Monostable Multivibrator using Op-Amp

In the realm of electronics, the monostable multivibrator stands as a fundamental building block used in various circuits for its ability to generate a single output pulse for a specified duration in response to an external trigger. When implemented using operational amplifiers (op-amps), these circuits showcase stability and precision in producing timed pulses. Monostable multivibrator is one popular circuit system used in digital electronics system. Other multivibator types include bistable multivibrator using transistors and astable multivibrator using transistors.

What is a Monostable Multivibrator?

A monostable multivibrator, often referred to as a "one-shot" circuit, has one stable state and another quasi-stable state. Upon receiving an external trigger, it temporarily switches from its stable state to the quasi-stable state for a predetermined period before returning to its stable state.

Op-Amps in Monostable Multivibrators

Implementing monostable multivibrators using op-amps involves utilizing the op-amp's characteristics to create a stable and predictable output pulse. The op-amp, with its high gain and precise operational abilities, forms the core of this circuit.

Basic Components:

  1. Operational Amplifier (Op-Amp): Acts as the primary component for amplification and switching.
  2. Resistors and Capacitors: Utilized to set the timing characteristics of the pulse generated.
  3. Trigger Input: An external signal or pulse that initiates the transition to the quasi-stable state.
  4. Output: The resulting pulse signal with a defined duration.

Circuit Design:

monostable multivibrator using op-amp

 The component values can be calculated using the online monostable multivibrator calculator.

The configuration of an op-amp-based monostable multivibrator typically follows a few key steps:

  1. Input Trigger: When a trigger signal is applied, it momentarily drives the op-amp output to a different state.
  2. Capacitor Charging: The capacitor in the circuit charges or discharges based on the op-amp's output.
  3. Output Pulse: The output generates a pulse for a specific duration, determined by the RC time constant (resistor-capacitor values) in the circuit.
  4. Return to Stable State: After the predetermined time elapses, the circuit automatically returns to its stable state.


  1. Precision Timing: Op-amps ensure accuracy in pulse duration due to their stable characteristics.
  2. Reliability: These circuits offer reliable operation, critical for various timing applications.
  3. Ease of Design: With well-defined equations governing timing, designing these circuits becomes systematic.


The versatility of monostable multivibrators using op-amps finds applications across various domains:

  • Pulse Generation: Useful in generating precise timing pulses for digital circuits or triggering events.
  • Delay Circuits: Employed in systems requiring timed delays between operations.
  • Instrumentation: Utilized in measurement and control systems where precise timing is crucial.


Monostable multivibrators like the astable multivibrator with op-amp and bistable multivibrator with op-amp can be constructed with op-amps and stand as indispensable electronics elements, offering precision, reliability, and versatility in generating timed pulses. Their application spans across industries and serves as a cornerstone in numerous electronic systems, showcasing the power and efficiency of op-amp-based circuit design. Understanding these circuits and their operational principles can greatly benefit engineers and enthusiasts exploring the realms of electronic timing and control.

Post a Comment

Previous Post Next Post