MAX3224ETP+

Overview

The MAX3224ETP+ is a single-driver, single-receiver RS-232 transceiver in a 20-pin TQFN-EP package. It operates from a +3.0V to +5.5V supply and achieves a typical 1µA shutdown current via AutoShutdown Plus. The device guarantees a maximum data rate of 250kbps with ±5V transmitter output swings. It features ±15kV ESD protection on I/O pins, an internal dual charge pump requiring four 0.1µF capacitors at 3.3V, and a READY output indicating charge pump regulation.

Feature Summary

• AutoShutdown Plus technology automatically reduces supply current to 1µA when the interface is idle for over 30 seconds or disconnected.
• Integrated dual charge pump generates required RS-232 voltage levels using only four small external capacitors.
• Proprietary low-dropout transmitter stage ensures true RS-232 performance across the full operating voltage range.
• Logic-level READY output asserts high when the charge pump is regulating and the device is ready for transmission.

Applications

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

Procurement Notes

Verify the specific suffix 'E' confirms the -40°C to +85°C industrial temperature range and 'TP+' indicates the lead-free TQFN-EP package. Confirm RoHS compliance status through official manufacturer documentation before finalizing procurement specifications.

Selection Notes

Select this component for applications requiring minimal standby power consumption without BIOS modifications. Ensure the design supports the 250kbps data rate limit. Verify that the system can accommodate the four external capacitors required for the internal charge pump operation.

Part Context

This part belongs to the MAX3224–MAX3227/MAX3244/MAX3245 family of 3V-powered RS-232 transceivers. It shares the AutoShutdown Plus feature and dual charge pump architecture with other members of the series, differing primarily in driver/receiver counts and guaranteed data rates.

Replacement Considerations

The MAX3226EETE+ offers identical functionality within the same family but utilizes a 16-pin TQFN-EP package instead of the 20-pin variant. Pin compatibility must be verified if replacing directly on existing PCB layouts.

FAQ

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

The device enters shutdown mode when the RS-232 cable is disconnected, peripheral transmitters are inactive, and the driving UART remains inactive for more than 30 seconds.

What is the function of the INVALID output pin?

The INVALID output goes low when no valid RS-232 voltage levels are detected on any receiver input, 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 they do not have internal pull-up resistors.