MAX3221EUE+ - 1/1 RS-232 Transceiver, 3V-5.5V | Analog Devices
MPN: MAX3221EUE+ ✓ ActiveMAX3221EUE+ Overview
An RS-232 transceiver is the interface circuit between a digital controller and a serial connector. The receiver converts bipolar RS-232 signal levels into CMOS-compatible logic, while the driver converts CMOS logic back into RS-232 levels. The MAX3221EUE+ therefore replaces a collection of discrete level-shifting, protection, and voltage-generation components with one integrated device.
Key features include a 1 µA shutdown supply current, automatic shutdown and wake-up behavior, a 3V to 5.5V operating supply range, and 235 kbps maximum signaling rate. The MAX3221E family is also identified as an EIA/TIA-232-F-compatible interface with enhanced ESD protection on the RS-232 pins. These characteristics suit equipment that must conserve power while maintaining a standard serial port.
Internally, the device uses Maxim's AutoShutdown approach. When the receiver does not detect a valid signal, the internal supply and drivers can shut down to reduce power consumption; activity on the receiver input restores operation. The charge-pump circuit and external capacitors generate the bipolar voltage needed by the RS-232 driver from a single positive supply.
Typical uses include point-of-sale terminals, industrial control panels, instrumentation, data-logging equipment, and embedded systems that expose a legacy RS-232 port. The single driver and single receiver arrangement makes the part appropriate for one-way or two-way links where two driver/receiver pairs would not be needed.
When laying out the board, place the charge-pump capacitors close to their designated pins and route the RS-232 connector side through the protected interface pins. Verify the external interface voltage levels before connecting equipment that uses non-±RS-232 signaling, because logic-level UART signals require a separate transceiver.
This page consolidates manufacturer specifications, package details, drop-in alternatives, and application guidance to help engineers evaluate the MAX3221EUE+ before integrating it into a new RS-232 design.
Drop-in alternatives for MAX3221EUE+ — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
MAX3221EEUE+
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
MAX3221EUE+T
✅ Drop-InContact for price
View Datasheet →MAX3221EUE+ Specifications
| Device Type | 1/1 RS-232 transceiver |
| Number of Drivers | 1 |
| Number of Receivers | 1 |
| Supply Voltage Range | 3 V to 5.5 V |
| Maximum Data Rate | 235 kbps |
| Shutdown Supply Current | 1 µA |
| Power Management Feature | AutoShutdown with automatic wake-up |
| Supply Topology | Single-supply operation with charge-pump voltage generation |
| External Charge-Pump Capacitors | 4 capacitors |
| ESD Protection | Enhanced ESD protection on RS-232 pins |
| ESD Rating | ±15 kV |
| Standard Compliance | TIA/EIA-232-F |
| Package | 16-pin TSSOP |
| Mounting Type | Surface mount |
| Operating Supply Current | 1 mA |
| Minimum Operating Temperature | -40 °C |
| RoHS Compliance | Compliant |
| REACH Compliance | Compliant |
| Automotive Qualification | Not AEC-Q100 qualified |
| Lead-Free Construction | Yes |
MAX3221EUE+ 16-pin tssop Pin Configuration Guide
Pin configuration for MAX3221EUE+ (16-pin tssop package). Pin numbering, functions, and connection diagrams are defined in the manufacturer datasheet. Refer to it for the exact footprint and soldering guidelines.
No detailed pinout data available for MAX3221EUE+.
Refer to the datasheet for full pin configuration.
Typical Applications
MAX3221EUE+ is suitable for 6 applications: Industrial Instrument Serial Port, Point-of-Sale Terminal Connectivity, Data Logger and Configuration Link, Security Camera and Access-Control Console, Embedded Service and Debug Interface, Medical and Laboratory Equipment Interface.
Industrial Instrument Serial Port
The MAX3221EUE+ is a practical choice for adding a standard RS-232 port to a controller that operates from 3.3 V or 5 V. Its 235 kbps data rate comfortably supports legacy instrument-control protocols, while the single driver and single receiver support one bidirectional serial link. The charge-pump circuit produces the required bipolar transmit voltage from one positive rail, eliminating a negative power supply. Place the four charge-pump capacitors as directed in the family data sheet and protect the cable connection with ±15 kV-rated ESD devices.
Recommended
Point-of-Sale Terminal Connectivity
A point-of-sale terminal often needs a legacy printer or scanner interface alongside a modern embedded controller. The MAX3221EUE+ provides one RS-232 driver and one receiver with a 235 kbps maximum rate, matching many peripheral control ports. Its 1 µA shutdown current and automatic wake-up behavior help limit idle consumption in intermittently connected systems. Because the device uses a 16-pin TSSOP package, it also supports compact board layouts where space and automated assembly are priorities.
