How many capacitance value should the IC connect as a decoupling capacitor?


We generally recommend that you connect the supply terminal with more than 0.1µF decoupling capacitor, when the supply voltage line is stability or does not describe its value in data sheet. Connecting 0.1µF decoupling capacitor can generally measure a static characteristics of IC.
You should connect with more than 0.1uF decoupling capacitor when the power supply line is unstable or the load transient occurs.
A decoupling capacitor describing in the data sheet is minimum capacitance to measure the static characteristics at a test circuit or a application circuit. You should design optimum values of decoupling capacitance by evaluating an electrical characteristics on the actual PCB, if you use the power control IC or high frequency signal control IC.