MAX220CWE+

Overview

The MAX220CWE+ is a +5V-powered, multichannel RS-232 line driver and receiver manufactured by Analog Devices Inc./Maxim Integrated. It operates within a supply voltage range of 4.5V to 5.5V with a typical operating current of 2mA at no load. The device provides full-duplex communication with two drivers and two receivers, supporting data rates up to 120kbps. Transmitter output voltages swing between ±5V and ±8V under standard loading. Propagation delays are typically 4µs for TTL-to-RS-232 transitions and 3µs for the reverse direction. The component utilizes an integrated charge pump requiring external capacitors (C1: 0.047µF; C2-C5: 0.33µF) to generate internal ±10V rails from the single +5V source.

Feature Summary

• Integrated charge pump circuitry eliminates the need for bipolar ±12V power supplies, enabling operation from a single +5V source.
• Designed for EIA/TIA-232E and V.28/V.24 communications interfaces where space constraints prevent the use of discrete voltage converters.
• Provides robust signal translation between TTL/CMOS logic levels and RS-232 voltage standards.

Applications

• Interface translation between microcontroller systems and serial peripherals
• Multidrop RS-232 network connections
• Portable diagnostics equipment

Procurement Notes

Verify the specific suffix 'CWE+' against the manufacturer's official ordering guide to confirm package type and temperature grade. Ensure that the required external capacitors match the datasheet specifications for the MAX220 variant. Confirm RoHS compliance status through the manufacturer's documentation prior to procurement.

Selection Notes

Select this component when board space is limited and a dedicated negative voltage rail is unavailable. Compare propagation delay and slew rate requirements against other family members like the MAX232 if higher data rates or different control features are needed. Verify that the external capacitor values align with the specific electrical characteristics defined for the MAX220 in the selection table.

Part Context

The MAX220CWE+ belongs to the MAX220–MAX249 family of +5V-powered RS-232 transceivers. This series is characterized by its ability to generate internal drive voltages using external capacitors rather than integrated on-chip pumps found in later variants. It serves as a foundational solution for legacy serial interface implementations in compact electronic designs.

Replacement Considerations

Direct functional substitutes within the same family include the MAX232CWE+ and MAX202CWE+. Note that these alternatives require significantly larger external capacitance values (typically 1.0µF) compared to the MAX220, which may impact PCB layout decisions.