MAX3243EEWI

Overview

The MAX3243EEWI is a true RS-232 transceiver from the MAX3243E series, manufactured by Analog Devices Inc./Maxim Integrated. It features three drivers and five receivers for full-duplex communication. The device operates on a single +3.0V to +5.5V supply and supports data rates up to 250kbps. It incorporates an AutoShutdown feature that reduces supply current to 1µA when no valid signal is detected. ESD protection is rated at ±15kV (HBM), ±8kV (Contact Discharge), and ±15kV (Air-Gap). The component is housed in a 28-pin SSOP package and functions within a temperature range of -40°C to +85°C.

Feature Summary

• AutoShutdown technology automatically disables charge pumps and drivers to achieve ultra-low 1µA standby current when the cable is disconnected or peripherals are off.
• Integrated dual charge pump generates internal ±5.5V rails using only four small 0.1µF external capacitors.
• Includes two always-active noninverting complementary receiver outputs (R2OUTB) to monitor external devices without forward biasing protection diodes during shutdown.
• Provides enhanced I/O protection against electrostatic discharge up to ±15kV across multiple testing standards.

Applications

• Notebook, subnotebook, and palmtop computers
• Battery-powered equipment and handheld devices
• Cellular phones and peripherals

Procurement Notes

Verify the specific ordering suffix 'EWI' against official manufacturer documentation to confirm the exact pin count, package type, and temperature grade. Ensure compatibility with system voltage requirements and interface standards before procurement.

Selection Notes

Select this component for applications requiring low power consumption and high ESD tolerance. Verify that the 28-pin SSOP footprint matches the PCB layout. Confirm that the 250kbps data rate meets the system's communication speed requirements.

Part Context

This part belongs to the MAX3221E/MAX3223E/MAX3243E family of low-power RS-232 transceivers. While sharing core features like AutoShutdown and ESD protection, it differs from siblings by offering a higher channel count (3 drivers/5 receivers) suitable for complex serial interfaces.

Replacement Considerations

Publicly confirmed substitute part numbers are not available in the provided source material.

FAQ

How does the AutoShutdown feature reduce power consumption?

It monitors receiver inputs and shuts off the onboard charge pump and drivers if no valid RS-232 signal levels are detected for 30µs, reducing supply current to 1µA.

What is the purpose of the R2OUTB output on the MAX3243E?

The R2OUTB is an always-active noninverting complementary receiver output that allows monitoring of external devices, such as Ring Indicators, even when other receivers are in a high-impedance state during shutdown.

What external components are required for operation?

The device requires four small 0.1µF capacitors for the dual charge pump when operating from a +3.3V supply.