General Description
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.

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

Applications
   ATE Equipment
   Data Acquisition
   Industrial and Process Control Systems
   Avionics
   Redundant/Backup Systems