*HELP regards AC,DC and transient Analysis
.AC -- Perform an Small Signal AC Analysis Linearized About the DC Operating Point.* The small signal(linear) AC portion of LTspice computes the AC complex node voltages as a function of frequency. First, the DC operating point of the circuit is found. Next, linearized small signal models for all of the nonlinear devices in the circuit are found for this operating point. Finally, using independent voltage and current sources as the driving signal, the resultant linearized circuit is solved in the frequency domain over the specified range of frequencies. This mode of analysis is useful for filters, networks, stability analyses, and noise considerations. Syntax: .ac <oct, dec, lin> <Nsteps> <StartFreq> <EndFreq> The frequency is swept between frequencies StartFreq and EndFreq. The number of steps is defined with the keyword "oct", "dec", or "lin" and Nsteps according to the following table: Keyword Nsteps Oct No. of steps per octave Dec No. of steps per decade Lin Total number of linearly spaced steps between StartFreq and EndFreq *.DC -- Perform a DC Source Sweep Analysis* This performs a DC analysis while sweeping the DC value of a source. It is useful for computing the DC transfer function of an amplifier or plotting the characteristic curves of a transistor for model verification. Syntax: .dc <srcnam> <Vstart> <Vstop> <Vincr> + [<srcnam2> <Vstart2> <Vstop2> <Vincr2>] The <srcnam> is either an independent voltage or current source that is to be swept from <Vstart> to <Vstop> in <Vincr> step sizes. In the following example, the default BSIM3v3.2.4 characteristic curves are plotted: * Example .dc sweep * M1 2 1 0 0 nbsim Vgs 1 0 3.5 Vds 2 0 3.5 .dc Vds 3.5 0 -0.05 Vgs 0 3.5 0.5 .model nbsim NMOS Level=8 .save I(Vds) .end *.TRAN -- Perform a Nonlinear Transient Analysis* Perform a transient analysis. This is the most direct simulation of a circuit. It basically computes what happens when the circuit is powered up. Test signals are often applied as independent sources. Syntax: .TRAN <Tstep> <Tstop> [Tstart [dTmax]] [modifiers] .TRAN <Tstop> [modifiers] The first form is the traditional .tran SPICE command. Tstep is the plotting increment for the waveforms but is also used as an initial step-size guess. LTspice uses waveform compression, so this parameter is of little value and can be omitted or set to zero. Tstop is the duration of the simulation. Transient analyses always start at time equal to zero. However, if Tstart is specified, the waveform data between zero and Tstart is not saved. This is a means of managing the size of waveform files by allowing startup transients to be ignored. The final parameter dTmax, is the maximum time step to take while integrating the circuit equations. If Tstart or dTmax is specified, Tstep must be specified. On Thu, Mar 10, 2011 at 3:05 PM, SanK <[email protected]> wrote: > I am a beginer in Electric EDA . > Can anyone please tell me how to do ac,dc & transienet analysis of an > inverter in Electric EDA. > > -- > You received this message because you are subscribed to the Google Groups > "Electric VLSI Editor" group. > To post to this group, send email to [email protected]. > To unsubscribe from this group, send email to > [email protected]. > For more options, visit this group at > http://groups.google.com/group/electricvlsi?hl=en. > > -- _ _ Thanks and Kind Regards: ATEEQ UR REHMAN SHAHEEN (2009-06-0002) MS Computer Engineering Lahore University of Management Sciences Cell# 03339116747 -- You received this message because you are subscribed to the Google Groups "Electric VLSI Editor" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/electricvlsi?hl=en.
