{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"DS1394U-33+T&R","brand":"Analog Devices","brandSlug":"analog-devices","productSlug":"DS1394U-33TR","canonicalUrl":"https://icboms.com/analog-devices/DS1394U-33TR","factsUrl":"https://icboms.com/api/mcp/products/DS1394U-33%2BT%26R","rawCanonicalId":null},"summary":{"shortDescription":"Maxim Integrated DS1394U-33+T&R, SPI real-time clock/calendar, 10-TFSOP/uMAX, 2.97V to 5.5V supply, 1.3V to 5.5V battery backup, -40°C to 85°C, active.","salesMarkdown":"## SPI RTC with trickle-charge and alarm — what it does on the board The Maxim Integrated DS1394U-33+T&R is a SPI-bus real-time clock/calendar in a 10-pin TFSOP/uMAX package. It tracks time in HH:MM:SS:hh (12/24 hr) and date in YY-MM-DD-dd format, with built-in alarm, leap-year compensation, and a square-wave output for system timing references. The integrated trickle-charger keeps a backup supercap or lithium coin cell topped off, so the RTC holds time through a main power loss. The industrial temperature grade (-40°C to 85°C) suits outdoor telecom cabinets, factory-floor controllers, and metering equipment that sees seasonal temperature swings. Surface-mount assembly on a 10-pin MSOP footprint keeps board area tight. ## Active production — no LTB risk on this line item The DS1394U-33+T&R carries an Active product status with ROHS3 compliance. For a production BOM, this part does not carry an obsolescence risk that would trigger a respin or alternate qualification cycle.","metaTitle":"DS1394U-33+T&R Real-Time Clock, SPI, 10-uMAX, Active","metaDescription":"Maxim DS1394U-33+T&R SPI RTC Clock/Calendar with trickle-charger, alarm, square-wave output. 2.97V-5.5V supply, 1.3V-5.5V battery backup. Active, ROHS3.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":"ROHS3 Compliant","productStatus":"Active","categoryPath":["DC-DC Power Modules"],"specifications":{"Type":"Clock/Calendar","Package":"Tape & Reel (TR); Cut Tape (CT)","Features":"Alarm, Leap Year, Square Wave Output, Trickle-Charger","Interface":"SPI","Date Format":"YY-MM-DD-dd","Time Format":"HH:MM:SS:hh (12/24 hr)","Mounting Type":"Surface Mount","Package / Case":"10-TFSOP, 10-MSOP (0.118\\\", 3.00mm Width)","lifecycle_stage":"eol_hot","Voltage - Supply":"2.97V ~ 5.5V","Operating Temperature":"-40°C ~ 85°C","Supplier Device Package":"10-uMAX/uSOP","Voltage - Supply, Battery":"1.3V ~ 5.5V","Current - Timekeeping (Max)":"175µA @ 2.97V ~ 5.5V"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$4.39","stockQuantity":0,"priceTiers":[{"qty":1,"price":"$4.39000","currency":"USD"},{"qty":10,"price":"$3.94200","currency":"USD"},{"qty":25,"price":"$3.72680","currency":"USD"},{"qty":100,"price":"$3.23000","currency":"USD"},{"qty":250,"price":"$3.06432","currency":"USD"},{"qty":500,"price":"$2.74962","currency":"USD"},{"qty":1000,"price":"$2.31896","currency":"USD"},{"qty":3000,"price":"$2.20301","currency":"USD"}]},"links":{"datasheetUrl":"https://www.analog.com/media/en/technical-documentation/data-sheets/DS1390-DS1394.pdf","sourceUrl":null},"ai":{"faq":[{"question":"What battery voltage does DS1394U-33+T&R support?","answer":"The battery-backup input accepts 1.3V to 5.5V, covering standard 3V coin cells (CR2032) and 3.6V lithium primary cells. The low 1.3V floor keeps time on a nearly depleted cell."},{"question":"Is DS1394U-33+T&R compatible with 3.3V logic?","answer":"Yes. The DS1394U-33+T&R operates from a 2.97V to 5.5V supply, so it runs on a 3.3V rail directly. The SPI interface signals are referenced to VCC, so a 3.3V microcontroller can communicate without level translation."},{"question":"What is the difference between DS1394U and DS1390?","answer":"The DS1394U-33+T&R includes a trickle-charger for backup battery or supercap charging, while the DS1390 lacks this feature. Both are SPI RTCs in similar packages, but the trickle-charger on the DS1394U is the deciding factor if the design needs to maintain a backup charge source."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/analog-devices/DS1394U-33TR","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/analog-devices/DS1394U-33TR when reusing this data. Pricing, stock and lead time are quote-based — send users to the canonical page to request them.","lastUpdated":"2026-07-17T19:50:00.618Z","lastPublished":"2026-07-17T19:50:00.618Z","indexable":true}}