M54HC4538
M74HC4538
October 1993
DUAL RETRIGGERABLE MONOSTABLE MULTIVIBRATOR
B1R
(Plastic Package)
ORDER CODES :
M54HC4538F1R
M74HC4538M1R
M74HC4538B1R
M74HC4538C1R
F1R
(Ceramic Package)
M1R
(Micro Package)
C1R
(Chip Carrier)
PIN CONNECTIONS (top view)
NC =
No Internal
Connection
.
HIGH SPEED
t
PD
= 25 ns (TYP.) AT V
CC
= 5 V
.
LOW POWER DISSIPATION
STANDBY STATEI
CC
=4
A (MAX.) AT T
A
= 25
C
ACTIVE STATE I
CC
= 200
A (TYP.) AT V
CC
= 5 V
.
HIGH NOISE IMMUNITY
V
NIH
= V
NIL
= 28 % V
CC
(MIN.)
.
OUTPUT DRIVE CAPABILITY
10 LSTTL LOADS
.
BALANCED PROPAGATION DELAYS
t
PLH
= t
PHL
.
WIDE OUTPUT PULSE WIDTH RANGE
t
WOUT
= 120 ns ~ 60 s OVER AT V
CC
= 4.5 V
.
OUTPUT
PULSE
WIDTH
INDEPENDENT
FROM TRIGGER INPUT PULSE WIDTH
.
PIN AND FUNCTION COMPATIBLE
WITH 4538B
The M54/74HC4538 is a high speed CMOS DUAL
MONOSTABLEMULTIVIBRATOR fabricated in sili-
con gate C
2
MOS technology. It has the same high
speed performance of LSTTL combined with true
CMOS low power consumption. Each multivibrator
features both a negative, A, and a positive, B, edge
triggered input, either of which can be used as an in-
hibit input. Also included is a clear input that when
taken low resets the one shot. The monostable
multivibrators are retriggerable. That is, they may be
triggered reapeatedly while their outputs are gener-
ating a pulse and the pulse will be extended. Pulse
width stability over a wide range of temperature and
supply is achieved using linear CMOS techniques.
The
output
pulse
equation
is
simply
:
PW = 0.7 (R)(C) where PW is in seconds, R in
Ohms, and C is in Farads.
All inputs are equipped with protection circuits
against static discharge and transient excess volt-
age.
DESCRIPTION
1/14
SYSTEM DIAGRAM
TIMING CHART
M54/M74HC4538
2/14
BLOCK DIAGRAM
Notes : 1. Cx, Rx, Dx are external components.
2. Dx is a clamping diode.
3. The external capacitor is charged to V
CC
in the stand-by state, i.e. no trigger. When the supply voltage is turned off Cx is discharged
mainlythrough an internal parasitic diode (see figures). IfCx is sufficiently largeand V
CC
decreases rapidy, there willbesome possibility
of damaging the I.C. with a surge current or latch-up. If the voltage supply filter capacitor is large enough and V
CC
decrease slowly,
the surge current is automatically limited and damage the I.C. is avoided. The maximum forward current of the parasitic diode is ap-
proximately 20 mA. In cases where Cx is large the time taken for the supply voltage to fall to 0.4 V
CC
can be calculated as follows :
t
f
(V
CC
0.7)
Cx/20 mA
In cases where t
f
is too short an external champing diode is required to protect the I.C. from the 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.
TRIGGER OPERATION
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 ;
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 Rx/Cx external falls.
When it reaches V
REFL
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. The voltage at R/C external begins to rise
with a time constant set by the external components
Rx, Cx.
Triggering the multivibrator causes Q to go high after
internal delay due to the flip-flop and the gate. Q re-
mains high until the voltage at R/C external rises
again to V
REFH
. At this point C2 output goes low and
G goes low. C2 stops operating. That means that
after triggering when the voltage at 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)
= 0.72 Cx
Rx
RE-TRIGGER OPERATION
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 Rx/Cx external falls to V
REFL
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 minimum time for a second trigger to be
effective, trr (Min.) depends on V
CC
and Cx.
