SN54AHCT123A, SN74AHCT123A
DUAL RETRIGGERABLE MONOSTABLE MULTIVIBRATORS


SCLS420G – JUNE 1998 – REVISED APRIL 2003
1POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
C0068 Inputs Are TTL-Voltage Compatible
C0068 Schmitt-Trigger Circuitry On A, B, and CLR
Inputs for Slow Input Transition Rates
C0068 Edge Triggered From Active-High or
Active-Low Gated Logic Inputs
C0068 Retriggerable for Very Long Output Pulses
C0068 Overriding Clear Terminates Output Pulse
C0068 Latch-Up Performance Exceeds 100 mA Per
JESD 78, Class II
C0068 ESD Protection Exceeds JESD 22
– 2000-V Human-Body Model (A114-A)
– 200-V Machine Model (A115-A)
– 1000-V Charged-Device Model (C101)
description/ordering information
These edge-triggered multivibrators feature
output pulse-duration control by three methods. In
the first method, the A input is low, and the B input
goes high. In the second method, the B input is
high, and the A input goes low. In the third method,
the A input is low, the B input is high, and the clear
(CLR) input goes high.
The output pulse duration is programmed by
selecting external resistance and capacitance
values. The external timing capacitor must be
connected between C
ext
and R
ext
/C
ext
(positive)
and an external resistor connected between
R
ext
/C
ext
and V
CC
. To obtain variable pulse
durations, connect an external variable resistance
between R
ext
/C
ext
and V
CC
. The output pulse
duration also can be reduced by taking CLR low.
ORDERING INFORMATION
T
A
PACKAGE
†
ORDERABLE
PART NUMBER
TOP-SIDE
MARKING
PDIP – N Tube SN74AHCT123AN SN74AHCT123AN
SOIC D
Tube SN74AHCT123AD
AHCT123A
40°Cto85°C
–
Tape and reel SN74AHCT123ADR
– C to 85
SSOP – DB Tape and reel SN74AHCT123ADBR HB123A
TSSOP – PW Tape and reel SN74AHCT123APWR HB123A
TVSOP – DGV Tape and reel SN74AHCT123ADGVR HB123A
CDIP – J Tube SNJ54AHCT123AJ SNJ54AHCT123AJ
–55°C to 125°C CFP – W Tube SNJ54AHCT123AW SNJ54AHCT123AW
LCCC – FK Tube SNJ54AHCT123AFK SNJ54AHCT123AFK
†
Package drawings, standard packing quantities, thermal data, symbolization, and PCB design guidelines are
available at www.ti.com/sc/package.
Copyright  2003, Texas Instruments Incorporated

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
SN54AHCT123A ...J OR W PACKAGE
SN74AHCT123A . . . D, DB, DGV, N, OR PW PACKAGE
(TOP VIEW)
SN54AHCT123A . . . FK PACKAGE
(TOP VIEW)
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
1A
1B
1CLR
1Q
2Q
2C
ext
2R
ext
/C
ext
GND
V
CC
1R
ext
/C
ext
1C
ext
1Q
2Q
2CLR
2B
2A
3212019
910111213
4
5
6
7
8
18
17
16
15
14
1C
ext
1Q
NC
2Q
2CLR
1CLR
1Q
NC
2Q
2C
ext
1B 1A NC
2A 2B
V 1R
2R
GND
NC
CC
NC – No internal connection
ext
/C
ext
ext
/C
ext
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of Texas Instruments
standard warranty. Production processing does not necessarily include
testing of all parameters.
On products compliant to MIL-PRF-38535, all parameters are tested
unless otherwise noted. On all other products, production
processing does not necessarily include testing of all parameters.