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±15kV ESD-Protected, RS-232 Transceivers for Multidrop Applications

±15kV ESD-Protected, RS-232 Transceivers for Multidrop Applications

Product Details

Key Features

Applications/Uses

Simplified Block Diagram

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Key Features

  • Pin-Selectable 5kΩ/High-Impedance Receivers
  • Transmitter Outputs Three-Stated by Logic Control
  • VL Pin for Compatibility with Mixed Voltage Systems
  • 1Tx/1Rx (MAX3323E) or 2Tx/2Rx (MAX3322E) Versions
  • 250kbps Data Rate
  • 1µA Low-Power Shutdown
  • High 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

Applications/Uses

  • Bar-Code Scanners
  • Data Splitters
  • Industrial Data Acquisition
  • Video Security

Description

The MAX3322E/MAX3323E 3.0V to 5.5V powered EIA/TIA-232 and V.28/V.24 communications interfaces are designed for multidrop applications with low power requirements, high data-rate capabilities, and enhanced electrostatic discharge (ESD) protection. All RS-232 inputs and outputs are protected to ±15kV using the IEC 1000-4-2 Air-Gap Discharge method, ±8kV using the IEC 1000-4-2 Contact Discharge method, and ±15kV using the Human Body Model.

The MAX3322E/MAX3323E have pin-selectable 5kΩ /high-impedance RS-232 receivers. These devices are capable of receiving data in high-impedance mode. In multidrop applications, one receiver has a 5kΩ input resistance, while the other receivers are high impedance to ensure the RS-232 standard is observed. Logic control permits selection of the functional mode: high impedance or RS-232 standard load. The transmitters are enabled by logic control to allow the multiplexing of the inputs to a single UART.

A proprietary low-dropout transmitter output stage enables 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. The MAX3322E/MAX3323E are capable of running at data rates up to 250kbps while maintaining RS-232-compliant output levels. The MAX3322E/MAX3323E have a unique VL pin that allows operation in mixed-logic voltage systems. Both input and output logic levels are pin programmable through the VL pin.

The MAX3322E is a 2Tx/2Rx device for hardware handshaking in standard RS-232 mode, and the MAX3323E is a 1Tx/1Rx, required in most multidrop applications.

The MAX3322E is offered in a space-saving TSSOP package. The MAX3323E is offered in 16-pin DIP and space-saving TSSOP packages.

Simplified Block Diagram

MAX3322E, MAX3323E: Typical Operating Circuit MAX3322E, MAX3323E: Typical Operating Circuit Zoom icon

Technical Docs

Support & Training

Search our knowledge base for answers to your technical questions.

Filtered Search

Our dedicated team of Applications Engineers are also available to answer your technical questions. Visit our support portal .