This type of source can be either a voltage or a current source. We often use it as a stimulus for transient response simulation of a circuit. It should never be used in a frequency response study because the model assumes it is in the time domain. The designation of the pulse source starts as any other independent source; i.e., the part name must begin with the letter V (for voltage) or I (for current). This is followed by the node names. Then, instead of "DC" or "AC," we use the keyword "PULSE" followed by the necessary parameter list. Items in the parameter list may be separated by spaces or commas. An example of a pulse type of voltage source follows:
The parameters for the pulse (to be entered in the order given) are:
V1 is the value when the pulse is not "on." This can be zero or negative as required. For a pulsed current source, the units would be "amps" instead of "volts."
V2 is the value when the pulse is fully turned on. This can also be zero or negative. (Obviously, V1 and V2 should not be equal.) Again, the units would be "amps" if this were a current pulse.
Td is the time delay. The default units are seconds. The time delay may be zero, but not negative.
Tr is the rise time of the pulse. PSpice allows this value to be zero, but zero rise time may cause convergence problems in some transient analysis simulations; i.e., there is a very good reason for the existence of this parameter. The default units are seconds.
Tf is the fall time in seconds of the pulse. See note on Tr before setting this to zero.
Tw is the pulse width. This is the time in seconds that the pulse is fully on.
Period is the total time in seconds of the pulse. Be aware that the pulse repeats if the simulation time exceeds the period.
Tidak ada komentar:
Posting Komentar