M54HC123/123A
M74HC123/123A
October 1993
DUAL RETRIGGERABLE MONOSTABLE MULTIVIBRATOR
B1R
(Plastic Package)
ORDER CODES :
M54HCXXXF1R M74HCXXXM1R
M74HCXXXB1R M74HCXXXC1R
F1R
(Ceramic Package)
M1R
(Micro Package)
C1R
(Chip Carrier)
PIN CONNECTIONS(top view)
NC =
No Internal
Connection
.HIGH SPEED
tPD = 25 ns (TYP) at VCC = 5V
.LOWPOWER DISSIPATION
STANDBYSTATEI
CC
=4 A(MAX.) AT T
A
=25C
ACTIVESTATE I
CC
=200 A (TYP.) AT V
CC
=5V
.HIGH NOISEIMMUNITY
VNIH = VNIL = 28 % VCC (MIN.)
.OUTPUT DRIVE CAPABILITY
10 LSTTL LOADS
.SYMMETRICAL OUTPUT IMPEDANCE
IOH = IOL = 4 mA (MIN.)
.BALANCEDPROPAGATION DELAYS
t
PLH
= t
PHL
.WIDE OPERATING VOLTAGE RANGE
VCC (OPR) = 2 V TO6 V
.WIDE OUTPUT PULSE WIDTHRANGE
t
WOUT
= 120 ns 60 s OVER AT V
CC
= 4.5 V
.PIN AND FUNCTION COMPATIBLE WITH
54/74LS123
The M54/74HC123 is a high speed CMOS MONO-
STABLE multivibrator fabricated with silicon gate
C
2
MOS technology. It achieves the high speed
operation similar to equivalent LSTTL while main-
taining the CMOS low power dissipation. There are
two trigger inputs, A INPUT (negative edge) and 8
INPUT (positive edge). These inputs are valid for
slowrising/falling signals, (tr = tf =I sec). The device
may also be triggered by using the CLR input (posi-
tive-edge) because of the Schmitt-trigger input ;
after triggering the output maintains the MONO-
STABLEstate for the time period determined by the
external resistor Rx and capacitor Cx. When Cx
10nF and Rx 10K, the output pulse width value
is approssimatively given by the formula: t
w(out)
= K
Cx Rx.
Two different pulse width constant are available:
K 0.45 for HC123 K 1 for HC123A.
Taking CLR low breaks this MONOSTABLE
STATE. If the next trigger pulse occurs during the
MONOSTABLEperiod it makes theMONOSTABLE
period longer. Limit for values of Cx and Rx :
Cx : NO LIMIT
Rx : V
CC
< 3.0 V 5 K to 1 M
VCC 3.0 V 1 K to 1 M
All inputs are equipped with protection circuits
DESCRIPTION
1/14
SYSTEM DIAGRAM
TIMING CHART
M54/M74HC123/123A
2/14
BLOCK DIAGRAM
Note :
(1) Cx, Rx, Dx are external components.
(2) Dx is a clamping diode.
Theexternal capacitor ischarged toVCC inthestand-by state, i.e. no trigger. Whenthesupply voltage is turned off Cx is discharged mainly
through an internal parasitic diode (see figures). If Cx is sufficiently large and VCC decreases rapidy, there will be somepossibility of da-
maging the I.C. witha surge current or latch-up. If the voltage supply filter capacitor is large enough and VCC decrease slowly, the surge
current is automatically limited and damage the I.C. is avoided. The maximum forward current of the parasitic diode is approximately 20
mA. In cases where Cx is large the time takenfor the supply voltage to fall to 0.4 VCC canbe calculated as follows :
tf (VCC 0.7) Cx/20mA
In cases where tf is too short an external clamping diode is required toprotect the I.C. fromthe surge current.
FUNCTIONAL DESCRIPTION
STAND-BY STATE
The external capacitor, Cx, is fully charged to V
CC
in the stand-by state. Hence, before triggering, tran-
sistor Qp and Qn (connected to the Rx/Cx node) are
both turned-off. The two comparators that control
the timing and the two reference voltage sources
stop operating. The total supply current is therefore
only leakage current.
TRIGGEROPERATION
Triggering occurs when :
1 st) A is low and B has a falling edge ;
2 nd) B is high and A has a rising edge ;
3 rd) Ais lowand Bishigh and C1 has a risingedge.
After the multivibrator has been retriggered com-
parator C1 and C2 start operating and Qn is turned
on. Cx then discharges through Qn. The voltage at
the node R/C external falls.
When it reaches VREFL the output of comparator C1
becomes low. This in turn resets the flip-flop and Qn
is turned off.
