This slide will take a look at a common application example for analog switches: the 74HC4851 8-to-1 analog multiplexer. These are often used in automotive applications to route a large number of analog signals, such as from various temperature sensors to a single high-quality A-to-D converter. Common requirements for the A-to-D are 12 bits of resolution and 5 mV accuracy with as little as 125 microsecond sample time per channel. The challenge is how to compensate for the additional charge being injected into the switch, causing voltage of the input signals to rise.