HCF4541B is a monolithic integrated circuit produced by Honeywell Corporation. It is mainly used as a timer and uses metal oxide semiconductor technology. It has two packaging forms: DIP and SOP. The device consists of a 16-stage binary counter, an oscillator controlled by two external resistors and a capacitor, an output control logic and an automatic power-on reset circuit. The counter can change at the positive edge clock transition and can be cleared by the MASTER RESET input. The output of this timer is the Q or Q output from the 8th, 13th, or 16th counter stage. The choice of the stage depends on the time.