At this point C1 stops functioning but C2 continues
to operate.
Thevoltage at R/Cexternal begins to rise withatime
constant set by the external components Rx, Cx.
Triggering the multivibrator causes Qto gohigh after
internal delay due to the flip-flop and the gate. Qre-
mains high until the voltage at R/C external rises
again to V
REFH
. At this point C2 output goes lowand
O goes low. C2 stop operating. That means that
after triggering when the voltage R/C external re-
turns to V
REFH
the multivibrator has returned to its
MONOSTABLE STATE. In the case where Rx Cx
are large enough and the discharge time of the ca-
pacitor and the delay time in the I.C. can be ignored,
the width of the output pulse tw (out) is as follows :
t
W(OUT)
= 0.46 Cx Rx (HC123)
tW(OUT) = Cx Rx (HC123A)
M54/M74HC123/123A
3/14
FUNCTIONAL DESCRIPTION (continued)
RE-TRIGGEREDOPERATION
When a second trigger pulse follows the first its ef-
fect will depend on the state of the multivibrator. If
the capacitor Cx is being charged the voltage level
of R/C external falls to Vrefl again and Q remains
high i.e. the retrigger pulse arrives in a time shorter
than the period Rx Cx seconds, the capacitor
charging time constant. If the second trigger pulse
is very close to the initial trigger pulse it is ineffective
; i.e. the second trigger must arrive in the capacitor
discharge cycle to be ineffective; Hence the mini-
mum time for a second trigger to be effective de-
pends on VCC and Cx.
RESET OPERATION
CL is normally high. If CL is low, the trigger is not ef-
fective because Q output goes low and trigger con-
trol flip-flop is reset.
Also transistor Op is turned on and Cx is charged
quicky to V
CC
. This means if CL input goes low, the
IC becomes waiting state both in operating and non
operating state.
TRUTH TABLE
INPUTS OUTPUTS
NOTE
A B CL Q Q
H H OUTPUT ENABLE
X L H L H INHIBIT
H X H L H INHIBIT
L H OUTPUT ENABLE
L H OUTPUT ENABLE
X X L L H INHIBIT
X: Dont Care Z: High Impedance
INPUT AND OUTPUT EQUIVALENT CIRCUIT
M54/M74HC123/123A
4/14
PIN DESCRIPTION
PIN No SYMBOL NAME AND FUNCTION
1, 9 1A, 2A Trigger Inputs (Negative
Edge Triggered)
2, 10 1B, 2B Trigger Inputs (Positive
Edge Triggered)
3, 11 1CLR,
2CLR
Direct Reset LOW and
Trigger Action at Positive
Edge
4, 12 1Q, 2Q Outputs (Active LOW)
7 2REXT/CEXT External Resistor
Capacitor Connection
13, 5 1Q, 2Q Outputs (Active HIGH)
14, 6 1C
EXT
2CEXT
External Capacitor
Connection
15 1R
EXT
/C
EXT
External Resistor
Capacitor Connection
8 GND Ground (0V)
16 VCC Positive Supply Voltage
IEC LOGIC SYMBOL
ABSOLUTE MAXIMUM RATING
Symbol Parameter Value Unit
VCC Supply Voltage -0.5 to +7 V
VI DC Input Voltage -0.5 to VCC + 0.5 V
V
O
DC Output Voltage -0.5 to V
CC
+ 0.5 V
IIK DC Input Diode Current 20 mA
I
OK
DC Output Diode Current 20 mA
I
O
DC Output Source Sink Current Per Output Pin 25 mA
ICC or IGND DC VCC or Ground Current 50 mA
P
D
Power Dissipation 500 (*) mW
T
stg
Storage Temperature -65 to +150
o
C
TL Lead Temperature (10 sec) 300
o
C
AbsoluteMaximumRatingsare those values beyond whichdamage tothedevice may occur. Functional operation under these conditionisnot implied.
(*) 500 mW: 65
o
C derate to 300 mWby 10mW/
o
C: 65
o
C to85
o
C
M54/M74HC123/123A
5/14
DC SPECIFICATIONS
Symbol Parameter
Test Conditions Value
Unit
VCC
(V)
T
A
= 25
o
C
54HC and 74HC
-40 to 85
o
C
74HC
-55 to 125
o
C
54HC
Min. Typ. Max. Min. Max. Min. Max.
