Question 12.4: Determine the total voltage gain of the 3656KG isolation amp...

The voltage gain of the input stage is

A_{v 1}=\frac{R_{f 1}}{R_{i 1}}+1=\frac{22  \mathrm{k} \Omega}{2.2  \mathrm{k} \Omega}+1=10+1=11

The voltage gain of the output stage is

A_{v 2}=\frac{R_{f 2}}{R_{i 2}}+1=\frac{47  \mathrm{k} \Omega}{10  \mathrm{k} \Omega}+1=4.7+1=5.7

The total voltage gain of the isolation amplifier is

A_{v(t o t)}=A_{v 1} A_{v 2}=(11)(5.7)=62.7

P R A C T I C E EXERCISE

Select resistor values in Figure 12–12 that will produce a total voltage gain of approximately 100.