M54/ M74HC4538
3/14
RESET OPERATION
CD is normally high. If CD is low, the trigger is not
effective because Q output goes low and trigger
control flip-flop is reset.
Also transistor Op is turned on and Cx is charged
quicky to V
CC
. This means if CD input goes low, the
IC becomes waiting state both in operating and non
operating state.
FUNCTIONAL DESCRIPTION (continued)
TRUTH TABLE
INPUTS
OUTPUTS
NOTE
A
B
CD
Q
Q
H
H
OUTPUT ENABLE
X
L
H
L
H
INHIBIT
H
X
H
L
H
INHIBIT
L
H
OUTPUT ENABLE
X
X
L
L
H
INHIBIT
INPUT AND OUTPUT EQUIVALENT CIRCUIT
PIN DESCRIPTION
PIN No
SYMBOL
NAME AND FUNCTION
1, 15
1T1, 2T1
External Capacitor
Connections
2, 14
1T2, 2T2
External Resistor/Capacitor
Connections
3, 13
1CD, 2CD
Direct Reset Inputs (Active
LOW)
4, 12
1A, 2A
Trigger Inputs (LOW to
HIGH, Edge-Triggered)
5, 11
1B, 2B
Trigger Inputs (HIGH to
LOW, Edge-Triggered)
6, 10
Q1, Q2
Pulse Outputs
7, 9
Q1, Q2
Complementary Pulse Outputs
8
GND
Ground (0V)
16
V
CC
Positive Supply Voltage
IEC LOGIC SYMBOL
M54/M74HC4538
4/14
ABSOLUTE MAXIMUM RATINGS
Symbol
Parameter
Value
Unit
V
CC
Supply Voltage
-0.5 to +7
V
V
I
DC Input Voltage
-0.5 to V
CC
+ 0.5
V
V
O
DC Output Voltage
-0.5 to V
CC
+ 0.5
V
I
IK
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
I
CC
or I
GND
DC V
CC
or Ground Current
50
mA
P
D
Power Dissipation
500 (*)
mW
T
stg
Storage Temperature
-65 to +150
o
C
T
L
Lead Temperature (10 sec)
300
o
C
Absolute Maximum Ratings are those values beyond which damage to the device may occur. Functional operation under these condition is not implied.
(*) 500 mW:
65
o
C derate to 300 mW by 10mW/
o
C: 65
o
C to 85
o
C
RECOMMENDED OPERATING CONDITIONS
Symbol
Parameter
Value
Unit
V
CC
Supply Voltage
2 to 6
V
V
I
Input Voltage
0 to V
CC
V
V
O
Output Voltage
0 to V
CC
V
T
op
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 (CLR only)
V
CC
= 2 V
0 to 1000
ns
V
CC
= 4.5 V
0 to 500
V
CC
= 6 V
0 to 400
C
X
External Capacitor
NO LIMITATION (*)
R
X
External Resistor
V
CC
3 V
5K to 1M (*)
V
CC
> 3 V
1K to 1M (*)
(*) The maximum allowable values of Cx and Rx are a function of leakage of capacitor Cx, the leakage of device and leakage due to the board
layout and surface resistance. Susceptibility to externally induced noise may occur for Rx > 1M
M54/ M74HC4538
5/14
DC SPECIFICATIONS
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.
