How to create Spice / LTSpice repeatable damped sinusoid
[Sorry for the necromancy]

Even if it has been answered, there is a much simpler, better, and faster way to do it:



V2 acts as a control source who outputs pulses with very narrow Toff. V1 has the trigger keyword which allows an external source turn on V1 when V(ctl) &gt;= 0.5 and off when V(ctl) &lt; 0.5. The trigger voltage can also have a specified value, for example [...] trigger V(ctl)&lt;1.3. This provides an exact sine with an exact 1-exp(-x) decaying shape, set in V1.