Monostable/astable multivibrator
DATA SHEET
Product specification
File under Integrated Circuits, IC04
January 1995
INTEGRATED CIRCUITS
HEF4047B
MSI
Monostable/astable 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
Monostable/astable multivibrator
HEF4047B
MSI
DESCRIPTION
The HEF4047B consists of a gatable astable multivibrator
with logic techniques incorporated to permit positive or
negative edge-triggered monostable multivibrator action
with retriggering and external counting options.
Inputs include + TRIGGER,
-
TRIGGER, ASTABLE,
ASTABLE, RETRIGGER and MR (Master Reset).
Buffered outputs are O, O and OSCILLATOR OUTPUT. In
all modes of operation an external capacitor (C
t
) must be
connected between C
TC
and RC
TC
, and an external
resistor (R
t
) must be connected between R
TC
and
RC
TC
(continued on next page).
FAMILY DATA, I
DD
LIMITS category MSI
See Family Specifications
Fig.1 Functional diagram.
January 1995
3
Philips Semiconductors
Product specification
Monostable/astable multivibrator
HEF4047B
MSI
Astable operation is enabled by a HIGH level on the
ASTABLE input. The period of the square wave at O and
O outputs is a function of the external components
employed. `True' input pulses on the ASTABLE or
`complement' pulses on the ASTABLE input, allow the
circuit to be used as a gatable multivibrator. The
OSCILLATOR OUTPUT period will be half of the O output
in the astable mode. However, a 50% duty factor is not
guaranteed at this output.
In the monostable mode, positive edge-triggering is
accomplished by applying a leading-edge pulse to the
+ TRIGGER input and a LOW level to the
-
TRIGGER
input. For negative edge-triggering, a trailing-edge pulse is
applied to the
-
TRIGGER and a HIGH level to the
+ TRIGGER. Input pulses may be of any duration relative
to the output pulse. The multivibrator can be retriggered
(on the leading-edge only) by applying a common pulse to
both the RETRIGGER and + TRIGGER inputs. In this
mode the output pulse remains HIGH as long as the input
pulse period is shorter than the period determined by the
RC components.
An external count down option can be implemented by
coupling O to an external `N' counter and resetting the
counter with the trigger pulse. The counter output pulse is
fed back to the ASTABLE input and has a duration equal
to N times the period of the multivibrator. A HIGH level on
the MR input assures no output pulse during an ON-power
condition. This input can also be activated to terminate the
output pulse at any time. In the monostable mode, a HIGH
level or power-ON reset pulse must be applied to MR,
whenever V
DD
is applied.
Fig.2 Pinning diagram.
HEF4047BP(N):
14-lead DIL; plastic
(SOT27-1)
HEF4047BD(F):
14-lead DIL; ceramic (cerdip)
(SOT73)
HEF4047BT(D):
14-lead SO; plastic
(SOT108-1)
( ): Package Designator North America
January 1995
4
Philips Semiconductors
Product specification
Monostable/astable multivibrator
HEF4047B
MSI
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Fig.3 Logic diagram.
(1) Special input protection that allows operating input voltages
outside the supply voltage lines. Compared to the standard input
protection pin 3 is more sensitive to static discharge; extra
handling precautions are recommended.
January 1995
5
Philips Semiconductors
Product specification
Monostable/astable multivibrator
HEF4047B
MSI
FUNCTIONAL CONNECTIONS
Notes
1. Input pulse to RESET of external counting chip; external counting chip output to pin 4.
2. In all cases, external resistor between pins 2 and 3, external capacitor between pins 1 and 3.
DC CHARACTERISTICS
V
SS
= 0 V; inputs at V
SS
or V
DD
FUNCTION
PINS CONNECTED TO
OUTPUT
PULSE
FROM
PINS
OUTPUT
PERIOD
OR
PULSE WIDTH
V
DD
V
SS
INPUT
PULSE
astable multivibrator
free running
4, 5, 6, 14
7, 8, 9, 12
-
10, 11, 13
at pins 10, 11:
true gating
4, 6, 14
7, 8, 9, 12
5
10, 11, 13
t
A
= 4,40 R
t
C
t
at pin 13:
t
A
= 2,20 R
t
C
t
complement gating
6, 14
5, 7, 8, 9, 12
4
10, 11, 13
monostable multivibrator
pos. edge-triggering
4, 14
5, 6, 7, 9, 12
8
10, 11
neg. edge-triggering
4, 8, 14
5, 7, 9, 12
6
10, 11
at pins 10, 11:
retriggerable
4, 14
5, 6, 7, 9
8, 12
10, 11
t
M
= 2,48 R
t
C
t
external count down
(1)
14
5, 6, 7, 8, 9, 12
-
10, 11
V
DD
V
SYMBOL
T
amb
(
C)
-
40
+
25
+
85
MAX.
