Oct 24, 2005 #1 R rocshrike Newbie level 2 Joined Oct 10, 2005 Messages 2 Helped 0 Reputation 0 Reaction score 0 Trophy points 1,281 Activity points 1,297 Do we need the -3dB frequence of opamp greater than the signal frequency? To reach a give resolution of Nyquist ADC, the DC gain of opamp must be greater than 2©(N-1), (according the book "mix signal design" by Baker), but if the -3dB frequency of opamp is smaller than the signal frequency, which means for this signal frequency, the gain is not enough to reach the required resolution.
Do we need the -3dB frequence of opamp greater than the signal frequency? To reach a give resolution of Nyquist ADC, the DC gain of opamp must be greater than 2©(N-1), (according the book "mix signal design" by Baker), but if the -3dB frequency of opamp is smaller than the signal frequency, which means for this signal frequency, the gain is not enough to reach the required resolution.
Oct 24, 2005 #2 W wsy979 Newbie level 6 Joined Dec 7, 2004 Messages 14 Helped 0 Reputation 0 Reaction score 0 Trophy points 1,281 Activity points 164 i think it is not a must i have done an OTA for S/H,it seems that the -3db bandwidth doesnot affect the error
i think it is not a must i have done an OTA for S/H,it seems that the -3db bandwidth doesnot affect the error
Oct 25, 2005 #3 S sunking Advanced Member level 3 Joined May 25, 2004 Messages 873 Helped 70 Reputation 140 Reaction score 23 Trophy points 1,298 Activity points 6,283 yes, it should greater than the signal frequency. Or it will generate gain error and INL&DNL
Oct 25, 2005 #4 W wsy979 Newbie level 6 Joined Dec 7, 2004 Messages 14 Helped 0 Reputation 0 Reaction score 0 Trophy points 1,281 Activity points 164 to dear sunking could u plz explain how the the -3db bandwidth generate the gain error or plz tell me what should i refer to for finding out the explanation thx regards
to dear sunking could u plz explain how the the -3db bandwidth generate the gain error or plz tell me what should i refer to for finding out the explanation thx regards