{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"LM2940CSX-12","brand":"Texas Instruments","brandSlug":"texas-instruments","productSlug":"LM2940CSX-12","canonicalUrl":"https://icboms.com/texas-instruments/LM2940CSX-12","factsUrl":"https://icboms.com/api/mcp/products/LM2940CSX-12","rawCanonicalId":null},"summary":{"shortDescription":"Texas Instruments LM2940CSX-12, fixed 12V output LDO, 1A, 0.8V dropout at 1A, 66dB PSRR at 120Hz, DDPAK/TO-263-3 surface mount, 0°C to 125°C operating temperature.","salesMarkdown":"## 12V fixed output with 0.8V dropout at 1A — the headroom trap The LM2940CSX-12 is a fixed 12V positive-output LDO from Texas Instruments, rated for 1A continuous output with a maximum dropout of 0.8V at that full load. That dropout figure is the spec that catches designers: a 12V rail fed from a 13V source leaves only 0.2V headroom, which is below the dropout floor — the regulator drops out and the output follows the input minus the pass element voltage. For reliable regulation, budget at least 1V above 12V at the input under worst-case load and lowest line. ## 66dB PSRR at 120Hz — post-rectifier filtering without a second stage That attenuation knocks down 1Vpp of 120Hz ripple to about 0.5mVpp at the output — enough for most analog and logic loads without a second LC filter. The PSRR rolls off above a few kHz, so switching-regulator feed-through at 100kHz or higher passes with less rejection; a post-filter or a separate low-noise LDO is needed for sensitive RF or audio rails. That means TI is not actively promoting it for new builds, and the eventual EOL notice is a matter of when, not if. For existing production, the part is still available through independent distribution on a quoted-to-order basis — no stock-holding claim, sourced per RFQ. ## Protection set and operating range The LM2940CSX-12 integrates over-current, over-temperature, reverse polarity, and short-circuit protection — a full guard band that reduces external clamp and foldback circuitry. Input voltage range extends to 26V maximum, giving a 14V headroom above the 12V output. Operating temperature is rated from 0°C to 125°C, which covers commercial and most industrial ambient environments but not extended automotive or military ranges.","metaTitle":"LM2940CSX-12 12V 1A LDO Regulator, NRND, DDPAK/TO-263-3","metaDescription":"Texas Instruments LM2940CSX-12 fixed 12V output LDO, 1A, 0.8V dropout at full load, 66dB PSRR at 120Hz. DDPAK/TO-263-3 surface mount.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"NRND","categoryPath":["Analog & Data Acquisition"],"specifications":{"Mfr":"Texas Instruments","PSRR":"66dB (120Hz)","Series":"-","Package":"Tape & Reel (TR); Cut Tape (CT)","Output Type":"Fixed","Mounting Type":"Surface Mount","Package / Case":"TO-263-4, D²Pak (3 Leads + Tab), TO-263AA","Product Status":"Not For New Designs","lifecycle_stage":"eol_hot","Control Features":"-","Current - Output":"1A","Base Product Number":"LM2940","Protection Features":"Over Current, Over Temperature, Reverse Polarity, Short Circuit","Number of Regulators":"1","Output Configuration":"Positive","Operating Temperature":"0°C~125°C","Voltage - Input (Max)":"26V","Voltage Dropout (Max)":"0.8V @ 1A","Current - Supply (Max)":"15 mA","Voltage - Output (Max)":"-","Supplier Device Package":"DDPAK/TO-263-3","Current - Quiescent (Iq)":"10 mA","Voltage - Output (Min/Fixed)":"12V"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$3.1200","priceTiers":null},"links":{"datasheetUrl":"https://cdn.icboms.com/0f0c629902ef7e44f0cd225fb2494cc7.pdf","sourceUrl":null,"alternativesUrl":"https://icboms.com/api/mcp/products/LM2940CSX-12/alternatives.json"},"ai":{"faq":[{"question":"Is LM2940CSX-12 compatible with LM2940T-12?","answer":"The LM2940T-12 is the TO-220 through-hole version of the same 12V fixed-output LDO. The LM2940CSX-12 is the DDPAK/TO-263-3 surface-mount variant. Electrically they are identical — same dropout, same PSRR, same protection features — but the packages are not footprint-compatible. The DDPAK version requires a different PCB layout and has a different thermal pad geometry."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/texas-instruments/LM2940CSX-12","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/texas-instruments/LM2940CSX-12 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}}