Simple Chipamp calculator (excel spreadsheet).

[armstrom]

I was crunching some numbers to determine what size power transformer I want to buy for my LM3886 so I decided to create a spreadsheet to make life easy. Sine so many people here are interested in the LM3886 (and other chip amps) I decided to share in case anyone finds it useful.

I provide two types of calculations:

The top table allows you to specify how you want the amp to perform (output wattage into what speaker impedance and with what input sensitivity) and calculates what your rail voltages should be and what to set your feedback-to-ground resistor to in order to achieve the desired characteristics.

The bottom table allows you to specify how your amp is configured (rail voltages, speaker impedance, feedback loop resistors, etc...) and it will tell you what your  output power, gain and input impedance are.

For all calculations I also provide gain in Av and dB as well as peak output voltage and peak output current.
Simply type your known/desired values into the top (blue) section of either table and the values will update in the bottom section.

Please see the notes for additional info.

I would appreciate any comments and/or suggested improvements.
-Matt

[Jack1962]

Cool , I'll check it out  :tu: