MAX3243CUI+

Overview

The MAX3243CUI+ is a true RS-232 transceiver featuring three drivers and five receivers in a 28-pin TSSOP package. It operates from a single +3.0V to +5.5V supply, utilizing an internal dual charge pump with four 0.1µF capacitors to generate ±5.5V rails. The device supports data rates up to 235kbps and incorporates AutoShutdown technology, reducing supply current to 1µA when no valid signal is detected on receiver inputs for 30µs. It includes an always-active complementary receiver output (R2OUTB) for external monitoring during shutdown. The component provides ±15kV ESD protection on RS-232 pins and complies with TIA/EIA-232-F standards.

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 eliminates the need for external ±12V supplies, enabling operation from a single low-voltage source.
• Complementary always-active receiver output allows continuous monitoring of RS-232 activity even when the main transceivers are in a high-impedance shutdown state.

Applications

• Battery-powered equipment requiring extended standby life
• Hand-held devices and portable diagnostics equipment
• Peripherals connecting to PC serial ports

Procurement Notes

Verify the specific ordering suffix against the manufacturer's official documentation to confirm the exact package type and temperature range. Ensure that any additional characters following the base model number correspond to the intended RoHS compliance status or tape-and-reel packaging configuration as defined in the latest datasheet revision.

Selection Notes

Select this component for designs requiring multiple RS-232 channels within a compact footprint while maintaining low power consumption. The inclusion of the complementary receiver output makes it suitable for systems needing to detect incoming signals without keeping the entire interface powered. Verify that the application logic voltage matches the supported CMOS/TTL families listed in the compatibility table.

Part Context

This part belongs to the MAX3221/MAX3223/MAX3243 family of low-voltage RS-232 transceivers. While the MAX3221 offers one driver/receiver and the MAX3223 provides two, the MAX3243 expands capacity to three drivers and five receivers. All variants share the same core AutoShutdown architecture and charge-pump technology, differing primarily in channel count and pin configurations.

Replacement Considerations

Publicly confirmed substitute part numbers include MAX3243CAI and MAX3243EAI. These alternatives offer identical functional specifications but differ in operating temperature ranges and package styles. Verify that the replacement package matches the PCB footprint requirements before implementation.