MAX3226EAE+

Overview

The MAX3226EAE+ is a single-driver, single-receiver RS-232 transceiver from the MAX3224–MAX3227 family. It operates on a +3.0V to +5.5V supply and guarantees a maximum data rate of 250kbps. The device features AutoShutdown Plus technology, achieving a typical supply current of 1µA when inactive. It includes an internal dual charge pump requiring four 0.1µF capacitors for operation at 3.3V. Key control pins include FORCEON, FORCEOFF, INVALID, and READY. The component is housed in a 16-pin SSOP package and supports full-duplex communication with EIA/TIA-232 standards.

Feature Summary

• AutoShutdown Plus functionality automatically reduces power consumption by disabling the charge pump and transmitters during periods of inactivity or cable disconnection.
• Integrated dual charge pump generates required RS-232 voltage levels using only four small external capacitors.
• INVALID output pin provides real-time status indication of valid RS-232 signal presence at receiver inputs.
• READY output pin asserts high to indicate that the internal charge pumps are regulating and the device is prepared for transmission.

Applications

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

Procurement Notes

Verify the specific suffix 'AE' corresponds to the SSOP-16 package and -40°C to +85°C temperature range. Confirm RoHS compliance status via the manufacturer's official documentation. Ensure ordering details match the exact part number to avoid discrepancies in package type or operating temperature specifications.

Selection Notes

Select this component for applications requiring low-power standby modes without BIOS modifications. Choose the MAX3226 variant over the MAX3227 if the application requires a guaranteed 250kbps data rate rather than 1Mbps. Verify that the system design accommodates the four required charge-pump capacitors and utilizes the FORCEON/FORCEOFF pins for precise power management control.

Part Context

This device belongs to the MAX3224–MAX3227 series of 3V-powered RS-232 transceivers. It shares core architectural features with the MAX3224 and MAX3225 but differs in guaranteed data rates and driver/receiver counts. The MAX3226 specifically offers one driver and one receiver with a 250kbps limit, distinguishing it from the higher-speed MAX3225/MAX3227 models within the same family.

Replacement Considerations

Public confirmed substitute part numbers: MAX3226EEAE+, MAX3226EAAE+, MAX3226EETE+. These variants offer identical electrical characteristics with differences primarily in packaging (SSOP, TSSOP, TQFN) and potentially extended industrial temperature ranges.

FAQ

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

The device enters shutdown mode when no valid signal transition is detected on any receiver or transmitter input for more than 30 seconds, or if the RS-232 cable is disconnected.

What is the function of the INVALID output pin?

The INVALID output goes low when no valid RS-232 voltage levels are detected on all receiver inputs, indicating the absence of a valid signal regardless of the FORCEON/FORCEOFF states.

Can unused transmitter inputs be left floating?

No, unused transmitter inputs should be connected to GND or VCC to prevent undefined states, as the device does not have internal pull-up resistors.