74LS123 DIP Dual Retriggerable One-Shot With Clear and Complementary Outputs
The 74LS123 is a high speed TTL integrated circuit containing two independent retriggerable monostable multivibrators. Each multivibrator is designed to generate an output pulse of a specific duration when triggered. Because it is retriggerable, an additional trigger pulse received during the timing cycle will restart the pulse period, allowing for the creation of continuous output pulses or pulse width modulation.
This IC features three separate trigger inputs per section, including two active low and one active high input, providing flexibility for positive or negative edge triggering. The device also includes an overriding direct clear input that can terminate the output pulse immediately. The output pulse width is precisely controlled by the selection of an external resistor and capacitor, making it an essential component for timing, sequencing, and delay applications in digital systems.
KEY FEATURES
- Dual independent retriggerable monostable multivibrators
- Overriding asynchronous clear for immediate pulse reset
- Multiple trigger inputs for edge sensitivity selection
- Complementary outputs providing both true and inverted pulses
- Low power Schottky technology for high speed timing
- Standard 16 pin dual in line package format
SPECIFICATIONS
- Supply Voltage 4.75V to 5.25V
- Operating Temperature 0 to 70 Celsius
- Logic Type TTL Low Power Schottky
- Minimum Input Pulse Width 40ns
- Typical Propagation Delay 28ns
- High Level Output Current -0.4mA
- Low Level Output Current 8mA
INTERFACES
- 1A Trigger input active low
- 1B Trigger input active high
- 1CLR Clear input active low
- 1REXT CEXT External timing resistor and capacitor
- 1CEXT External timing capacitor
- 1Q Pulse output true
- 1QBAR Pulse output inverted
- 2A Trigger input active low
- 2B Trigger input active high
- 2CLR Clear input active low
- 2REXT CEXT External timing resistor and capacitor
- 2CEXT External timing capacitor
- 2Q Pulse output true
- 2QBAR Pulse output inverted
- VCC Positive supply voltage
- GND Ground reference
