{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"LM3503SQX-16","brand":"Texas Instruments","brandSlug":"texas-instruments","productSlug":"LM3503SQX-16","canonicalUrl":"https://icboms.com/texas-instruments/LM3503SQX-16","factsUrl":"https://icboms.com/api/mcp/products/LM3503SQX-16","rawCanonicalId":null},"summary":{"shortDescription":"National Semiconductor LM3503SQX-16, DC DC Regulator, Step-Up (Boost) topology, 1 MHz switching frequency, 16 V output, 2 channels, 400 mA switch, Analog and PWM dimming, 16-WFQFN exposed pad package, -40°C to 85°C operating range.","salesMarkdown":"## Boost regulator for small-format LED backlights The National Semiconductor LM3503SQX-16 is a step-up (boost) DC DC regulator designed to drive LED strings in backlight applications. It integrates two outputs with a 400 mA switch, switching at 1 MHz to keep the inductor and output capacitors small enough for thin-profile displays. Output voltage is regulated to 16 V, which supports a string of roughly four to five white LEDs per channel depending on forward voltage. Dimming is handled either through an analog control voltage or a PWM signal, giving the system designer flexibility between smooth brightness adjustment and wider dimming range. ## 16 V output ceiling and dimming options The 16 V maximum output sets a practical limit on series LED count. For a typical white LED, four in series reaches 16 V plus headroom for the current-sense resistor — five is marginal. Both analog and PWM dimming modes are available. Analog dimming adjusts LED current continuously via a DC voltage; PWM dimming switches the output on and off at a frequency above visible flicker for a wider contrast ratio. The 1 MHz switching rate keeps the inductor ripple low even at high PWM dimming ratios. No official replacement or pin-compatible successor is listed on the record. ## Package and supply range The LM3503SQX-16 is supplied in a 16-lead WFQFN with exposed pad, measuring 4 mm × 4 mm.","metaTitle":"LM3503SQX-16 DC DC Regulator, 1 MHz Boost, 16 V Output","metaDescription":"National Semiconductor LM3503SQX-16 DC DC Regulator, step-up boost topology, 1 MHz frequency, 16 V output, 400 mA switch, analog/PWM dimming.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Obsolete","categoryPath":["Power Management (PMIC / Gate Driver)"],"specifications":{"Mfr":"Texas Instruments","Type":"DC DC Regulator","Series":"-","Dimming":"Analog, PWM","Package":"Tape & Reel (TR)","Topology":"Step-Up (Boost)","Frequency":"1MHz","Applications":"Backlight","Mounting Type":"Surface Mount","Package / Case":"16-WFQFN Exposed Pad","Product Status":"Obsolete","lifecycle_stage":"eol_hot","Voltage - Output":"16V","Number of Outputs":"2","Internal Switch(s)":"Yes","Base Product Number":"LM3503","Operating Temperature":"-40°C~85°C(TA)","Voltage - Supply (Max)":"5.5V","Voltage - Supply (Min)":"2.5V","Supplier Device Package":"16-WQFN (4x4)","Current - Output / Channel":"400mA (Switch)"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.icboms.com/b5f4b20f44a7c0b93377b093bbaea4ad.pdf","sourceUrl":null,"alternativesUrl":"https://icboms.com/api/mcp/products/LM3503SQX-16/alternatives.json"},"ai":{"faq":[{"question":"What is a direct replacement for the LM3503SQX-16?","answer":"For new designs, consider a current-production boost LED driver with similar 1 MHz switching and 16 V output capability from TI or an alternate vendor."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/texas-instruments/LM3503SQX-16","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/texas-instruments/LM3503SQX-16 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}}