Analog Devices Inc./Maxim Integrated MAX213ECAI

Product Summary MAX213ECAI+ RS-232 Line Driver/Receiver by Analog Devices Inc./Maxim Integrated

The MAX213ECAI+ is a robust, high-performance RS-232 transceiver IC designed and manufactured by Analog Devices Inc./Maxim Integrated. Engineered for full-duplex communication, this device integrates four drivers and four receivers within a compact 28-SSOP package. Its advanced ESD protection and single-supply charge-pump architecture make it an ideal solution for portable, battery-powered, and diagnostic equipment requiring reliable serial communications in challenging environments. As part of the broader MAX202E–MAX213E, MAX232E/MAX241E family, the MAX213ECAI+ delivers full compliance with EIA/TIA-232E and V.28 standards at data rates up to 120kbps.

Main Characteristics and Benefits of the MAX213ECAI+

The MAX213ECAI+ distinguishes itself through several key features that promote robust operation, integration, and design flexibility:

High ±15kV ESD Human Body Model (HBM) protection on RS-232 inputs and outputs, ensuring reliable performance in environments prone to electro-static discharge.

Integrated charge-pump circuitry allows operation from a single +5V power rail, eliminating the need for dual ±12V supplies required by conventional RS-232 transceivers.

Low power consumption, featuring a 15μA shutdown mode for power-sensitive applications.

28-SSOP package offering reduced board footprint and enabling up to 40% space savings compared to SO packages.

CMOS/TTL-compatible input thresholds, simplifying interfacing with microcontrollers and digital logic.

Device architecture supports full EIA/TIA-232E and CCITT V.28 compliance under worst-case load and temperature conditions.

Internal Design and Block Diagram of the MAX213ECAI+

At its core, the MAX213ECAI+ integrates charge-pump voltage converters, four transmitter (driver) channels, and four receiver channels. The charge-pump subsystem creates the necessary RS-232 voltage levels (+10V, -10V) from a single +5V input using readily available external capacitors. Each driver and receiver is protected by advanced ESD structures that withstand high-voltage discharges under various operating conditions, including normal operation, shutdown, and power-down. Functionally, the MAX213ECAI+ supports up to 120kbps data rates while maintaining voltage swings required by serial communication standards.

ESD Safeguard Features in the MAX213ECAI+

Engineered for environments where cable connections may be frequently altered or exposed to harsh electrical transients, the MAX213ECAI+ incorporates Analog Devices’/Maxim Integrated’s industry-leading ESD protection technology. Key aspects include:

RS-232 inputs and outputs are shielded to ±15kV per the Human Body Model (HBM).

IEC1000-4-2 compliance enables survival against ±8kV contact-discharge and ±15kV air-gap discharge, aiding systems to achieve the stringent level 4 ESD immunity required for finished equipment.

Embedded protection structures prevent latch-up or damage during ESD events, ensuring uninterrupted operation where competitors may require manual reset.

Operation Details Charge Pump, Output Drivers, and Input Receivers

The charge-pump subsystem utilizes external 0.1μF capacitors for voltage doubling and inversion, generating +10V and -10V needed for RS-232 signaling. In typical engineering scenarios, the charge-pump’s efficiency and ripple performance depend on capacitor type, value, and temperature stability.

Driver circuits in the MAX213ECAI+ generate RS-232 compliant voltages (±8V typical output swing into 5kΩ) from logic-level inputs. Unused transmitter inputs benefit from internal pull-up resistors, allowing them to be left unconnected. Receivers convert RS-232 signals to CMOS logic levels with tight thresholds (0.8V low, 2.4V high) and 0.5V hysteresis for noise immunity—except for receivers R4 and R5, which lose hysteresis during shutdown but remain operational for low-power monitoring purposes.

