{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"UC3845AD8TRG4","brand":"Texas Instruments","brandSlug":"texas-instruments","productSlug":"UC3845AD8TRG4","canonicalUrl":"https://icboms.com/texas-instruments/UC3845AD8TRG4","factsUrl":"https://icboms.com/api/mcp/products/UC3845AD8TRG4","rawCanonicalId":null},"summary":{"shortDescription":"Texas Instruments UC3845AD8TRG4, current-mode PWM controller, 48% max duty cycle, up to 500kHz switching, 7.6V-30V supply, 8-SOIC, 0°C to 70°C.","salesMarkdown":"## 48% duty cycle — the UC3845 differentiator Its defining parametric constraint is a maximum duty cycle of 48%, which sets it apart from the UC3842 (96% duty) and UC3843/4 (100% duty) siblings. This lower duty ceiling is intentional — it guarantees adequate reset time in single-ended forward converters and prevents transformer saturation in flyback topologies operating in continuous conduction mode. ## Switching frequency and supply headroom The oscillator runs up to 500 kHz, allowing the designer to shrink the magnetic components — transformer and output inductor — at the cost of higher switching losses. The supply range spans 7.6 V to 30 V on Vcc, which covers most off-line bias rails and industrial DC buses. No clock sync input is provided, so the switching frequency is set by a single RT/CT network; multiple converters on the same board must either free-run or use an external clock injection circuit.","metaTitle":"UC3845AD8TRG4 PWM Controller, 48% Duty Cycle, Up to 500kHz","metaDescription":"UC3845AD8TRG4 current-mode PWM controller from TI. Active production. 48% max duty cycle, up to 500kHz switching, 7.6V-30V supply. 8-SOIC package.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Active","categoryPath":["Power Management (PMIC / Gate Driver)"],"specifications":{"Mfr":"Texas Instruments","Series":"-","Package":"Tape & Reel (TR)","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)","lifecycle_stage":"eol_hot","Control Features":"Frequency Control","Duty Cycle (Max)":"48%","Number of Outputs":"1","Serial Interfaces":"-","Base Product Number":"UC3845","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":null,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.icboms.com/167f8b16f2b0abe2748ff562a0463921.pdf","sourceUrl":null,"alternativesUrl":"https://icboms.com/api/mcp/products/UC3845AD8TRG4/alternatives.json"},"ai":{"faq":[{"question":"Is UC3845AD8TRG4 equivalent to UC3842 or UC3843?","answer":"UC3845AD8TRG4 is pin-compatible with other UC384x family members but differs in maximum duty cycle: 48% versus 96% for UC3842 and 100% for UC3843/4. The duty cycle limit is the primary selection criterion — choose the variant that matches the transformer reset requirement of your topology."},{"question":"What is the function of UC3845AD8TRG4?","answer":"It is a current-mode PWM controller supporting step-up (boost), step-down (buck), and step-up/step-down (flyback, forward) topologies. It drives an external power transistor with a single-ended output."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/texas-instruments/UC3845AD8TRG4","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/texas-instruments/UC3845AD8TRG4 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}}