MAX3244EWI

Overview

The MAX3244EWI+ is a true RS-232 transceiver from the MAX3244E series, manufactured by Analog Devices (Maxim Integrated). It features three drivers and five receivers with full-duplex communication capability. The device operates on a single +3.0V to +5.5V supply and achieves a typical supply current of 1µA through AutoShutdown Plus technology. It guarantees data rates up to 250kbps with a propagation delay of 0.15µs. The component includes ±15kV ESD protection on I/O pins and is housed in a 28-pin SO-Wide package.

Feature Summary

• AutoShutdown Plus functionality automatically reduces power consumption when the interface is idle or disconnected.
• Integrated dual charge pump generates required RS-232 voltage levels using only four small capacitors.
• Proprietary low-dropout transmitter stage ensures true RS-232 performance across the operating voltage range.
• Dedicated R2OUTB output allows monitoring of receiver activity while other outputs remain high impedance.

Applications

• Notebook, subnotebook, and palmtop computers
• Cellular phones and handheld equipment
• Battery-powered peripherals and printers

Procurement Notes

Verify the specific suffix 'EWI+' against the manufacturer's official ordering guide to confirm the exact pin-compatible package variant and lead-free compliance status. Cross-reference the datasheet revision number to ensure all electrical characteristics match the design requirements before finalizing procurement.

Selection Notes

Select this component for designs requiring low-power standby modes without BIOS modifications. Ensure the application supports the 250kbps maximum data rate rather than the 1Mbps variants. Verify that the system can accommodate the external capacitor requirements for the internal charge pump operation within the specified temperature range.

Part Context

This part belongs to the MAX3224–MAX3227/MAX3244/MAX3245 family of 3V-powered RS-232 transceivers. It shares core architectural features with the MAX3224 and MAX3245 but is distinguished by its specific driver/receiver count and guaranteed data rate specifications defined in the official product documentation.

Replacement Considerations

Public confirmed substitute part numbers include MAX3243EEAI+ and MAX3243EETJ+T.

FAQ

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

The device enters shutdown mode when valid signal transitions are not detected on any receiver or transmitter input for more than 30 seconds, such as when the cable is disconnected or peripherals are inactive.

What is the function of the R2OUTB pin on the MAX3244?

R2OUTB provides an always-active, noninverting complementary receiver output. It allows the system to monitor ring indicator signals or receiver activity even when the main receiver outputs are in a high-impedance shutdown state.

Can the MAX3244 drive serial mice directly?

Yes, the MAX3244 is specifically designed to power serial mice from low-voltage supplies and has been tested with leading mouse brands to ensure compatibility.