VIH High Level Input
Voltage
2.0 1.5 1.5 1.5
V
4.5 3.15 3.15 3.15
6.0 4.2 4.2 4.2
VIL Low Level Input
Voltage
2.0 0.5 0.5 0.5
V
4.5 1.35 1.35 1.35
6.0 1.8 1.8 1.8
VOH High Level
Output Voltage
2.0
VI =
VIH
or
V
IL
IO=-20 A
1.9 2.0 1.9 1.9
V
4.5 4.4 4.5 4.4 4.4
6.0 5.9 6.0 5.9 5.9
4.5 IO=-4.0 mA 4.18 4.31 4.13 4.10
6.0 IO=-5.2 mA 5.68 5.8 5.63 5.60
V
OL
Low Level Output
Voltage
2.0
V
I
=
V
IH
or
VIL
I
O
= 20 A
0.0 0.1 0.1 0.1
V
4.5 0.0 0.1 0.1 0.1
6.0 0.0 0.1 0.1 0.1
4.5 I
O
= 4.0 mA 0.17 0.26 0.33 0.40
6.0 IO= 5.2 mA 0.18 0.26 0.33 0.40
I
I
Input Leakage
Current
6.0
V
I
= V
CC
or GND 0.1 1 1 A
I
I
R/C Terminal Off
State Current
6.0
V
I
= V
CC
or GND 0.1 1 1 A
I
CC
Quiescent Supply
Current
6.0 V
I
= V
CC
or GND 4 40 80 A
ICC Active State
Supply Current (1)
2.0 VI = VCC or GND
Pin 7 or 15
V
IN
= V
CC
/2
45 200 260 320 A
4.5 500 600 780 960 A
6.0 0.7 1 1.3 1.6 mA
(1): Per Circuit
RECOMMENDED OPERATING CONDITIONS
Symbol Parameter Value Unit
VCC Supply Voltage 2 to 6 V
V
I
Input Voltage 0 to V
CC
V
VO Output Voltage 0 to VCC V
Top Operating Temperature: M54HC Series
M74HC Series
-55 to +125
-40 to +85
o
C
o
C
t
r
, t
f
Input Rise and Fall Time 0 to 1000 ns
0 to 500
0 to 400
C
X
External Capacitor NO LIMITATION
pF
RX External Resistor VCC < 3 V 5K to 1M
VCC 3 V 1K to 1M
(*) The maximum allowable values of Cx andRx are a function of leakage of capacitor Cx, the leakage of device and leakagedue to the board
layout and surface resistance. Susceptibility to externally induced noise may occur for Rx > 1M
M54/M74HC123/123A
6/14
AC ELECTRICAL CHARACTERISTICS (CL = 50 pF, Input tr = tf = 6 ns)
Symbol Parameter
Test Conditions Value
Unit
V
CC
(V)
T
A
= 25
o
C
54HC and 74HC
-40 to 85
o
C
74HC
-55 to 125
o
C
54HC
Min. Typ. Max. Min. Max. Min. Max.
t
TLH
t
THL
Output Transition
Time
2.0 30 75 95 110
ns
4.5 8 15 19 22
6.0 7 13 16 19
tPLH
t
PHL
Propagation
Delay Time
(A, B - Q, Q)
2.0 102 210 265 315
ns
4.5 29 42 53 63
6.0 22 36 45 54
tPLH
tPHL
Propagation
Delay Time
(CLRTRIGGER- Q,Q)
2.0 102 235 295 355
ns
4.5 31 47 59 71
6.0 23 40 50 60
tPLH
tPHL
Propagation
Delay Time
(CLR - Q, Q)
2.0 68 160 200 240
ns
4.5 20 32 40 48
6.0 16 27 34 41
t
WOUT
Output Pulse
Width
(for HC123)
2.0 C
X
= 100 pF
RX = 10 K
1.4
s
4.5 1.2
6.0 1.1
2.0 C
X
= 0.1 F
R
X
= 100 K
4.6
ms
4.5 4.4
6.0 4.3
t
WOUT
Output Pulse
Width
(for HC123A)
2.0 C
X
= 100 pF
R
X
= 10 K
1.9
s
4.5 1.6
6.0 1.5
2.0 CX = 0.1 F
R
X
= 100 K
9.8
ms
4.5 9.5
6.0 9.4
tWOUT Output Pulse
Width Error
Between Circuits
in Same Package
1
%
t
W(H)
t
W(L)
Minimum Pulse
Width
2.0 75 95 110
ns
4.5 15 19 22
6.0 13 16 19
t
W(L)
Minimum Pulse
Width (CLR)
2.0 75 95 110
ns
4.5 15 19 22
6.0 13 16 19
t
rr
Minimum
Retrigger Time
2.0 C
X
= 100 pF
R
X
= 1 K
325
ns
4.5 108
6.0 78
2.0 CX = 0.1 F
R
X
= 100 K
5
s
4.5 1.4
6.0 1.2
CIN Input Capacitance 5 10 10 10 pF
CPD (*) Power Dissipation
Capacitance
162
pF
(*) CPD isdefined as the value of the ICs internal equivalent capacitance which is calculated from the operating current consumption without load.
