GC User tool at Nat Semi

[jackinnj]

National Semi put up a user tool spreadsheet for the Overture Series chip-amps on their website:
http://www.national.com/appinfo/audio/files/Overture_Design_Guide13.xls

just plug in the variables in the blue cells and NatSemi does the rest.

 

[Pedja]

Before the start, it is not bad to read this.

Pedja

 

[Hybrid fourdoor]

After reading the Bridged and Parrallel document over at national that correspondse with this tool I discovered that there seems to be a contradiction between the two. In the document it says that in parrallel mode the formula for R(load) as seen by each IC is (number of IC's)*(speaker load), so a 1ohm speaker is like a 4 ohm load with a 4 IC parrallel circuit, however in the excell sheet you can clearly see above that it is doing (speaker load) / (number of IC's) so a 4 ohm load would be 1 ohm to each IC with previous example.

Which one is right?

 

[peranders]

The right thing is that each amp contributes less if there are many in parallel = the amp sees a lower load (higher impedance)