MAX3243ECAI+

Overview

The MAX3243ECAI+ is a low-voltage RS-232 transceiver manufactured by Analog Devices Inc. (Maxim Integrated). It features three drivers and five receivers, supporting full-duplex communication at data rates up to 250kbps. The device operates from a single +3.0V to +5.5V supply and incorporates an AutoShutdown feature that reduces supply current to 1µA when the cable is disconnected or peripherals are off. It includes ±15kV ESD protection on all I/O pins and utilizes a dual charge pump requiring four 0.1µF capacitors for operation.

Feature Summary

• AutoShutdown technology automatically disables the charge pump and drivers to minimize power consumption during idle states.
• Integrated dual charge pumps generate internal ±5.5V supplies from a single low-voltage source using minimal external components.
• Enhanced electrostatic discharge protection ensures robustness against high-voltage static events without latch-up risks.
• Dedicated complementary receiver outputs allow continuous monitoring of external signals even when primary receivers are disabled.

Applications

• Notebook, subnotebook, and palmtop computers
• Battery-powered handheld equipment and cellular phones
• Serial mouse interface circuits
• Peripherals such as printers

Procurement Notes

Verify the specific suffix 'CAI+' corresponds to the SSOP-28 package with a commercial temperature range of 0°C to +70°C. Confirm RoHS compliance status through official manufacturer documentation prior to integration. Ensure ordering details match the exact pinout and electrical specifications required for the target design.

Selection Notes

Select this component for designs requiring multiple serial ports within space-constrained mobile devices. The integrated charge pump eliminates the need for external voltage inverters. Verify that the application environment remains within the specified operating temperature limits and that the 250kbps data rate meets system timing requirements.

Part Context

This part belongs to the MAX3221E/MAX3223E/MAX3243E family of low-voltage RS-232 transceivers. While sharing core architecture and AutoShutdown capabilities, the MAX3243E is distinguished by its higher channel count of three drivers and five receivers compared to the single-driver MAX3221E or dual-driver MAX3223E variants.

Replacement Considerations

Public confirmed substitute part numbers: MAX3243ECPE+, MAX3243EEAI+, MAX3243ECDWR.

FAQ

How does the AutoShutdown feature reduce power consumption?

When valid RS-232 signal levels are absent on all receiver inputs for 30µs, the AutoShutdown circuitry disables the onboard charge pump and drivers, reducing the supply current to 1µA.

What is the function of the R2OUTB output on the MAX3243E?

R2OUTB is a noninverting complementary receiver output that remains always active. It allows external devices to be monitored without forward biasing protection diodes in powered-down circuitry.

What capacitor values are required for the charge pump?

For operation from a +3.3V supply, four small 0.1µF capacitors are required for C1 through C4. Different supply voltages may require different capacitance values as specified in the datasheet.