How to use the piece-wise linear (PWL) voltage and current sources?
The piece-wise linear voltage sources allow you to describe a transient voltage waveform by connecting time-voltage pairs, which you define. The following are schematic parts that can be used, along with their property definitions:
Name: VPWL
Use: Piece-wise linear voltage source
Symbol Properties and example settings:
Properties:
Ti, where i=1,2..8. These are simulation time values.
Vi, where i=1,2..8. These are voltages corresponding to the simulation time values.
Example property settings:
T1=0s V1=1V
T2=10us V2=2V
T3=20us V3=3V
T4=22us V4=3V
T5=100us V5=10V
T6=110us V6=11V
T7=120us V7=12V
T8=200us V8=1V
Name: VPWL_ENH
Use: Piece-wise linear voltage source
Symbol Properties and example settings:
Properties:
FIRST_NPAIRS - First line containing PWL pairs, i.e. (time, voltage) pairs.
SECOND_NPAIRS - Second line containing PWL pairs, to be concatenated with FIRST_NPAIRS.
THIRD_NPAIRS - Third line containing PWL pairs, to be concatenated with SECOND_NPAIRS
REPEAT_VALUE - Number of times to repeat the specified PWL waveform
TSF - Time scaling factor (multiplies time values specified)
VSF - Voltage scaling factor (multiplies voltages specified)
Example property settings:
FIRST_NPAIRS=(0s,1V) (10us,2V) (20us,3V)
SECOND_NPAIRS=(22us,3V) (100us,10V) (110us,11V)
THIRD_NPAIRS=(120us,12V) (200us,1V)
REPEAT_VALUE=100
Name: VPWL_FILE
Use: Piece-wise linear voltage source
Properties:
FILE - Name of file containing PWL pairs
TSF - Time scaling factor (multiplies time values specified)
VSF - Voltage scaling factor (multiplies voltages specified)
Example property settings:
FILE=pwl.txt
where "pwl.txt" is a file in the design directly. The format of the file is as follows. Do not include a header line.
0s 1V
10us 2V
20us 3V
22us 3V
100us 10V
110us 11V
120us 12V
200us 1V
Name: VPWL_RE_FOREVER
Use: Piece-wise linear voltage source
Properties:
FIRST_NPAIRS - First line containing PWL pairs, i.e. (time, voltage) pairs.
SECOND_NPAIRS - Second line containing PWL pairs, to be concatenated with FIRST_NPAIRS.
THIRD_NPAIRS - Third line containing PWL pairs, to be concatenated with SECOND_NPAIRS
TSF - Time scaling factor (multiplies time values specified)
VSF - Voltage scaling factor (multiplies voltages specified)
Example property settings:
FIRST_NPAIRS=(0s,1V) (10us,2V) (20us,3V)
SECOND_NPAIRS=(22us,3V) (100us,10V) (110us,11V)
THIRD_NPAIRS=(120us,12V) (200us,1V)
Name: VPWL_RE_N_TIMES
Use: Piece-wise linear voltage source
Properties:
FIRST_NPAIRS - First line containing PWL pairs, i.e. (time, voltage) pairs.
SECOND_NPAIRS - Second line containing PWL pairs, to be concatenated with FIRST_NPAIRS.
THIRD_NPAIRS - Third line containing PWL pairs, to be concatenated with SECOND_NPAIRS
REPEAT_VALUE - Number of times to repeat the PWL waveform
TSF - Time scaling factor (multiplies time values specified)
VSF - Voltage scaling factor (multiplies voltages specified)
Example property settings:
FIRST_NPAIRS=(0s,1V) (10us,2V) (20us,3V)
SECOND_NPAIRS=(22us,3V) (100us,10V) (110us,11V)
THIRD_NPAIRS=(120us,12V) (200us,1V)
REPEAT_VALUE=100
Name: VPWL_F_RE_N_TIMES
Use: Piece-wise linear voltage source
Properties:
FILE - Name of file containing PWL pairs
REPEAT_VALUE - Number of times to repeat the PWL waveform
TSF - Time scaling factor (multiplies time values specified)
VSF - Voltage scaling factor (multiplies voltages specified)
Example property settings:
REPEAT_VALUE=100
FILE=pwl.txt
where "pwl.txt" is a file in the design directly. The format of the file is as follows. Do not include a header line.
0s 1V
10us 2V
20us 3V
22us 3V
100us 10V
110us 11V
120us 12V
200us 1V
Name: VPWL_F_RE_FOREVER
Use: Piece-wise linear voltage source
Properties:
FILE - Name of file containing PWL pairs
TSF - Time scaling factor (multiplies time values specified)
VSF - Voltage scaling factor (multiplies voltages specified)
Example property settings:
FILE=pwl.txt
where "pwl.txt" is a file in the design directly. The format of the file is as follows. Do not include a header line.
0s 1V
10us 2V
20us 3V
22us 3V
100us 10V
110us 11V
120us 12V
200us 1V
If you want to describe a current source, by entering time-current data, use the analogous parts:
IPWL, IPWL_ENH, IPWL_FILE, IPWL_RE_FOREVER, IPWL_RE_N_TIMES, IPWL_F_RE_N_TIMES, IPWL_F_RE_FOREVER
Name : VPWL_abm
For details please refer solution 11786012
Name : VPWL_File
For details please refer solution 11094668
Also of interest: Part Properties in the PSpice Help defines all of the user-defined properties on the PSpice schematic parts, and is a help to know which properties to set on the xPWLx symbols in the SOURCE libray.
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