MIN.
MAX.
MAX.
Leakage current
15
I
3
0,3
-
0,3
1
A
pin 3 at
V
DD
or V
SS
pin 3; output
transistor OFF
January 1995
6
Philips Semiconductors
Product specification
Monostable/astable multivibrator
HEF4047B
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
ASTABLE, ASTABLE
OSC. OUTPUT
5
95
190
68 ns
+
(0,55 ns/pF) C
L
HIGH to LOW
10
t
PHL
45
90
43 ns
+
(0,23 ns/pF) C
L
15
30
60
22 ns
+
(0,16 ns/pF) C
L
5
85
170
58 ns
+
(0,55 ns/pF) C
L
LOW to HIGH
10
t
PLH
40
80
29 ns
+
(0,23 ns/pF) C
L
15
30
60
22 ns
+
(0,16 ns/pF) C
L
ASTABLE, ASTABLE
O, O
5
150
300
123 ns
+
(0,55 ns/pF) C
L
HIGH to LOW
10
t
PHL
65
130
54 ns
+
(0,23 ns/pF) C
L
15
50
100
42 ns
+
(0,16 ns/pF) C
L
5
130
260
103 ns
+
(0,55 ns/pF) C
L
LOW to HIGH
10
t
PLH
60
120
49 ns
+
(0,23 ns/pF) C
L
15
45
90
37 ns
+
(0,16 ns/pF) C
L
+
/
-
TRIGGER
O, O
5
160
320
133 ns
+
(0,55 ns/pF) C
L
HIGH to LOW
10
t
PHL
65
130
54 ns
+
(0,23 ns/pF) C
L
15
50
100
42 ns
+
(0,16 ns/pF) C
L
5
155
310
128 ns
+
(0,55 ns/pF) C
L
LOW to HIGH
10
t
PLH
65
130
54 ns
+
(0,23 ns/pF) C
L
15
50
100
42 ns
+
(0,16 ns/pF) C
L
+
TRIGGER, RETRIGGER
O
5
65
130
38 ns
+
(0,55 ns/pF) C
L
HIGH to LOW
10
t
PHL
30
60
19 ns
+
(0,23 ns/pF) C
L
15
25
50
17 ns
+
(0,16 ns/pF) C
L
+
TRIGGER, RETRIGGER
O
5
95
190
68 ns
+
(0,55 ns/pF) C
L
LOW to HIGH
10
t
PLH
40
80
29 ns
+
(0,23 ns/pF) C
L
15
30
60
22 ns
+
(0,16 ns/pF) C
L
MR
O
5
100
200
83 ns
+
(0,55 ns/pF) C
L
HIGH to LOW
10
t
PHL
45
90
34 ns
+
(0,23 ns/pF) C
L
15
35
70
27 ns
+
(0,16 ns/pF) C
L
MR
O
5
100
200
83 ns
+
(0,55 ns/pF) C
L
LOW to HIGH
10
t
PLH
45
90
34 ns
+
(0,23 ns/pF) C
L
15
35
70
27 ns
+
(0,16 ns/pF) C
L
Output transition times
5
60
120
10 ns
+
(1,0 ns/pF) C
L
HIGH to LOW
10
t
THL
30
60
9 ns
+
(0,42 ns/pF) C
L
15
20
40
6 ns
+
(0,28 ns/pF) C
L
5
60
120
10 ns
+
(1,0 ns/pF) C
L
LOW to HIGH
10
t
TLH
30
60
9 ns
+
(0,42 ns/pF) C
L
15
20
40
6 ns
+
(0,28 ns/pF) C
L
January 1995
7
Philips Semiconductors
Product specification
Monostable/astable multivibrator
HEF4047B
MSI
Minimum MR pulse
5
60
30
width; HIGH
10
t
WMRH
30
15
15
20
10
Minimum input
pulse width; any
5
220
110
input exept MR
10
t
W
100
50
15
70
35
V
DD
V
SYMBOL MIN. TYP. MAX.
