74HC Series Logic
- NXP 74HC4538D, 652, The NXP 74HC4538 is a dual retriggerable/resettable monostable multivibrator. Each multivibrator has two pins (n REXT/CEXT & n CEXT) for connecting the external timing components CEXT & REXT. The multivibrator may be triggered by either the positive or the negative edges of the input pulse. NXP 74HC4538D, 652 Dual Monostable Multi-Vibrator SMD