Power-Down and Activation Controls for the MAX213ECAI+

System designers benefit from flexible shutdown and enable functions within the MAX213ECAI+. The shutdown control (active-low) disables charge pumps and transmitter outputs, reducing total supply current to 15μA. Enable control allows receiver outputs to enter a high-impedance state, supporting wire-OR configurations or multi-port connections at the UART, without impacting driver or charge-pump operation.

Upon exiting shutdown, charge-pump voltages are restored within 2ms (with 0.1μF capacitors), guaranteeing rapid readiness. Receivers R4 and R5 are uniquely maintained active during shutdown, enabling ongoing detection of line activity in ultra-low-power monitoring modes—a critical feature for battery-operated designs.

Electrical Specifications and Performance of the MAX213ECAI+

The MAX213ECAI+ is characterized by:

Operating supply voltage: +5V ±10%

Guaranteed output swing: ±5V minimum under worst-case load and temperature conditions

Driver short-circuit tolerance: continuous (T_OUT)

Receiver input resistance: nominal 5kΩ to ground

Data rate support: up to 120kbps

Power dissipation: 28-SSOP package rated at 762mW (derating above +70°C: 9.52mW/°C)

Operating temperature range: 0°C to +70°C (MAX2__EC__)

Storage temperature: -65°C to +165°C

Pin configuration and functions tailored for single-supply, portable, and space-constrained systems

Packaging Information and Handling for the MAX213ECAI+

The MAX213ECAI+ is offered in a 28-pin SSOP package, conforming to JEDEC standards (MS001-XX/MO-058AB) with RoHS compliance options. Engineers must consider package dimensions, land pattern guidelines, and lead coplanarity when laying out PCB footprints. The SSOP form factor contributes to high integration and significant board area savings, supporting miniaturized devices without compromising ESD or thermal performance.

Usage Recommendations and Capacitor Selection for the MAX213ECAI+

Optimal operation of the MAX213ECAI+ depends on the following critical guidelines:

Use quality ceramic capacitors (0.1μF nominal) for charge-pump functions (C1–C4); values up to 10μF are permissible when tighter ripple control or power draw from V+ and Vis required.

Ensure good temperature stability of the capacitors, as low-temperature ESR increases can affect charge-pump ripple and output swing.

Bypass VCC with at least 0.1μF to ground for noise suppression; in noise-sensitive applications, match bypass capacitance to charge-pump capacitor value.

MAX213ECAI+ transmitter is designed for one receiver per driver; parallel transmitters if driving multiple receivers is needed.

For high data rate (>120kbps) applications, minimize capacitive load on transmitter outputs (i.e., use shorter cables) to ensure compliant voltage swings.

Alternative or Substitute Products for the MAX213ECAI+

The MAX213ECAI+ belongs to a large family of RS-232 transceivers by Analog Devices Inc./Maxim Integrated, offering a selection of models tailored for different design constraints:

MAX211E and MAX241E: Provide similar architecture and ESD protection; available in 28-pin SO and SSOP packages, with variations in receiver and driver counts.

MAX202E and MAX232E: Feature similar ESD protection but housed in smaller (16-pin TSSOP/SO/DIP) packages with reduced channel counts, suitable for space-constrained or lower channel count applications.

MAX203E and MAX205E: Integrated internal charge-pump capacitors for simplified BOM and assembly; MAX205E available in 24-pin wide DIP, especially for legacy or low-profile designs.

Selection of an appropriate replacement depends on required channel count, package style, system voltage, and need for internal/external charge-pump capacitors.

Conclusion

The MAX213ECAI+ RS-232 transceiver sets a high standard for reliable serial communication in portable and diagnostics applications, combining robust ESD protection, flexible single-supply operation, integrated shutdown and enable controls, and minimal PCB footprint. Its thoughtful features, noise immunity, and family compatibility make it a primary candidate for engineering teams seeking high-reliability performance in environments subject to harsh electrical conditions. When specifying transceivers for RS-232 links, the MAX213ECAI+ provides assurance of compliance, durability, and ease of integration, supported by a flexible ecosystem of potential equivalent models to match diverse design requirements.