MAX3322EEUP+T

Overview

The MAX3322EEUP+T 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 two drivers and two receivers in a 20-pin TSSOP package, supporting full-duplex communication. The device includes pin-selectable receiver inputs (5kΩ or high impedance) and a dedicated VL logic supply pin (1.65V to 5.5V) for mixed-voltage compatibility. ESD protection on I/O pins reaches ±15kV (HBM), ±8kV (IEC Contact), and ±15kV (IEC Air-Gap). Shutdown current is typically 1µA.

Feature Summary

• Pin-selectable receiver input resistance allows switching between standard 5kΩ termination and high-impedance modes for multidrop bus sharing.
• Dedicated VL logic supply pin enables direct interface with mixed-voltage systems ranging from 1.65V to 5.5V.
• Transmitters can be three-stated via logic control to facilitate transmission-line sharing among multiple devices.
• Integrated dual charge pumps generate required RS-232 voltages using only four small capacitors.

Applications

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

Procurement Notes

Verify the component matches the exact part number MAX3322EEUP+T, ensuring the suffix indicates lead-free status and tape-and-reel packaging. Confirm the manufacturer is Analog Devices Inc./Maxim Integrated. Check that the temperature range corresponds to -40°C to +85°C. Validate the 20-TSSOP package type against physical inspection requirements.

Selection Notes

Select this component when designing multidrop RS-232 networks requiring low power consumption and enhanced ESD protection. The MAX3322E variant provides two drivers and two receivers suitable for hardware handshaking. Ensure the system utilizes a separate VL logic supply if interfacing with microprocessors operating at voltages different from the main VCC supply.

Part Context

This device belongs to the MAX3322E/MAX3323E family of RS-232 transceivers optimized for multidrop environments. While the MAX3323E offers a single driver and receiver configuration, the MAX3322E provides the additional channels necessary for complex peripheral connections. Both variants share identical electrical characteristics and package options within their respective channel counts.

Replacement Considerations

Public confirmed substitute part numbers are not available in the provided documentation.

FAQ

How does the RENABLE pin affect receiver operation?

Driving RENABLE high connects a 5kΩ resistor across the receiver input and ground for standard operation. 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 function of the VL pin?

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

How is the device protected against electrostatic discharge?

All RS-232 inputs and outputs feature ESD protection structures rated at ±15kV using the Human Body Model, ±8kV using the IEC 1000-4-2 Contact Discharge method, and ±15kV using the IEC 1000-4-2 Air-Gap Discharge method.