{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"UC3842AD8TR","brand":"Texas Instruments","brandSlug":"texas-instruments","productSlug":"UC3842AD8TR","canonicalUrl":"https://icboms.com/texas-instruments/UC3842AD8TR","factsUrl":"https://icboms.com/api/mcp/products/UC3842AD8TR","rawCanonicalId":null},"summary":{"shortDescription":"Texas Instruments UC3842AD8TR, PWM current-mode controller, 8-SOIC surface-mount, 10V–30V supply, up to 500 kHz switching, 96% max duty cycle, 0°C–70°C commercial temperature range.","salesMarkdown":"## What the supply range and duty cycle mean for your converter design The UC3842AD8TR is a current-mode PWM controller from the industry-standard UC3842 family, designed for step-up, step-down, and step-up/step-down topologies including boost, buck, flyback, and forward converters. Its 10V–30V Vcc supply range gives you flexibility to bias the controller from a regulated auxiliary winding or a simple Zener dropper — the 10V undervoltage lockout threshold ensures the gate drive is clean before the MOSFET starts switching. A 96% maximum duty cycle means this controller can maintain output regulation even when the input-to-output voltage ratio is high, as in a flyback converter with a 12V output from a 400V DC bus. The single transistor-driver output drives an external N-channel MOSFET directly; no external buffer is needed for moderate gate charge. ## Switching frequency and temperature — sizing the magnetics and the enclosure The oscillator runs up to 500 kHz, which lets you shrink the transformer or inductor core compared to a lower-frequency design. If your end product lives in an outdoor cabinet, a motor-drive panel, or under-hood automotive, this part will not meet the thermal spec — step up to the industrial-temperature variant (UC3842AD8TR has no industrial-grade suffix in this package; the UC3842AD8 is the same die but the AD8TR is the tape-reel commercial version). ## Active production — no end-of-life clock ticking There is no announced last-time buy or discontinuation window. The 8-SOIC package is a standard, widely stocked footprint — the tape-and-reel variant is the production-friendly format for pick-and-place lines. ## What the 8-SOIC package asks of your PCB layout The controller itself dissipates under 0.5 W, so no exposed thermal pad is needed — standard FR-4 copper pours under the package are sufficient. The frequency-control pin is brought out for external RC programming; keep the timing resistor and capacitor as close as possible to the RT/CT pin to minimize noise injection into the oscillator. The output configuration is positive, isolation capable — the controller's ground reference is the primary-side return, and the transformer's secondary side is isolated via the optocoupler feedback loop. No synchronous rectifier is integrated; you add an external SR controller on the secondary if needed.","metaTitle":"UC3842AD8TR – TI PWM Current-Mode Controller, 8-SOIC, Active","metaDescription":"UC3842AD8TR from Texas Instruments: PWM current-mode controller, 10V–30V supply, up to 500 kHz, 96% duty cycle, 8-SOIC. Active lifecycle, ROHS3 compliant.","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":"UC3842","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)":"10V ~ 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/UC3842AD8TR/alternatives.json"},"ai":{"faq":[{"question":"What is the difference between UC3842AD8TR and UC3842AD8?","answer":"The two parts share the same die and electrical ratings. The UC3842AD8TR is the tape-and-reel packaging option, while UC3842AD8 is typically supplied in tubes or bulk. Functionally they are identical — the TR suffix only affects the shipping format for automated assembly."},{"question":"Can I use UC3842AD8TR in a flyback converter?","answer":"Yes — the UC3842AD8TR supports flyback topology. The 96% duty cycle and current-mode control make it well suited for flyback designs up to around 150 W with proper transformer design and snubber network."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/texas-instruments/UC3842AD8TR","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/texas-instruments/UC3842AD8TR 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}}