Decoupling capacitor

Summary
A decoupling Capacitor is typically used to avoid voltage fluctuation near ASICs. Placed Between the VCC and GND pins, this small value cap ensures that ASICs will not be affected by AC transients caused by other parts of the system. 0.1uF is a reasonable value for a decoupling capacitor.

PCB Placement
Decoupling capacitors should be placed as close as possible to the ASIC.