Fault-Protected, High-Voltage, Dual Analog Switches

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The MAX4631/MAX4632/MAX4633 high-voltage, dual analog switches are pin compatible with the industry-standard DG401/DG403/DG405. They upgrade the existing devices with fault-protected inputs and rail-to-rail signal handling capabilities. The MAX4631/MAX4632/MAX4633's normally open (NO) and normally closed (NC) terminals are protected from overvoltage faults up to 36V during power-up or power-down. During a fault condition, these terminals become open circuit and only nanoamperes of leakage current flow from the source, yet the switch output (COM_) continues to furnish up to 18mA of the appropriate polarity supply voltage to the load. This ensures unambiguous rail-to-rail outputs when a fault begins and ends. On-resistance is 85Ω (max) at +25°C and is matched between switches to 6Ω (max). Off-leakage current is only 0.5nA at +25°C and 5nA at +85°C.

The MAX4631 has two NO single-pole/single-throw (SPST) switches. The MAX4632 has two NO/NC single-pole/double-throw (SPDT) switches. The MAX4633 has two NO double-pole/single-throw (DPST) switches.

These CMOS switches operate with dual power supplies ranging from ±4.5V to ±18V or a single supply between +9V and +36V. All digital inputs have +0.8V and +2.4V logic thresholds, ensuring both TTL- and CMOS-logic compatibility when using ±15V or a single +12V supply.
MAX4631, MAX4632, MAX4633: Pin Configuration MAX4631, MAX4632, MAX4633: Pin Configuration Enlarge+

Key Features

  • Fault Protection
    • ±40V with Power Off
    • ±36V with ±15V Supplies (MAX4631/MAX4633)
    • ±25V with ±15V Supplies (MAX4632)
  • Rail-to-Rail Signal Handling
  • No Power-Supply Sequencing Required
  • All Switches Off with Power Off
  • Output Clamped to Appropriate Supply Voltage During Fault Condition; No Transition Glitch
  • 85Ω (max) Signal Paths with ±15V Supplies
  • ±4.5V to ±18V Dual Supplies
  • +9V to +36V Single Supply
  • Low Power Consumption: <6mW
  • Pin Compatible with Industry-Standard DG401/DG403/DG405
  • TTL- and CMOS-Logic Compatible Inputs with Single +9V to +15V, or ±15V Supplies


  • Automated Test Equipment (ATE)
  • Avionics
  • Data Acquisition
  • Industrial and Process Control Systems
  • Redundant/Backup Systems

See parametric specs for Switches and Multiplexers (Mid and High Voltage) (299)

Part NumberFunctionsConfig.# ChannelsNormal PositionVSUPPLY (Single)
VSUPPLY (Single)
(min)(max)(min)(max)(max)(max)(max)(max)(See Notes)
MAX4631 SwitchSPST2Open9364.518850.5500400102218
SOIC (N)/16
SOIC (N)/16
$4.48 @1k
MAX4633 DPSTOpen
SOIC (N)/16
$4.83 @1k

Pricing Notes:
This pricing is BUDGETARY, for comparing similar parts. Prices are in U.S. dollars and subject to change. Quantity pricing may vary substantially and international prices may differ due to local duties, taxes, fees, and exchange rates. For volume-specific and version-specific prices and delivery, please see the price and availability page or contact an authorized distributor.
Request Reliability Report for: MAX4631 
Device   Fab Process   Technology   Sample size   Rejects   FIT at 25°C   FIT at 55°C   Material Composition  

Note : The failure rates are summarized by technology and mapped to the associated material part numbers. The failure rates are highly dependent on the number of units tested.

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