MAX221CAE+

Drivers, Receivers, Transceivers Overview

The MAX221CAE+ is a single transmit/receive RS-232 transceiver powered by a +5V supply. It features an AutoShutdown function that reduces the supply current to 1µA when no valid signal is detected. The device supports data rates up to 250kbps and includes internal charge pumps requiring four 0.1µF capacitors. It operates within a commercial temperature range of 0°C to +70°C and is housed in a 16-pin SSOP package.

Drivers, Receivers, Transceivers Feature Summary

• AutoShutdown technology enables ultra-low power consumption by automatically disabling the transmitter and charge pump when the cable is disconnected or peripheral is off, reducing supply current to 1µA without BIOS changes.
• Integrated dual charge pumps generate the necessary positive and negative voltages from a single +5V supply, eliminating the need for external dual-voltage sources.
• INVALID output pin indicates the presence of a valid RS-232 signal level at the receiver input, allowing system-level power management integration.

Drivers, Receivers, Transceivers Applications

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

Drivers, Receivers, Transceivers Procurement Notes

Verify the specific suffix 'AE' confirms the SSOP-16 package and commercial temperature range (0°C to +70°C). Confirm RoHS compliance status through official documentation. Ensure the ordering code matches the required package style and thermal grade before procurement.

Drivers, Receivers, Transceivers Selection Notes

Select this component for applications requiring minimal board space and low standby power. The MAX221E variants offer extended temperature ranges (-40°C to +85°C) and enhanced ESD protection if environmental conditions require it. Verify capacitor requirements for the internal charge pump circuitry during design.

Drivers, Receivers, Transceivers Part Context

The MAX221 belongs to the Maxim Integrated MAX220–MAX249 family of +5V-powered multichannel RS-232 drivers and receivers. This family is designed for communications interfaces where ±12V supplies are unavailable. The MAX221 specifically provides a single channel solution with integrated power management capabilities.

Drivers, Receivers, Transceivers Replacement Considerations

Refer to the MAX221E datasheet for equivalent devices featuring enhanced ±15kV ESD protection. Other members of the MAX220–MAX249 family may serve as alternatives depending on channel count and package requirements.

Drivers, Receivers, Transceivers FAQ

How does the AutoShutdown feature reduce power consumption?

When the receiver input detects no valid RS-232 signal levels for 30µs, the AutoShutdown logic disables the transmitter and on-board charge pump, reducing the supply current to 1µA.

What is the function of the INVALID pin?

The INVALID output is pulled low when no valid RS-232 signal level is present on the receiver input and goes high when a valid signal is detected, indicating port activity.

What capacitors are required for operation?

Four 0.1µF capacitors are required for the internal charge pumps (C1, C2, C3, C4). Polarized or nonpolarized capacitors are acceptable, provided polarity is observed if polarized types are used.