MAX3243EAI

Overview

The MAX3243EAI is a full-duplex RS-232 transceiver featuring three drivers and five receivers in a 28-pin SSOP package. It operates from a single +3.0V to +5.5V supply, utilizing an internal dual charge pump to generate ±5.5V levels without external ±12V rails. The device supports data rates up to 235kbps with typical propagation delays of 0.3µs. It incorporates AutoShutdown technology, reducing supply current to 1µA when no valid signal is detected on receiver inputs for 30µs. An always-active complementary receiver output (R2OUTB) allows monitoring during shutdown.

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 eliminates the need for external negative voltage supplies or complex power management.
• Complementary R2OUTB receiver remains active during shutdown to monitor external devices without forward-biasing connected logic.

Applications

• Battery-powered equipment requiring low standby current
• Hand-held portable devices
• Portable diagnostics equipment

Procurement Notes

Verify the specific ordering suffix against the manufacturer's official documentation to confirm temperature range and RoHS compliance status. Ensure the component matches the required 28-pin SSOP footprint and electrical specifications before integration into the design.

Selection Notes

Select this component for applications needing multiple transmit and receive channels within a compact form factor. The integrated charge pump simplifies board layout by removing external inductors or negative voltage generators. Verify that the system logic levels are compatible with the specified input thresholds.

Part Context

This part belongs to the MAX3221/MAX3223/MAX3243 family of 3V RS-232 transceivers. While sharing the same core AutoShutdown architecture and charge pump technology, it differs from the MAX3221 and MAX3223 by providing three drivers and five receivers instead of one or two.

Replacement Considerations

MAX3243CAI

FAQ

How does the AutoShutdown feature determine when to enter low-power mode?

The device enters AutoShutdown mode if no valid RS-232 signal levels are present on all receiver inputs for a duration of 30µs.

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

R2OUTB is a complementary, always-active receiver output that allows monitoring of RS-232 activity even when the main receivers are in a high-impedance state due to shutdown.

Can the MAX3243 drive serial mice directly?

Yes, the MAX3243 is specifically designed to drive serial mice from low-voltage supplies, though the AutoShutdown feature should be disabled via FORCEOFF and FORCEON pins for this application.