The M55155/25XB02 is a radiation hardened, monolithic, CMOS programmable timer circuit. It features a versatile programmable counter and can be used to measure time intervals, generate time pulses, and produce an output pulse at a preset or programmable time. It includes an accurate oscillator, a Free-Running Counter, an Output Control, and a Programmable Time Selection Logic. The timer is capable of operating on a voltage range between 3V and 15V, and its power down control helps conserve energy when not in use. The device is ideal for industrial applications in space or other radiation-hardened environments.