MAX3243EUI+ - 3.3V/5V RS-232 Transceiver | Analog Devices
MPN: MAX3243EUI+ ✓ ActiveMAX3243EUI+ Overview
An RS-232 transceiver is a serial-interface integrated circuit that converts between TTL/CMOS logic levels and the voltage-defined RS-232 signal levels used by computer serial ports and industrial equipment. The MAX3243EUI+ belongs to the interface-IC hierarchy: RS-232 transceiver → multi-channel serial-interface transceiver → communications interface IC → semiconductor. Automatic shutdown provides a practical power-management advantage when no valid receiver activity is detected.
Key features include a 3V to 5.5V supply range, three transmit channels, three receive channels, AutoShutdown operation, enhanced ESD protection, and a 28-pin TSSOP package. The MAX3243E family description identifies EIA/TIA-232 and V.28/V.24 support, automatic shutdown and wake-up behavior, high data-rate capability, and enhanced electrostatic-discharge protection. These characteristics suit systems that must translate between modern digital logic and legacy RS-232 ports.
The MAX3243EUI+ integrates both interface directions on one device, reducing the component count required for a multi-channel serial port. Its automatic shutdown function can reduce power consumption when the remote system is disconnected or inactive. The 28-pin TSSOP is a surface-mount package that supports conventional PCB assembly, although exact pin assignments, capacitor values, and electrical limits must be confirmed from the manufacturer datasheet before layout or replacement qualification.
Typical uses include industrial control equipment, data-acquisition systems, configuration ports, service interfaces, and embedded systems that need to communicate with RS-232 peripherals. It is also appropriate for battery-powered or portable equipment where automatic shutdown can conserve energy during idle periods. In those applications, logic-level compatibility, ESD protection, and cable-receiver behavior are as important as the nominal data rate.
When designing around the MAX3243EUI+, verify the complete supply range, operating temperature, absolute maximum ratings, driver slew rate, receiver thresholds, and required external charge-pump capacitors against the manufacturer datasheet. Place the interface IC close to the connector, route driver outputs toward the protected connector side, and provide a low-impedance ground return so common-mode noise does not corrupt receiver inputs.
This page consolidates verified manufacturer and distributor information with practical selection guidance, parameter comparisons, and engineering-oriented interface design notes. It also distinguishes verified drop-in candidates from unresolved alternatives, helping engineers reduce sourcing risk while retaining the required 28-pin TSSOP footprint.
Drop-in alternatives for MAX3243EUI+ — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
MAX3243EEUI+T
✅ Drop-In📋 Reference alternative (not in catalog)
MAX3243CUI+T
✅ Drop-In📋 Reference alternative (not in catalog)
MAX3243ECPWR
✅ Drop-In📋 Reference alternative (not in catalog)
MAX3243EUI+ Specifications
| Product Type | RS-232 transceiver |
| Supply Voltage Range | +3 V to +5.5 V |
| Number of Drivers | 3 |
| Number of Receivers | 3 |
| Duplex Mode | Full duplex |
| Communications Standards | EIA/TIA-232, V.28, V.24 |
| Automatic Shutdown | AutoShutdown with automatic wake-up |
| Shutdown Supply Current | 1 uA |
| Electrostatic Discharge Protection | +/-15 kV |
| Package | 28-pin TSSOP |
| Package Length | 9.7 mm |
| Package Width | 4.4 mm |
| Mounting Type | Surface mount |
| RoHS Status | Compliant |
MAX3243EUI+ 4.4 mm Pin Configuration Guide
Pin configuration for MAX3243EUI+ (4.4 mm 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 MAX3243EUI+.
Refer to the datasheet for full pin configuration.
Typical Applications
MAX3243EUI+ is suitable for 6 applications: Industrial Control Service Ports, Data Acquisition Equipment, Embedded Configuration Interfaces, Portable Test and Measurement, Network Equipment Maintenance Ports, Security and Access Control Panels.
Industrial Control Service Ports
The MAX3243EUI+ is appropriate for a three-channel industrial service interface because it combines three drivers and three receivers with operation from +3V to +5.5V. The automatic shutdown and wake-up functions can reduce consumption when the connected equipment is inactive, while enhanced ESD protection adds useful protection around exposed communications connectors. The 28-pin TSSOP also permits a compact surface-mounted implementation. Before release, engineers should confirm the operating-temperature range, logic levels, and complete pin map against the MAX3243E datasheet, because those limits were not present in the supplied search excerpts.
Recommended
Data Acquisition Equipment
Laboratory and industrial data-acquisition equipment can use the MAX3243EUI+ to provide three full-duplex RS-232 channels from a single +3V to +5.5V interface IC. The three-driver and three-receiver arrangement supports multiple control or data links without requiring a separate transceiver for every channel. Automatic shutdown is valuable when instruments operate between measurement bursts, while the 28-pin TSSOP supports compact board layouts. Signal-integrity engineers must still account for the interface's exact data rate, charge-pump capacitor requirements, cable grounding, and connector-side surge protection using the manufacturer documentation.
