In an ideal switch, as shown in the this slide, whatever input is applied to the switch should appear at the output or vice versa. In real world that is not possible, switches always have some losses. The competitive environment today creates a constant need for higher performance. One common method to optimize system performance is to use FET switches. The TI signal switch product family consists of digital, analog and specialty switches to provide high performance, low-power replacements for standard bus-interface devices when signal buffering is not required. Texas Instruments also has smart switches with impedance detection micro-USB switches to support USB, UART, audio and charger applications. These switches are used in the cell phones, note book, MID, etc.