MAX3221EUE+T

Overview

The MAX3221EUE+T is a single-driver, single-receiver RS-232 transceiver in a 16-pin TSSOP package. It operates from a +3.0V to +5.5V supply with a typical shutdown current of 1µA. The device supports data rates up to 235kbps and features AutoShutdown functionality that disables the power supply when no valid signal is detected on receiver inputs for 30µs. It includes an INVALID output pin indicating active or shutdown status. Electrical characteristics specify a maximum propagation delay of 0.3µs and input voltage tolerance of ±25V.

Feature Summary

• AutoShutdown technology reduces supply current to 1µA by disabling internal charge pumps and drivers when receiver inputs remain inactive for 30µs.
• Integrated dual charge pump generates true RS-232 voltages from a single low-voltage supply without requiring external ±12V sources.
• INVALID output pin provides a logic signal reflecting the presence of valid RS-232 levels at the receiver inputs.

Applications

• Battery-powered equipment
• Hand-held devices
• Portable diagnostics equipment

Procurement Notes

Verify the suffix 'T' indicates tape-and-reel packaging configuration. Confirm the 'E' grade designation corresponds to the -40°C to +85°C industrial temperature range. Ensure the '+T' suffix aligns with RoHS compliance requirements specified in the manufacturer's ordering information table.

Selection Notes

Select this component for applications requiring minimal quiescent current during idle periods. The integrated charge pump simplifies board layout by eliminating external high-voltage generation circuits. Verify that the 235kbps maximum data rate meets system timing requirements and that the 16-pin TSSOP footprint fits the available PCB space.

Part Context

This part belongs to the MAX3221/MAX3223/MAX3243 family of 3V-powered RS-232 transceivers. While the MAX3223 offers two drivers and receivers, and the MAX3243 provides three drivers with five receivers, the MAX3221 specifically addresses single-channel communication needs within the same low-power architecture.

Replacement Considerations

MAX3221CAE+T serves as a commercial-grade alternative with a 0°C to +70°C operating range. MAX3221EAE+T provides identical electrical specifications but utilizes a 16-pin SSOP package instead of TSSOP.

FAQ

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

The device enters AutoShutdown mode when all receiver inputs remain between +0.3V and -0.3V for a duration of 30µs, subsequently disabling the onboard power supply and drivers.

What is the function of the INVALID output pin?

The INVALID output indicates the status of the receiver inputs; it goes high when valid RS-232 levels are present and low when the device is in the shutdown state due to lack of activity.

Can the MAX3221 interface directly with 5V logic families?

Yes, the device can directly interface with 5V logic families including ACT and HCT CMOS when operating from a 5V supply, though it is incompatible with AC, HC, or CD4000 CMOS families.