Although not specified in the electrical characteristics table, the MAX4999 will pass anything that is within the rails of the part, GND and VCC. The ON-RESISTANCE vs. VCOM plots on page 6 of the datasheet illustrate the typical operating range of the analog signal path. The chip is intended for switching USB data lines, but it could also be used in any switching application. Make sure the signal is within the rails and bandwidth rating of the MAX4999. As mentioned on page 7 of the datasheet, Analog Signal Levels, the internal charge pump provides transmission gate biasing that allows analog signals to exceed the VCC supply, but less than +4V as specified in the absolute maximum rating section on page 2. If the VCC supply is at the minimum 3.0V specified, the analog path will still be able to pass a signal that is up to 3.6V.