Fsw=380kHz,deltaVcin=0.5V
Cin=3.42*10e-7=0.34uF
However, when we download the calculator tool(LM5007QickStartCalculator) and the calculated result is 3.4uF. Please help to clarify which is correct one? Very thanks.