74123 retriggerable one-shot timing network Does the 74123 include an internal timing resistor, or must timing be set externally?

Introduction / Context:
The 74123 is a dual retriggerable monostable multivibrator commonly used to create precise pulses. Understanding whether timing components are internal or external affects design flexibility and accuracy.

Given Data / Assumptions:

• Device: 74123 (retriggerable one-shot).
• Question: presence of an internal timing resistor.
• Typical usage: external R and C define pulse width.

Concept / Approach:

Most retriggerable monostables in this family rely on an external resistor-capacitor network to set the output pulse width, allowing a wide range of timing values by component selection.

Step-by-Step Solution:

Verification / Alternative check:

Typical application schematics show explicit Rext and Cext connected to the timing terminals; varying either changes t_w, confirming external determination of timing.

Why Other Options Are Wrong:

“yes”: would imply a built-in fixed resistor limiting timing range; that is contrary to standard 74123 usage and pinouts where external components are required.

Common Pitfalls:

Confusing the 74123 with devices like the 74121 that may reference an internal resistor/current source convention in some variants; always consult the specific part's timing pins.

Final Answer:

no