#avr Logs

Feb 12 2020

12:28 AM * nuxil yawns
01:00 AM nuxil: Im trying to simulate|make a sallen "butterworth" low pass filter with a cutoff freq at around 4.5 KHz
01:01 AM nuxil: but man. why is Ltspice taking such a dump on me. when i do simulate it, i get a fc of 3.8KHz. 700Hz below what i want.
01:01 AM nuxil: https://i.gyazo.com/03894bb607b5aed5c44599b842968a50.png
01:02 AM nuxil: what have i done wrong.? i dont expect a perfect result. but 700Hz off i was to much.
01:03 AM nuxil: *was -> way
04:01 AM davor_ is now known as davor
08:21 AM rue_bed: IIR?
08:34 AM rue_bed: actual analog?
10:07 AM nuxil: yes analog.
10:12 AM nuxil: mic -> filter -> adc -> dft -> shiftregister ->blink leds
10:12 AM nuxil: :p
10:13 AM nuxil: well. thats the idea.
10:17 AM nuxil: 4.5khz cut off might be a bit high though. i might tune that down a bit. but ltspice is not simulating my filter well. annoys me.
10:27 AM nuxil: i know ltspice is not simulating the perfect opamp. "unless you make one". but this filert i posted earlyer has like over 15% error compared to the math on the paper
07:05 PM rue_mohr: ah
07:19 PM nuxil: are you working on any projects at the moment?
11:54 PM day__ is now known as day