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  2. Switches and Multiplexers
  3. Robust Switches and Multiplexers
  4. Fault Protection and Detection Switches and Multiplexers
  5. ADG7421F


Features and Benefits

  • Overvoltage fault protection up to ±60 V on S1 and S2 pins
  • Power-off protection up to ±60 V on S1 and S2 pins
  • Overvoltage detection on S1 and S2 pins
  • Known state output without digital inputs present
  • Low on resistance: 12 Ω typical
  • Ultraflat, on resistance: 0.005 Ω typical
  • Low fault detection threshold voltage: 0.1 V typical
  • 3 kV HBM ESD rating
  • Latch-up immune under any circumstance
  • ±1.8 V to ±2.5 V dual supply operation
  • 1.8 V to 5.5 V single-supply operation
  • 10-Lead, 3 mm × 2 mm LFCSP

Product Details

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.


  • Analog input/output modules
  • Process control/distributed control systems 
  • Data acquisition 
  • Instrumentation 
  • Avionics 
  • Automatic test equipment 
  • Communication systems
  • Relay replacement

Product Lifecycle icon-recommended Recommended for New Designs

This product has been released to the market. The data sheet contains all final specifications and operating conditions. For new designs, ADI recommends utilization of these products.

Evaluation Kits (1)

Tools & Simulations


LTspice® is a powerful, fast and free simulation software, schematic capture and waveform viewer with enhancements and models for improving the simulation of analog circuits.


Models for the following parts are available in LTspice:


IBIS Model

Product Recommendations

ADG7421F Companion Parts

Recommended Analog to Digital Converters

  • 8-Channel, Low Noise, Low Power, 24-Bit, Sigma-Delta ADC with PGA and Reference: AD7124-8.
  • 4-Channel, Low Noise, Low Power, 24-Bit, Sigma-Delta ADC with PGA and Reference: AD7124-4.

Recommended Power Products

  • Ultralow Quiescent Current, 150 mA, CMOS Linear Regulators: ADP162.

Design Resources

ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well.  "Zero defects" for shipped products is always our goal.View our quality and reliability program and certifications for more information.

Part Number Material Declaration Reliability Data Pin/Package Drawing CAD Symbols, Footprints & 3D Models
ADG7421FBCPZ-RL7 Material Declaration Reliability Data 10-Lead LFCSP (3mm x 2mm x 0.75mm)
Wafer Fabrication Data

Sample & Buy

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Buy Now Pricing

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List Pricing

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Lead Times

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Evaluation Boards

Pricing displayed is based on 1-piece.

Up to two boards can be purchased through Analog.com. To order more than two, please purchase through one of our listed distributors.

Pricing displayed is based on 1-piece. The USA list pricing shown is for budgetary use only, shown in United States dollars (FOB USA per unit), and is subject to change. International prices may vary due to local duties, taxes, fees and exchange rates.