The designer might ask why not simply use resistors to perform voltage division? Resistors can certainly be used for some applications but they consume power and limit the operating frequency and create a delay (when the designer includes the C of the input device). Figure 1 illustrates the use of two resistors to limit the voltage on the DSP. For simplicity, this article will not take into account tolerance issues. That will be left to the reader if he chooses this approach. In all cases, we will use V1 = 3.3 V, V2 = 1.2 V, f = 35 MHz, and CIN = 10 pf. If 640 and 330 resistors