Mar 9, 2006 #1 A ambition Junior Member level 2 Joined May 28, 2005 Messages 20 Helped 0 Reputation 0 Reaction score 0 Trophy points 1,281 Activity points 1,483 I want the cufoff of the LPF to be 5kHz ... my question is how can I choose the Rs and Cs? I have calculated the w which is 1/(2*pi* 5k) but the result is very small can someone explain to me , how can I come up with the resistors and capacitors values ? thanks
I want the cufoff of the LPF to be 5kHz ... my question is how can I choose the Rs and Cs? I have calculated the w which is 1/(2*pi* 5k) but the result is very small can someone explain to me , how can I come up with the resistors and capacitors values ? thanks
Mar 9, 2006 #2 J jcpu Full Member level 4 Joined Dec 17, 2005 Messages 214 Helped 18 Reputation 36 Reaction score 5 Trophy points 1,298 Activity points 2,968 Hello, information here could be helpful: http://www.circuitsage.com/filter.html Calculation gives R~10KOHm and C~several nF These are reasonable for board level implementation.
Hello, information here could be helpful: http://www.circuitsage.com/filter.html Calculation gives R~10KOHm and C~several nF These are reasonable for board level implementation.
Mar 9, 2006 #3 Davood Amerion Advanced Member level 2 Joined Mar 1, 2005 Messages 579 Helped 116 Reputation 232 Reaction score 24 Trophy points 1,298 Location Persia Activity points 6,345 check below links: http://www.ecircuitcenter.com/Circuits/opsalkey1/opsalkey1.htm **broken link removed**
check below links: http://www.ecircuitcenter.com/Circuits/opsalkey1/opsalkey1.htm **broken link removed**
Mar 9, 2006 #4 M mpig09 Full Member level 4 Joined Aug 26, 2005 Messages 232 Helped 8 Reputation 16 Reaction score 2 Trophy points 1,298 Location Taipei Activity points 2,810 Dear ambition : please use transfer function of the low pass filter to simulate with Matlab , you can find the valid value for every R & C !! mpig09
Dear ambition : please use transfer function of the low pass filter to simulate with Matlab , you can find the valid value for every R & C !! mpig09
Mar 9, 2006 #5 J jlee Member level 2 Joined Feb 8, 2006 Messages 53 Helped 7 Reputation 14 Reaction score 1 Trophy points 1,288 Activity points 1,884 This is a Active Biquad Sallen-Key Low-Pass Filter. The equations to find the poles, wp and Qp are being taught in Berkeley's EE247 ADC class. Please refer to the lecture note: **broken link removed** Slide #4.
This is a Active Biquad Sallen-Key Low-Pass Filter. The equations to find the poles, wp and Qp are being taught in Berkeley's EE247 ADC class. Please refer to the lecture note: **broken link removed** Slide #4.
Mar 10, 2006 #6 M mircea Member level 1 Joined Sep 7, 2005 Messages 38 Helped 4 Reputation 8 Reaction score 2 Trophy points 1,288 Location Romania Activity points 1,598 fc=1/(2*3.1415*R*C)=5kHz just choose 2 values convenient for you which verify the formula above. rgds, M
fc=1/(2*3.1415*R*C)=5kHz just choose 2 values convenient for you which verify the formula above. rgds, M
Mar 10, 2006 #7 Z zenisle Full Member level 2 Joined Sep 11, 2005 Messages 127 Helped 4 Reputation 8 Reaction score 2 Trophy points 1,298 Activity points 1,987 equations to find the poles, wp and Qp are being taught