The NE555D with Timers & Support Products SINGLE PRECISION TIMER is a precision timer manufactured by Texas Instruments. It is a dual-in-line packaged, 8-pin integrated circuit timer. It operates off of a single 5V supply with output voltage levels compatible with TTL logic. The NE555D offers a wide range of operating modes and adjustable timing range. Features include active low reset, adjustable duty cycle, selectable trigger and threshold levels and adjustable timing from microseconds to hours. It is suitable for use in many applications, such as oscillators, pulse generation, timers, delays and one-shot circuits.