(RefertoTest Circuit). Averageopertingcurrent canbeobtainedbythefollowingequation. ICC(opr) =CPDVCC fIN +ICC Duty/100+IC/2(per monostable)
(ICC: Active Supply Current) (Duty:%)
M54/M74HC123/123A
7/14
Output Pulse Width Constant Characteristics
(for HC123)
Output Pulse Width Characteristics (for HC123)
Output Pulse Width Constant Characteristics
(for HC123A)
Output Pulse Width Characteristics (for HC123A)
M54/M74HC123/123A
8/14
TEST CIRCUIT I
CC
(Opr)
* TRANSITIONTIME OF INPUT WAVEFORM IS THE SAME AS
THAT IN SASEOF SWITCHINGCHARACTERISTICSTESTS.
SWITCHING CHARACTERISTICS TEST WAVEFORM
M54/M74HC123/123A
9/14
Plastic DIP16 (0.25) MECHANICAL DATA
DIM.
mm inch
MIN. TYP. MAX. MIN. TYP. MAX.
a1 0.51 0.020
B 0.77 1.65 0.030 0.065
b 0.5 0.020
b1 0.25 0.010
D 20 0.787
E 8.5 0.335
e 2.54 0.100
e3 17.78 0.700
F 7.1 0.280
I 5.1 0.201
L 3.3 0.130
Z 1.27 0.050
P001C
M54/M74HC123/123A
10/14
Ceramic DIP16/1 MECHANICAL DATA
DIM.
mm inch
MIN. TYP. MAX. MIN. TYP. MAX.
A 20 0.787
B 7 0.276
D 3.3 0.130
E 0.38 0.015
e3 17.78 0.700
F 2.29 2.79 0.090 0.110
G 0.4 0.55 0.016 0.022
H 1.17 1.52 0.046 0.060
L 0.22 0.31 0.009 0.012
M 0.51 1.27 0.020 0.050
N 10.3 0.406
P 7.8 8.05 0.307 0.317
Q 5.08 0.200
P053D
M54/M74HC123/123A
11/14
SO16 (Narrow) MECHANICAL DATA
DIM.
mm inch
MIN. TYP. MAX. MIN. TYP. MAX.
A 1.75 0.068
a1 0.1 0.2 0.004 0.007
a2 1.65 0.064
b 0.35 0.46 0.013 0.018
b1 0.19 0.25 0.007 0.010
C 0.5 0.019
c1 45 (typ.)
D 9.8 10 0.385 0.393
E 5.8 6.2 0.228 0.244
e 1.27 0.050
e3 8.89 0.350
F 3.8 4.0 0.149 0.157
G 4.6 5.3 0.181 0.208
L 0.5 1.27 0.019 0.050
M 0.62 0.024
S 8 (max.)
P013H
M54/M74HC123/123A
12/14
PLCC20 MECHANICAL DATA
DIM.
mm inch
MIN. TYP. MAX. MIN. TYP. MAX.
A 9.78 10.03 0.385 0.395
B 8.89 9.04 0.350 0.356
D 4.2 4.57 0.165 0.180
d1 2.54 0.100
d2 0.56 0.022
E 7.37 8.38 0.290 0.330
e 1.27 0.050
e3 5.08 0.200
F 0.38 0.015
G 0.101 0.004
M 1.27 0.050
M1 1.14 0.045
P027A
M54/M74HC123/123A
13/14
Information furnished is believed to be accurate and reliable. However, SGS-THOMSON Microelectronics assumes no responsability for the
consequences of use of such information nor for any infringement of patents or other rights of third parties which may results from its use. No
license is granted by implication or otherwise under any patent or patent rights of SGS-THOMSON Microelectronics. Specificationsmentioned
in this publication are subject to change without notice. This publication supersedes and replaces all information previously supplied.
SGS-THOMSON Microelectronicsproductsare not authorized for use ascritical componentsin life support devices or systems without express
written approval of SGS-THOMSON Microelectonics.
1994 SGS-THOMSON Microelectronics - All Rights Reserved
SGS-THOMSON Microelectronics GROUP OF COMPANIES
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M54/M74HC123/123A
14/14
