Cadence® system design and verification solutions, integrated under our System Development Suite, provide the simulation, acceleration, emulation, and management capabilities.
System Development Suite Related Products A-Z
Cadence® digital design and signoff solutions provide a fast path to design closure and better predictability, helping you meet your power, performance, and area (PPA) targets.
Full-Flow Digital Solution Related Products A-Z
Cadence® custom, analog, and RF design solutions can help you save time by automating many routine tasks, from block-level and mixed-signal simulation to routing and library characterization.
Overview Related Products A-Z
Driving efficiency and accuracy in advanced packaging, system planning, and multi-fabric interoperability, Cadence® package implementation products deliver the automation and accuracy.
Cadence® PCB design solutions enable shorter, more predictable design cycles with greater integration of component design and system-level simulation for a constraint-driven flow.
An open IP platform for you to customize your app-driven SoC design.
Comprehensive solutions and methodologies.
Helping you meet your broader business goals.
A global customer support infrastructure with around-the-clock help.
24/7 Support - Cadence Online Support
Locate the latest software updates, service request, technical documentation, solutions and more in your personalized environment.
Cadence offers various software services for download. This page describes our offerings, including the Allegro FREE Physical Viewer.
Get the most out of your investment in Cadence technologies through a wide range of training offerings.
This course combines our Allegro PCB Editor Basic Techniques, followed by Allegro PCB Editor Intermediate Techniques.
Virtuoso Analog Design Environment Verifier 16.7
Learn learn to perform requirements-driven analog verification using the Virtuoso ADE Verifier tool.
Exchange ideas, news, technical information, and best practices.
The community is open to everyone, and to provide the most value, we require participants to follow our Community Guidelines that facilitate a quality exchange of ideas and information.
It's not all about the technlogy. Here we exchange ideas on the Cadence Academic Network and other subjects of general interest.
Cadence is a leading provider of system design tools, software, IP, and services.
I am simulating a chopper stabilized opamp circuit in which I need to
do noise analysis. As
the biasing point is changing with time periodically, I need to do PSS
analysis and for Noise PNoise analysis. As I am changing my minimum
frequency of the signal beat frequency is getting changed but every time
am getting a peak in noise plot at 1KHz only. It is irrespective of all
frequencies in circuit. In circuit signal frequency is around 500Hz and
clock frequency is arounf 1MHz.
This peak is coming only at 1KHz only. What is wrong, being done by me during simulation ?
It's hard to tell what your setup is. Maybe a picture of the PSS form would help? (you can attach it via the Options tab when posting). Also if you can paste the options and analysis statements from the bottom of your input.scs, that would help.
In reply to Andrew Beckett:
Here I send the netlist of the circuit.
In reply to kapiljainwal:
Generally speaking when analysing the noise of a clocked system, you would do the PSS analysis with just the clock present, and not a large-signal input present too. This means it will then do a small-signal analysis of the noise with the aliasing and noise folding caused by the sampled data system itself - and will also be a lot faster as you then don't need to include the 1kHz signal in the PSS solution.
If you do include the 1kHz signal as a large signal input, you'll be able to see the intermodulation of the noise with this large 1kHz signal too - normally that's only important if the large signal input is large enough to create distortion - because then you might get intermodulation with these distortion harmonics which could impact the noise performance - but for most normal situations there's no need to have the large signal input. Think about how you'd analyse the noise for an opamp; you wouldn't normally have a large-signal input present at the same time.
If you do have 1kHz signal input, this will cause flicker noise to mix with the 1kHz signal and its harmonics. Given that flicker noise is infinite at 0Hz (as it is 1/f), you'll end up with an "infinite" (or very large) noise at multiples of 1kHz. Since your frequency sweep may not exactly hit the multiples of 1kHz, you'll probably just see peaks.
So I'd try again without the 1kHz large signal being present.