May 2007
74VHC123A
tm
Dual Retriggerable Monostable Multivibrator
Features
General Description
■ High Speed: t = 8.1ns (Typ.) at T = 25°C
The VHC123A is an advanced high speed CMOS
Monostable Multivibrator fabricated with silicon gate
CMOS technology. It achieves the high speed operation
similar to equivalent Bipolar Schottky TTL while main-
taining the CMOS low power dissipation. Each multi-
vibrator features both a negative, A, and a positive, B,
transition triggered input, either of which can be used as
an inhibit input. Also included is a clear input that when
taken low resets the one-shot. The VHC123A can be
triggered on the positive transition of the clear while A is
held low and B is held high. The output pulse width is
PD
A
■ Low Power Dissipation: I = 4µA (Max) at T = 25°C
CC
A
■ Active State: I = 600µA (Max.) at T = 25°C
CC
A
■ High Noise Immunity: V
= V
= 28% V (Min.)
NIH
NIL CC
■ Power down protection is provided on all inputs
■ Pin and function compatible with 74HC123A
determined by the equation: PW = (R )(C ); where PW
x
x
is in seconds, R is in ohms, and C is in farads.
Limits for R and C are:
x
x
External capacitor, C : No limit
x
External resistors, R : V = 2.0V, 5 kΩ min
x
CC
CC
V
> 3.0V, 1 kΩ min
An input protection circuit ensures that 0 to 7V can be
applied to the input pins without regard to the supply
voltage. This device can be used to interface 5V to 3V
systems and two supply systems such as battery back
up. This circuit prevents device destruction due to mis-
matched supply and input voltages.
Ordering Information
Package
Order Number
74VHC123AM
Number
Package Description
M16A
16-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-012, 0.150” Narrow
16-Lead Small Outline Package (SOP), EIAJ TYPE II, 5.3mm Wide
74VHC123ASJ
74VHC123AMTC
M16D
MTC16
16-Lead Thin Shrink Small Outline Package (TSSOP), JEDEC MO-153, 4.4mm
Wide
Surface mount packages are also available on Tape and Reel. Specify by appending the suffix letter “X” to the
ordering number.
©1993 Fairchild Semiconductor Corporation
74VHC123A Rev. 1.2
www.fairchildsemi.com