monostable

1. ! "
#$%$ &' & &'
1. Introduction
1.1 Le fonctionnement
1.1.1 ( ) ) * +
,* , " - + -" .
( ) " + * /
( " * 0" 1 * , , " , ) "
2
*" "3 0 - " * + "4 5 " "** * 6
- + , "4 2 & 4 +- ,* 3"4 *" - " ) "
6 " "4 2
1.1.2 , + 3 * +" *" +- " "4 ) - 6
+ ) . 3 " + 0 , +- " 6 -"
" 7"," "4 / *" 3" , + 2
," . 5 3" , + 4 "4 . * + + 5 " "4
/ 4" 2
1.2 Exemple de chronogrammes de fonctionnement
1.2.1 Cas du monostable

2. ! "
1.2.2 Cas de l'astable
1.3 Représentation
1.3.1 Cas du monostable
," . " * + 8 8+ 3 , "4 * 1 + 9
- : / -"** " 2 "4 )
-"3 + +- 2

3. ;
! "
1.3.2 Cas de l'astable
2. Exemples d'utilisation en électronique
2.1 Le monostable
# : , +-,* 4 0 2
5 ,* . ,* ,4 + * 9"< + :"4 " + +- "*
+ :. *" "3 * "*+ )-,* +-1 *4 0 * 1 *
,* / "7 " , "4 * " 3 "+ + -,* 2
2.2 L'astable
9, : , + .3 " +- 3 "
+-9 3 => + 6 +- ?' @2
3. Réalisations structurelles
5 + ,4 * 4 * " , "4 " "4 /*",
) 0 * *" , 0" .
& " + * 3 )+ " +- + " /
& " +- & )+ " +- + " /
( " +- 3 * " " 6+ " + "
=0 + , " 9 @2

4. ! "
3.1 ASTABLE et MONOSTABLE : Circuit intégré NE555
% * " +" "* + + 3 " 52
* , " " " + ,* " " " + , + 6
+ 2
A4 "3 :: ) * " - " 4 " "4 - , "4 2
* + ", ," .
.#"
. + + 9 ,
; .
. , 6B
C . + 4" ,
D .E 9"3
F .!
3.1.1 On désire utiliser le même circuit en astable :
:: A4 "3 + + ," 6 - " "4 2
G * + . H )D = & I ' @J H 9 H ,* " 9" 2
H )D ' J H 4 H ,* " 4"2
E , & ) ' J + ," 6 4 3 " * + +
: KLB + "** )F 2 "** " " " ": +
" 50" + ,* " 2
$ :5 .JH

5. ! "
3.1.2 On désire utiliser le même circuit en monostable :
:: A4 "3 + + ," 6 - , "4 2
E" , + . H ) J
E , J + ," 6 4 ,* + + , 2
$ :5 .JH
3.2 ASTABLE : Oscillateur à Trigger de Schmitt
" * * +M , *" : = J@ + *
N 33 O+ 9 3 J#$ + + 4" , .! L H ) ! /
! H ) ! 2

6. C
! "
$ + -6 - 3 + ,*) + " J + 9"3 * J#$
" , I !2
"2 P "0" " + " + ! Q
42 &0 H RΩ J H ) " " " + ,* τ2
2 J ,* 9 3",, + .
+2 E " " " " " + ,* τ 6 "* + + (2

7. D
! "
3.3 ASTABLE : à Amplificateur Intégré Linéaire
" " " +- &2 2 2 : " 3, + ,, " 2
" , , , I ! + *":" 2
H RΩ / H )RΩ / ; H )D RΩ JH D
& - 3 )J + 9"3 .(J H !2
"2 J ,* 9 3",, + * " 0" *" 2

8. F
! "
42 E " " " " " + ,* + " 6 ": + 3 "
! 2
3.4 MONOSTABLE : à portes logiques CMOS
"2 J ,* 9 3",, + " + .
G )G .* 3 %$% + 9 3 J#$ /& , " .! H I !2
+ * .!
H RΩ /J H
J + " .(J H ! /! H $! /! H !
42 E " " " "3 +-,* =S@+ ! " 5 , + " 2

9. ! "
3.5 MONOSTABLE : Circuit spécialisé 74121
$ + " , "4 6 -"+ + * " D 2 "+ , "
+ + * 4 +" N # #$ JL O2
"+ + -,* + + 1 + , =I T@2
"0" 6:" .
+ 9 ," )
+, ,* " )
* * 9 3",, + 3 " 5+- + 2