{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"UC3844N","brand":"Texas Instruments","brandSlug":"texas-instruments","productSlug":"UC3844N","canonicalUrl":"https://icboms.com/texas-instruments/UC3844N","factsUrl":"https://icboms.com/api/mcp/products/UC3844N","rawCanonicalId":null},"summary":{"shortDescription":"Texas Instruments UC3844N current-mode PWM controller, 8-PDIP, switching up to 500 kHz, 48% max duty cycle, 12 V to 28 V supply, 0°C to 70°C operating temperature.","salesMarkdown":"## What this PWM controller is and where it lands in the power stage The UC3844N: It handles boost, buck, buck-boost, flyback, and forward topologies, with a single transistor-driver output and a 48% max duty cycle that keeps the transformer reset in single-ended forward designs. Switching frequency runs up to 500 kHz, which lets you shrink the magnetics but pushes the layout discipline — keep the sense resistor and compensation loop tight to avoid subharmonic oscillation at duty cycles above 50%. Supply range is 12 V to 28 V on Vcc, with an internal UVLO that holds the output off until the rail crosses the startup threshold. The controller includes frequency control and is isolation-capable on the output side. ## Operating temperature and package — bench-friendly, not industrial Fine for benchtop supplies, office equipment, or appliance PSUs, but it will not hold up in a motor drive cabinet or outdoor telecom enclosure without active cooling or a temperature-controlled environment. The 8-pin PDIP package (0.300-inch body) is through-hole — easy to socket, easy to swap on site with a standard extraction tool. No hot-air station needed, and the pin spacing is wide enough that orientation is obvious even under a desk lamp. ## Lifecycle reality — obsolete, sourced through surplus channels The part is sourced through vetted independent distribution channels.","metaTitle":"UC3844N Current-Mode PWM Controller, 48% Duty, 500 kHz","metaDescription":"Texas Instruments UC3844N current-mode PWM controller. Switching up to 500 kHz, 48% max duty, 12-28 V supply, 8-PDIP.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Obsolete","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, Buck-Boost, Flyback, Forward","Clock Sync":"No","Output Type":"Transistor Driver","Mounting Type":"Through Hole","Output Phases":"1","Package / Case":"8-DIP (0.300\\\", 7.62mm)","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":"8-PDIP","Voltage - Supply (Vcc/Vdd)":"12V ~ 28V"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$0.9700","priceTiers":null},"links":{"datasheetUrl":"https://cdn.icboms.com/3edad1712993fb3b1751953d793dcfb6.pdf","sourceUrl":null,"alternativesUrl":"https://icboms.com/api/mcp/products/UC3844N/alternatives.json"},"ai":{"faq":[{"question":"Can UC3844N replace UC3842N or UC3843N?","answer":"The UC3844N has a 48% max duty cycle, while UC3842N runs at 96% and UC3843N at 100%. They share the same 8-pin PDIP footprint and pinout, but the duty-cycle limit is different — a direct swap only works if the design was originally built for the 48% clamp. Check the transformer reset and output voltage before substituting."},{"question":"What is UC3844N used for?","answer":"It is a current-mode PWM controller for boost, buck, buck-boost, flyback, and forward converters. Typical applications include offline AC-DC power supplies, battery chargers, and isolated DC-DC modules where the 48% duty limit keeps the transformer core reset in single-ended designs."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/texas-instruments/UC3844N","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/texas-instruments/UC3844N 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}}