disp('chapter 9 ex9.7') disp('given') disp('design a monostable multivibrator to have output pulse width 1ms when triggered by 2volt,100*10^(-6)s input pulse') disp('using 741 op-amp with a supply of +or-12volt') PW=1*10^(-3) t=100*10^(-6) disp('I2>IBmax') disp('let I2=50*10^(-6)A and VBE=0.7volt') IBmax=500*10^(-9) I2=50*10^(-6) VBE=0.7 Vcc=12 disp('let VR2<Vi') disp('let VR2=0.5volt') VR2=0.5 disp('R2=VR2/I2') R2=VR2/I2 disp('ohms',R2) //standard value disp('R1=(Vcc-VR2)/I2') R1=(Vcc-VR2)/I2 disp('ohms',R1) disp('use 220kohm standard value') R1=220000 disp('E=VR2-[-Vosat]') E=VR2-[-Vcc+1] disp('volts',E) disp('Eo=-(+Vosat-VR2)') Eo=-(Vcc-1-VR2) disp('volts',Eo) disp('ec=Vosat') ec=Vcc-1 disp('volts',ec) disp('C2=PW/((R1||R2)*ln[(E-Eo)/(E-ec)])') C2=PW/((R1*R2/(R1+R2))*2.303*log10([(E-Eo)/(E-ec)])) disp('farads',C2) disp('R3max=0.1*VBE/IBmax') R3max=0.1*VBE/IBmax disp('ohms',R3max) disp('use 120kohm standard value') R3=120000 disp('C1=0.1*t/R3') C1=0.1*t/R3 disp('farads',C1) disp('use 91pF standard value')