Hi
can someone help me derive transfer function of low pass biquad 2nd order filter. The transfer function should be Vout/Vin but my problem is if all the positive inputs to the opAmps are grounded the Vout is then 0.
Example, for the first amp
V3 = A(V+ - V3)
V3/A = V+ - V3
lim(A) -inf
V+ = V3
if V+ is grounded then is 0 and V3 = 0.
Thanks
can someone help me derive transfer function of low pass biquad 2nd order filter. The transfer function should be Vout/Vin but my problem is if all the positive inputs to the opAmps are grounded the Vout is then 0.
Example, for the first amp
V3 = A(V+ - V3)
V3/A = V+ - V3
lim(A) -inf
V+ = V3
if V+ is grounded then is 0 and V3 = 0.
Thanks
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