DATA SHEET
Product specification
File under Integrated Circuits, IC04
January 1995
INTEGRATED CIRCUITS
HEF4538B
MSI
Dual precision monostable
multivibrator
For a complete data sheet, please also download:
The IC04 LOCMOS HE4000B Logic
Family Specifications HEF, HEC
The IC04 LOCMOS HE4000B Logic
Package Outlines/Information HEF, HEC
January 1995
2
Philips Semiconductors
Product specification
Dual precision monostable multivibrator
HEF4538B
MSI
DESCRIPTION
The HEF4538B is a dual retriggerable-resettable
monostable multivibrator. Each multivibrator has an active
LOW trigger/retrigger input (I
0
), an active HIGH
trigger/retrigger input (I
1
), an overriding active LOW direct
reset input (C
D
), an output (O) and its complement (O),
and two pins (C
TC
,
(1)
RC
TC
) for connecting the external
timing components C
t
and R
t
. Typical pulse width variation
over temperature range is
0,2%.
The HEF4538B may be triggered by either the positive or
the negative edges of the input pulse and will produce an
accurate output pulse with a pulse width range of 10
s to
infinity. The duration and accuracy of the output pulse are
determined by the external timing components C
t
and R
t
.
The output pulse width (T) is equal to R
t
C
t
. The linear
design techniques in LOCMOS guarantee precise control
of the output pulse width.
A LOW level at C
D
terminates the output pulse
immediately. Schmitt-trigger action in the trigger inputs
makes the circuit highly tolerant to slower rise and fall
times.
Fig.1 Functional diagram.
PINNING
Note
1. Always connected to ground.
FAMILY DATA, I
DD
LIMITS category MSI
See Family specifications.
HEF4538BP(N):
16-lead DIL; plastic (SOT38-1)
HEF4538BD(F):
16-lead DIL; ceramic (cerdip) (SOT74)
HEF4538BT(D):
16-lead SO; plastic (SOT109-1)
( ): Package Designator North America
I
0A,
I
0B
input (HIGH to LOW triggered)
I
1A
, I
1B
input (LOW to HIGH triggered)
C
DA
, C
DB
direct reset input (active LOW)
O
A
, O
B
output
O
A
, O
B
complementary output (active LOW)
C
TC A
, C
TC B
external capacitor connections
(1)
RC
TC A
, RC
TC B
external capacitor/ resistor
connections
Fig.2 Pinning diagram.
January 1995
3
Philips Semiconductors
Product specification
Dual precision monostable multivibrator
HEF4538B
MSI
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Fig.3 Logic diagram.
January 1995
4
Philips Semiconductors
Product specification
Dual precision monostable multivibrator
HEF4538B
MSI
FUNCTION TABLE
Notes
1. H = HIGH state (the more positive voltage)
L = LOW state (the less positive voltage)
X = state is immaterial
= positive output pulse
= negative output pulse
= positive-going transition
= negative-going transition
INPUTS
OUTPUTS
I
0
I
1
C
D
O
O
L
H
H
H
X
X
L
L
H
Fig.4
Connection of the external timing
components R
t
and C
t
.
DC CHARACTERISTICS
V
SS
= 0 V
Note
1. Only one monostable is switching: current present during output pulse (output O is HIGH).
V
DD
V
SYMBOL
T
amb
(
C)
-
40
+
25
+
85
TYP.
MAX.
TYP.
MAX.
TYP.
MAX.
Supply current
5
55
A
active state
10
I
D
150
A
(see note)
15
220
A
Input leakage
current
15
I
IN
300
1000 nA
(pins 2 and 14)
January 1995
5
Philips Semiconductors
Product specification
Dual precision monostable multivibrator
HEF4538B
MSI
AC CHARACTERISTICS
V
SS
= 0 V; T
amb
= 25
C; C
L
= 50 pF; input transition times
20 ns
V
DD
V
SYMBOL
MIN.
TYP.
MAX.
