Hello,
I am an electrical engineering student and taking an advanced circuits class.
I have been tasked to design a circuit from a given H(s) transfer function. The guidelines I must operate within are using:
- an op-amp
- resistors ranging from 100Ω to 10MΩ
- capacitors ranging from 200pF to 10μF.

The given transfer functions are:

H1(s) = (0.1s + 6000)/(s + 1200)
H2(s) = 60000/(s+500)^2

Any insight or help in to this problem would be greatly appreciated.

 

Hello,

I found this post in "the completed projects forum", where it will stay "moderated" (invisible to others).
As it says it is for completed projects and not for questions.
I moved it over here and made it visible, so others can reply on the post.

As it looks like homework, what have you done to get a solution?

Bertus

 

I only looked because I'm completely useless at this and hoped to learn from somebody else's answer.

 

Is this for the design of an active filter?

 

The "S" terms would seem to indicate that. Hoping aje35 responds.

 

The first one looks like a lag filter, or more appropriately a lag-lead, which means the lag is dominant. The second one looks like a critically damped 2nd order low pass filter.

 

H1(s) = (0.1s + 6000)/(s + 1200)

Find the DC gain of the transfer function (when s\(\rightarrow\)0)
In this case that gives 6000/1200 = 5

You also have a pole at s = 1200 rad/sec
And a zero at 6000/0.1 = 60000 rad/sec
This is a low-pass shelving filter, so you could perhaps use the opamp to provide a gain of 5, and then follow it with this:

H2(s) = 60000/(s+500)^2

Here you have a DC gain of 0.24
And two poles at 500 rad/sec

You could perhaps use a filter like this:

which takes care of the DC gain and one pole, then follow it with a passive RC filter to give the second pole.