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LaunchpadP1.1 attached to touch screen topP1.2 attached to touch screen right

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But…

P1.1 and P1.2 attached to J3

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Multivibrators and wave

shaping circuits

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Multivibrators

• Bistable

• Monostable (one shot)

• stable

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Monostable !ultivibrator   V  c  c

C1

   R   1   1   k

-

++

3

2

6

   7

   4

Comparator 

   R

   2   1   k

   R   3   1   k

Vin

Vout

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Figure 13.19 (a) "he bistable circuit o# $ig. 13.1% with the negative input ter!inal o# the op a!p disconnected #ro!ground and connected to an input signal v I. (b) "he trans#er characteristic o# the circuit in (a) #or increasing v I. (c) "he

trans#er characteristic #or decreasing v I. (d) "he co!plete trans#er characteristics.

Schmitt Trigger(voltage output)

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Figure 13.24 (a) &onnecting a bistable !ultivibrator with inverting trans#er characteristics in a #eedbac' loop with an& circuit results in a suare*wave generator.

Relaxation !cillator" a!tablemultivibrator

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Figure 13.24 (Continued) (b) "he circuit obtained when the

bistable !ultivibrator is i!ple!ented with the circuit o# $ig. 13.1+(a).(c) ,ave#or!s at various nodes o# the circuit in (b). "his circuit iscalled an astable !ultivibrator.

Relaxation!cillator

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Figure 13.23 Li!iter circuits are used to obtain !ore precise output levels #or the bistable circuit. -n both circuitsthe value o# R should be chosen to ield the current reuired #or the proper operation o# the /ener diodes. (a) $orthis circuit L0  V  Z 1

 0 V D and L  (V  Z 2 0 V D) where V D is the #orward diode drop. (b) $or this circuit L0  V  Z  0 V D1

 0

V D2 and L  (V  Z  0 V D3

 0 V D4).

utput #imiting

100

5 0 49100 10 000

thresholdv . V,= ± = ±+

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Figure 13.2$ bloc' diagra! representationo# the internal circuit o# the 555 integrated*

circuit ti!er.

%%% Timer

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Figure 13.29 (a) "he 555 ti!er connected to i!ple!ent an astable !ultivibrator. (b) ,ave#or!s o# the circuit in (a).

&!table

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Figure 13.2' (a) "he 555 ti!er connected to i!ple!ent a !onostable !ultivibrator. (b) ,ave#or!s o# the circuit in(a).

6control  varies width

ono!table

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6ariable voltage

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Figure 13.31 (a) three*seg!ent

sine*wave shaper. (b) "he inputtriangular wave#or! and the outputappro7i!atel sinusoidal wave#or!