The ALD4501 timer is a high performance QUAD monolithic timing circuit built with advanced silicon gate CMOS technology. It offers the benefits of high input impedance, thereby allowing smaller timing capacitors and longer timing cycle; high speed with typical cycle time of 500ns; low power dissipation for battery operated environment; and reduced supply current spikes allowing smaller and lower cost decoupling capacitors. Each of the four timers can be independently operated in either the monostable, astable, or 50% duty cycle mode.