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