Reverse engineering the popular 555 timer chip (CMOS version)
NE555P Single Precision Timer Chip IC Impulsgenerator 4.5V-18V 10mA Compatible con TTL CMOS para electrodomésticos y juguetes eléctricos, 50 unidades : Amazon.es: Bricolaje y herramientas
ICM7555PAZ CMOS Timer - Altronics
TLC551 IC Timer - CMOS 555 with 1V to 15V power, up to 1.8MHz [TLC551CP] : ID 5222 : $3.95 : Adafruit Industries, Unique & fun DIY electronics and kits