Analog Devices Inc./Maxim Integrated MAX213CWI+T

Summary of MAX213CWI+T RS-232 Transceiver

The MAX213CWI+T from Analog Devices Inc./Maxim Integrated is a highly integrated RS-232 transceiver IC, designed for robust serial communications in a variety of applications. Housed in a 28-pin wide small-outline integrated circuit (SOIC) package, the MAX213CWI+T offers a four-driver, four-receiver configuration and operates from a single +5V supply. It targets engineers and procurement professionals seeking a compact, power-efficient solution for RS-232 and V.28 interface requirements in portable and battery-powered equipment, as well as handheld diagnostic devices.

Primary Attributes and Advantages of MAX213CWI+T

The MAX213CWI+T stands out for its board-space and component-count minimization. Key technical features include:

Integrated charge-pump voltage converters, enabling ±10V generation from a single +5V supply without external bipolar supplies.

Support for 0.1μF low-profile external capacitors, suitable for space-constrained PCB layouts.

Full compliance with EIA/TIA-232E and V.28 specifications, supporting data rates above 120kbps with output swings guaranteed at ±5V under worst-case conditions.

Low-power operation with industry-leading shutdown modes. MAX213-specific features include a 75μW ring indicator monitoring mode with two receivers active in shutdown, ideal for power-sensitive designs.

Enhanced noise immunity with CMOS/TTL-compatible inputs and tighter input threshold tolerances (+0.8V and +2.4V) than RS-232 standards demand.

Collectively, these features allow the MAX213CWI+T to simplify RS-232 design, especially in applications where board space and battery life are critical concerns.

In-depth Functional Analysis of MAX213CWI+T

The MAX213CWI+T integrates three core functional sections:

Charge-Pump Voltage Conversion: The device employs two charge-pump stages with external capacitors to convert the +5V input into the necessary internal ±10V rails for RS-232 signaling. The first charge-pump doubles +5V to +10V, stored on V+, while the second inverts this to -10V for V-.

RS-232 Drivers (Transmitters): Each of the four drivers delivers an output swing of up to ±8V into standard loads, meeting stringent RS-232 output requirements. Input stage compatibility with CMOS and TTL levels is ensured, while onboard pull-up resistors enable floating input detection and minimize supply current in shutdown.

RS-232 Receivers: The four receivers invert RS-232 inputs to CMOS-level outputs. The input thresholds are set for robust noise margins and compatibility with logic-level signals. Notably, two of the MAX213CWI+T receivers (R4 and R5) remain active in shutdown, supporting ring-indicator applications or bus activity monitoring with minimal power draw.

Electrical Specifications and Thermal Properties of MAX213CWI+T

Understanding the electrical and thermal limits is crucial for reliable system integration:

Power Supply Voltage (VCC): +4.5V to +5.5V (nominal operation at +5V)

Absolute maximum voltages: VCC up to +6V, input voltages on TIN up to (VCC + 0.3V), RIN tolerates ±30V

Output swing: TOUT from (V+ +0.3V) to (V– –0.3V), able to withstand output shorts indefinitely

Operating Temperature Range: 0°C to +70°C for the commercial “C” grade; extended and military temperatures available in respective variants

Maximum power dissipation for the 28-pin wide SOIC package: 1000mW at +70°C (derating applies above this temperature)

Shutdown supply current: As low as 15μA with receivers R4 and R5 monitoring

These parameters are foundational for evaluating thermal management, voltage margins, and power supply design in your embedded system or interface board.

Design Recommendations and Usage Instructions for MAX213CWI+T

Selecting proper external components and considering application scenarios are key steps:

External Capacitors: Ceramic capacitors (0.1μF) are recommended for charge pumps; designers should verify capacitance stability across temperatures or upgrade to higher values if signal levels are critical. Low ESR supports minimized ripple on generated supply rails.

Shutdown and Enable Modes: Power can be conserved by leveraging shutdown mode; two receivers (R4 and R5) continue to function, which is useful for wake or ring detection in standby applications. A 1ms wake-up delay applies after exiting shutdown.

Multi-Receiver Drive: Outputs are intended for one receiver each, but paralleling drivers is possible if driving multiple loads is unavoidable.

Power-Supply Decoupling: Decouple VCC with a capacitor equal in value to those used for charge-pumping to ensure stable operation in noise-sensitive systems.

V+ and V– Rails: Limited external power can be sourced from these pins, though at the expense of noise margin and output swing.

Applying the MAX213CWI+T in a typical system involves ensuring correct capacitive coupling, observing supply and signal integrity requirements, and—and unique to this model—utilizing its innovative dual-active-receiver feature in shutdown to enable intelligent, low-power system monitoring.

Packaging Details and Pin Layout of MAX213CWI+T

The MAX213CWI+T is supplied in a 28-pin wide SOIC package, which enables straightforward surface-mount assembly and efficient thermal dissipation. This form factor provides 40% footprint reduction compared to traditional wide dual in-line (DIP) packages, supporting high-density or compact layouts. The full pinout includes clear demarcation for driver and receiver input/output signals as well as for the necessary charge-pump capacitors, as shown in manufacturer diagrams and typical applications.

Possible Alternative or Substitute Devices for MAX213CWI+T

When evaluating alternatives or considering footprint or functionally compatible parts for the MAX213CWI+T, engineers may reference other Analog Devices Inc./Maxim Integrated products in the same family:

MAX211: Also a 4-driver/4-receiver device available in a 28-pin package, but without shutdown mode with active receivers.

MAX206, MAX205: For applications that require even further power savings or a different shutdown/enable configuration.

MAX203: For designs with extremely limited PCB space and an integrated capacitor solution (no external capacitors required).

MAX208, MAX209: Offering different combinations of drivers and receivers or pinouts, suitable for tailored RS-232 interface needs.

Consider application-specific needs—such as shutdown behavior, package size, and external component count—when selecting among these alternatives.

Conclusion

The MAX213CWI+T RS-232 transceiver delivers a high level of functional integration, energy efficiency, and flexible shutdown monitoring in a compact package. Its single-supply operation, minimal capacitor requirements, and robust signal integrity make it an ideal choice for battery-powered, space-constrained serial data applications. By carefully considering the device’s unique features, electrical limits, application requirements, and available package options, engineers and procurement specialists can confidently select and integrate the MAX213CWI+T into both new designs and existing system upgrades that demand reliable, standards-compliant serial communication.