Datasheet

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.=–=