NTE Electronics NTE74HC123

The NTE74HC123 is a dual monostable multivibrator in a 16-pin plastic DIP package, triggered by negative-to-positive reset pulses. External resistor (RX) and external capacitor (CX) control the timing and accuracy of the circuit. Adjusting RX and CX allows a wide range of pulse widths at the Q and Q̄ outputs. Pulse triggering at the Ā and B inputs occurs at specific voltage levels, independent of the rise and fall times of the trigger pulse.

Once triggered, the output pulse width can be extended by retriggering inputs Ā and B. The output pulse can be terminated by a low level on the reset (R) pin. Both trailing-edge triggering (A) and leading-edge triggering (B) inputs are provided, allowing triggering from either edge of the input pulse. If either monostable circuit is not used, each input (A, B, and R) of the unused device must be tied high or low.

The minimum value of external resistor RX is typically 5kΩ. The minimum value of external capacitor CX is 0pF. At VCC = 5V, the pulse width is calculated by the formula tW = 0.45 × RX × CX.

• Override reset to terminate output pulse
• Triggerable from leading or trailing edge
• Q and Q̄ buffered outputs
• Independent reset
• Wide output pulse width range
• Both Ā and B inputs with Schmitt trigger
• Fan-out (full temperature range): 10 LS-TTL loads for standard outputs, 15 LS-TTL loads for bus driver outputs
• Balanced propagation delay and transition time
• Significantly reduced power consumption compared to LS-TTL logic ICs