74123 Dual Retriggerable Monostable Multivibrator With Clear DIP-16 IC

The 74123 is a monolithic integrated circuit that contains two independent retrigger able monostable multivibrators in a single DIP-16 package. A monostable multivibrator, also known as a “one-shot,” is a circuit that produces a single output pulse of a predetermined duration each time it is triggered by an external signal. This chip is designed to generate precise, timed intervals from transient input signals.

The device offers significant flexibility in how it is triggered and controlled. Each multivibrator features both active-low (A) and active-high (B) trigger inputs, allowing it to be initiated by either a rising or falling edge from gated logic signals. A key characteristic is its retrigger able capability, which allows the output pulse to be extended by applying a new trigger before the initial timing period expires. Furthermore, an overriding Clear input provides immediate termination of the output pulse.

The duration of the output pulse is not fixed internally but is programmed by connecting external timing components a resistor (R_T) and a capacitor (C_ext). This allows the pulse width to be tailored from nanoseconds to seconds, making the chip highly versatile. The output is provided in both true (Q) and complementary (Q̅) forms, offering additional logic flexibility for system design