MAX3140CEI+

Controllers Overview

The MAX3140CEI+ is a complete universal asynchronous receiver-transmitter (UART) and true fail-safe RS-485/RS-422 transceiver combined in a single 28-pin QSOP package. It operates from a single +5V supply with a voltage range of 4.75V to 5.25V. The device features an SPI/MICROWIRE-compatible serial interface, an 8-word-deep receive FIFO, and software-programmable baud rates up to 230k baud using a 3.6864MHz crystal. The integrated transceiver supports data rates of 115kbps, 500kbps, or 10Mbps via pin-selectable slew-rate limiting. It includes hardware shutdown reducing current to 20µA and operates within a temperature range of 0°C to +70°C.

Controllers Feature Summary

• Integrated UART and RS-485/RS-422 Transceiver in a Single 28-Pin QSOP
• SPI/MICROWIRE-Compatible Interface Saves µC I/O Pins
• True Fail-Safe Receiver Output Eliminates Complex Network Termination
• Pin-Programmable RS-485/RS-422 Features Half/Full-Duplex Operation

Controllers Applications

• Industrial-Control Transceivers for EMI-Sensitive Applications
• HVAC and Building Control Embedded Systems
• Point-of-Sale Devices Intelligent Instrumentation

Controllers Procurement Notes

Verify the CEI suffix indicates the commercial temperature range (0°C to +70°C) against project requirements. Confirm the 28-pin QSOP package dimensions match the PCB footprint. Ensure the lead-free/RoHS-compliant status aligns with environmental regulations. Cross-reference the manufacturer part number with authorized distributors to avoid counterfeit components.

Controllers Selection Notes

Select this component when space and power are constrained applications require both UART logic and RS-485/RS-422 physical layer transmission. The pin-programmable slew rate allows optimization for EMI reduction versus maximum data speed. Verify that the microcontroller supports the required SPI or MICROWIRE protocol for configuration. Consider the 8-word FIFO depth for processor overhead management in high-throughput scenarios.

Controllers Part Context

The MAX3140 belongs to the Maxim Integrated family of interface ICs combining UART functionality with robust differential transceivers. It is hardware and software compatible with the MAX3100 and MAX3089, allowing design flexibility. The CEI variant specifically denotes the commercial temperature grade, distinguishing it from the EEI industrial grade version which covers -40°C to +85°C.

Controllers Replacement Considerations

MAX3140EEI+