DC Frequency

The DC Frequency sweep is a type of frequency sweep which may be added as a frequency entry in a Sweep Set in the Sweeps page of the Circuit Settings dialog box. A DC Frequency sweep is pictured below followed by definitions of the control fields.

This sweep type should be used if you only need data at a DC Point and do not wish to perform an adaptive sweep. If you will be using an Adaptive sweep, you may also automatically calculate a response at a DC point by specifying an ABS sweep whose starting frequency is zero, so there would be no need to specify this sweep.

The DC Frequency sweep analyzes your circuit at a low, non-zero frequency to approximate response data for the DC point. This type of response data is necessary for some circuit analysis tools. The DC analysis frequency may be calculated automatically by em, or input manually by the user. Select the Auto radio button if you wish the software to automatically choose the frequency. Select the Manual radio button and enter the desired frequency in the Frequency text entry box if you wish to set the frequency.

The low, non-zero frequency must be chosen carefully. If the frequency is too high, then the analysis is done at a point where the response of the circuit is greatly different than the true DC value. If the frequency is too low, then precision errors occur which produce faulty data. An algorithm is provided with your software to automatically calculate this frequency which has a 95% success rate.

Once the simulation is complete, the user should carefully review the DC point data for accuracy.

You may not calculate current density data for this type of sweep. If it is part of a Sweep Set with other frequency entries, and the current density data option is selected, the current density data is computed for the other frequency sweeps.