74123 Dual Retrigger able 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.
Features:
- Contains Two Independent Retrigger able Monostables.
- DC Triggering from Active-High or Active-Low Inputs.
- Overriding Clear Terminates Output Pulse.
- Output Pulse Duration Controlled by External RC Network.
- Complementary Outputs (Q and Q̅).
- Standard Plastic DIP-16 Package.
Specifications:
| Parameter | Specification |
|---|---|
| Technology Family: | Standard TTL (74) |
| Supply Voltage (Vcc): | 4.75V to 5.25V |
| Logic Level – High (Vih): | 2.0V (Min) |
| Logic Level – Low (Vil): | 0.8V (Max) |
| Operating Temperature: | 0°C to 70°C |
| Propagation Delay (Typ): | 33 ns |
| Output Current (High): | -800 μA |
| Output Current (Low): | 16 mA |
| External Timing Resistor (Rext): | 5 kΩ to 25 kΩ |
| External Capacitance (Cext): | No restriction |
| Package: | DIP-16 |
Pinout Diagram:
Footprint Diagram:
Applications:
- Pulse Stretching.
- Timing Circuit Generation.
- Frequency Division.
- Switch Debouncing.
- Sequential Timing Systems.
Package Contents:
- 1x SN74123N Dual Retrigger able Monostable Multivibrator With Clear DIP-16 IC
