MAX3322EEUP+

Overview

The MAX3322EEUP+ is a dual RS-232 transceiver designed for multidrop applications, operating from a 3.0V to 5.5V supply with a maximum data rate of 250kbps. It features pin-selectable 5kΩ or high-impedance receiver inputs and logic-controlled transmitter three-stating. The device includes a dual charge pump requiring four 0.1µF capacitors for operation at 3.3V. ESD protection on all I/O pins reaches ±15kV (Human Body Model) and ±8kV (IEC Contact Discharge). It operates within a temperature range of -40°C to +85°C in a 20-pin TSSOP package.

Feature Summary

• Pin-selectable receiver input resistance allows configuration between standard 5kΩ termination and high-impedance modes for multidrop bus compatibility.
• Logic-controlled transmitter enablement facilitates transmission-line sharing by placing outputs in a high-impedance state when disabled.
• Integrated dual charge pump generates required RS-232 voltage levels using only four small external capacitors.
• Enhanced electrostatic discharge protection ensures robustness against handling and assembly stresses.

Applications

• Bar-code scanners
• Video security systems
• Industrial data acquisition
• Data splitters

Procurement Notes

Verify the component designation matches the specific Analog Devices/Maxim Integrated part number. Confirm the suffix indicates the lead-free (+) status and the EEUP package variant. Ensure the source documentation corresponds to the official datasheet for accurate electrical specifications and pin configurations.

Selection Notes

Select this component for designs requiring RS-232 communication in multidrop environments where multiple receivers share a single bus line. The separate VL pin allows interface compatibility with mixed logic voltage systems, supporting lower microprocessor I/O voltages down to 1.65V while maintaining full RS-232 compliance.

Part Context

This device belongs to the MAX3322E/MAX3323E family of low-power, high-speed RS-232 transceivers. The MAX3322E specifically provides two transmitters and two receivers, distinguishing it from the single-channel MAX3323E. Both variants are engineered for applications demanding enhanced ESD protection and flexible logic level interfacing.

Replacement Considerations

The MAX3323E serves as a functional alternative within the same family but offers only one transmitter and one receiver instead of two. Verify that the reduced channel count meets the system requirements before substitution.

FAQ

How does the RENABLE pin affect receiver operation?

Driving RENABLE high connects an internal 5kΩ resistor across the receiver input for standard RS-232 loads. Driving it low places the receiver input in a high-impedance state while maintaining receiving capability, which is essential for multidrop applications.

What is the purpose of the VL pin?

The VL pin serves as the logic-level supply input, setting the output voltage levels for receiver outputs and the input thresholds for transmitters and shutdown controls. It supports operation from 1.65V to 5.5V, enabling compatibility with various logic families.

Can the transmitters be paralleled?

Yes, transmitters can be paralleled to drive multiple receivers or mice. Logic control via TXENABLE manages transmission-line sharing by enabling or disabling specific transmitters.