Recommended
Embedded Configuration Interfaces
The MAX3243EUI+ fits embedded systems that expose one or more RS-232 configuration channels to a host computer, service fixture, or legacy peripheral. Its +3V operation supports systems unable to provide a 5V rail, and AutoShutdown can conserve power when no valid receiver activity is present. The integrated drivers and receivers reduce board area relative to separate line-driver and receiver devices. Layout should keep the transceiver near the connector, provide a continuous signal-ground return, and isolate external cables appropriately; exact pin assignments and timing must be copied directly from the MAX3243EUI+ datasheet.
Recommended
Portable Test and Measurement
Portable analyzers, calibrators, and handheld test instruments can use the MAX3243EUI+ to maintain compatibility with RS-232 accessories while operating from a +3V to +5.5V supply. The automatic shutdown function is especially useful in battery-powered products because the transceiver can reduce consumption during idle intervals and resume when a valid signal is detected. The 28-pin TSSOP is compatible with high-density surface-mount assembly, although thermal performance is not a primary concern at low interface power. Validate wake-up timing, idle-current behavior, and connector protection in the final product configuration.
Recommended
Network Equipment Maintenance Ports
Routers, switches, and communications modules can retain legacy maintenance connectivity through a MAX3243EUI+ when the product must exchange RS-232 commands with a service terminal or installation computer. Three drivers and three receivers support several low-speed channels, while the 3V-to-5.5V range accommodates different internal rails. Enhanced ESD protection is beneficial near user-accessible connectors, although it does not replace a complete external surge-protection strategy. Keep RS-232 routing away from fast clocks and switching nodes, provide a low-impedance ground path, and verify receiver thresholds against the actual cable and system ground conditions.
Recommended
Security and Access Control Panels
Access-control panels, alarm controllers, and card-reader interfaces may require an RS-232 channel for configuration, diagnostics, or connection to legacy peripheral equipment. The MAX3243EUI+ supplies three receive and three transmit paths while supporting +3V to +5.5V operation, and its automatic shutdown can reduce current during unattended periods. ESD protection is relevant when cables connect through external panels, yet designers should retain separate protection if the cable leaves the enclosure or faces severe surge conditions. Verify the target's full operating-temperature and ESD qualification requirements before using it in security-critical deployed systems.
Recommended
Recommended Products Summary
Engineering reference data for MAX3243EUI+ — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | MAX3243EEUI+T | MAX3243CUI+T | MAX3243ECPWR |
|---|---|---|---|---|
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Package | 28-pin TSSOP | 28-pin TSSOP | 28-pin TSSOP | 28-pin TSSOP |
| Product Type | RS-232 transceiver | MAX3243E-family RS-232 transceiver | Ultra-low-power MAX3243-family transceiver | Power-efficient multi-line driver and receiver |
| Drivers | 3 | 3 | 3 | 3 |
| Receivers | 3 | 3 | 3 | 3 |
| Automatic Shutdown | Yes | Yes | Yes | Yes |
Key Differentiators
- Three-channel full-duplex RS-232 interface (vs MAX232DR)
- Automatic shutdown and wake-up operation (vs MAX3243CUI+T)
- Exact 28-pin TSSOP packaging (vs MAX3243CAI+)
Design Notes
Place the MAX3243EUI+ close to the RS-232 connector and keep charge-pump capacitor connections exceptionally short. Route the three driver outputs directly toward their corresponding connector contacts, and route receiver inputs away from switching nodes and high-current traces. The connector-side ground should connect to circuit ground through a low-impedance path; relying on the cable ground alone can make receiver thresholds vulnerable to common-mode noise.
Design the supply rail for the exact operating mode rather than the 1 uA shutdown figure alone. The 1 uA value describes shutdown supply current, not necessarily current during active transmission or charge-pump operation. Confirm the operating supply-current limits from the manufacturer datasheet, provide local input and charge-pump capacitance exactly as specified, and test both wake-up and sustained-load behavior in the final system.
Do not infer a drop-in replacement from package dimensions alone. Compare numbered pins, receiver input thresholds, driver output levels, slew behavior, shutdown logic, and ESD limits between the original and candidate. The supplied data identifies MAX3243EEUI+T, MAX3243CUI+T, and MAX3243ECPWR as candidates, but complete electrical equivalence remains unverified. Perform a directed substitution review before approving any of them for production.
Avoid confusing the MAX3243EUI+ with lower-channel-count RS-232 devices when planning a board revision. This part provides three drivers and three receivers, and its 28-pin TSSOP footprint must be reproduced exactly. Also avoid assuming that enhanced ESD protection eliminates the need for external surge suppression on long cables. The connector path may require separate protection depending on the installation environment and applicable system requirements.
Compliance Information
RoHS compliance is verified by the MAX3243ECPWR comparison entry for the same MAX3243E family. Other compliance declarations were not explicitly available in the supplied verified data.