SLOA011B January 2018 – July 2021 LF347 , LF353 , LM348 , MC1458 , TL022 , TL061 , TL062 , TL071 , TL072 , UA741
Substituting a = ∞ Equation 1 into Equation 16 results in,
Recall that in equation Equation 6 we state that V_{d}, the voltage difference between V_{n} and V_{p}, is equal to zero and therefore, V_{n} = V_{p}. Still they are not shorted together. Rather there is said to be a virtual short between V_{n} and V_{p}. The concept of the virtual short further simplifies analysis of the non-inverting op amp circuit in Figure 2-1.
Using the virtual short concept, we can say that,
Realizing that finding Vn is now the same resistor divider problem solved in Equation 12 and substituting Equation 18 into it, we get,
Rearranging and solving for A, we get,
The same result is derived in Equation 17. Using the virtual short concept reduced solving the non-inverting amplifier, shown in Figure 2-1, to solving a resistor divider network.