Electronics - Operational Amplifiers - Discussion
Discussion Forum : Operational Amplifiers - General Questions (Q.No. 17)
17.
If a noninverting amplifier has an RIN of 1000 ohms and an RFB of 2.5 kilohms, what is the RIN voltage when 1.42 mV is applied to the correct input?
Discussion:
16 comments Page 1 of 2.
Shaiq said:
5 years ago
Thank you all for explaining.
(1)
Saifudheen said:
7 years ago
Vo=vin * (1+R2/R1)=1.42*3.5.
The voltage across R1 = Vo*(R1/(R1+R2)) = Vo/3.5 = 1.42mv.
The voltage across R1 = Vo*(R1/(R1+R2)) = Vo/3.5 = 1.42mv.
(1)
Satish kumar said:
8 years ago
Vo=Vin(1+Rf/Rin)).
Vo=1.42*10^3(1+2.5*10^3/100.0)
Vo=4.97mV.
The Voltage across Rin=Rin*Vo/Rin+Rf.
= 1.42mV.
Vo=1.42*10^3(1+2.5*10^3/100.0)
Vo=4.97mV.
The Voltage across Rin=Rin*Vo/Rin+Rf.
= 1.42mV.
Naeem Khattak said:
8 years ago
@Daks.
Thanks for solving the question in detail.
Thanks for solving the question in detail.
Manisha khurana said:
9 years ago
This is not virtual ground situation. Virtual ground is the case when terminal is grounded directly but here there is feedback from output.
Ajinkya said:
9 years ago
As the circuit is non-inverting, it means there is no change at the o/p voltage. That means I/p voltage = o/p voltage.
Thank you.
Thank you.
Caro said:
1 decade ago
2.5/1000+1x1.42 = 1.42.
Daks said:
1 decade ago
Vin = Vo((Rf/R1)+1)).
Vin = 1.42mv*3.5
Vin = 4.97mv.
The current passing throughout RF and R1.
RF+R1 = 3.5K.
I = Vout/RT.
I = 4.97mV/3.5k.
I = 1.42X10-6 amps.
Vr = I*R1.
Vr = 1.42x10-6 x 1k.
Vr = 1.42mv.
Vin = 1.42mv*3.5
Vin = 4.97mv.
The current passing throughout RF and R1.
RF+R1 = 3.5K.
I = Vout/RT.
I = 4.97mV/3.5k.
I = 1.42X10-6 amps.
Vr = I*R1.
Vr = 1.42x10-6 x 1k.
Vr = 1.42mv.
(1)
Dharm said:
1 decade ago
How to solve this ?
ASHOK KUMAR.R said:
1 decade ago
According to the Virtual Ground concept if the inverting terminal is Grounded then the Rin will looks like parallel to that of the source.
So the voltage drop across the Rin is equal to the applied voltage.
So voltage across Rin is 1.42mA.
So the voltage drop across the Rin is equal to the applied voltage.
So voltage across Rin is 1.42mA.
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