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ADV7842 Bypass / Decoupling Capacitors on power supply pins

Question asked by lfoster on May 22, 2013
Latest reply on May 23, 2013 by lfoster

In User Guide 214, page 481, it says:

“It is recommended to bypass each power supply pin with a 0.1 uF and a 10 nF capacitor where possible. The fundamental idea is to have a bypass capacitor within about 0.5 cm of each power pin.”

 

In the "HDMI_RX_PowerSupplies_RevA_050411.pdf" document, it gives basically the same recommendations for cap values. "Decouple each pin with 10nF and 100nF capacitors as close to the pin as possible"

 

In the Evaluation Board Schematic, though, the Decoupling cap / Plane cap scheme is different. Here, we have a bunch of 220pF caps, labeled as "Plane Caps" and only a few of the 0.1uF & 10nF caps, labeled as "Decoupling Caps".

 

Which method is preferred? Thanks.

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