Transistor-Transistor Logic (TTL) Monostable Multivibrators

Reviewed by: Jon Lowy, consulting engineer

Description

Transistor-Transistor Logic (TTL) Monostable Multivibrators are electronic circuits designed to produce a single output pulse of a specific duration in response to an external trigger signal. They are used to standardize pulse widths and ensure consistent timing in digital circuits.

Working Principle

TTL Monostable Multivibrators operate by switching between two states: a stable state and a temporary unstable state. When triggered, the circuit transitions from its stable state to the unstable state, generating an output pulse. The duration of this pulse is determined by external components such as resistors and capacitors. Once the pulse duration elapses, the circuit returns to its stable state. This functionality is useful for creating precise timing intervals and ensuring that digital systems respond predictably to input signals.

Applications

TTL Monostable Multivibrators are commonly used in digital circuits where precise timing is crucial. Specific examples include pulse width modulation, debouncing mechanical switches, and generating time delays in communication systems. They are also employed in timing applications such as frequency counting and pulse generation for testing and measurement equipment.

Advantages over other Monostable Multivibrators

One advantage of TTL Monostable Multivibrators is their compatibility with TTL logic levels, which makes them easy to integrate into existing TTL-based systems. They also offer relatively fast switching times and low power consumption compared to other types of monostable multivibrators, such as those based on CMOS technology.

Limitations

TTL Monostable Multivibrators have limitations in terms of pulse duration accuracy, which can be affected by temperature variations and component tolerances. Additionally, they may not be suitable for applications requiring very long pulse durations, as the external components needed to achieve these durations can become impractically large.

Considerations

When selecting TTL Monostable Multivibrators, consider the initial cost of the components, which is generally low due to their widespread availability. Operating expenses are minimal, but it's important to account for potential variations in pulse duration due to environmental factors. Durability is typically high, but accuracy can be a concern if precise timing is critical. Replacement and maintenance costs are usually low, but regular calibration may be necessary to ensure consistent performance in sensitive applications.

23 Results
Monostable Multivibrators -- 1450828 [SN74LS221N from Texas Instruments Standard Linear and Logic]
from RS Components, Ltd.

Dual monostable multivibrator,SN74LS221N [See More]

  • Logic Family: TTL; LS
  • Propagation Delay: 80
  • Number of units in IC: 2
  • Operating Current: 4.7
SN54121 Monostable Multivibrators With Schmitt-trigger Inputs -- 5962-9755301QCA
from Texas Instruments

Monostable Multivibrators With Schmitt-trigger Inputs 14-CDIP -55 to 125 [See More]

  • Logic Family: TTL; TTL
  • Package Type: Other; CDIP,CFP
  • Supply Voltage: 4.75
  • Propagation Delay: 80
Dual non-retriggerable monostable multivibrator with reset -- 74HCT221D,112
from Nexperia B.V.

The 74HCT221 is a dual non-retriggerable monostable multivibrator. Each multivibrator features edge-triggered inputs (nA and nB), either of which can be used as an enable input. Pulse triggering occurs at a particular voltage level and is not directly related to the transition time of the input... [See More]

  • Logic Family: TTL; TTL
  • Supply Voltage: 5V; 4.5 - 5.5
  • Type: Retriggerable
  • Features: Master Reset; ESD Protection
9601FMQB
from Rochester Electronics

9601 - Monostable Multivibrator, 96 Series, 1-Func, TTL, CDFP14 [See More]

  • Logic Family: TTL
  • Package Type: Other; CFP14
Monostable Multivibrators -- 307632 [SN74LS123N from Texas Instruments Standard Linear and Logic]
from RS Components, Ltd.

Dual monostable multivibrator,SN74LS123N [See More]

  • Logic Family: TTL; LS
  • Propagation Delay: 56
  • Number of units in IC: 2
  • Operating Current: 12
SN54123 Retriggerable Monostable Multivibrators -- JM38510/01203BEA
from Texas Instruments

Retriggerable Monostable Multivibrators 16-CDIP -55 to 125 [See More]

  • Logic Family: TTL; TTL
  • Supply Voltage: 4.75
  • Type: Retriggerable
  • Package Type: Other; CDIP,CFP
Dual retriggerable monostable multivibrator with reset -- 74AHCT123ABQ,115
from Nexperia B.V.

