/diy/ - Do It Yourself

Can anyone tell me how to get an FFT cutoff-style low-pass waveform out of passives and such? I want to get rid of the sharp edge at the start of the transition as well as at the end. I want a smooth waveform to minimise the bandwidth of amplitude-shift keying.

>>1664252
>dealing with the awful quiescent current, pinout, and inability to vary duty-cycle independently of frequency
>not using schmitt inverters and digital logic for timing purposes