ahgu
Full Member level 3
reduce 120hz harmonics?
My TL074 OPAMP has gain of 40dB, and I see 10-20mV of 120hz, 240hz harmonics at the output. I think my ground noise is at 0.1mV, the LDO says it has 30-40uV RMS. Is it a good ground plane with noise of 0.1mV? I think I did the layout pretty good with ground plane and signal separation.
But the 120hz harmonics is a little too high and shows up on the speaker, how can I remove or reduce the harmonics?
And is it possible to reduce the ground noise even lower?
thanks
ahgu
My TL074 OPAMP has gain of 40dB, and I see 10-20mV of 120hz, 240hz harmonics at the output. I think my ground noise is at 0.1mV, the LDO says it has 30-40uV RMS. Is it a good ground plane with noise of 0.1mV? I think I did the layout pretty good with ground plane and signal separation.
But the 120hz harmonics is a little too high and shows up on the speaker, how can I remove or reduce the harmonics?
And is it possible to reduce the ground noise even lower?
thanks
ahgu