DM74LS123 Dual Retriggerable One-Shot with Clear and Complementary Outputs
August 1986
Revised April 2000
DM74LS123
Dual Retriggerable One-Shot
with Clear and Complementary Outputs
General Description
The DM74LS123 is a dual retriggerable monostable multi-
vibrator capable of generating output pulses from a few
nano-seconds to extremely long duration up to 100% duty
cycle. Each device has three inputs permitting the choice of
either leading edge or trailing edge triggering. Pin (A) is an
active-LOW transition trigger input and pin (B) is an active-
HIGH transition trigger input. The clear (CLR) input termi-
nates the output pulse at a predetermined time indepen-
dent of the timing components. The clear input also serves
as a trigger input when it is pulsed with a low level pulse
transition ( ). To obtain the best trouble free operation
from this device please read the operating rules as well as
the Fairchild Semiconductor one-shot application notes
carefully and observe recommendations.
Features
s
DC triggered from active-HIGH transition or active-LOW
transition inputs
s
Retriggerable to 100% duty cycle
s
Compensated for V
CC
and temperature variations
s
Triggerable from CLEAR input
s
DTL, TTL compatible
s
Input clamp diodes
Ordering Code:
Order Number
DM74LS123M
DM74LS123SJ
DM74LS123N
Package Number
M16A
M16D
N16E
Package Description
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
16-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide
Devices also available in Tape and Reel. Specify by appending the suffix letter 鈥淴鈥?to the ordering code.
Connection Diagram
Function Table
Inputs
CLEAR
L
X
X
H
H
鈫?/div>
A
X
H
X
L
鈫?/div>
L
B
X
X
L
鈫?/div>
H
H
Q
L
L
Outputs
Q
H
H
H
=
HIGH Logic Level
L
=
LOW Logic Level
X
=
Can Be Either LOW or HIGH
鈫?=
Positive Going Transition
鈫?=
Negative Going Transition
=
A Positive Pulse
=
A Negative Pulse
L
H
漏 2000 Fairchild Semiconductor Corporation
DS006386
www.fairchildsemi.com
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