MAX3243CUI

Overview

The MAX3243CUI is a true RS-232 transceiver manufactured by Analog Devices Inc./Maxim Integrated, housed in a 28-pin TSSOP package. It operates from a single +3.0V to +5.5V supply and features three drivers and five receivers with full-duplex communication capability. The device incorporates an AutoShutdown feature that reduces 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 integrated dual charge pumps requiring only 0.1µF capacitors for 3.3V operation.

Feature Summary

• AutoShutdown technology automatically disables the onboard power supply and drivers upon detecting invalid signal levels, significantly reducing power consumption during idle periods.
• Integrated high-efficiency dual charge-pump circuitry generates required internal voltages directly from a single low-voltage supply, eliminating the need for external ±12V sources.
• Includes a complementary always-active receiver output (R2OUTB) that remains functional during shutdown mode to monitor external peripheral activity without forward-biasing connected logic devices.

Applications

• Battery-powered equipment requiring extended operational life
• Hand-held portable devices with limited power budgets
• Portable diagnostics equipment interfacing via serial ports

Procurement Notes

Verify the specific suffix 'C' indicates the commercial temperature range of 0°C to +70°C. Confirm the 'U' designation corresponds to the 28-pin TSSOP package type. Ensure compatibility with the intended system voltage requirements within the specified 3.0V to 5.5V operating range before finalizing procurement.

Selection Notes

Select this component when designing systems that require low-power standby modes alongside standard RS-232 connectivity. The inclusion of an always-active receiver makes it suitable for applications needing ring indicator monitoring while the main system is powered down. Verify that the 28-pin TSSOP footprint aligns with the PCB layout constraints.

Part Context

This part belongs to the MAX3221/MAX3223/MAX3243 family of low-voltage RS-232 transceivers. While sharing core functionality with the MAX3221 and MAX3223, the MAX3243 variant specifically provides three drivers and five receivers. The CUI suffix distinguishes it from other package options like SSOP or Wide SOIC available within the same electrical specification family.

Replacement Considerations

MAX3243CAI+ offers identical electrical specifications but utilizes a 28-pin SSOP package instead of TSSOP. MAX3243EUI+ provides the same pinout and features but extends the operating temperature range to -40°C to +85°C for industrial environments.