MAX241EWI+

Overview

The MAX241EWI+ is a +5V-powered, multichannel RS-232 transceiver featuring four drivers and five receivers. It operates in full-duplex mode with a data rate of 120 kb/s and supports a supply voltage range of 4.5V to 5.5V. The device draws 15 mA during normal operation and includes a shutdown function for power reduction. It functions within an operating temperature range of -40°C to +85°C and utilizes a 28-pin SO-Wide package.

Feature Summary

• Integrated charge pump circuitry eliminates the need for external bipolar ±12V supplies, enabling single +5V operation.
• Includes a low-power shutdown mode that significantly reduces current consumption when the device is inactive.
• Provides TTL/CMOS-compatible inputs and outputs alongside standard RS-232 driver and receiver channels.

Applications

• Interface translation between TTL/CMOS logic and RS-232 serial ports
• Multidrop RS-232 communication networks
• Portable diagnostic equipment requiring low-power serial connectivity

Procurement Notes

Verify the specific suffix 'EWI+' against the manufacturer's official ordering guide to confirm the wide SOIC package and industrial temperature grade. Ensure the component source provides valid traceability documentation. Confirm RoHS compliance status matches the required environmental standards for the target assembly process before finalizing procurement orders.

Selection Notes

Select this component when designing systems requiring multiple independent RS-232 channels powered by a single +5V rail. The integrated charge pump simplifies PCB layout by removing bulky external capacitors found in older designs. Verify that the 120 kb/s data rate meets the application requirements and that the 28-pin footprint fits the available board space constraints.

Part Context

This part belongs to the Maxim Integrated MAX220–MAX249 family of line drivers and receivers. These devices are designed for EIA/TIA-232E and V.28/V.24 interfaces where generating high voltages from a single supply is necessary. The MAX241 variant specifically offers a higher channel count compared to dual-driver counterparts in the same series.

Replacement Considerations

Direct replacements include other members of the MAX220–MAX249 family such as the MAX241EEWI+. Verify pin compatibility and ensure the replacement maintains the required 28-pin SOIC package dimensions and thermal characteristics for the existing design.

FAQ

Does the MAX241EWI+ require external capacitors for its internal charge pump?

Yes, the datasheet specifies the use of external capacitors (typically C1–C4) to support the internal dual charge-pump DC-DC voltage converters that generate the required ±10V levels.

What is the input voltage tolerance for the RS-232 receiver pins?

The RS-232 receiver inputs can withstand voltages up to ±30V without damage, providing protection against accidental connection to live RS-232 lines.

How does the shutdown feature affect the V+ and V- outputs?

When the shutdown pin is activated, the internal charge pumps cease operation. Consequently, the V+ output falls to approximately +5V and the V- output falls to 0V.