MAX3243CUI+T

Overview

The MAX3243CUI+T is a +3.0V to +5.5V RS-232 transceiver in a 28-pin TSSOP package, rated for the commercial temperature range of 0°C to +70°C. It integrates three drivers and five receivers with an always-active complementary receiver output (R2OUTB). The device features 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 and utilizes internal dual charge pumps requiring only 0.1µF capacitors for operation.

Feature Summary

• AutoShutdown functionality reduces power consumption by disabling the onboard power supply and drivers when valid signal levels are absent from receiver inputs.
• Integrated dual charge pump circuitry generates required voltage levels from a single low-voltage supply without external ±12V sources.
• Complementary noninverting receiver output remains active during shutdown states to monitor external peripheral activity.

Applications

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

Procurement Notes

Verify the specific suffix 'U' corresponds to the 28-pin TSSOP package and the 'C' indicates the 0°C to +70°C operating range. Confirm that the '+' suffix denotes compliance with lead-free manufacturing standards as per the manufacturer's ordering information table before finalizing procurement specifications.

Selection Notes

Select this component when a full-duplex RS-232 interface with multiple transmitter and receiver channels is required within a compact surface-mount footprint. Ensure the application environment remains within the specified commercial temperature limits and that the system can accommodate the 0.1µF capacitor requirements for optimal performance at 3.3V operation.

Part Context

This part belongs to the MAX3243 family of RS-232 transceivers designed for low-voltage systems. It shares core architectural features with the MAX3221 and MAX3223 but provides expanded I/O capabilities with three drivers and five receivers. The device is manufactured by Analog Devices Inc./Maxim Integrated.

Replacement Considerations

Direct pin-compatible alternatives within the same series include the MAX3243CAI+T (SSOP package) and the MAX3243EUI+T (extended temperature range). Verify package dimensions and thermal characteristics when substituting between SSOP, TSSOP, or Wide SO variants.

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, subsequently shutting down the onboard power supply and drivers to achieve 1µA supply current.

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

R2OUTB is a complementary, always-active noninverting receiver output that allows monitoring of external device 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 by connecting FORCEOFF and FORCEON to VCC for this application.