The 74AHC123A; 74AHCT123A is a dual retriggerable monostable multivibrator with reset. The basic output pulse width is programmed by selection of external components (REXT and CEXT). Once triggered this basic pulse width may be extended by retriggering either of the edge triggered inputs (nA or... [See More]

  • Logic Family: TTL; TTL
  • Supply Voltage: 5V; 4.5 - 5.5
  • Type: Retriggerable
  • Features: Master Reset; ESD Protection
9601PC [9601PC from onsemi]
from Rochester Electronics

Monostable Multivibrator, 96 Series, 1-Func, TTL [See More]

  • Logic Family: TTL
  • Package Type: DIP; Other; DIP14
SN54221 Dual Monostable Multivibrators With Schmitt-trigger Inputs -- 5962-8771101EA
from Texas Instruments

Dual Monostable Multivibrators With Schmitt-trigger Inputs 16-CDIP -55 to 125 [See More]

  • Logic Family: TTL; TTL
  • Package Type: Other; CDIP
  • Supply Voltage: 4.75
  • Propagation Delay: 80
Dual retriggerable monostable multivibrator with reset -- 74AHCT123APW,112
from Nexperia B.V.

The 74AHC123A; 74AHCT123A is a dual retriggerable monostable multivibrator with reset. The basic output pulse width is programmed by selection of external components (REXT and CEXT). Once triggered this basic pulse width may be extended by retriggering either of the edge triggered inputs (nA or... [See More]

  • Logic Family: TTL; TTL
  • Supply Voltage: 5V; 4.5 - 5.5
  • Type: Retriggerable
  • Features: Master Reset; ESD Protection
DM74LS123SJ [DM74LS123SJ from onsemi]
from Rochester Electronics

Monostable Multivibrator, LS Series, 2-Func, TTL, PDSO16 [See More]

  • Logic Family: TTL
  • Package Type: SOP; Other; SOP16
SN74121 Monostable multivibrator with Schmitt-trigger inputs -- SN74121D
from Texas Instruments

Monostable multivibrator with Schmitt-trigger inputs 14-SOIC 0 to 70 [See More]

  • Logic Family: TTL; TTL
  • Package Type: Other; PDIP,SO,SOIC
  • Supply Voltage: 5V; 4.75
  • Propagation Delay: 80
Single retriggerable monostable multivibrator; Schmitt trigger inputs -- 74LVC1G123DC,125
from Nexperia B.V.

The 74LVC1G123 is a single retriggerable monostable multivibrator with Schmitt trigger inputs. Output pulse width is controlled by three methods: The basic pulse is programmed by selection of an external resistor (REXT) and capacitor (CEXT). Once triggered, the basic output pulse width may be... [See More]

  • Logic Family: TTL; CMOS; CMOS/LVTTL
  • Supply Voltage: 1.8V; 2.5V; 3V; 3.3V; 3.6V; 5V; 1.65 - 5.5
  • Type: Retriggerable
  • Features: Schmitt Trigger; ESD Protection
JM38510/31403B2A [JM38510/31403B2A from Texas Instruments High-Performance Analog]
from Rochester Electronics

Monostable Multivibrator, Retriggerable with Clear, TTL [See More]

  • Logic Family: TTL
  • Package Type: Other; CLCC20
  • Type: Retriggerable
SN74221 Dual monostable multivibrators with Schmitt-trigger inputs -- SN74221N
from Texas Instruments

Dual monostable multivibrators with Schmitt-trigger inputs 16-PDIP 0 to 70 [See More]

  • Logic Family: TTL; TTL
  • Package Type: Other; PDIP,SO
  • Supply Voltage: 5V; 4.75
  • Propagation Delay: 80
Single retriggerable monostable multivibrator; Schmitt trigger inputs -- 74LVC1G123DP,125
from Nexperia B.V.

