Decoupling capacitors should be ceramic type of a stable dielectric. For lower value capacitance, it is appropriate to use Class 1 dielectric capacitors, C0G (also referred to as NPO). Class 2 X7R should be used for the larger values. It is
recommended that 0.01-µF and 0.001-µF capacitors be used to decouple supply pins nearest the pair of USB transceiver circuits. The 0.001-µF should be C0G dielectric. This will help decouple the power supply at the frequency range of highspeed USB switching. The other power supply pins should be decoupled with 0.1-µF X7R capacitors. It is important to have short trace runs for the power and ground connections from the EZ-USB FX2 component to solid power and ground planes.
The specific recommendation for the ceramic capacitor nearest each EZ-USB FX2 power pin is shown in the table below:
|QFN PIN NUMBER||CAPACITOR VALUE||QFN PIN NUMBER||CAPACITOR VALUE|
|7||.01 uF||43||.1 uF|
|11||.001 uF||55||.1 uF|
|17||.1 uF||3||.1 uF|
|27||.1 uF||3||.22 uF|