MAX3244EEUI+

Overview

The MAX3244EEUI+ is a true RS-232 transceiver manufactured by Analog Devices Inc./Maxim Integrated, housed in a 28-pin TSSOP package. It operates on a single +3.0V to +5.5V supply and features three drivers and five receivers for full-duplex communication. The device guarantees a maximum data rate of 250kbps and achieves a typical supply current of 1µA through AutoShutdown Plus technology. It includes an INVALID output signal and utilizes a dual charge pump requiring four small capacitors.

Feature Summary

• AutoShutdown Plus functionality automatically reduces power consumption when the interface is idle or disconnected
• Integrated INVALID output detects valid RS-232 voltage levels on receiver inputs
• Proprietary low-dropout transmitter stage ensures true RS-232 performance from low-voltage supplies
• R2OUTB provides an always-active noninverting receiver output for monitoring during shutdown

Applications

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

Procurement Notes

Verify the specific suffix EEUI corresponds to the -40°C to +85°C extended temperature range and the 28-pin TSSOP package configuration. Confirm lead-free/RoHS compliance status as indicated by the '+' designation in the ordering information section of the official documentation.

Selection Notes

Select this component for applications requiring automatic power management without BIOS modifications. Ensure the design supports the required external capacitor values for the charge pump at the target operating voltage. Verify that the 250kbps data rate meets system requirements, as higher speeds are not guaranteed for this specific part variant.

Part Context

This device belongs to the MAX3224–MAX3227/MAX3244/MAX3245 family of 3V-powered RS-232 interfaces. It shares core architecture with the MAX3245 but differs in guaranteed data rate specifications. The family emphasizes low-power operation and space-saving packaging options for portable electronics.

Replacement Considerations

Public confirmed substitute part numbers: MAX3244ECPI+, MAX3244EPEI+, MAX3244EEWI+. Verify pin compatibility and temperature range alignment before substitution.

FAQ

How does the AutoShutdown Plus feature operate?

The device enters a low-power shutdown mode when all receiver and transmitter inputs remain inactive for more than 30 seconds. It wakes up upon sensing a valid transition at any input.

What is the function of the R2OUTB pin?

R2OUTB is an always-active, noninverting complementary receiver output. It allows monitoring of receiver activity while other receivers are in high-impedance shutdown state.

What is the purpose of the INVALID output?

The INVALID output goes low when no valid RS-232 voltage levels are detected on any receiver input, indicating the absence of a valid signal.