Mixed Signal Frequency Response ?

Hi altogether,

we do have a mixed signal filter design, concerning of digital logic in
verilog and analog devices (transistors,caps,resistors).
Is there a way to simulate the transfer characteristic of this design for
different input frequencies ?
The Spectre Simulator is not usable due to the digital logic.
AMS is (as far as I know) not capable of doing sweeps for a defined source.

Any ideas ?

Regards,

Stefan

P.S: A lot of software is available like IUS 5.4 and IC5.1.41

 

Hi Stefan,

It rather depends on the kind of filter it is. If it is a matter of digital
control logic which is not doing some DSP, then you can use IC5141 USR1
together with IUS54 and do an AMS Designer simulation where you can do a
transient to get the circuit into the right state, and then an AC analysis
from there. This is supported in the AMS Designer in ADE flow, and can also be
done in the AMS Designer in HED flow by adding the ac analysis into your
simulation control file by hand. In both cases you'd need a source in the
design with "mag" set to indicate the small signal input voltage.

If however the digital logic is part ofthe filter, then you'll have to do
transient analyses for a variety of input signals and then FFT the result.
Hard to be more precise without knowing the specifics.

Regards,

Andrew.