As an example design, start with the circuit in Figure 8-4.

• Set the target gain and split the R_G element in half. For this example, target a gain of 41 V/V.
• Assess the DC common-mode biasing on the noninverting inputs. The DC biasing must be in range and have a gain of 1 to the output. This is not illustrated in Figure 8-3.
• If a DC reference is used as the mid-R _G bias, setting the reference equal to the noninverting input bias voltage sets the output common-mode to that voltage. Using a capacitor as illustrated in Figure 8-3 accomplishes the same results.