4538 Dual Precision Monostable Multivibrator

A CD4538 CMOS integrated circuit providing a dual precision monostable multivibrator. Two retriggerable one-shot timers producing a precise pulse of a length set by an RC network. More accurate and stable than a 555 for pulse generation. Being 4000-series CMOS it runs on anything from 3 to 18 volts, which makes it far more flexible than 5V-only TTL logic and lets it work directly in battery and higher voltage circuits. It also draws almost no current when idle. The trade-off is speed: CMOS of this family is slower than 74HC logic, so it suits control, timing and teaching applications rather than fast data paths. Unused inputs must be tied to a supply rail, never left floating. Wide 3-18V supply range, unlike 5V-only TTL; Extremely low quiescent current suits battery circuits; High noise immunity from the wide logic swing; Standard 16-pin DIP fits breadboards and sockets