Reports a method of design 2nth-order Voltage-controlled Voltage Source(VCVS) low-pass filter

based on analyzing the error isogram by MathCAD

the paper put forward the optimal design plan of 2nth-order VCVS unit-gain Butterworth

f

0

Hz low-pass filter:firstly

decompose 2nth-order filter into n 2nd-order filters.For the ith one

if monomial coefficient of the polynomial exp

ression is

α

i

select two capacitances

C

1

i

and

C

2

i

making

C

2

i

/

C

1

i

0.25

α

i

2

and then calculate value of the two resistances by the same expression 1/

π

α

i

f

0

C

1

i

.Obviously

the design plan has the advantages of convenience

low-cost.And with the aid of Monte Carlo analysis

parameter sweep analysis and real circuit experiment the design plan has also been verified its advantage of stability.In addition

analysises also shows different

C

R

have different influence on the filter features.