MAX3491CSD+

Overview

The MAX3491CSD+ is a full-duplex RS-485/RS-422 transceiver manufactured by Analog Devices Inc. It operates from a single 3.0V to 3.6V supply and supports data rates up to 10Mbps. The device features one driver and one receiver in a 14-pin SO package (S14+1). Key electrical parameters include a typical supply current of 2.2mA, a shutdown current of 2nA, and a common-mode input voltage range of -7V to +12V. Driver outputs are protected by short-circuit current limiting and thermal shutdown circuitry.

Feature Summary

• Full-duplex communication capability with independent driver and receiver enable controls
• Low-power shutdown mode achieving 2nA supply current when both RE is high and DE is low
• Fail-safe receiver that guarantees a logic-high output if inputs are open circuit
• Driver overload protection via short-circuit current limiting and thermal shutdown

Applications

• Telecommunications systems requiring RS-485 or RS-422 interfaces
• Industrial-control local area networks
• Transceivers for EMI-sensitive applications

Procurement Notes

Verify the component authenticity by checking the manufacturer marking against the official datasheet specifications. Confirm the package type matches the 14-pin SO outline number 21-0041. Ensure the temperature grade corresponds to the 'C' suffix for the 0°C to +70°C operating range. Cross-reference the ordering information table to validate the specific part number configuration before finalizing procurement.

Selection Notes

Select the MAX3491CSD+ when full-duplex operation is required alongside half-duplex alternatives like the MAX3485. This part is suitable for designs needing separate transmit and receive lines. Verify that the system requires a 14-pin footprint rather than an 8-pin layout. Ensure the application environment stays within the commercial temperature range of 0°C to +70°C for this specific suffix.

Part Context

The MAX3491 belongs to the MAX3483/MAX3485/MAX3486/MAX3488/MAX3490/MAX3491 family of 3.3V low-power transceivers. Unlike the half-duplex MAX3485, the MAX3491 provides full-duplex communication. It shares similar power characteristics and interface standards with other members of the series but utilizes a distinct 14-pin package to accommodate separate driver and receiver control pins.

Replacement Considerations

The MAX3490ESA+ serves as a functional substitute for full-duplex operations but utilizes an 8-pin package instead of the 14-pin SO format. Designers must account for pinout differences and potential PCB layout modifications when substituting between these variants.