mega 555The 555 block diagram represent the internal structure of 555. It contain a voltage divider, 2 comparators, SR flip-flop, output driver. The voltage divider produce 13 Vcc, 23 Vcc voltages.GA.555 (Toll Free in the U.S.). 818.255.7100. 866.494.7179 Technical Support. 866.349.0276 Music Searches. 818.255.7199 Fax. General Questions: info