The MAX4578/MAX4579 are high-voltage, 8-channel CMOS multiplexers. The MAX4578 and dual 4-channel MAX4579 are ideal for precision ADC calibration and system self-monitoring applications. These calibration multiplexers (cal-muxes) have precision resistordividers to generate accurate voltage ratios from an input reference voltage. The reference ratios include 15/4096 and 4081/4096 of the external reference voltage, accurate to 15 bits, and 1/2(V+) and 5/8(V+ - V-), accurate to 8 bits. The external reference voltage as well as ground can also be switched to the output. The MAX4578/MAX4579 have enable inputs and address latching. All digital inputs have 0.8V and 2.4V logic thresholds, ensuring both TTL- and CMOS-logic compatibility when using a single +12V or dual 15V supplies. Protection diodes at all inputs provide >2kV ESD rating.