MAX3243EEAI+T

Overview

The MAX3243EEAI+T is a full-duplex RS-232 transceiver in a 28-pin SSOP package, featuring three drivers and five receivers. It operates from a single +3.0V to +5.5V supply with an integrated dual charge pump eliminating external ±12V requirements. The device incorporates AutoShutdown technology, reducing supply current to 1µA when no valid signal is detected on receiver inputs for 30µs. It supports data rates up to 235kbps with typical propagation delays of 0.3µs. The component includes an always-active complementary receiver output (R2OUTB) for monitoring during shutdown and provides 15kV ESD protection.

Feature Summary

• AutoShutdown functionality reduces power consumption by disabling the onboard power supply and drivers when valid RS-232 signals are absent.
• Integrated dual charge-pump circuitry generates required voltage levels from a single low-voltage supply without external transformers.
• Complementary R2OUTB pin remains active during shutdown to monitor external devices while other receiver outputs enter high-impedance states.

Applications

• Battery-powered equipment requiring extended standby life
• Hand-held portable diagnostic instruments
• Portable peripherals connecting to host systems

Procurement Notes

Verify the specific suffix 'EAI' corresponds to the -40°C to +85°C temperature range and SSOP-28 package configuration. Confirm that the '+T' designation indicates tape-and-reel packaging rather than tube distribution. Cross-reference the manufacturer's latest ordering guide to ensure the part number matches current production status and RoHS compliance requirements.

Selection Notes

Select this component when system design requires multiple serial channels within a compact footprint. The inclusion of an always-active receiver output distinguishes it from similar parts lacking this feature. Ensure the application logic can accommodate the 30µs detection delay before entering the low-power shutdown state. Verify that the single-supply architecture aligns with the available power rails in the target environment.

Part Context

This device belongs to the MAX3243E family of low-voltage RS-232 transceivers manufactured by Maxim Integrated. It shares core architectural features with the MAX3221 and MAX3223 but offers higher channel density with three drivers and five receivers. The EEAI variant specifically denotes the industrial temperature grade and surface-mount SSOP packaging format.

Replacement Considerations

MAX3243IDW: Texas Instruments equivalent offering identical electrical specifications and pinout compatibility in a SOIC-28 package.

FAQ

How does the AutoShutdown feature determine when to disable the transmitters?

The device disables the power supply and drivers if all receiver inputs remain between +0.3V and -0.3V for a duration exceeding 30µs.

What is the function of the R2OUTB pin on the MAX3243?

R2OUTB is a complementary receiver output that remains active even when the main receivers are in a high-impedance shutdown state, allowing continuous monitoring of RS-232 activity.

Can the MAX3243 drive serial mice directly?

Yes, the MAX3243 is designed to drive serial mice; however, the AutoShutdown feature must be disabled by tying FORCEOFF and FORCEON to VCC to prevent interference with mouse operation.