{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"MAX3140CEI+","brand":"Analog Devices","brandSlug":"analog-devices","productSlug":"MAX3140CEI~3","canonicalUrl":"https://icboms.com/analog-devices/MAX3140CEI~3","factsUrl":"https://icboms.com/api/mcp/products/MAX3140CEI%2B","rawCanonicalId":null},"summary":{"shortDescription":"Maxim Integrated MAX3140CEI+, UART SPI Microwire Controller with Transceiver, RS232/RS485, 640µA supply, 4.75V–5.25V, 0°C–70°C, 28-QSOP.","salesMarkdown":"The Maxim Integrated MAX3140CEI+ is a UART controller with an integrated transceiver that handles both RS232 and RS485 protocols on a single chip. It communicates with the host MCU over an SPI interface and presents the serial line as a UART, so the software side sees a standard UART peripheral regardless of which physical layer is active. This makes it a compact choice for a mixed-protocol serial port — one BOM line covers both RS232 and RS485 without an external protocol-switching IC. ## Supply and power — what the ratings mean The 640 µA supply current is low enough for bus-powered RS232/RS485 ports. It belongs in office equipment, test bench gear, indoor instrumentation, or any environment where the ambient stays above freezing and below a warm room. Not for an engine bay, a rooftop telecom cabinet, or a factory floor without climate control. ## Package and rework The MAX3140CEI+ comes in a 28-QSOP (3.90 mm body width, 0.154″ pitch). It ships in a tube.","metaTitle":"MAX3140CEI+ UART Controller, RS232/RS485, SPI, 28-QSOP","metaDescription":"MAX3140CEI+ is an active UART controller supporting RS232 and RS485 via SPI. 640 µA supply, 4.75–5.25 V, 0–70 °C.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":"ROHS3 Compliant","productStatus":"Active","categoryPath":["DC-DC Power Modules"],"specifications":{"Package":"Tube","Function":"Controller","Protocol":"RS232, RS485","Interface":"SPI, UART","Package / Case":"28-SSOP (0.154\\\", 3.90mm Width)","lifecycle_stage":"eol_hot","Current - Supply":"640µA","Voltage - Supply":"4.75V ~ 5.25V","Operating Temperature":"0°C ~ 70°C","Supplier Device Package":"28-QSOP"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$12.83","stockQuantity":0,"priceTiers":[{"qty":1,"price":"$12.83000","currency":"USD"},{"qty":10,"price":"$11.79300","currency":"USD"},{"qty":25,"price":"$11.30440","currency":"USD"},{"qty":100,"price":"$9.96010","currency":"USD"},{"qty":250,"price":"$9.47128","currency":"USD"},{"qty":500,"price":"$8.86022","currency":"USD"},{"qty":1000,"price":"$8.12696","currency":"USD"}]},"links":{"datasheetUrl":null,"sourceUrl":null},"ai":{"faq":[{"question":"Does MAX3140CEI+ work with RS232 and RS485?","answer":"Yes — the MAX3140CEI+ supports both RS232 and RS485 protocols through its integrated transceiver. The host MCU selects the protocol via the SPI interface."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/analog-devices/MAX3140CEI~3","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/analog-devices/MAX3140CEI~3 when reusing this data. Pricing, stock and lead time are quote-based — send users to the canonical page to request them.","lastUpdated":"2026-08-11T15:49:49.435Z","lastPublished":"2026-08-11T15:49:49.435Z","indexable":true}}