[sdiy] Square to Sine

[Magnus Danielson]

Hi Elain,

On 04/04/2017 04:09 PM, Elain Klopke wrote:
>
>     If you use an op-amp as buffer (filter output to + input, output to
>     - input) such as TL-072 you won't have much drop to worry about.
>
>     For pass-band you will have essentially no loading from the caps,
>     and the op-amp will do nothing, so you will be close to unity gain
>     then for the pass-band. It all depends on how the cut-off corner of
>     the filter depends on the base frequency of the signal. If you think
>     the loss will be a little too much, alter the feedback of the buffer
>     op-amp to that of an amplifier with two resistors allows for the
>     needed gain without making the design too complex.
>
>
> I'm assuming that the circuit would go something like this: output from
> PIC -> RC network chain -> Non-inverting amplifier -> 4066 switch matrix
>
> I'm thinking the non-inverting amp since the resistors for the gain
> aren't dependent on the resistors involved in the filter networks.
> Unless of course I'm entirely wrong on how that works...

Exactly. Straight and simple.

Cheers,
Magnus