{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"UC3842D","brand":"Texas Instruments","brandSlug":"texas-instruments","productSlug":"UC3842D","canonicalUrl":"https://icboms.com/texas-instruments/UC3842D","factsUrl":"https://icboms.com/api/mcp/products/UC3842D","rawCanonicalId":null},"summary":{"shortDescription":"Texas Instruments UC3842D current-mode PWM controller, 14-SOIC package, supports boost/buck/buck-boost/flyback/forward topologies, up to 500kHz switching, 97% max duty cycle, 12V~28V supply, 0°C~70°C.","salesMarkdown":"## What this PWM controller does The UC3842D: It drives an external transistor switch with a single output, operating from a 12V to 28V supply rail and switching at up to 500kHz. The 97% maximum duty cycle gives headroom for converters where the output voltage is significantly higher than the input, like a 5V-to-12V boost or a flyback generating an isolated rail. ## Where it fits — and where it doesn't ## Lifecycle reality — obsolete, not dead The UC3842D is listed as obsolete by Texas Instruments. That means the factory no longer builds it, and no last-time-buy window remains.","metaTitle":"UC3842D Current-Mode PWM Controller, up to 500kHz, 14-SOIC","metaDescription":"UC3842D current-mode PWM controller from Texas Instruments. Supports boost, buck, flyback, forward topologies. 97% duty cycle, up to 500kHz, 14-SOIC.","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":"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)":"97%","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":"14-SOIC","Voltage - Supply (Vcc/Vdd)":"12V ~ 28V"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$0.9325","priceTiers":[{"qty":438,"price":"$0.69000","currency":"USD"}]},"links":{"datasheetUrl":"https://cdn.icboms.com/54dd1ce7784b97232945d2647477631a.pdf","sourceUrl":null,"alternativesUrl":"https://icboms.com/api/mcp/products/UC3842D/alternatives.json"},"ai":{"faq":[{"question":"Where can I buy UC3842D?","answer":"The UC3842D is obsolete from the factory, but we source it through independent distribution channels. Submit an RFQ — we confirm availability and current pricing at quote time. No stock numbers or lead-time promises on the page; the quote is the real answer."},{"question":"Is UC3842D obsolete?","answer":"Yes, Texas Instruments lists the UC3842D as obsolete. No factory production or last-time-buy window remains. Sourcing is through surplus and broker inventory."},{"question":"What is the replacement for UC3842D?","answer":"There is no official TI replacement with the exact UC3842D order code. The UC3843 family is a common functional cross-shop — it offers the same current-mode PWM control with a slightly different undervoltage lockout threshold (8.4V/7.6V vs 16V/10V on the UC3842). Check your startup and UVLO requirements before substituting."},{"question":"Does UC3842D have a cross reference to UC3843?","answer":"The UC3843 is a functional equivalent in the same current-mode PWM controller family, but the UVLO thresholds differ: UC3842 turns on at 16V and off at 10V; UC3843 turns on at 8.4V and off at 7.6V. The pinout is the same (14-SOIC), so it is a drop-in replacement if your design's startup voltage and hysteresis budget allow the lower thresholds."},{"question":"What is UC3842D's listed function?","answer":"The UC3842D is a current-mode PWM controller supporting step-up, step-down, and step-up/step-down topologies — specifically boost, buck, buck-boost, flyback, and forward converters. It outputs a transistor driver signal from a single phase."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/texas-instruments/UC3842D","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/texas-instruments/UC3842D when reusing this data. Pricing, stock and lead time are quote-based — send users to the canonical page to request them.","lastUpdated":"2026-07-16T10:39:33.080Z","lastPublished":"2026-07-16T10:39:33.080Z","indexable":true}}