MAX3250EAI+T

Overview

The MAX3250EAI+T is a dual-die, ±50V isolated RS-232 transceiver operating from a single 3.0V to 5.5V supply. It integrates two receivers and two drivers with a guaranteed data rate of 250kbps. Power transfers across the isolation barrier via external ±100V capacitors, while internal charge pumps generate ±5.5V for RS-232 signaling. The device features a FAULT open-drain output to indicate excessive isolated-side voltage conditions. It operates within an industrial temperature range of -40°C to +85°C and is housed in a 28-pin SSOP package.

Feature Summary

• Provides ±50V isolation between logic and RS-232 sides to handle high common-mode voltages
• Integrates dual charge pumps to generate true RS-232 levels from low-voltage supplies
• Includes FAULT output to signal overvoltage conditions on the isolated side
• Supports shutdown mode for low-power operation and multi-interface multiplexing

Applications

• Industrial Control Systems
• Programmable Logic Controllers
• Point-of-Sale Equipment
• PC-to-Router Connections
• Diagnostic Ports

Procurement Notes

Verify the specific ordering suffix against official documentation to confirm temperature range and packaging details. Ensure external capacitor values match the required VCC operating voltage to maintain proper power transfer across the isolation barrier. Confirm that the selected components meet the necessary voltage ratings for the application environment.

Selection Notes

Select this component when high common-mode voltage tolerance is required without using optocouplers or transformers. Verify that the system can accommodate the required external capacitors for power isolation and charge pump operation. Consider the shutdown feature if multiple interface protocols share a single UART connection.

Part Context

The MAX3250 serves as a low-cost replacement for opto-isolated RS-232 transceivers by integrating isolation and communication functions into a single IC. It eliminates the need for inductors or transformers, simplifying EMI compliance. The dual-die design allows for robust performance in noisy environments where ground potential differences exist.

Replacement Considerations

Direct replacements include the MAX3250CAI+ for commercial temperature ranges. Verify pin compatibility and electrical specifications before substituting with other isolated RS-232 transceivers from different manufacturers.