File format:pwl

pwl

Name	Piecewise linear function
Status	unsupported
Common extension(s)	.txt
ASCII format	yes
Compression	none

pwl is a file format that can be used to define the signal of voltage/current sources in a SPICE simulation.

Format

The file consists of multiple lines, where each line contains one time/value pair. The time values have to be in increasing order.

The content in the file is then accessed with the PWL file=… statement from the simulation.

PWL in different SPICE implementations

LTspice

• Description of PWL on the Linear Technology website.
• Additional information on LTwiki.

LTspice recognizes CR (0x0D), LF (0x0A) and CR+LF as newline indicator.
When editing the properties of a voltage/current source in the LTspice editor and choosing the PWL file, the "Open File" dialog uses "ASCII File (*.txt)" as the default filter (but the simulation can use every other file extension too).

• 

  green: AM signal imported using the PWL file=… statement.
  blue: Demodulated signal.

• 

  green: AM signal imported using the PWL REPEAT FOREVER file=… ENDREPEAT statement.
  blue: Demodulated signal.

• 

  Error during the simulation if the timestamps are not increasing.