The OPAx486 features a proprietary input stage design that allows an input differential voltage to be applied while maintaining high input impedance. Typically, high-voltage CMOS or bipolar-junction input amplifiers feature antiparallel diodes that protect input transistors from large gate to source (V_GS) voltages that can exceed the semiconductor process maximum and permanently damage the device. Large V_GS voltages can be forced when applying a large input step, switching between channels, or attempting to use the amplifier as a comparator.

The OPAx486 solves these problems with a switched-input technique that prevents large input bias currents when large differential voltages are applied. This input architecture addresses many issues seen in switched or multiplexed applications, where large disruptions to RC filtering networks are caused by fast switching between large potentials.Figure 6-2 shows a typical application where MUX-Friendly inputs can improve settling time performance. The OPAx486 offers outstanding settling performance as a result of these design innovations and built-in slew-rate boost and wide bandwidth. The OPAx486 can also be used as a comparator. Differential and common-mode input ranges still apply.

Figure 6-2 Multiplexed Application