TYPICAL EXTRAPOLATION
FORMULA
Propagation delays
I
0
, I
1
O
5
200
460 ns
173 ns
+
(0,55 ns/pF) C
L
HIGH to LOW
10
t
PHL
90
180 ns
79 ns
+
(0,23 ns/pF) C
L
15
60
120 ns
52 ns
+
(0,16 ns/pF) C
L
I
0
, I
1
O
5
220
440 ns
193 ns
+
(0,55 ns/pF) C
L
LOW to HIGH
10
t
PLH
85
190 ns
74 ns
+
(0,23 ns/pF) C
L
15
60
120 ns
52 ns
+
(0,16 ns/pF) C
L
C
D
O
5
125
250 ns
98 ns
+
(0,55 ns/pF) C
L
HIGH to LOW
10
t
PHL
55
110 ns
44 ns
+
(0,23 ns/pF) C
L
15
40
80 ns
32 ns
+
(0,16 ns/pF) C
L
C
D
O
5
125
250 ns
98 ns
+
(0,55 ns/pF) C
L
LOW to HIGH
10
t
PLH
55
110 ns
44 ns
+
(0,23 ns/pF) C
L
15
40
80 ns
32 ns
+
(0,16 ns/pF) C
L
Recovery times
5
20
40 ns
C
D
I
0
, I
1
10
t
RCD
10
20 ns
15
5
10 ns
Retrigger times
5
0
ns
O, O
I
0
, I
1
10
t
RO
0
ns
15
0
ns
Minimum I
0
5
90
45
ns
pulse width; LOW
10
t
WI0L
30
15
ns
15
24
12
ns
Minimum I
1
5
50
25
ns
pulse width; HIGH
10
t
WI1H
24
12
ns
15
20
10
ns
Minimum C
D
5
55
25
ns
pulse width; LOW
10
t
WCDL
25
12
ns
15
20
10
ns
Output O or O
5
218
230
242
s
R
t
= 100 k
C
t
= 0,002
F
pulse width
10
t
WO
213
224
235
s
15
211
223
234
s
Output O or O
5
10,3
10,8
11,3
ms
R
t
= 100 k
C
t
= 0,1
F
pulse width
10
t
WO
10,2
10,7
11,2
ms
15
10,1
10,6
11,1
ms
Output O or O
5
1,01
1,09
1,11 s
R
t
= 100 k
C
t
= 10
F
pulse width
10
t
WO
0,99
1,04
1,09 s
15
0,99
1,04
1,09 s
January 1995
6
Philips Semiconductors
Product specification
Dual precision monostable multivibrator
HEF4538B
MSI
AC CHARACTERISTICS
V
SS
= 0 V; T
amb
= 25
C; C
L
= 50 pF; input transition times
20 ns
Note
1. The maximum permissible resistance R
t
, which holds the specified accuracy of t
WO
, depends on the leakage current
of the capacitor C
t
and the leakage of the HEF4538B.
V
DD
V
SYMBOL
MIN.
TYP.
MAX.
Change in output O
5
0,2
%
pulse width over
10
t
WO
0,2
%
temperature (T
amb
)
15
0,2
%
Change in output O
pulse width over
t
WO
1,5
%
V
DD
range 5 to 15 V
Pulse width variation
5
1
%
R
t
= 100 k
C
t
= 2 nF to 10
F
between circuits
10
t
WO
1
%
in same package
15
1
%
External timing
resistor
R
t
5
-
(1)
k
External timing
capacitor
C
t
2000
-
no limits
pF
Input capacitance
(pin 2 or 14)
C
IN
15
pF
January 1995
7
Philips Semiconductors
Product specification
Dual precision monostable multivibrator
HEF4538B
MSI
Fig.5 Waveforms showing minimum I
0
, I
1
, O and C
D
pulse widths, recovery times and propagation delays.
Fig.6 Timing diagram.
(1) Positive edge triggering.
(2) Positive edge re-triggering (pulse lengthening).
(3) Negative edge triggering.
(4) Reset (pulse shortening).
(5) T = R
t
C
t
.
January 1995
8
Philips Semiconductors
Product specification
Dual precision monostable multivibrator
HEF4538B
MSI
Fig.7
Typical normalized change in output pulse width as a function of ambient temperature; 0% at
V
DD
= 10 V and T
amb
= 25
C.
(a) R
t
= 100 k
; C
t
= 100 nF..
(b) R
t
= 100 k
; C
t
= 2 nF.
Fig.8
Typical normalized change in output pulse
width as a function of the supply voltage at
T
amb
= 25
C; 0% at
V
DD
= 10 V; R
t
= 100 k
.
Fig.9
Total supply current as a function of the
output duty factor; R
t
= 100 k
;
C
t
= 100 nF; C
L
= 50 pF. One monostable
multivibrator switching only.
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