MAX3212CAI

Overview

The MAX3212CAI+ is a true RS-232 transceiver designed for 2.7V to 3.6V single-supply operation, featuring three drivers and five receivers. It incorporates AutoShutdown technology to reduce supply current to 1µA when no valid signal is detected. The device guarantees a data rate of 235kbps and meets EIA/TIA-232E and EIA/TIA-562 specifications. It utilizes a switch-mode power supply with external components to generate internal ±6.5V rails. The component is housed in a 28-pin SSOP package and operates within a commercial temperature range of 0°C to +70°C.

Feature Summary

• AutoShutdown mode reduces supply current to 1µA by disabling the onboard power supply and drivers when valid receiver signals are absent.
• Integrated switch-mode power supply generates necessary voltage levels using minimal external components including one inductor and two diodes.
• Complementary receiver output remains active during shutdown to monitor incoming activity without biasing connected devices.

Applications

• Notebook and Palmtop Computers
• Battery-Powered Equipment
• Peripherals

Procurement Notes

Verify that the ordering suffix matches the required temperature grade and package type. Confirm RoHS compliance status as indicated on the manufacturer's official documentation. Ensure the specific variant aligns with the intended operating environment before finalizing procurement orders.

Selection Notes

Select this component for applications requiring low-voltage operation between 2.7V and 3.6V. It is suitable for systems needing three transmit and five receive channels. Consider the external passive component requirements for the charge pump circuit when designing the PCB layout.

Part Context

This part belongs to the MAX3212 family of RS-232 transceivers from Maxim Integrated. It shares functional similarities with other low-power serial interface devices but is distinct due to its specific 3-driver/5-receiver configuration and proprietary AutoShutdown feature optimized for battery-powered portable electronics.

Replacement Considerations

Direct substitutes include the MAX3212CWI (Wide SO package) or the MAX3212EAI (Extended temperature range). Verify pinout compatibility and electrical characteristics before substitution.

FAQ

How does the AutoShutdown feature function?

The AutoShutdown feature monitors receiver inputs. If no valid RS-232 signal level is detected for approximately 30µs, the onboard power supply and drivers shut down, reducing supply current to 1µA. The system reactivates upon detection of a valid signal.

What is the purpose of the R5OUTB pin?

R5OUTB provides a complementary, non-inverting output for Receiver 5. It remains always active regardless of the EN control state or shutdown status, allowing monitoring of RS-232 activity while other receivers are disabled.

Can the MAX3212 drive serial mice?

Yes, the MAX3212 is specifically designed for mouse driveability. It has been tested with various major mouse models and meets their current and voltage requirements even under worst-case load conditions.