Recommended
Data Logger and Configuration Link
The MAX3221EUE+ suits equipment that uses a PC or service computer to retrieve measurements or update configuration over RS-232. The single receiver accepts the host's incoming commands, and the single driver returns data or acknowledgments. At 235 kbps, the interface supports substantially faster transfer rates than the low-speed ports found in older laboratory instruments. The AutoShutdown function allows the logger to remain in a low-power state until a valid receiver signal initiates communication.
Recommended
Security Camera and Access-Control Console
Installations with legacy configuration tools can use the MAX3221EUE+ to connect a controller to an RS-232 service port. The 3 V to 5.5 V supply range supports both modern low-voltage processors and conventional 5 V controller logic, while the enhanced ±15 kV ESD protection on RS-232 pins is valuable when the cable may be exposed to electrostatic discharge. The part's one-driver/one-receiver arrangement is sufficient for a dedicated service or control channel where a full multi-port RS-232 hub is unnecessary.
Recommended
Embedded Service and Debug Interface
The MAX3221EUE+ provides a compact service interface for embedded systems that need a simple PC connection for firmware loading, status reporting, or field diagnostics. One driver and one receiver are sufficient for a full-duplex service channel, and the 235 kbps rate matches common boot-loader and console protocols. Automatic wake-up reduces the software burden associated with power management. Keep the connector-side routing short and follow the manufacturer's recommended charge-pump capacitor placement for reliable operation.
Recommended
Medical and Laboratory Equipment Interface
Laboratory analyzers and legacy medical accessories often retain RS-232 ports for configuration and data transfer. The MAX3221EUE+ can bridge those bipolar signals to a modern 3.3 V controller while avoiding a separate negative supply rail. Its 235 kbps rate supports the modest transfer rates typical of instrument command protocols, while enhanced ESD protection improves interface resilience. Verify device-specific isolation, creepage, and regulatory requirements separately because the transceiver itself does not provide galvanic isolation.
Recommended
Recommended Products Summary
Engineering reference data for MAX3221EUE+ — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | MAX3221EEUE+ | MAX3221EUE+T |
|---|---|---|---|
| Brand | Analog Devices | Analog Devices | Analog Devices |
| Package | 16-pin TSSOP | 16-pin TSSOP - same | 16-pin TSSOP - same |
| Device Function | 1-driver/1-receiver RS-232 transceiver | 1-driver/1-receiver RS-232 transceiver | 1-driver/1-receiver RS-232 transceiver |
| Supply Voltage Range | 3 V to 5.5 V | 3 V to 5.5 V | 3 V to 5.5 V |
| ESD Protection | ±15 kV | ±15 kV | ±15 kV |
| External Charge-Pump Capacitors | 4 | 4 | 4 |
| Power Management | AutoShutdown with automatic wake-up | AutoShutdown with automatic wake-up | AutoShutdown with automatic wake-up |
| Interface Compliance | TIA/EIA-232-F | TIA/EIA-232-F | TIA/EIA-232-F |
Key Differentiators
- Single 3 V to 5.5 V supply with integrated charge-pump generation (vs MAX3221EUE+T)
- Enhanced cable-side ESD protection for exposed service ports (vs MAX3221EEUE+)
- Compact single-channel interface in a 16-pin TSSOP (vs ICL3221EIVZ)
Design Notes
Place the four external charge-pump capacitors close to their designated MAX3221EUE+ pins and keep the associated traces short. The manufacturer application circuit defines the required connections and values. Long capacitor loops can reduce charge-pump effectiveness, increase radiated noise, and contribute to transmission errors. Route the RS-232 connector traces away from clock, switching-regulator, and high-current power paths where practical.
Keep the cable-side RS-232 nets physically separated from logic and clock nets because the driver transitions between positive and negative voltage levels. Use the manufacturer's pin-description table for the exact input, output, ground, and supply assignments. Avoid connecting a logic-level UART directly to the RS-232 driver or receiver pins, and apply the recommended ESD-protection arrangement at an externally accessible connector.
Do not treat MAX3221EUE+, MAX3221EEUE+, and the non-E ordering variants as identical without reviewing their ordering codes. ESD rating, temperature range, and production status can differ between family members even when the package is unchanged. Also verify that the host UART operates from the same 3 V to 5.5 V rail family and that the firmware accounts for the device's automatic wake-up behavior.
Compliance Information
RoHS and REACH compliance are indicated for the MAX3221 family. The MAX3221EUE+ is an industrial interface transceiver and is not identified as an AEC-Q100-qualified automotive device. Halogen-free and conflict-minerals declarations are not stated for this ordering code.
