MAX3243CWI+

Overview

The MAX3243CWI+ is a true RS-232 transceiver operating from a single +3.0V to +5.5V supply, featuring three drivers and five receivers in a 28-pin Wide SO package. It incorporates AutoShutdown technology to achieve 1µA supply current when no valid signal is detected on receiver inputs for 30µs. The device supports data rates up to 235kbps with typical propagation delays of 0.3µs. It includes an always-active complementary receiver output (R2OUTB) for external monitoring during shutdown. The component provides ±15kV ESD protection and requires only 0.1µF capacitors for 3.3V operation.

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 components.
• Complementary receiver output remains active during shutdown to monitor peripheral activity while other outputs are high-impedance.

Applications

• Battery-powered equipment
• Hand-held devices
• Portable diagnostics equipment

Procurement Notes

Verify that the ordering suffix corresponds to the Wide SO package variant rather than SSOP or TSSOP alternatives within the same family. Confirm the temperature range specification matches the 'C' grade requirements for your specific application environment before finalizing procurement orders.

Selection Notes

Select this component when system design requires multiple serial channels with minimal standby power consumption. Ensure the host logic voltage compatibility aligns with the specified input thresholds for both 3.3V and 5V systems. Verify that the available board space accommodates the necessary external capacitors for the charge pump circuitry.

Part Context

This part belongs to the MAX3221/MAX3223/MAX3243 family of low-power RS-232 transceivers. While sharing core AutoShutdown capabilities, it differs from the MAX3221 and MAX3223 by offering three drivers and five receivers instead of one or two pairs. It serves as a higher-channel-count solution for multi-port serial interfaces.

Replacement Considerations

Public confirmed substitute part numbers include V62/06624-01YE and V62-06624-01XE.

FAQ

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

The device enters AutoShutdown mode after detecting no valid signal levels on all receiver inputs for a duration of 30µs, reducing supply current to 1µA.

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 AutoShutdown must be disabled by connecting FORCEOFF and FORCEON to VCC for this application.