±15kV ESD-Protected, +5V, 1µA, Single RS-232 Transceiver with AutoShutdown

Industry's Smallest, Low-Power, Single RS-232 Transceiver Featuring ±15kV ESD Protection

Please check latest availability status for a specific part variant.


The MAX221E is a +5V powered, single transmit/receive RS-232 and V.28 communications interface with automatic shutdown/wake-up features and high data rate capabilities.

The MAX221E features enhanced electrostatic discharge (ESD) protection. Both the transmitter output and receiver input are protected to ±15kV using the IEC 1000-4-2 Air-Gap Discharge Method, to ±8kV using the IEC 1000-4-2 Contact Discharge Method, and to ±15kV using the Human Body Model.

The MAX221E achieves a low 1µA supply current with Maxim's revolutionary AutoShutdown™ feature. AutoShutdown saves power without changes to the existing BIOS or operating system by entering low-power shutdown mode when the RS-232 cable is disconnected or when the transmitter of the connected peripheral is off. The MAX221E wakes up and drives the active-low INVALID pin high when an active RS-232 cable is connected, signaling the host that a peripheral is connected to the communications port.

The MAX221E is available in a 16-pin SSOP package as well as a 16-pin TSSOP that uses 50% less board space than a 16-pin SO.
MAX221E: Typical Operating Circuit MAX221E: Typical Operating Circuit Enlarge+

Key Features

  • Single RS-232 Transceiver in a Small 16-Pin TSSOP
  • ESD Protection for RS-232 I/O Pins
    • ±15kV-Human Body Model
    • ±8kV-IEC 1000-4-2, Contact Discharge
    • ±15kV-IEC 1000-4-2, Air-Gap Discharge
  • Latchup Free
  • 1µA Supply Current
  • AutoShutdown Saves Power without Changes to BIOS
  • Guaranteed 250kbps Data Rate


  • Industrial Systems
  • Maintenance/Diagnostic Ports
  • Set-Top Boxes
  • Telecommunications
Part NumberVSUPPLY
TxRxData Rate
Internal Charge PumpExt. CapsCap. Value
ESD Protect.
Rx Active in ShutdnPackage/PinsBudgetary
mintypnomSee Notes
MAX221E 5112505Yes40.1151
$1.70 @1k
See All RS-232 Line Driver/Receivers (136)
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.

CAD Symbols and Footprints

  • MAX221EAE
  • MAX221EAE+
  • MAX221EAE+T
  • MAX221EAE-T
  • MAX221ECAE
  • MAX221ECAE+
  • MAX221ECAE+T
  • MAX221ECAE-T
  • MAX221ECUE
  • MAX221ECUE+
  • MAX221ECUE+T
  • MAX221ECUE-T
  • MAX221EEAE
  • MAX221EEAE+
  • MAX221EEAE+T
  • MAX221EEAE-T
  • MAX221EEUE
  • MAX221EEUE+
  • MAX221EEUE+T
  • MAX221EEUE-T
  • MAX221EUE
  • MAX221EUE+
  • MAX221EUE+T
  • MAX221EUE-T
  • Device   Fab Process   Technology   Sample size   Rejects   FIT at 25°C   FIT at 55°C  

    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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