MAX3131EAI

Overview

The MAX3131EAI is a hybrid microcircuit integrating an IrDA 1.2 compatible infrared transceiver and a dual-driver/dual-receiver RS-232 interface within a single 28-pin SSOP package. It operates on a single +3.0V to +5.5V supply, delivering true RS-232 performance via a high-efficiency dual charge-pump power supply. The infrared channel supports data rates from 2.4kbps to 115kbps with a high-gain PIN-diode amplifier and a 200mA LED driver. The RS-232 section supports data rates up to 120kbps (typical 235kbps). Supply current is 370µA, reducing to 1µA in shutdown mode.

Feature Summary

• Integrates IrDA 1.2 infrared transceiver and RS-232 interface in one package
• On-board encoder/decoder allows communication with non-IrDA UARTs
• High-current infrared LED drive capability of 200mA
• Low-power shutdown reduces supply current to 1µA

Applications

• Personal Digital Assistants (PDAs)
• Palmtop Computers
• Battery-Powered Systems
• Hand-Held Equipment
• IrDA Applications

Procurement Notes

Verify component authenticity through authorized distributors or the manufacturer directly. Confirm that the specific ordering suffix matches the required temperature range and package type. Check for RoHS compliance status as older revisions may differ. Ensure the source provides valid traceability documentation for quality assurance purposes.

Selection Notes

Select this component when simultaneous independent IrDA and RS-232 communication is required without multiplexing. Verify that the system UART can provide a 16x baud rate clock if the internal ENDEC is utilized. Ensure the external optical components meet the specified irradiance and capacitance requirements for reliable operation.

Part Context

This device belongs to the MAX3130/MAX3131 family of 3V to 5.5V IrDA infrared transceivers with integrated RS-232 interfaces. The MAX3131 variant specifically features separate IrDA and RS-232 transceivers, unlike the MAX3130 which multiplexes them onto shared pins.

Replacement Considerations

MAX3131EAI+

FAQ

How does the MAX3131 handle communication with non-IrDA UARTs?

The device includes an on-board encoder/decoder (ENDEC) that compresses and stretches signals to and from the external UART, enabling IrDA communication even with non-IrDA compatible UARTs.

What is the maximum data rate supported by the RS-232 interface?

The RS-232 transceiver supports data rates up to 120kbps, though typical operation often reaches 235kbps under specific load conditions.

How is the infrared LED current controlled?

The infrared LED current is set using an external current-setting resistor connected between VCC and the LEDC pin, based on the forward voltage of the LED and the desired drive current.