Product Overview: 74HC123N by NXP Semiconductors

The 74HC123N is a high-speed Si-gate CMOS device and is pin compatible with low-power Schottky TTL (LSTTL). It is fabricated with silicon gate CMOS technology which ensures that it has the high noise immunity and low power consumption typical of CMOS integrated circuits, as well as the speeds similar to LSTTL.

This dual retriggerable monostable multivibrator (also known as a one-shot pulse generator) is designed for timing applications in a wide range of digital systems. It features two individual monostable multivibrators with direct and complementary outputs which can be triggered from either the rising or falling edge of the input pulse, providing versatility in its deployment.

Each multivibrator has an active LOW trigger/retrigger input (nA), an active HIGH trigger/retrigger input (nB), an overriding active LOW direct reset input (nCD), two complementary outputs (nQ and nQ), and a toggleable output pulse width control by three methods:

• External capacitor (Cx)
• External resistor (Rx)
• External resistor (Rt) and capacitor (Ct) for adjustable timing

The pulse duration and accuracy are determined by external timing components (Rx and Cx or Rt and Ct). The 74HC123N ensures a minimum pulse width of 190 ns, which can be extended by connecting a capacitor to the Cx pin. Furthermore, the output pulse can be extended by retriggering the inputs before the end of the pulse duration, making it suitable for a wide array of timing tasks.

With a wide operating voltage range from 2.0V to 6.0V, the 74HC123N can be used in environments with variable supply voltages. Its outputs can drive up to 10 LSTTL loads, which means it can easily interface with other logic families. The device is available in a 16-pin DIP (Dual In-line Package), making it easy to integrate into both prototyping and production environments.

Overall, the 74HC123N from NXP Semiconductors is a reliable and flexible solution for timing requirements in digital logic systems, offering the precision and stability needed for critical timing applications.