Introduction to Arduino - Arduino Sketches: Tools and Techniques for Programming Wizardry - page 15

To make the LilyPad as small and as light as possible, some sacrii ces were
made. The LilyPad does not have a voltage regulator, so it is vitally important to
deliver at least 2.7 volts, but more important, no more than 5.5 volts; otherwise,
the LilyPad will be destroyed (see Figure 1-10).
Figure 1-9: The Arduino Due
Figure 1-10: The LilyPad Arduino