MAX231EWE+

Overview

The MAX231EWE+ is a dual-channel RS-232 transceiver from the Analog Devices/MAXIM MAX220-MAX249 family, designed for EIA/TIA-232E and V.28/V.24 interfaces. It operates on a single +5V supply (4.5V to 5.5V) using an internal charge pump to generate ±10V levels. The device features two drivers and two receivers with full-duplex communication capability. It requires four external capacitors: C1 and C2 are typically 0.1µF, while C3, C4, and C5 are 0.33µF. The datasheet specifies a typical data rate of 120kbps, a maximum propagation delay of 10µs, and an operating temperature range of -40°C to +85°C.

Feature Summary

• Integrated charge pump circuitry eliminates the need for bipolar ±12V supplies, enabling single +5V operation.
• Provides bidirectional logic level translation between TTL/CMOS inputs and RS-232 output voltages.
• Includes shutdown mode functionality to significantly reduce power consumption in standby applications.

Applications

• Interface translation between microcontrollers and serial peripherals
• Multidrop RS-232 network connections
• Portable diagnostic equipment requiring low-power serial communication

Procurement Notes

Verify the specific suffix 'EWE+' against the manufacturer's current ordering guide to confirm package type and RoHS compliance status. Ensure that the required external capacitors are included in the bill of materials, as this component does not integrate them internally unlike other variants in the series.

Selection Notes

Select this part when a dual-driver configuration is required alongside integrated voltage generation. Compare against the MAX232 for similar performance or the MAX233 if board space savings from integrated capacitors are prioritized over external component costs.

Part Context

This component belongs to the MAX220–MAX249 family of multichannel RS-232 drivers and receivers. The family offers various channel counts and integration levels, ranging from devices requiring multiple external capacitors to those with fully integrated charge pumps and capacitors for minimal footprint designs.

Replacement Considerations

The MAX232EWE+ serves as a direct functional substitute within the same family. Verify pin compatibility and ensure the replacement variant supports the required -40°C to +85°C industrial temperature range.

FAQ

Does the MAX231EWE+ include internal capacitors?

No, the MAX231 requires four external capacitors (C1-C4) to operate its internal charge pump circuitry.

What is the maximum data rate supported by this device?

The datasheet specifies a typical data rate of 120kbps under standard operating conditions.

How does the shutdown feature affect the charge pump?

When the shutdown pin is activated, the charge pump stops generating voltage, causing V+ to fall to +5V and V- to fall to 0V to minimize power usage.