Description

The ADG7421F is a low voltage, dual single-pole/single-throw (SPST), low on-resistance switch that features overvoltage protection, power-off protection, and overvoltage detection on the source pins.When no power supplies are present, the switch remains in the off condition, and the switch inputs are high impedance. When powered, if the analog input signal levels on the Sx pins exceed VDD or VSS by a threshold voltage, VT, the switch automatically turns off and the digital FF (fault flag) pin drops to a logic low to indicate a fault.Input signal levels up to +60 V or ?60 V relative to ground are blocked, in both the powered and unpowered condition. The switches turn on with a Logic 1 input and conducts equally well in both directions with an analog signal range of VSS + 0.1 V to VDD ? 0.55 V for a 5 V single supply. The digital input is compatible with 1.8 V logic inputs over the full operating supply range.The ADG7421F is ideal for providing overvoltage protection for small signals such as resistance temperature device (RTD) inputs (see Figure 56 in the data sheet) and thermocouple inputs (see Figure 55). The ability to protect against high voltages up to ?60 V coupled with a low voltage supply can enable complete low voltage input stages for industrial applications.APPLICATIONS Analog input/output modules Process control/distributed control systems? Data acquisition? Instrumentation? Avionics? Automatic test equipment? Communication systems Relay replacement

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Part number: EVAL-ADG7421FEBZ

More details from Analog Devices Inc.