The 74LVC1G123 is a single retriggerable monostable multivibrator with Schmitt trigger inputs. Output pulse width is controlled by three methods: The basic pulse is programmed by selection of an external resistor (REXT) and capacitor (CEXT). Once triggered, the basic output pulse width may be... [See More]

  • Logic Family: TTL; CMOS; CMOS/LVTTL
  • Supply Voltage: 1.8V; 2.5V; 3V; 3.3V; 3.6V; 5V; 1.65 - 5.5
  • Type: Retriggerable
  • Features: Schmitt Trigger; ESD Protection
SN74123N [SN74123N from Texas Instruments High-Performance Analog]
from Rochester Electronics

Monostable Multivibrator, TTL/H/L Series, 2-Func, TTL, PDIP16 [See More]

  • Logic Family: TTL
  • Package Type: DIP; PDIP; Other; PDIP16
Single retriggerable monostable multivibrator; Schmitt trigger inputs -- 74LVC1G123GN,115
from Nexperia B.V.

The 74LVC1G123 is a single retriggerable monostable multivibrator with Schmitt trigger inputs. Output pulse width is controlled by three methods: The basic pulse is programmed by selection of an external resistor (REXT) and capacitor (CEXT). Once triggered, the basic output pulse width may be... [See More]

  • Logic Family: TTL; CMOS; CMOS/LVTTL
  • Supply Voltage: 1.8V; 2.5V; 3V; 3.3V; 3.6V; 5V; 1.65 - 5.5
  • Type: Retriggerable
  • Features: Schmitt Trigger; ESD Protection
SN74LS123D [SN74LS123D from Texas Instruments High-Performance Analog]
from Rochester Electronics

Monostable Multivibrator, LS Series, 2-Func, TTL, PDSO16 [See More]

  • Logic Family: TTL
  • Package Type: SOIC; Other; SOIC16
Single retriggerable monostable multivibrator; Schmitt trigger inputs -- 74LVC1G123GS,115
from Nexperia B.V.

The 74LVC1G123 is a single retriggerable monostable multivibrator with Schmitt trigger inputs. Output pulse width is controlled by three methods: The basic pulse is programmed by selection of an external resistor (REXT) and capacitor (CEXT). Once triggered, the basic output pulse width may be... [See More]

  • Logic Family: TTL; CMOS; CMOS/LVTTL
  • Supply Voltage: 1.8V; 2.5V; 3V; 3.3V; 3.6V; 5V; 1.65 - 5.5
  • Type: Retriggerable
  • Features: Schmitt Trigger; ESD Protection
SN74LS123DBR [SN74LS123DBR from Texas Instruments High-Performance Analog]
from Rochester Electronics

Monostable Multivibrator, LS Series, 2-Func, TTL, PDSO16 [See More]

  • Logic Family: TTL
  • Package Type: SOP; SSOP; Other; SSOP16
Single retriggerable monostable multivibrator; Schmitt trigger inputs -- 74LVC1G123GT,115
from Nexperia B.V.

The 74LVC1G123 is a single retriggerable monostable multivibrator with Schmitt trigger inputs. Output pulse width is controlled by three methods: The basic pulse is programmed by selection of an external resistor (REXT) and capacitor (CEXT). Once triggered, the basic output pulse width may be... [See More]

  • Logic Family: TTL; CMOS; CMOS/LVTTL
  • Supply Voltage: 1.8V; 2.5V; 3V; 3.3V; 3.6V; 5V; 1.65 - 5.5
  • Type: Retriggerable
  • Features: Schmitt Trigger; ESD Protection
Bidirectional Monostable Multivibrator -- 8T20/E,F
from Lansdale Semiconductor, Inc.

The digital 8T series is a standard TTL compatible family of interface circuits that is used in such applications as line driving and receiving, tri-state buses, "party line" bus systems, driving LEDs and other displays, MOS interface and a variety of timing circuits and special purpose buffer... [See More]

  • Logic Family: TTL
  • Number of units in IC: 1
  • Package Type: DIP (optional feature); Other (optional feature); Lead Flat Pack
  • Number of Pins: 16