the relationship between integrators and low pass filters

[foreverloves]

what is the relationship between integrators and low pass filters?

can we say integrators are the basis of low pass filters?

if i designed a integrator, how can i design a low pass filter based on it??


many many thanks!!!!!

 

[surreyian]

Re: the relationship between integrators and low pass filter

integrator as LPF.

if u have a 10KHz (=100us) square pulse signal.
now u have a signal 100Khz (=10us) coming into it. 10x of 10us will fix into 100us. integratin this 10us will give a 0. because the starting point and the ending point are the same, hence intergrator acts as a LPF

 

[foreverloves]

Re: the relationship between integrators and low pass filter

integrator as LPF.

if u have a 10KHz (=100us) square pulse signal.
now u have a signal 100Khz (=10us) coming into it. 10x of 10us will fix into 100us. integratin this 10us will give a 0. because the starting point and the ending point are the same, hence intergrator acts as a LPF

thank you for your reply!

but I am still puzzled

"if u have a 10KHz (=100us) square pulse signal.
now u have a signal 100Khz (=10us) coming into it."

what do you mean? a signal come into another signal?

 

[hsez]

I think an integrator is a 1st order LPF.
You can cascade some integrators to behave as
a high order LPF.

 

[jinxingsun]

You can understand the integrator by the numbers of poles!

 

[foreverloves]

Re: the relationship between integrators and low pass filter

if the transfer function is H(s)=A/s, the integrator has one pole,right?
I have no idea if there exist any kind of integrators which have more than one pole.

for a first order low pass filter, the transfer function is H(s)=A/(1+Bs) , it also has one pole

then what do you mean by understand integrator by the number of poles?

thank you!!

 

[ree]

Re: the relationship between integrators and low pass filter

if the integerator equation is H(s)=A/s (and s=jw)
if you draw it in the frequency domain it'll give you LPF

 

[co_aa]

Re: the relationship between integrators and low pass filter

integrator is a/S, in freq domain, it is straight line from very high(f->0) to very low(f->large) with -20db/dec

low pass filter a/(s+b), from dc to b(rad/s), gain is a,
after b(rad/s), it is -20db/dec straight line

so you can think lowpass as low freq, pass; high freq, reject;
but integrator is low freq, huge gain; high freq, reject.