multiple clock qpss
Hi,
In fact, both autonomous and driven(non-autonomous) circuits can be successfully simulated with PSS but you need to be aware of how to configure the simulation. I quote following from the spectreRF manual. Just a moment ago, I have simulated a SC circuit with PSS, QPSS (with periodic clock signal and sinsoid input). All you need to do is simply "do not supply the pair of nodes in PSS".
=====================================================
The PSS analysis works with both autonomous and driven circuits.
*Autonomous (non-driven) circuits are time-invariant circuits with time-varying responses. Thus, autonomous circuits generate non-constant waveforms even though they are not driven by a time-varying stimulus.The most common autonomous circuit is an oscillator.
*Driven (non-autonomous) circuits require some time-varying stimulus to generate a time-varying response. Some common driven circuits include amplifiers, filters, mixers, and so on.
For autonomous circuits, since they do not have drive signals and you do not know the actual period of oscillation in advance, you estimate the oscillation period and the PSS analysis computes the precise period along with the periodic solution waveforms. PSS analysis of an autonomous circuit, requires you to specify a pair of nodes, p and n. In fact this is how PSS analysis determines whether it is being applied to an autonomous or a driven circuit. If the pair of nodes is supplied, the PSS analysis assumes the circuit is autonomous; if not, the circuit is assumed to be driven. See Chapter 5, "Simulating Oscillators," for an example.
For driven circuits, you specify either the period of the analysis, the period parameter, or its corresponding fundamental frequency, the fund parameter. The period parameter value must be an integer multiple of the period of the drive signals.
The errpreset parameter works differently for autonomous (non-driven) and driven (non-autonomous) circuits. For detailed information, see "The errpreset Parameter in PSS Analysis".