V
IH
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
V
IL
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
V
OH
High Level
Output Voltage
2.0
V
I
=
V
IH
or
V
IL
I
O
=-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
I
O
=-4.0 mA
4.18
4.31
4.13
4.10
6.0
I
O
=-5.2 mA
5.68
5.8
5.63
5.60
V
OL
Low Level Output
Voltage
2.0
V
I
=
V
IH
or
V
IL
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
0.37
0.40
6.0
I
O
= 5.2 mA
0.18
0.26
0.37
0.40
I
I
Input Leakage
Current
6.0
V
I
= V
CC
or GND
0.1
1
1
A
I
I
Input Leakage
Current
6.0
V
I
= V
CC
or GND
Rext/Cext
0.1
1
1
A
I
CC
Quiescent Supply
Current
6.0
V
I
= V
CC
or GND
4
40
80
A
I
CC
Quiescent Supply
Current
2.0
V
I
= V
CC
or GND
pins 2, 14
V
I
= V
CC
/2
40
120
160
A
4.5
0.2
0.3
0.4
mA
6.0
0.3
0.6
0.8
mA
M54/M74HC4538
6/14
AC ELECTRICAL CHARACTERISTICS (C
L
= 50 pF, Input t
r
= t
f
= 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
t
PLH
t
PHL
Propagation
Delay Time
(A, B - Q, Q)
2.0
120
250
315
375
ns
4.5
30
50
63
75
6.0
25
43
54
64
t
PLH
t
PHL
Propagation
Delay Time
(CD - Q, Q)
2.0
100
195
245
295
ns
4.5
25
39
49
59
6.0
20
33
42
50
t
WOUT
Output Pulse
Width
2.0
C
X
= 0
R
X
= 5K
540
1200
1500
1800
ns
4.5
R
X
= 1K
180
250
320
375
6.0
R
X
= 1K
150
200
260
320
2.0
C
X
= 0.01
F
R
X
= 10K
70
83
96
70
96
70
96
s
4.5
69
77
85
69
85
69
85
6.0
69
77
85
69
85
69
85
2.0
C
X
= 0.1
F
R
X
= 10K
0.67
0.75
0.83
0.67
0.83
0.67
0.9
ms
4.5
0.67
0.73
0.77
0.67
0.77
0.67
0.8
6.0
0.67
0.73
0.77
0.67
0.77
0.67
0.8
t
WOUT
Output Pulse
Width Error
Between Circuits
(In same pack)
1
%
t
W(H)
t
W(L)
Minimum Pulse
Width
(CLOCK)
2.0
30
75
95
110
ns
4.5
8
15
19
22
6.0
7
13
16
19
t
W(L)
Minimum Pulse
Width
(CLEAR)
2.0
30
75
95
110
ns
4.5
8
15
19
22
6.0
7
13
16
19
t
REM
Minimum Clear
Removal Time
2.0
0
15
15
20
ns
4.5
0
5
5
7
6.0
0
5
5
t
s
Minimum
Retrigger Time
2.0
C
X
= 0.1
F
R
X
= 1K
380
6
ns
4.5
92
6.0
72
2.0
C
X
= 0.01
F
R
X
= 1K
6
s
4.5
1.4
6.0
1.2
C
IN
Input Capacitance
5
10
10
10
pF
C
PD
(*)
Power Dissipation
Capacitance
70
pF
(*) C
PD
is defined as the value of the IC's internal equivalent capacitance which is calculated from the operating current consumption without load.
(Refer to Test Circuit). Average operting current can be obtained by the following equation. I
CC
(opr) = C
PD
V
CC
f
IN
+ I
CC
`
Duty/100 + I
CC
/2 (per circuit)
(I
CC
` = Active Supply Current)
(Duty = %))
M54/ M74HC4538
7/14
TEST CIRCUIT I
CC
(Opr.)
INPUT WAVEFORM IS THE SAME AS THAT IN CASE OF
SWITCHING CHARACTERISTICS TEST.
Output Pulse Width Constant K = Supply Voltage.
t
WOUT
- Cx Characteristics (Typ).
t
rr
- V
CC
Characteristics (Typ).
M54/M74HC4538
8/14
SWITCHING CHARACTERISTICS TEST WAVEFORM
M54/ M74HC4538
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/M74HC4538
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/ M74HC4538
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/M74HC4538
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/ M74HC4538
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. Specifications mentioned
in this publication are subject to change without notice. This publication supersedes and replaces all information previously supplied.
SGS-THOMSON Microelectronics products are not authorized for use as critical components in 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
Australia - Brazil - France - Germany - Hong Kong - Italy - Japan - Korea - Malaysia - Malta - Morocco - The Netherlands -
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M54/M74HC4538
14/14
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