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Design >> Analog Design >> Feedback system of resonator
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Message started by krishna95 on Jun 16^th, 2019, 8:31am

Title: Feedback system of resonator
Post by krishna95 on Jun 16^th, 2019, 8:31am

Hi, I am trying to simulate a feedback resonator system in cadence. It has two components besides input and output ports. Both these components are modeled using VerilogA and are connected in a feedback mode to enable a resonator option(figure attached). One of the components is a four port component that has two outputs and two inputs(input and feedback). one of the outputs goes to the feedback input.
I am trying to do a transient response simulation to understand the system dynamics. I have two questions.
1. The system is a feedback system. So I guess there should be a delay definition for simulation to run smoothly. But I don't get any error with the transient simulation(in figure attached). So I am not certain if the feedback is really working. How much I can trust this result?
2. How many times the signal (rotates)/moves in the feedback loop if the transient simulation time is set to say 1 ns? Does it have any relationship with the feedback duration?

Title: Re: Feedback system of resonator
Post by Ken Kundert on Jun 17^th, 2019, 9:45pm

Spectre, like SPICE, is an implicit differential equation solver. It correctly handles feedback without the need for any of the things you mention.

-Ken