MAX3291CPD+

Overview

The MAX3291CPD+ is a full-duplex RS-485/RS-422 transceiver featuring driver preemphasis to reduce intersymbol interference for high-speed, long-distance communication. It operates from a single +5V supply with a typical no-load supply current of 3mA and a low-current shutdown mode drawing 100nA. The device supports data rates of 5Mbps to 10Mbps and includes a fail-safe receiver input that guarantees a logic-high output if the input is open circuit. Its 1/4-unit-load receiver input impedance allows up to 128 transceivers on the bus. The component is housed in a 14-pin Plastic DIP package and functions within an operating temperature range of 0°C to +70°C.

Feature Summary

• Driver preemphasis circuitry extends reliable communication distance and increases data rate by reducing intersymbol interference caused by long cables.
• Fail-safe receiver input guarantees a logic-high output state when the differential input terminals are left open circuit.
• Low-current shutdown mode reduces supply current to 100nA when both receiver enable and driver enable inputs are controlled appropriately.
• 1/4-unit-load receiver input impedance permits connection of up to 128 transceivers on a single communication bus.

Applications

• Long-distance, high-speed RS-485/RS-422 communications
• Telecommunications systems
• Industrial-control networks
• Local area networks

Procurement Notes

Verify the specific suffix CPD+ corresponds to the commercial temperature grade (0°C to +70°C) and 14-pin Plastic DIP package configuration. Confirm RoHS compliance status through official manufacturer documentation or authorized distributor declarations prior to integration. Ensure the ordering part number matches the required pinout and electrical specifications for the target design environment.

Selection Notes

Select the MAX3291CPD+ when fixed preemphasis timing optimized for 5Mbps to 10Mbps data rates is sufficient. Choose this part over the MAX3292 variant if resistor-programmable preemphasis intervals are not required. Verify that the system power supply remains stable at +5V ±5% to maintain specified driver output voltages and propagation delays within acceptable limits for the application.

Part Context

The MAX3291 belongs to the Maxim Integrated RS-485/RS-422 transceiver family designed for high-speed serial communication. It serves as a pin-compatible alternative to legacy devices such as the SN75180, MAX489, MAX491, MAX3080, MAX3083, MAX3086, and MAX1482. This compatibility facilitates direct upgrades in existing designs requiring improved performance over long cable runs without altering the printed circuit board layout.

Replacement Considerations

Public confirmed substitute part numbers include MAX3291CSD, MAX3291ESD, and MAX3291EPD. These variants share identical functionality but differ in temperature ranges and packaging types. Verify that the replacement package matches the assembly requirements and that the temperature rating aligns with the operational environment constraints.