MAX3238EAI+

Overview

The MAX3238EAI+ is a true RS-232 transceiver manufactured by Analog Devices Inc./Maxim Integrated, designed for notebook and subnotebook computer applications. It features five drivers and three receivers with full-duplex communication capability. The device operates on a single +3.0V to +5.5V supply voltage and achieves a guaranteed data rate of 250kbps. Utilizing AutoShutdown Plus technology, it reduces supply current to 1µA when no signal transitions are detected for 30 seconds. The component includes an always-active complementary receiver output (R1OUTB) and meets EIA/TIA-232 specifications down to 3.0V. It is housed in a 28-pin SSOP package.

Feature Summary

• AutoShutdown Plus functionality reduces power consumption by shutting down the onboard power supply and drivers after 30 seconds of inactivity, while keeping receivers active.
• Integrated dual charge-pump power supply generates true RS-232 voltages from a single low-voltage supply without requiring external inductors.
• Includes an extra, always-active noninverting receiver output (R1OUTB) that allows monitoring of external devices like modems even when VCC is removed.
• Flow-through pinout design simplifies PCB layout and ensures compatibility with standard RS-232 interface requirements.

Applications

• Notebook, Subnotebook, and Palmtop Computers
• High-Speed Modems
• Battery-Powered Equipment
• Hand-Held Equipment

Procurement Notes

Verify the manufacturer part number matches exactly: MAX3238EAI+. Confirm the suffix 'E' indicates the industrial temperature range (-40°C to +85°C) and 'AI+' denotes the SSOP-28 package with lead-free compliance. Cross-reference the datasheet revision to ensure feature consistency, particularly regarding the AutoShutdown Plus behavior and capacitor requirements.

Selection Notes

Select this component for systems requiring low-power RS-232 communication in portable devices. Ensure the system voltage falls within the 3.0V to 5.5V range. Verify that the application can tolerate the 30-second timeout before shutdown or utilize FORCEON/FORCEOFF pins for manual control. Check capacitor values against Table 3 in the datasheet for specific VCC levels to maintain stable charge pump operation.

Part Context

This device belongs to the MAX3238 family of true RS-232 transceivers. It is distinct from other Maxim RS-232 parts by its specific combination of five drivers, three receivers, and the proprietary AutoShutdown Plus feature. The 'E' grade specifies industrial temperature performance, differentiating it from commercial variants like the MAX3238CAI.

Replacement Considerations

Direct pin-compatible replacements include the MAX3238CAI for commercial temperature ranges. For automotive applications, consider the MAX3238IPWG4Q1 which offers AEC-Q100 qualification. Verify that any substitute maintains the 5-driver/3-receiver configuration and AutoShutdown Plus functionality if power management is critical.