The 74LS123N is a Retriggerable Monostable Multivibrator with Reset from the 74LS series. Manufactured by Fairchild/ON Semiconductor, this device can be used to generate accurate output pulses of a specific duration upon triggering. The pulse width is determined by an external resistor (Rext) and capacitor (Cext). The device is retriggerable, meaning that if it receives another trigger input during the output pulse, the pulse is extended. The 74LS123N also features a reset input, which can be used to terminate the output pulse prematurely.

Applications

• Timing circuits
• Pulse delay generation
• Pulse stretching
• Missing pulse detection
• Sequential timing
• Anti-coincidence circuitry

Features

• Retriggerable monostable operation
• Pulse width control through external Rext and Cext
• Reset input for pulse termination
• TTL compatible inputs and outputs
• Wide supply voltage range
• High noise immunity

Benefits

• Provides accurate and stable output pulses
• Offers flexibility in pulse width adjustment
• Allows for synchronous or asynchronous pulse termination
• Ensures compatibility with other TTL logic devices
• Enables reliable operation in noisy environments
• Simplifies circuit design with minimal external components

Additional Details

The 74LS123N is designed to operate with a supply voltage of 5V. The pulse width (tw) is approximately equal to Rext * Cext, where Rext is in ohms and Cext is in farads. A wide range of resistor and capacitor values can be used to achieve desired pulse widths. The reset input is active-LOW, meaning that the output pulse is terminated when the reset input is brought LOW. The device has Schmitt-trigger inputs, which provide high noise immunity. The 74LS123N comes in a DIP (Dual In-line Package). It is commonly used in applications where accurate timing and pulse generation are required.

The 74LS123N monostable multivibrator is a reliable solution for many timing applications, offering flexibility and ease of use. Its retriggerable capability allows for the generation of extended pulses, while the reset function provides precise control over the output.