Features and Benefits

  • Triple USB Switch in Tiny 16-Pin QSOP Package
  • Autoreset Feature Saves System Power
  • Guaranteed 500mA Load Current per Channel
  • Built-In 20ms Fault-Blanking Circuitry
  • Active-High/Active-Low Control Logic
  • Fully Compliant to USB Specifications
  • 4V to 5.5V Input Voltage Range
  • Independent Shutdown Control
  • Independent Fault Indicator Outputs
  • Thermal-Overload Protection
  • 3µA Standby Current

Product Details

The MAX1940 triple current-limited switch with auto-reset supplies a guaranteed 500mA load per channel in accordance with USB specifications. The MAX1940 operates from a 4V to 5.5V input supply and consumes only 60µA of quiescent current when operating and only 3µA in standby. Selectable active-high/active-low control logic and independent shutdown controls for each channel provide additional flexibility. An autoreset feature latches the switch off in the event of a short circuit, saving system power. The switch reactivates upon removal of the shorted condition.

The MAX1940 provides several safety features to protect the USB port. Built-in thermal-overload protection turns off the switch when the die temperature exceeds +160°C. Accurate internal current-limiting circuitry protects the input supply against both overload and short-circuit conditions. Independent open-drain fault signals (active-low FAULTA, active-low FAULTB, and active-low FAULTC) notify the microprocessor when a thermal-overload, current-limit, undervoltage lockout (UVLO), or short-circuit fault occurs. A 20ms fault-blanking feature enables the circuit to ignore momentary faults, such as those caused when hot-swapping a capacitive load, preventing false alarms to the host system. The fault-blanking feature also prevents fault signals from being issued when the device powers up the load.

The MAX1940 is available in a space-saving 16-pin QSOP package and operates over the extended (-40°C to +85°C) temperature range.


  • Computers: Desktop, Workstation, Server
  • Docking Stations
  • Notebook Computers
  • PDAs and Palmtop Computers
  • USB Hubs
  • USB Ports

Product Lifecycle icon-recommended Production

At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.

Product Recommendations

MAX1940 Companion Parts

Recommended Related Parts

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.

PCN-PDN Information

Sample & Buy

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Buy Now Pricing

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List Pricing

(*)The 1Ku list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Analog Devices, Inc. authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.


Lead Times

Please see the latest communication from our CCO regarding lead times.



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