Figure 12 in the datasheet shows how to make a linear sawtooth.Hello,
You will need a sawtooth generator to create theb wanted effect.
The signal of a 555 will not be linear.
On this page of the EDUCYPEDIA you will find some links to the schematics:
http://educypedia.karadimov.info/electronics/analogsquare.htm
Bertus
by Aaron Carman
by Aaron Carman
by Aaron Carman
by Jake Hertz