The IC 4538 is a Dual Monostable Multivibrator with an independently controlled trigger and reset. The device can be triggered and reset, and the control inputs are latched internally. There are two trigger inputs to allow for either rising or falling edge triggering. The reset inputs are active LOW, preventing triggering while they are active.

Using linear CMOS techniques, precise control of output pulse width was achieved. External components RX and CX determine pulse duration and precision. On power-down, the device does not allow the timing capacitor to drain through the timing pin. As a result, no extra protection resistor in series with the timing pin is required. On all pins, static discharge protection is provided.