KCC's Quizzes AQQ305 about a mutual exponentiation equation
1. Quote of the month: "A train station is where a train stops. A bus station is where a bus stops. I have a work station on my desk, so..." - unknown
2. Quiz AQQ305 about finding a mutual exponential equation
Good luck, and try to be among the
View All
September Monthly Blog Quiz! Read the blog, take the quiz, and you could win a gift card
Quiz: How Well Do You Know Adaptive Power Switching?
Is your I/O module overheating? The AD74416H's Adaptive Power Switching (APS) can cut heat dissipation by up to 40% — but how well do you really understand how it works?
Read the blog first: Cooling
View All
High input resistance and high gain Inverting amplifier can be needed in some applications.
In such case an even larger feedback resistor is required. Too large resistors have issues like precision, availability and excessive stray capacitance.
The here below circuit is a way to maintain both a high input resistance, a high gain and still using not too large feedback resistors.
Questions:

Good luck and try to be among the first!
And communicate this around you (colleagues, partners, customers and friends)!

The inverting input of the opamp can be considered at virtual ground potential.
The R2 and Rg resistors are in parallel.
R2g= R2Rg/(R2+Rg) = 100/101.
Ro = R3 + R2g = 100 + 100/101 = 101k
Since the input is available at the junction of R2 and R3.
The gain can be evaluated as Av= Ro/R2g
2. Av = - 101/0.99 = -102
1. Rin in this case is R1 = 100k.
ANd you are right again ! Congratulations!
ANd you are right again ! Congratulations!