MAX3221ECAE

Overview

The MAX3221ECAE is a single-driver, single-receiver RS-232 transceiver operating from a +3.0V to +5.5V supply. It features AutoShutdown technology that reduces supply current to 1µA when no valid signal is detected. The device supports data rates up to 250kbps and includes ±15kV ESD protection on all I/O pins. It utilizes a dual charge pump requiring four 0.1µF capacitors for operation. The component is housed in a 16-pin SSOP package and operates within a commercial temperature range of 0°C to +70°C.

Feature Summary

• AutoShutdown feature automatically powers down the charge pump and drivers to conserve energy when the RS-232 cable is disconnected or peripheral transmitters are off.
• Integrated dual charge pump generates true RS-232 voltage levels from low-voltage supplies using small external capacitors.
• Enhanced electrostatic discharge protection on transmitter outputs and receiver inputs ensures robustness against handling and assembly stresses.

Applications

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

Procurement Notes

Verify the specific suffix 'CAE' corresponds to the 16-pin SSOP package and the 0°C to +70°C commercial temperature range. Confirm RoHS compliance status as indicated by the '+' designation in ordering information. Ensure the source document matches the Analog Devices/Maxim Integrated datasheet revision for accurate pinout and electrical specifications.

Selection Notes

Select this part for space-constrained designs requiring only one transmit and receive channel. It is suitable for systems needing automatic power management without BIOS modifications. Compare with MAX3223E if two channels are required, or MAX3243E for complete serial port functionality with additional receivers.

Part Context

This component belongs to the MAX3221E/MAX3223E/MAX3243E family of 3V-powered RS-232 transceivers. The family shares common features such as AutoShutdown and high ESD protection, differing primarily in the number of drivers and receivers provided per device.

Replacement Considerations

MAX3223ECAP+ offers two drivers and two receivers in a 20-pin SSOP package. MAX3221EEAE+ provides the same single-channel functionality but operates in an extended industrial temperature range of -40°C to +85°C.

FAQ

How does the AutoShutdown feature reduce power consumption?

It monitors receiver inputs and shuts off the onboard charge pump and drivers if no valid RS-232 signal levels are detected for 30µs, reducing supply current to 1µA.

What is the purpose of the INVALID output pin?

The INVALID output goes low when no valid RS-232 signal levels are present on any receiver input, indicating the device may be in shutdown mode.

Can the MAX3221ECAE drive serial mice directly?

No, the MAX3221ECAE has only one driver. The MAX3243E is specifically designed for mouse driveability due to its multiple drivers and regulated charge pump capabilities.