TYPICAL EXTRAPOLATION
FORMULA
APPLICATION INFORMATION
General features:
Monostable (one-shot) or astable (free-running)
operation
True and complemented buffered outputs
Only one external R and C required
Monostable multivibrator features:
Positive- or negative-edge triggering
Output pulse width independent of trigger pulse duration
Retriggerable option for pulse-width expansion
Long pulse width possible using small RC components
by means of external counter provision
Fast recovery time essentially independent of pulse
width
Pulse-width accuracy maintained at duty cycles
approaching 100%
Astable multivibrator features:
Free-running or gatable operating modes
50% duty cycle
Oscillator output available
January 1995
8
Philips Semiconductors
Product specification
Monostable/astable multivibrator
HEF4047B
MSI
1. Astable mode design information
a. Unit-to-unit transfer-voltage variations
The following analysis presents worst-case variations from unit-to-unit as a function of transfer-voltage (V
TR
) shift for free
running (astable) operation.
Values for t
A
are:
thus if t
A
= 4,40 R
t
C
t
is used, the maximum variation will be (+ 7,0%;
-
0,0%) at 10 V.
typ. : V
TR
= 0,5 V
DD
;
t
A
= 4,40 R
t
C
t
V
DD
= 5 or 10 V
min. : V
TR
= 0,3 V
DD
;
t
A
= 4,71 R
t
C
t
max.: V
TR
= 0,7 V
DD
;
t
A
= 4,71 R
t
C
t
V
DD
= 15 V
min. : V
TR
= 4 V;
t
A
= 4,84 R
t
C
t
max.: V
TR
= 11 V;
t
A
= 4,84 R
t
C
t
Fig.4 Astable mode waveforms.
t
1
R
t
C
t
In
V
TR
V
DD
V
TR
+
----------------------------
=
t
2
R
t
C
t
In
V
DD
V
TR
2V
DD
V
TR
-------------------------------
=
t
A
2 t
1
t
2
+
(
)
2R
t
C
t
In
V
TR
(
)
V
DD
V
TR
(
)
V
DD
V
TR
+
(
)
2V
DD
V
TR
(
)
-------------------------------------------------------------------------
, where t
A
Astable mode pulse width.
=
=
=
January 1995
9
Philips Semiconductors
Product specification
Monostable/astable multivibrator
HEF4047B
MSI
b. Variations due to changes in V
DD
In addition to variations from unit-to-unit, the astable period may vary as a function of frequency with respect to V
DD
.
Typical variations are presented graphically in Figs 5 and 6 with 10 V as a reference.
CURVE
f
O
kHz
C
t
pF
R
t
k
A
10
100
220
B
5
100
470
C
1
1000
220
Fig.5 Typical O and O period accuracy as a function of supply voltage; astable mode; T
amb
= 25
C.
January 1995
10
Philips Semiconductors
Product specification
Monostable/astable multivibrator
HEF4047B
MSI
CURVE
f
O
kHz
C
t
pF
R
t
k
A
500
10
47
B
225
100
10
C
100
100
22
D
50
100
47
Fig.6 Typical O and O period accuracy as a function of supply voltage; astable mode; T
amb
= 25
C.
January 1995
11
Philips Semiconductors
Product specification
Monostable/astable multivibrator
HEF4047B
MSI
2. Monostable mode design information
The following analysis presents worst case variations from unit-to-unit as a function of transfer-voltage (V
TR
) shift for
one-shot (monostalbe) operation.
Values for t
M
are:
Note
1. In the astable mode, the first positive half cycle has a duration of t
M
; succeeding durations are
1
/
2
t
A
.
thus if t
M
= 2,48 R
t
C
t
is used, the maximum variation will be (+ 12%;
-
0,0%) at 10 V.
typ. : V
TR
= 0,5 V
DD
; t
M
= 2,48 R
t
C
t
V
DD
= 5 to10 V
min. : V
TR
= 0,3 V
DD
; t
M
= 2,78 R
t
C
t
max.: V
TR
= 0,7 V
DD
; t
M
= 2,52 R
t
C
t
V
DD
= 15 V
min. : V
TR
= 4 V;
t
M
= 2,88 R
t
C
t
max.: V
TR
= 11 V;
t
M
= 2,56 R
t
C
t
Fig.7 Monostable waveforms.
t
1
`
R
t
C
t
In
V
TR
2V
DD
--------------
=
t
M
t
1
'
t
2
+
(
)
=
t
M
R
t
C
t
In
V
TR
(
)
V
DD
V
TR
(
)
2V
DD
V
TR
(
)
2V
DD
(
)
------------------------------------------------------------
, where t
M
Monostable mode pulse width.
