I would like to use the AD8351 as a variable gain amplifier for a differential signal to an ADC with a differential input. The data sheet gives an equation for the voltage gain, Av, based on Rg and Rl. However, the example circuits for driving an ADC do not show Rl anywhere in the circuit (where there is Rl shown in Figure 34, but not in Figure 40). Is there a different equation that I should use to calculate the voltage gain when driving an ADC? Or is there a value that I should use for Rl when driving an ADC like Figure 40 in the datasheet?