Continue to Site

Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

CT and DT signal processing

Status
Not open for further replies.

svensl

Full Member level 1
Joined
Mar 25, 2005
Messages
99
Helped
1
Reputation
2
Reaction score
0
Trophy points
1,286
Activity points
2,202
Hello all,

I was wonderig whether I can mix CT and DT processing blocks. For example. Consider a CT integrator Fs/s in series with discrete time differentiator 1-z^(-1). I would like to find the overall transfer function and am inclined to write the poduct of the two:
Fs/jw*(1-exp(-jwTs)) where Ts is the sampling time? Can I do this and mix CT and DT blocks?

sven
 

I don't think you can just multiply them direclty -- it would not make sense. It is like mixing apples and oranges. So you have to transform one of the transfer functions, then you can do the multiplication. For example, you can take the s-domain transfer function and use
the Tustin (Bilinear) Discretization. See page 3 of this document **broken link removed**

In this transformation you basically use the replacement
\[s=\frac{2}{T} \frac{z-1}{z+1}\]
where \[T\] is your sampling period.

This transformation is also available in Matlab. Take a look at the documentation for the
c2d function.
Code:
discap1 = c2d(contap,0.1,'tustin');
bode(contap,discap,discap1)

I hope this information will help you out.

Best regards,
v_c
 
Last edited by a moderator:

    svensl

    Points: 2
    Helpful Answer Positive Rating
Thanks v_c for this informaton. It was really helpful.
 

Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top