MM54C221 MM74C221 Dual Monostable Multivibrator
February 1988
MM54C221 MM74C221 Dual Monostable Multivibrator
General Description
The MM54C221 MM74C221 dual monostable multivibrator is a monolithic complementary MOS integrated circuit Each multivibrator features a negative-transition-triggered input and a positive-transition-triggered input either of which can be used as an inhibit input and a clear input Once fired the output pulses are independent of further transitions of the A and B inputs.
Dual Monostable Multivibrator
MM54C221 MM74C221 Dual Monostable Multivibrator
February 1988
MM54C221 MM74C221 Dual Monostable Multivibrator
General Description
The MM54C221 MM74C221 dual monostable multivibrator is a monolithic complementary MOS integrated circuit Each multivibrator features a negative-transition-triggered input and a positive-transition-triggered input either of which can be used as an inhibit input and a clear input Once fired the output pulses are independent of further transitions of the A and B inputs and are a function of the external timing components CEXT and REXT The pulse width is stable over a wide range of temperature and VCC Pulse stability will be limited by the accuracy of external timing components The pulse width is approximately defined by the relationship tW(OUT) CEXT REXT For further information and applications see AN-138
Features
Y Y Y Y
Wide supply voltage range Guaranteed noise margin High noise immunity Low power TTL compatibility
4 5V to 15V 1 0V 0 45 VCC (typ ) fan out of 2 driving 74L
Connection Diagrams
Timing Component Dual-In-Line Package
TL F 5904 – 1
TL F 5904 – 2
Top View Order Number MM54C221 or MM74C221
Truth Table
Inputs Clear L X X H H A X H X L B X X L Q L L L Outputs Q H H H
H L
e e e e e e e
u v
X
u
H
High level Low level Transition from low to high Transition from high to low One high level pulse One low level pulse Irrelevant
v
C1995 National Semiconductor Corporation
TL F 5904
RRD-B30M105 Printed in U S A
Absolute Maximum Ratin.