5V, Isolated, RS-232 Driver Receiver

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The MAX250 and MAX251 chip set form the heart of a complete, electronically isolated, RS-232 dual transmitter/receiver. By combining many functions on two chips, the cost and complexity required for an isolated digital interface is greatly reduced. Four low cost optocouplers, four capacitors, a diode and a small pot-core type transformer are all that are required to complete a 19.2k baud transceiver. Faster data rates are possible by using high speed optocouplers. In addition to the driving and receiving circuitry for the optocouplers, the chip set includes a push-pull transformer driver to supply power to the interface's isolated side.

Other convenient features include single +5V operation, a low power shutdown mode, and output enable control for three-state operation. The MAX250 and MAX251 are supplied in 14 lead DIP, 14 lead small outline and 20 leadless chip carrier packages.

The MAX252 has all the required components for RS-232 communication in a single package.
MAX250, MAX251: Pin Configuration MAX250, MAX251: Pin Configuration Enlarge+

Key Features

  • Isolated Data Interface
  • Single +5V Supply
  • Uses Low Cost Optocouplers
  • 5µW Power Shutdown
  • 2 Transmitters and 2 Receivers


  • Bridge Ground Differentials
  • Data Links To Analog Circuits
  • High Noise Data Communications
  • Industrial Communications
Part NumberVSUPPLY
TxRxData Rate
Internal Charge PumpPackage/PinsBudgetary
mintypSee Notes
MAX250 5221160.1Yes
SOIC (N)/14
$4.39 @1k
SOIC (N)/14
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.

Quality and Environmental Data

Product Reliability Reports: MAX251.pdf 
Lead-Free Package Tin (Sn) Whisker Reports
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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