Feb 16, 2017 #1 ashrafsazid Advanced Member level 4 Joined Sep 17, 2016 Messages 104 Helped 1 Reputation 2 Reaction score 2 Trophy points 1,298 Location Germany Activity points 2,219 Hi, Can anybody please suggest me how to implement this block diagram using Capacitors? I tried but messed up because when I try with one gain coefficient, it changes the already calculated capacitance for other branch. Thanks
Hi, Can anybody please suggest me how to implement this block diagram using Capacitors? I tried but messed up because when I try with one gain coefficient, it changes the already calculated capacitance for other branch. Thanks
Feb 17, 2017 #2 pancho_hideboo Advanced Member level 5 Joined Oct 21, 2006 Messages 2,847 Helped 767 Reputation 1,536 Reaction score 733 Trophy points 1,393 Location Real Homeless Activity points 17,490 1+1.1+0.5=2.6 You have to scale down. a1=1/2.6 a2=1.1/2.6 a3=0.5/2.6 Assume Ctotal=C1+C2+C3=100fF C1/Ctotal=a1 C2/Ctotal=a2 C3/Ctotal=a3 After summation, you have to compensation of scale down. This is done by adjusting quantizer. If you use 1bit comparator, compensation is not needed. Last edited: Feb 17, 2017
1+1.1+0.5=2.6 You have to scale down. a1=1/2.6 a2=1.1/2.6 a3=0.5/2.6 Assume Ctotal=C1+C2+C3=100fF C1/Ctotal=a1 C2/Ctotal=a2 C3/Ctotal=a3 After summation, you have to compensation of scale down. This is done by adjusting quantizer. If you use 1bit comparator, compensation is not needed.
Feb 20, 2017 #3 ashrafsazid Advanced Member level 4 Joined Sep 17, 2016 Messages 104 Helped 1 Reputation 2 Reaction score 2 Trophy points 1,298 Location Germany Activity points 2,219 Hi Pancho, Thanks for your reply. Is the final configuration of this adder will be like this?
Feb 20, 2017 #4 pancho_hideboo Advanced Member level 5 Joined Oct 21, 2006 Messages 2,847 Helped 767 Reputation 1,536 Reaction score 733 Trophy points 1,393 Location Real Homeless Activity points 17,490 Wrong. Don't place Ctotal.
Feb 20, 2017 #5 ashrafsazid Advanced Member level 4 Joined Sep 17, 2016 Messages 104 Helped 1 Reputation 2 Reaction score 2 Trophy points 1,298 Location Germany Activity points 2,219 So is it like this only? as this following figure shows? Can you please give me some theoretical reference about this summer?
So is it like this only? as this following figure shows? Can you please give me some theoretical reference about this summer?
Feb 20, 2017 #6 pancho_hideboo Advanced Member level 5 Joined Oct 21, 2006 Messages 2,847 Helped 767 Reputation 1,536 Reaction score 733 Trophy points 1,393 Location Real Homeless Activity points 17,490 ashrafsazid said: So is it like this only? as this following figure shows? Click to expand... Correct. ashrafsazid said: Can you please give me some theoretical reference about this summer? Click to expand... Consider simple voltage division. Assume G1, G2, G3 instead of C1, C2, C3. Vout=(G1*Vin1+G2*Vin2+G3*Vin3)/(G1+G2+G3) Next replace G1, G2, G3 with s*C1, s*C2, s*C3. Here s means Laplace operator. Vout=(C1*Vin1+C2*Vin2+C3*Vin3)/(C1+C2+C3)=a1*Vin1+a2*Vin2+a3*Vin3 a1=C1/Ctotal a2=C2/Ctotal a3=C3/Ctotal Ctotal=C1+C2+C3 If you would like to care about parasitic capacitance, add Cparasitic to summation node. Ctotal=C1+C2+C3+Cparasitic You have to understand capacitance summation requires charge and discharge using by swicth. Last edited: Feb 20, 2017
ashrafsazid said: So is it like this only? as this following figure shows? Click to expand... Correct. ashrafsazid said: Can you please give me some theoretical reference about this summer? Click to expand... Consider simple voltage division. Assume G1, G2, G3 instead of C1, C2, C3. Vout=(G1*Vin1+G2*Vin2+G3*Vin3)/(G1+G2+G3) Next replace G1, G2, G3 with s*C1, s*C2, s*C3. Here s means Laplace operator. Vout=(C1*Vin1+C2*Vin2+C3*Vin3)/(C1+C2+C3)=a1*Vin1+a2*Vin2+a3*Vin3 a1=C1/Ctotal a2=C2/Ctotal a3=C3/Ctotal Ctotal=C1+C2+C3 If you would like to care about parasitic capacitance, add Cparasitic to summation node. Ctotal=C1+C2+C3+Cparasitic You have to understand capacitance summation requires charge and discharge using by swicth.