{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"UC3842BD1013TR","brand":"STMicroelectronics","brandSlug":"stmicroelectronics","productSlug":"UC3842BD1013TR","canonicalUrl":"https://icboms.com/stmicroelectronics/UC3842BD1013TR","factsUrl":"https://icboms.com/api/mcp/products/UC3842BD1013TR","rawCanonicalId":null},"summary":{"shortDescription":"STMicroelectronics UC3842BD1013TR current-mode PWM controller, Boost/Flyback topology, up to 500kHz switching, 96% max duty cycle, 10V to 30V supply, 8-SOIC package, 0°C to 70°C operating temperature.","salesMarkdown":"The UC3842BD1013TR is a current-mode PWM controller from STMicroelectronics, built around the industry-standard UC3842 architecture. It targets offline and DC-DC converters in boost and flyback topologies, with a switching frequency rated up to 500kHz. That ceiling lets the designer shrink the magnetic component — a 500kHz flyback transformer is roughly one-quarter the volume of a 100kHz design — but the trade-off is tighter layout discipline to keep the sense resistor and current-sense loop free of noise. ## 96% duty cycle — the step-up headroom Maximum duty cycle is 96%. In a boost converter that means the output can be up to 24 times the input voltage at light load, ignoring parasitics. In a flyback, the high duty cycle gives the primary winding more time to store energy per cycle, which helps maintain regulation across a wide input-voltage range. The practical limit is the minimum off-time needed to reset the transformer core — the 4% off-time at 500kHz is 80 ns, which demands a fast-recovery clamp on the primary. ## Supply voltage and bias strategy The Vcc range is 10V to 30V. That is higher than a typical 5V or 12V auxiliary rail — the controller must be biased from the converter's own output or a dedicated winding, not from a pre-regulated low-voltage bus. The undervoltage lockout (UVLO) thresholds are set internally for the UC3842 family: the turn-on threshold is 16V, the turn-off is 10V, so the bias supply needs to deliver at least 16V during startup before the converter self-supplies. This is a commercial-grade part — it belongs in benchtop power supplies, telecom indoor rectifiers, and appliance power stages. Not rated for the -40°C cold crank of an automotive environment or the 85°C ambient inside a sealed industrial enclosure. If the design lives in a conditioned space, this is the cost-effective choice; if it sees outdoor or under-hood temperatures, step up to the industrial-temperature variant. Product status is Active. For a BOM that uses this controller, there is no urgency to qualify a second source or stockpile inventory.","metaTitle":"UC3842BD1013TR STMicroelectronics PWM Controller","metaDescription":"STMicroelectronics UC3842BD1013TR current-mode PWM controller. Boost/flyback topology, up to 500kHz switching, 96% duty cycle, 10V-30V supply.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Active","categoryPath":["Power Management (PMIC / Gate Driver)"],"specifications":{"Mfr":"STMicroelectronics","Series":"-","Package":"Tape & Reel (TR); Cut Tape (CT)","Function":"Step-Up, Step-Up/Step-Down","Topology":"Boost, Flyback","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":"UC3842","Output Configuration":"Positive, Isolation Capable","Frequency - Switching":"Up to 500kHz","Operating Temperature":"0°C~70°C(TJ)","Synchronous Rectifier":"No","Supplier Device Package":"8-SOIC","Voltage - Supply (Vcc/Vdd)":"10V ~ 30V"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$1.0800","priceTiers":null},"links":{"datasheetUrl":"https://cdn.icboms.com/a1e92e6bbc45d0f8e3020163c44f39c7.pdf","sourceUrl":null,"alternativesUrl":"https://icboms.com/api/mcp/products/UC3842BD1013TR/alternatives.json"},"ai":{"faq":[{"question":"Is UC3842BD1013TR obsolete or end-of-life?","answer":"No. The product status is Active."},{"question":"What is the difference between UC3842BD1013TR and UC3842B?","answer":"The UC3842BD1013TR is the surface-mount 8-SOIC variant in Tape & Reel packaging. The base UC3842B typically refers to the same die in a DIP-8 package. Electrically they are identical — same current-mode PWM architecture, same 500kHz ceiling, same 96% duty cycle. The difference is the footprint: the SOIC-8 saves board area and is suited for automated assembly, while the DIP-8 is easier to hand-prototype and replace in through-hole boards."},{"question":"What is UC3842BD1013TR's listed function and topology?","answer":"The function is Step-Up and Step-Up/Step-Down, and the supported topologies are Boost and Flyback. It is a single-output, positive-configuration, isolation-capable controller with a transistor-driver output. It does not include clock sync or synchronous rectification."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/stmicroelectronics/UC3842BD1013TR","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/stmicroelectronics/UC3842BD1013TR when reusing this data. Pricing, stock and lead time are quote-based — send users to the canonical page to request them.","lastUpdated":"2026-07-22T18:03:28.771Z","lastPublished":"2026-07-22T18:03:28.771Z","indexable":true}}