{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"UC3842ADG4","brand":"Texas Instruments","brandSlug":"texas-instruments","productSlug":"UC3842ADG4","canonicalUrl":"https://icboms.com/texas-instruments/UC3842ADG4","factsUrl":"https://icboms.com/api/mcp/products/UC3842ADG4","rawCanonicalId":null},"summary":{"shortDescription":"Texas Instruments UC3842ADG4 current-mode PWM controller, 14-SOIC, 10V-30V supply, up to 500 kHz switching, 96% max duty cycle, 0°C to 70°C.","salesMarkdown":"## 500 kHz switching ceiling and 96% duty cycle Switching frequency goes up to 500 kHz, which lets you shrink the transformer or inductor core size compared to a 100 kHz design — the trade-off is higher switching losses in the MOSFET and snubber components. The 96% maximum duty cycle gives headroom for low-dropout operation in a buck converter or wide input-range flyback; at 96 % the off-time is only 4 % of the period, so the transformer reset voltage needs careful design. ## Topology flexibility: boost, buck, flyback, forward This current-mode controller supports step-up, step-down, and step-up/step-down topologies — boost, buck, flyback, and forward converters are all on the table. The single output drives an external MOSFET via a transistor driver stage; the control loop uses frequency compensation through the COMP pin, and the part includes frequency control (oscillator timing via Rt/Ct). Vcc supply range is 10 V to 30 V, which covers standard bias rails from 12 V to 24 V industrial supplies. No synchronous rectifier option; the output is a single transistor driver, not a totem-pole pair. ## 14-SOIC package — rework-friendly footprint Housed in a 14-SOIC (0.154-inch width, 3.90 mm body), surface-mount package. The 1.27 mm pitch is easy to hand-solder and inspect under a microscope; no thermal pad underneath, so the power dissipation path is through the leads and copper plane. Ships in Tube form.","metaTitle":"UC3842ADG4 PWM Controller, 500 kHz, 96% Duty Cycle, Active","metaDescription":"Texas Instruments UC3842ADG4 current-mode PWM controller. Up to 500 kHz switching, 96% max duty cycle, 10V-30V supply, 14-SOIC.","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":"14-SOIC (0.154\\\", 3.90mm Width)","lifecycle_stage":"eol_hot","Control Features":"Frequency Control","Duty Cycle (Max)":"96%","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)":"10V ~ 30V"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.icboms.com/536891bbf6907bbea70f31ce571541e7.pdf","sourceUrl":null,"alternativesUrl":"https://icboms.com/api/mcp/products/UC3842ADG4/alternatives.json"},"ai":{"faq":[{"question":"What is the maximum duty cycle of UC3842ADG4?","answer":"The maximum duty cycle is 96 %, which allows the controller to stay on for nearly the whole switching period — useful for low-dropout buck or wide-input flyback designs where the off-time is short."},{"question":"Is UC3842ADG4 obsolete or active?","answer":"New designs can proceed without LTB risk."},{"question":"What topology can UC3842ADG4 be used in?","answer":"It supports boost, buck, flyback, and forward topologies — step-up, step-down, and step-up/step-down configurations are all within its capability."},{"question":"What is the difference between UC3842ADG4 and UC3842?","answer":"The UC3842ADG4 is the surface-mount 14-SOIC variant of the base UC3842 (which is typically available in DIP-8 or SOIC-8). The 'DG4' suffix indicates the SOIC-14 package and a specific lead-free / RoHS-compliant finish. Functionally they share the same current-mode PWM control core, but the pinout differs — the 14-SOIC version has additional NC pins and a different pin arrangement, so they are not drop-in replacements without a PCB layout change."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/texas-instruments/UC3842ADG4","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/texas-instruments/UC3842ADG4 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}}