MAX3292ESD+T

Overview

The MAX3292ESD+T is a full-duplex RS-485/RS-422 transceiver featuring driver preemphasis circuitry to reduce intersymbol interference. It operates from a single +5V supply and supports data rates up to 10Mbps, programmable via an external resistor on the PSET pin. The device includes a low-current shutdown mode drawing 100nA, a fail-safe receiver input guaranteeing a logic-high output when open, and a 1/4-unit-load impedance allowing up to 128 transceivers on the bus. It is housed in a 14-pin SOIC package and specified for operation between -40°C and +85°C.

Feature Summary

• Driver preemphasis circuitry extends reliable communication distance and increases data rate by reducing intersymbol interference caused by long cables.
• Programmable data rates up to 10Mbps using a single external resistor to set the preemphasis interval.
• Fail-safe receiver input guarantees a logic-high output if the differential input is left open-circuit.
• Low-current shutdown mode reduces supply current to 100nA when both receiver and driver are disabled.

Applications

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

Procurement Notes

Verify the component matches the specific ordering suffix ESD+T, which indicates the 14-pin SOIC package, -40°C to +85°C temperature range, and tape-and-reel packaging. Confirm that the supplier provides documentation verifying the lead-free status associated with the plus sign in the part number. Cross-reference the manufacturer's official datasheet to ensure the preemphasis functionality aligns with system requirements.

Selection Notes

Select this component when designing for high-speed serial communication over long cable runs where intersymbol interference is a concern. The MAX3292 allows flexible timing adjustment via an external resistor, unlike the fixed-interval MAX3291. Ensure the application requires full-duplex operation and a +5V supply. Verify that the 1/4-unit-load receiver impedance meets the bus loading requirements for connecting multiple nodes.

Part Context

The MAX3292 belongs to the MAX3291/MAX3292 family of high-speed RS-485/RS-422 transceivers designed for robust data transmission. It shares pin compatibility with legacy devices like the ’75180 and MAX489, facilitating direct upgrades in existing designs. The primary distinction within the family is the programmable preemphasis interval provided by the MAX3292, offering greater flexibility compared to the fixed parameters of the MAX3291.

Replacement Considerations

The MAX3291CSD+T is a pin-compatible alternative with a fixed preemphasis interval. Other compatible parts include the MAX489, MAX491, MAX3080, MAX3083, MAX3086, and MAX1482. Verify that substitute components support the required data rates and voltage levels before implementation.

FAQ

How is the preemphasis interval configured on the MAX3292?

The preemphasis interval is set by connecting a resistor (RPSET) from the PSET pin to VCC. A capacitor (CPSET) should also be connected from PSET to VCC. The value of RPSET determines the interval duration based on the data rate.

What is the maximum number of transceivers supported on the bus?

The MAX3292 features a 1/4-unit-load receiver input impedance, allowing up to 128 transceivers to be connected in parallel on a single communication line.

How does the device enter low-power shutdown mode?

Shutdown is initiated by driving the Receiver Enable (RE) pin high and the Driver Enable (DE) pin low. In this state, the supply current typically drops to 100nA.