- #1
zak8000
- 74
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small signal diode modelling i understand what it is but when i get asked a question like:
if vin(t)=2.5+cos(2*pi*100*t) for 0<t<30
use the small signal model of the diode to predict the output voltage of the circuit i have added. assume the opamp is ideal R=2000 Is=10e-16
so i know that the small signal equation is
id=(ID/VT)*vd where VT=0.0252
now since the opamp is ideal zero current is drawn in and since the configuration is in the inverting configuration then Vout=-vD
now i know i have to somehow dervive and expression for Vout using the small signal diode model equation which is
id(ac current)=(ID(dc current)/0.0252))*vd(ac voltage)
i also know that ID=Is*e(vD/VT)
=(10e-16)*e(vD/0.0252)
subbing into the small signal diode model equation
id=((10e-16)*e(vD/0.0252)/0.0252)*vd
and now i get lost and stuck because i don't know what to do or if i am doing the right thing in order to derive and expression for vout using the small signal diode model
please help!
if vin(t)=2.5+cos(2*pi*100*t) for 0<t<30
use the small signal model of the diode to predict the output voltage of the circuit i have added. assume the opamp is ideal R=2000 Is=10e-16
so i know that the small signal equation is
id=(ID/VT)*vd where VT=0.0252
now since the opamp is ideal zero current is drawn in and since the configuration is in the inverting configuration then Vout=-vD
now i know i have to somehow dervive and expression for Vout using the small signal diode model equation which is
id(ac current)=(ID(dc current)/0.0252))*vd(ac voltage)
i also know that ID=Is*e(vD/VT)
=(10e-16)*e(vD/0.0252)
subbing into the small signal diode model equation
id=((10e-16)*e(vD/0.0252)/0.0252)*vd
and now i get lost and stuck because i don't know what to do or if i am doing the right thing in order to derive and expression for vout using the small signal diode model
please help!