MAX3221CAE+

Overview

The MAX3221CAE+ is a single-driver, single-receiver RS-232 transceiver in a 16-pin SSOP package. It operates from a +3.0V to +5.5V supply and achieves 1µA supply current via AutoShutdown when no valid signal is detected on receiver inputs for 30µs. The device supports data rates up to 235kbps with typical propagation delays of 0.3µs. Input hysteresis is specified at 0.3V. Operating temperature range is 0°C to +70°C.

Feature Summary

• AutoShutdown feature reduces supply current to 1µA when no valid RS-232 signal is present on receiver inputs for 30µs
• Integrated dual charge-pump circuitry generates internal ±5.5V supplies from a single +3.0V to +5.5V source
• Transmitters convert CMOS logic levels to true EIA/TIA-232 voltage levels without requiring external ±12V supplies

Applications

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

Procurement Notes

Verify the component manufacturer designation as Analog Devices Inc./Maxim Integrated. Confirm the specific ordering suffix CAE corresponds to the commercial temperature range (0°C to +70°C) and 16-SSOP package. Ensure documentation matches the official Maxim Integrated datasheet revision history for accurate electrical specifications.

Selection Notes

Select this part for applications requiring low-power standby modes through automatic shutdown detection. Verify that the required data rate does not exceed 235kbps under worst-case load conditions. Ensure the system power supply remains within the +3.0V to +5.5V operating range to maintain proper charge pump functionality and transmitter output swing.

Part Context

The MAX3221 serves as the single-channel variant within the MAX3221/MAX3223/MAX3243 family. While the MAX3223 provides two drivers and receivers, and the MAX3243 offers three drivers and five receivers with an always-active complementary receiver, the MAX3221 focuses on space-constrained designs needing only one full-duplex RS-232 link.

Replacement Considerations

MAX3221EAE+

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 at least 30µs, shutting down the onboard power supply and drivers.

What capacitor values are required for operation at 3.3V?

For VCC voltages between 3.0V and 3.6V, the datasheet specifies using 0.1µF capacitors for C1, C2, C3, and C4.

Can the MAX3221 interface directly with 5V logic families?

Yes, the device can directly interface with various 5V logic families, including ACT and HCT CMOS, when operating from a 5V supply.