±15kV ESD-Protected, 1µA, 3.0V to 5.5V, 250kbps, RS-232 Transceivers with AutoShutdown

Please check latest availability status for a specific part variant.


The MAX3221E/MAX3223E/MAX3243E are 3V-powered EIA/TIA-232 and V.28/V.24 communications interfaces with automatic shutdown/wakeup features, high data-rate capabilities, and enhanced electrostatic discharge (ESD) protection. All transmitter outputs and receiver inputs are protected to ±15kV using IEC 1000-4-2 Air-Gap Discharge, to ±8kV using IEC 1000-4-2 Contact Discharge, and to ±15kV using the Human Body Model.

The MAX3221E/MAX3223E/MAX3243E achieve a 1µA supply current with Maxim's revolutionary AutoShutdown™ feature. They save 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 transmitters of the connected peripherals are off.

The transceivers have a proprietary low-dropout transmitter output stage, delivering true RS-232 performance from a +3.0V to +5.5V supply with a dual charge pump. The charge pump requires only four small 0.1µF capacitors for operation from a +3.3V supply. Each device is guaranteed to run at data rates of 250kbps while maintaining RS-232 output levels.

The MAX3221E contains just one driver and one receiver, making it the smallest single-supply RS-232 transceiver. The MAX3223E has two drivers and two receivers. The MAX3243E is a complete 3-driver/5-receiver serial port ideal for notebook or subnotebook computers. It also includes two noninverting receiver outputs that are always active, allowing external devices to be monitored without forward biasing the protection diodes in circuitry that may be powered down.

The MAX3221E, MAX3223E, and MAX3243E are available in space-saving TQFN, SSOP, and TSSOP packages.

Key Features

  • For Space-Constrained Applications:
    • MAX3228E/MAX3229E: ±15kV ESD-Protected, +2.5V to +5.5V RS-232 Transceivers in UCSP™
    • MAX3222E/MAX3232E/MAX3237E/MAX3241E/MAX3246E: ±15kV ESD-Protected Down to 10nA, +3.0V to +5.5V, Up to 1Mbps, True RS-232 Transceivers (MAX3246E Available in a UCSP Package)
  • For Data Cable Applications:
    • MAX3380E/MAX3381E: +2.35V to +5.5V, 1µA, 2Tx/2Rx RS-232 Transceivers with ±15kV ESD-Protected I/O and Logic Pins


  • Battery-Powered Equipment
  • Cell Phones
  • Handheld Equipment
  • Notebook, Subnotebook, and Palmtop Computers
  • Peripherals
  • Printers
Part NumberVSUPPLY
TxRxData Rate
Internal Charge PumpExt. CapsCap. Value
ESD Protect.
Rx Active in ShutdnPackage/PinsBudgetary
mintypnomSee Notes
$1.87 @1k
MAX3223E 222
$2.95 @1k
MAX3243E 351
SOIC (W)/28
$6.75 @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.

MAX3223EEVKIT: Evaluation Kit for the MAX3223E

Technical Documents

Tutorial 2141 Determining Clock Accuracy Requirements for UART Communications
Tutorial 739 Design Considerations for Data-Lump Cables

Quality and Environmental Data

Product Reliability Reports: MAX3243E.pdf 
Lead-Free Package Tin (Sn) Whisker Reports

Additional Resources

RS232 Resources

CAD Symbols and Footprints

  • MAX3243EEAI+
  • MAX3243EEAI+T
  • MAX3243EETI+
  • MAX3243EETI+T
  • MAX3243EETJ+
  • MAX3243EETJ+T
  • MAX3243EEUI+
  • MAX3243EEUI+T
  • MAX3243EEWI+
  • MAX3243EEWI+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.

    Quality Management System >
    Environmental Management System >


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