The IC 4528 is a Dual Retriggerable Resettable/Monostable Multivibrator. It may be triggered from either edge of an input pulse and produces an output pulse over a wide range of widths, the duration of which is determined by the external timing components, CX and RX.

Each multivibrator has an active LOW input (nA), an active HIGH input (nB), an active LOW clear direct input (nCD), an output (nQ) and its complement (nQ), and two external timing components connecting pins (nCEXT, always connected to ground, and nREXT/CEXT).