EDA_hg81
Advanced Member level 2
adc ground bounce how to fix
I am working on a 12 bit ADC and the input voltage range is 0V to 5V.
At the front end only simple one pole RC ( 33ohm and 100pF )lows pass filter is implemented.
A 75K sine wave (with 20 mV amplitude) noise was noticed before I switched the cap value from 100 PF to 0.1UF.
Right now the 75K sine wave noise is gone but I still notice a high frequency noise 500K to 1.25MHZ with 20mV amplitude.
I am wondering what the problem is.
Why the low pass filter looks like a high pass filter?
Thanks.
I am working on a 12 bit ADC and the input voltage range is 0V to 5V.
At the front end only simple one pole RC ( 33ohm and 100pF )lows pass filter is implemented.
A 75K sine wave (with 20 mV amplitude) noise was noticed before I switched the cap value from 100 PF to 0.1UF.
Right now the 75K sine wave noise is gone but I still notice a high frequency noise 500K to 1.25MHZ with 20mV amplitude.
I am wondering what the problem is.
Why the low pass filter looks like a high pass filter?
Thanks.