Functional Description

• Dual Monostable Multivibrator

General

The 74HC123D is a high speed CMOS MONOSTABLE MULTIVIBRATOR fabricated with silicon gate C2MOS

technology.

It achieves the high speed operation similar to equivalent LSTTL while maintaining the CMOS low power

dissipation.

There are two trigger inputs, A input (negative edge), and B input (positive edge). These inputs are valid for a

slow rise/fall time signal (tr = tf = 1 s) as they are schmitt trigger inputs. This device may also be triggered by

using CLR input (positive edge).

After triggering, the output stays in a MONOSTABLE state for a time period determined by the external resistor

and capacitor (RX, CX). A low level at the CLR input breaks this state. In the MONOSTABLE state, if a new

trigger is applied, it extends the MONOSTABLE period (retrigger mode).

Limits for CX and RX are:

External capacitor, CX: No limit

External resistor, RX: VCC = 2.0 V more than 5 kΩ

VCC ≥ 3.0 V more than 1 kΩ

All inputs are equipped with protection circuits against static discharge or transient excess voltage.

Features (Note)

(1) Wide operating temperature range: Topr = -40 to 125 (Note 1)

(2) High speed: tpd = 25 ns (typ.) at VCC = 5 V

(3) Low power dissipation:

Standby state: ICC = 4.0 μA (max) at Ta = 25

Active state: ICC = 1000 μA (max) at Ta = 25

(4) Balanced propagation delays: tPLH » tPHL

(5) Wide operating voltage range: VCC(opr) = 2.0 to 6.0 V