{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"UC3845AD8","brand":"Texas Instruments","brandSlug":"texas-instruments","productSlug":"UC3845AD8","canonicalUrl":"https://icboms.com/texas-instruments/UC3845AD8","factsUrl":"https://icboms.com/api/mcp/products/UC3845AD8","rawCanonicalId":null},"summary":{"shortDescription":"Texas Instruments UC3845AD8 current-mode PWM controller, 48% max duty cycle, up to 500kHz switching, 7.6V to 30V supply, 8-SOIC package, 0°C to 70°C operating temperature.","salesMarkdown":"## Current-mode PWM controller for single-ended topologies The Texas Instruments UC3845AD8 is a current-mode PWM controller designed for single-ended power converters. It supports boost, buck, flyback, and forward topologies, with a single transistor-driver output. The 48% maximum duty cycle is tailored for flyback and forward converters where transformer reset requires the off-time to exceed the on-time. Switching frequency reaches up to 500 kHz, enabling compact magnetics. The wide supply range from 7.6 V to 30 V allows direct connection to rectified DC bus voltages without an intermediate regulator. ## 48% duty cycle — why it matters for flyback designs The 48% duty cycle ceiling is a deliberate limit for single-ended topologies. In a flyback converter, the transformer core must reset during the off-time; exceeding 50% duty cycle risks saturation and primary-side switch stress. This part ensures the off-time is always longer than the on-time, simplifying transformer design and improving reliability. The controller lacks clock synchronization and synchronous rectification capability, so it is best suited for non-interleaved, single-phase designs where external sync is not required.","metaTitle":"UC3845AD8 PWM Controller, 48% Duty Cycle, 500kHz, 8-SOIC","metaDescription":"UC3845AD8 current-mode PWM controller. 48% max duty cycle, up to 500kHz switching. Boost, buck, flyback, forward topologies. 7.6V-30V supply.","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":"Tube","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)":"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":"$1.3300","priceTiers":null},"links":{"datasheetUrl":"https://cdn.icboms.com/167f8b16f2b0abe2748ff562a0463921.pdf","sourceUrl":null,"alternativesUrl":"https://icboms.com/api/mcp/products/UC3845AD8/alternatives.json"},"ai":{"faq":[{"question":"What is the maximum duty cycle of UC3845AD8?","answer":"The maximum duty cycle is 48%. This limit prevents transformer saturation in single-ended topologies like flyback and forward converters, where the off-time must exceed the on-time for core reset."},{"question":"Is UC3845AD8 suitable for a flyback converter?","answer":"Yes. The UC3845AD8 is specifically designed for flyback and forward topologies. The 48% duty cycle limit and current-mode control make it a standard choice for offline flyback supplies up to about 100 W."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/texas-instruments/UC3845AD8","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/texas-instruments/UC3845AD8 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}}