MAX3226EETE+

Overview

The MAX3226EETE+ is a single-channel, full-duplex RS-232 transceiver manufactured by Analog Devices Inc. (Maxim Integrated). It operates on a single +3.0V to +5.5V supply and guarantees a data rate of 250kbps. The device features AutoShutdown Plus technology, reducing supply current to 1μA when inputs are inactive for over 30 seconds. It includes ±15kV ESD protection on all I/O pins and utilizes a dual charge pump with four 0.1μF capacitors. The component is housed in a 16-pin TQFN-EP package and supports an operating temperature range from -40°C to +85°C.

Feature Summary

• AutoShutdown Plus functionality automatically reduces power consumption by shutting down internal charge pumps during periods of inactivity.
• Integrated dual charge pump generates required positive and negative voltage rails using only four small external capacitors.
• Robust electrostatic discharge protection rated at ±15kV via air-gap discharge and ±8kV via contact discharge.
• READY output pin provides a logic-level indication that the internal charge pumps are regulating and the device is ready for transmission.

Applications

• Notebook, subnotebook, and palmtop computers
• Cellular phones and battery-powered equipment
• Hand-held devices and peripherals such as printers
• Automotive communication systems

Procurement Notes

Verify the specific suffix 'EETE+' corresponds to the TQFN-EP-16 package and the extended industrial temperature range (-40°C to +85°C) before procurement. Confirm RoHS compliance status through official manufacturer documentation or authorized distributor declarations. Ensure the ordering part number matches the exact pinout and thermal pad requirements specified in the datasheet to prevent integration errors.

Selection Notes

Select this component for applications requiring low-power standby modes and high ESD tolerance in space-constrained designs. The MAX3226E variant is appropriate where a single transmitter and receiver are sufficient, unlike the MAX3224E which offers two channels. Verify that the system UART can tolerate the 30-second inactivity threshold for automatic shutdown. Ensure the PCB layout accommodates the exposed pad for optimal thermal dissipation and grounding.

Part Context

The MAX3226EETE+ belongs to the MAX3224E/MAX3225E/MAX3226E/MAX3227E family of RS-232 transceivers. This series shares common features including AutoShutdown Plus, MegaBaud capabilities (in other variants), and robust ESD protection. The MAX3226E specifically provides one driver and one receiver, distinguishing it from the dual-driver MAX3224E and the high-speed MAX3225E.

Replacement Considerations

MAX3226EEUE+ (TSSOP-16 package)

FAQ

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

The device enters low-power shutdown mode when the RS-232 cable is disconnected, peripheral transmitters are inactive, and the driving UART remains inactive for more than 30 seconds. It wakes up upon sensing a valid transition at any transmitter or receiver input.

What is the function of the READY output pin?

The READY output asserts high when the internal charge pumps are regulating and the device has generated the necessary voltage levels to begin transmitting. It goes low when the device is in shutdown mode.

What external components are required for the charge pump operation?

The device requires four small 0.1μF capacitors for operation from a 3.3V supply. These capacitors serve as flying and reservoir capacitors for the dual charge pump to generate V+ and V- supplies.