=
=
January 1995
12
Philips Semiconductors
Product specification
Monostable/astable multivibrator
HEF4047B
MSI
3. Retrigger mode operation
The HEF4047B can be used in the retrigger mode to extend the output pulse duration, or to compare the frequency of
an input signal with that of the internal oscillator. In the retrigger mode the input pulse is applied to pins 8 and 12, and
the output is taken from pin 10 or 11. Normal monostable action is obtained when one retrigger pulse is applied (Fig.8).
Extended pulse duration is obtained when more than one pulse is applied. For two input pulses, t
RE
= t
1
' + t
1
+ 2t
2
.
For more than two pulses, t
RE
(output O), terminates at some variable time, t
D
, after the termination of the last retrigger
pulse; t
D
is variable because t
RE
(output O) terminates after the second positive edge of the oscillator output appears at
flip-flop 4.
4. External counter option
Time t
M
can be extended by any amount with the use of external counting circuitry. Advantages include digitally
controlled pulse duration, small timing capacitors for long time periods, and extremely fast recovery time. A typical
implementation is shown in Fig.9.
The pulse duration at the output is:
Where t
ext
= pulse duration of the circuitry, and N is the number of counts used.
Fig.8 Retrigger mode waveforms.
t
ext
N
1
(
)
t
A
( )
t
M
1 2 t
A
/
+
(
)
+
=
Fig.9 Implementation of external counter option.
January 1995
13
Philips Semiconductors
Product specification
Monostable/astable multivibrator
HEF4047B
MSI
5. Timing component limitations
The capacitor used in the circuit should be non-polarized and have low leakage (i.e. the parallel resistance of the
capacitor should be an order of magnitude greater than the external resistor used).
There is no upper or lower limit for either R
t
or C
t
value to maintain oscillation.
However, in consideration of accuracy, C
t
must be much larger than the inherent stray capacitance in the system (unless
this capacitance can be measured and taken into account).
R
t
must be much larger than the LOCMOS `ON' resistance in series with it, which typically is hundreds of ohms.
The recommended values for R
t
and C
t
to maintain agreement with previously calculated formulae without trimming
should be:
C
t
100 pF, up to any practical value,
10 k
R
t
1 M
.
6. Power consumption
In the standby mode (monostable or astable), power dissipation will be a function of leakage current in the circuit.
For dynamic operation, the power needed to charge the external timing capacitor C
t
is given by the following formulae:
Because the power dissipation does not depend on R
t
, a design for minimum power dissipation would be a small value
of C
t
. The value of R would depend on the desired period (within the limitations discussed previously).
Typical power consumption in astable mode is shown in Figs 10, 11 and 12.
Astable mode:
P = 2 C
t
V
2
f (f at output pin 13)
P = 4 C
t
V
2
f (f at output pins 10 and 11)
Monostable mode:
P =
2 9 C
t
V
2
,
duty cycle
(
)
T
---------------------------------------------------------------------
f at output pins 10 and 11
(
)
January 1995
14
Philips Semiconductors
Product specification
Monostable/astable multivibrator
HEF4047B
MSI
Fig.10 Power consumption as a function of the output frequency at O or O; V
DD
= 5 V; astable mode.
Fig.11 Power consumption as a function of the output frequency at O or O; V
DD
= 10 V; astable mode.
January 1995
15
Philips Semiconductors
Product specification
Monostable/astable multivibrator
HEF4047B
MSI
Fig.12 Power consumption as a function of the output frequency at O or O; V
DD
= 15 V; astable mode.
Document Outline
- DESCRIPTION
- FUNCTIONAL CONNECTIONS
- DC CHARACTERISTICS
- AC CHARACTERISTICS
- APPLICATION INFORMATION
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