MAX221ECUE+T

Overview

The MAX221ECUE+T is a single transmit/receive RS-232 transceiver powered by a +5V supply. It operates within a temperature range of 0°C to +70°C and is housed in a 16-pin TSSOP package. The device supports data rates up to 250kbps with a typical propagation delay of 0.15µs. Supply current is reduced to 1µA via AutoShutdown when no valid signal is detected for 30µs. ESD protection on I/O pins reaches ±15kV (Human Body Model) and ±8kV (IEC Contact Discharge). Internal charge pumps generate V+ and V- from the single supply using four 0.1µF capacitors.

Feature Summary

• AutoShutdown feature reduces supply current to 1µA when no valid RS-232 signal is present, eliminating the need for BIOS modifications.
• Integrated dual charge-pump voltage converter generates positive and negative voltages from a single +5V supply without external transformers.
• Enhanced electrostatic discharge protection on transmitter output and receiver input withstands high-voltage static events without latchup.
• INVALID pin provides an active-low signal indicating the absence of valid RS-232 levels at the receiver input.

Applications

• Maintenance and diagnostic ports
• Industrial systems
• Telecommunications equipment
• Set-top boxes

Procurement Notes

Verify the specific ordering suffix against the manufacturer's official documentation to confirm the exact temperature grade and package variant. Confirm that the component meets all required environmental standards for the intended deployment environment before finalizing procurement decisions.

Selection Notes

Select this component for applications requiring low-power standby modes without software intervention. Ensure the design accommodates the internal charge pump requirements by providing adequate decoupling capacitors near the IC. Verify that the operating temperature range aligns with the system's thermal constraints.

Part Context

This part belongs to the MAX221E family of single-channel RS-232 transceivers. It shares functional similarities with other Maxim integrated circuit interface devices designed for serial communication. The device integrates level translation and power generation into a compact footprint suitable for space-constrained electronic designs.

Replacement Considerations

Cross-reference with other MAX221 variants such as MAX221EEUE+T for extended temperature ranges. Verify pin compatibility and electrical specifications against alternative single-channel RS-232 transceivers if sourcing changes are necessary.

FAQ

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

The device enters shutdown mode when it senses no valid RS-232 signal levels on the receiver input for a duration of 30µs, reducing supply current to 1µA.

What is the function of the INVALID pin?

The INVALID pin is pulled low when no valid RS-232 signal level is detected on the receiver input, signaling that the port is inactive or disconnected.

Can the MAX221ECUE+T operate without external capacitors?

No, the internal charge pumps require four external 0.1µF capacitors (C1–C4) to generate the necessary positive and negative voltage supplies.