{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"UC3843AD8TR","brand":"Texas Instruments","brandSlug":"texas-instruments","productSlug":"UC3843AD8TR","canonicalUrl":"https://icboms.com/texas-instruments/UC3843AD8TR","factsUrl":"https://icboms.com/api/mcp/products/UC3843AD8TR","rawCanonicalId":null},"summary":{"shortDescription":"Texas Instruments UC3843AD8TR, current-mode PWM controller, 8-SOIC package, up to 500 kHz switching, 96% max duty cycle, 7.6 V to 30 V supply, active production.","salesMarkdown":"## 500 kHz switching ceiling — what it buys the BOM The UC3843AD8TR is a current-mode PWM controller from TI's UCx84x family, rated for switching frequencies up to 500 kHz. That ceiling lets you shrink the transformer core in a flyback or forward converter compared to a 47 kHz part like the UCC2806DWTR, but there is no clock-sync pin — if your design shares a switching rail across multiple converters, you either free-run or add external sync logic. The 96% maximum duty cycle is the headline number for low-dropout step-down or forward-converter operation. A 50% duty-cycle controller forces a two-switch topology at the same input/output ratio; this part keeps the bill of materials simpler for a single-ended design. Vcc range is 7.6 V to 30 V — the undervoltage lockout thresholds are fixed inside the UC3843 variant (8.4 V on, 7.6 V off). That UVLO window suits a primary-side bias winding that needs a clean start-up before the auxiliary winding takes over. Output is a single transistor-drive stage, positive and isolation-capable. The driver sources and sinks the gate charge of an external MOSFET directly; no buffer stage needed for most 1 A–5 A FETs at 500 kHz. Control features include frequency control — an external RC sets the oscillator timing. No soft-start or enable pin on this base variant; those live on the UC3844/45 siblings if the BOM needs them. ROHS3 compliant. For an under-hood or industrial extended-temp build, the LM5150QURUMRQ1 covers -40°C to 150°C but at a higher per-unit cost and with a different pinout. ## Package and footprint — 8-SOIC 8-SOIC, 0.154-inch body width, 3.90 mm. Surface-mount only. No thermal pad underneath — the die dissipates through the leadframe and the copper traces on the PCB. A 2-layer board with solid ground pour under the controller handles the thermal budget for most 10 W–50 W converters.","metaTitle":"UC3843AD8TR – TI Current-Mode PWM Controller, 8-SOIC, Active","metaDescription":"Texas Instruments UC3843AD8TR current-mode PWM controller. 500 kHz switching, 96% duty cycle, 7.6V–30V supply. Active lifecycle, 8-SOIC. Sourced per RFQ.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":"ROHS3 Compliant","productStatus":"Active","categoryPath":["Power Management (PMIC / Gate Driver)"],"specifications":{"Mfr":"Texas Instruments","Series":"-","Package":"Tape & Reel (TR); Cut Tape (CT)","Function":"Step-Up, Step-Down, Step-Up/Step-Down","Topology":"Boost, Buck, Flyback, Forward","Clock Sync":"No","Output Type":"Transistor Driver","Mounting Type":"Surface Mount","Output Phases":"1","Package / Case":"8-SOIC (0.154\\\", 3.90mm Width)","Product Status":"Active","lifecycle_stage":"eol_hot","Control Features":"Frequency Control","Duty Cycle (Max)":"96%","Number of Outputs":"1","Serial Interfaces":"-","Base Product Number":"UC3843","Output Configuration":"Positive, Isolation Capable","Frequency - Switching":"Up to 500kHz","Operating Temperature":"0°C~70°C(TA)","Synchronous Rectifier":"No","Supplier Device Package":"8-SOIC","Voltage - Supply (Vcc/Vdd)":"7.6V ~ 30V"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$1.1200","priceTiers":[{"qty":1,"price":"$1.12000","currency":"USD"},{"qty":10,"price":"$1.00100","currency":"USD"},{"qty":25,"price":"$0.94960","currency":"USD"},{"qty":100,"price":"$0.78020","currency":"USD"},{"qty":250,"price":"$0.72928","currency":"USD"},{"qty":500,"price":"$0.64448","currency":"USD"},{"qty":1000,"price":"$0.50880","currency":"USD"},{"qty":2500,"price":"$0.48000","currency":"USD"}]},"links":{"datasheetUrl":"https://cdn.icboms.com/536891bbf6907bbea70f31ce571541e7.pdf","sourceUrl":null,"alternativesUrl":"https://icboms.com/api/mcp/products/UC3843AD8TR/alternatives.json"},"ai":{"faq":[{"question":"Is UC3843AD8TR obsolete?","answer":"No. Texas Instruments lists the product status as Active."},{"question":"What is the difference between UC3843AD8TR and UC3843AD8T?","answer":"The suffix 'TR' indicates Tape & Reel packaging; 'T' typically denotes tube or alternate reel quantity. The silicon and electrical ratings are identical. Confirm the reel quantity with your distributor — the TR suffix usually means a full 2,500-piece reel."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/texas-instruments/UC3843AD8TR","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/texas-instruments/UC3843AD8TR 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}}