Single 8/Differential 4-Channel CMOS Analog Multiplexers with Active Overvoltage Protection

The HI-548/883 and HI-549/883 are analog multiplexers with active overvoltage protection and guaranteed rON matching. Analog input levels may greatly exceed either power supply without damaging the device or disturbing the signal path of other channels. Active protection circuitry assures that signal fidelity is maintained even under fault conditions that would destroy other multiplexers. Analog inputs can withstand constant 70VP-P levels with ±15V supplies. Digital inputs will also sustain continuous faults up to 4V greater than either supply. In addition, signal sources are protected from short circuiting should multiplexer supply loss occur. Each input presents 1kΩ of resistance under this condition. These features make the HI-548/883 and HI-549/883 ideal for use in systems where the analog inputs originate from external equipment or separately powered circuitry. Both devices are fabricated with 44V Dielectrically Isolated CMOS technology. The HI-548/883 is an 8-channel device, and the HI-549/883 is a 4-channel differential version. If input overvoltage protection is not needed, the HI-508/883 and HI-509/883 multiplexers are recommended. For further information see Application Note AN520.