74VHC221A
器件描述：Dual Non-Retriggerable Monostable Multivibrator
器件厂商：FAIRCHILD [Fairchild Semiconductor]
文件大小：100.67KB，共9页
Sponsor by e络盟器件资料摘要：
April 1994
Revised May 1999
7
4
VH
C22
1
A Dual
Non-
Retr
igger
able
Monost
able
Mult
ivi
b
ra
tor
© 1999 Fairchild Semiconductor Corporation DS011680.prf www.fairchildsemi.com
74VHC221A
Dual Non-Retriggerable Monostable Multivibrator
General Description
The VHC221A 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 maintaining the
CMOS low power dissipation. Each multivibrator 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 VHC221A can be triggered on the positive
transition of the clear while A is held LOW and B is held
HIGH. The VHC221A is non-retriggerable, and therefore
cannot be retriggered until the output pulse times out. The
output pulse width is determined by the equation:
PW = (Rx)(Cx); where PW is in seconds, R is in ohms,
and C is in farads.
Limits for R
x
and C
x
are:
External capacitor, C
x
: No limit
External resistors, R
x
: V
CC
= 2.0V, 5 kΩ min
V
CC
> 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 volt-
age. This device can be used to interface 5V to 3V systems
and two supply systems such as battery back up. This cir-
cuit prevents device destruction due to mismatched supply
and input voltages.
Features
a73 High Speed: t
PD
= 8.1 ns (typ) at V
CC
= 5V
a73 Low Power Dissipation: I
CC
= 4 µA (Max) at T
A
= 25°C
a73 Active State: I
CC
= 600 µA (Max) at T
A
= 25°C
a73 High Noise Immunity: V
NIH
= V
NIL
= 28% V
CC
(min)
a73 Power down protection is provided on all inputs
a73 Pin and function compatible with 74HC221A
Ordering Code:
Surface mount packages are also available on Tape and Reel. Specify by appending the suffix letter “X” to the ordering code.
Logic Symbol
IEEE/IEC
Connection Diagram
Order Number Package Number Package Description
74VHC221AM M16A 16-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-012, 0.150 Narrow
74VHC221ASJ M16D 16-Lead Small Outline Package (SOP), EIAJ TYPE II, 5.3mm Wide
74VHC221AMTC MTC16 16-Lead Thin Shrink Small Outline Package (TSSOP), JEDEC MO-153, 4.4mm Wide
74VHC221AN N16E 16-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide
Revised May 1999
7
4
VH
C22
1
A Dual
Non-
Retr
igger
able
Monost
able
Mult
ivi
b
ra
tor
© 1999 Fairchild Semiconductor Corporation DS011680.prf www.fairchildsemi.com
74VHC221A
Dual Non-Retriggerable Monostable Multivibrator
General Description
The VHC221A 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 maintaining the
CMOS low power dissipation. Each multivibrator 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 VHC221A can be triggered on the positive
transition of the clear while A is held LOW and B is held
HIGH. The VHC221A is non-retriggerable, and therefore
cannot be retriggered until the output pulse times out. The
output pulse width is determined by the equation:
PW = (Rx)(Cx); where PW is in seconds, R is in ohms,
and C is in farads.
Limits for R
x
and C
x
are:
External capacitor, C
x
: No limit
External resistors, R
x
: V
CC
= 2.0V, 5 kΩ min
V
CC
> 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 volt-
age. This device can be used to interface 5V to 3V systems
and two supply systems such as battery back up. This cir-
cuit prevents device destruction due to mismatched supply
and input voltages.
Features
a73 High Speed: t
PD
= 8.1 ns (typ) at V
CC
= 5V
a73 Low Power Dissipation: I
CC
= 4 µA (Max) at T
A
= 25°C
a73 Active State: I
CC
= 600 µA (Max) at T
A
= 25°C
a73 High Noise Immunity: V
NIH
= V
NIL
= 28% V
CC
(min)
a73 Power down protection is provided on all inputs
a73 Pin and function compatible with 74HC221A
Ordering Code:
Surface mount packages are also available on Tape and Reel. Specify by appending the suffix letter “X” to the ordering code.
Logic Symbol
IEEE/IEC
Connection Diagram
Order Number Package Number Package Description
74VHC221AM M16A 16-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-012, 0.150 Narrow
74VHC221ASJ M16D 16-Lead Small Outline Package (SOP), EIAJ TYPE II, 5.3mm Wide
74VHC221AMTC MTC16 16-Lead Thin Shrink Small Outline Package (TSSOP), JEDEC MO-153, 4.4mm Wide
74VHC221AN N16E 16-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide