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MAX1940
Triple USB Switch with Autoreset and Fault Blanking


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Data Sheet
FULL DATA SHEET (PDF, 332kB)
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Description
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.

Key Features   Applications/Uses
  • 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
  • UL Certification Pending

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

    Key Specifications:   USB Power Switches
    Part Number Functions Number of Switches Max. Load Current (A) RON (typ) (Ω) Fault Indicator Fault Blanking Timeout (ms) Switch Op. Voltage Range (V) Package Operating Temp. Range (°C) Price**
    MAX1940 
    Active High/Active Low Control Logic
    3 0.5 0.085 Yes 20 4.0 to 5.5 QSOP/16 -40 to +85 $1.25 @ 1k
    See All USB Power Switches (28)
    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 prices and delivery, please see the price and availability page or contact an authorized distributor.

    Diagram
    MAX1940: Typical Operating Circuit
    Typical Operating Circuit

    Evaluation Kits
    none

    Design Guides
  • POWER MANAGEMENT FOR BATTERY-POWERED EQUIPMENT (PDF)

    Reliability Reports
  • Show FIT data for:
  • Request Reliability Report for:

    Software/Models
    none

    Ordering Information
    Notes:

    1. Other options and links for purchasing parts are listed at: http://www.maxim-ic.com/sales.
    2. Didn't Find What You Need? Ask our applications engineers. Expert assistance in finding parts, usually within one business day.
    3. Part number suffixes: T or T&R = tape and reel; + = RoHS/lead-free; # = RoHS/lead-exempt. More: SeeFull Data Sheet or Part Naming Conventions.
    4. * Some packages have variations, listed on the drawing. "PkgCode/Variation" tells which variation the product uses. Note that "+", "#", "-" in the part number suffix describes RoHS status. Package drawings may show a different suffix character.


    Devices: 1-4 of 4

    MAX1940 Free
    Sample
    Buy
    Package: TYPE PINS FOOTPRINT
      DRAWING CODE/VAR *
    Temp RoHS/Lead-Free?
    Materials Analysis
    MAX1940EEE  
    QSOP;16 pin;
    Dwg: 21-0055 (PDF)
    Use pkgcode/variation: E16-5*
    -40°C to +85°C RoHS/Lead-Free: No
    Materials Analysis
    MAX1940EEE-T  



    -40°C to +85°C See data sheet
    MAX1940EEE+  
    QSOP;16 pin;
    Dwg: 21-0055 (PDF)
    Use pkgcode/variation: E16+5*
    -40°C to +85°C RoHS/Lead-Free: Lead Free
    Materials Analysis
    MAX1940EEE+T  



    -40°C to +85°C See data sheet

    More Information
  • New Product Press Release 2002-10-03 

    Related Products
    MAX1812 Dual USB Switch with Fault Blanking
    MAX1823, MAX1823A, MAX1823B, MAX1823H Dual USB Switch with Fault Blanking and Autoreset

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    Document Ref.: 19-2497; Rev 0; 2002-08-23
    This page last modified: 2007-07-16



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