{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"UC3844DTR","brand":"Texas Instruments","brandSlug":"texas-instruments","productSlug":"UC3844DTR","canonicalUrl":"https://icboms.com/texas-instruments/UC3844DTR","factsUrl":"https://icboms.com/api/mcp/products/UC3844DTR","rawCanonicalId":null},"summary":{"shortDescription":"Texas Instruments UC3844DTR current-mode PWM controller, 14-SOIC, 48% max duty cycle, switching up to 500 kHz, 12V~28V supply, 0°C~70°C.","salesMarkdown":"## Current-mode PWM controller for flyback and forward converters The Texas Instruments UC3844DTR is a current-mode PWM controller designed for single-ended topologies including boost, buck, buck-boost, flyback, and forward converters. It delivers a single transistor-driver output with a maximum duty cycle of 48%, which sets the practical input-output voltage ratio for the transformer in isolated designs. ## 48% duty cycle — the topology gate The 48% duty cycle ceiling is the key parametric constraint. In a flyback converter, this limits the reflected voltage and the maximum step-up ratio from input to output. For a forward converter, the reset winding must clamp the transformer within the off-time, and the 48% duty ensures the core resets fully before the next cycle. Switching frequency reaches up to 500 kHz, which allows smaller magnetics and output capacitors compared to lower-frequency controllers. The practical switching speed is bounded by the 12V to 28V supply range and the gate-drive current available from the transistor driver output.","metaTitle":"UC3844DTR Current-Mode PWM Controller, 48% Duty Cycle","metaDescription":"UC3844DTR is a current-mode PWM controller from TI, supporting boost, buck, flyback, and forward topologies.","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); Cut Tape (CT)","Function":"Step-Up, Step-Down, Step-Up/Step-Down","Topology":"Boost, Buck, Buck-Boost, Flyback, Forward","Clock Sync":"No","Output Type":"Transistor Driver","Mounting Type":"Surface Mount","Output Phases":"1","Package / Case":"14-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":"UC3844","Output Configuration":"Positive, Isolation Capable","Frequency - Switching":"Up to 500kHz","Operating Temperature":"0°C~70°C(TA)","Synchronous Rectifier":"No","Supplier Device Package":"14-SOIC","Voltage - Supply (Vcc/Vdd)":"12V ~ 28V"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$1.3600","priceTiers":null},"links":{"datasheetUrl":"https://cdn.icboms.com/3edad1712993fb3b1751953d793dcfb6.pdf","sourceUrl":null,"alternativesUrl":"https://icboms.com/api/mcp/products/UC3844DTR/alternatives.json"},"ai":{"faq":[{"question":"What is the maximum duty cycle of UC3844DTR?","answer":"The maximum duty cycle is 48%. This is a fixed limit for the current-mode PWM controller and governs the transformer turns ratio in flyback and forward designs."},{"question":"Can UC3844DTR be used for flyback converters?","answer":"Yes. The UC3844DTR supports flyback topology directly, along with boost, buck, buck-boost, and forward converters. The 48% duty cycle is well-suited for single-switch flyback converters operating in discontinuous conduction mode."},{"question":"What is the difference between UC3842 and UC3844?","answer":"The primary difference is the maximum duty cycle: the UC3842 offers up to 96% duty, while the UC3844 is limited to 48%. The UC3844 is preferred for forward converters where the transformer must reset within the off-time."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/texas-instruments/UC3844DTR","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/texas-instruments/UC3844DTR 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}}