{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"LM2940SX-9.0","brand":"Texas Instruments","brandSlug":"texas-instruments","productSlug":"LM2940SX-9.0","canonicalUrl":"https://icboms.com/texas-instruments/LM2940SX-9.0","factsUrl":"https://icboms.com/api/mcp/products/LM2940SX-9.0","rawCanonicalId":null},"summary":{"shortDescription":"Texas Instruments LM2940SX-9.0, positive fixed 9V LDO regulator, 1A output, 64dB PSRR at 120Hz, 1V max dropout at 1A, -40°C to 125°C, TO-263-4 (D²Pak), surface mount.","salesMarkdown":"## Fixed 9 V rail at 1 A — dropout headroom and noise rejection The LM2940SX-9.0 is a positive fixed-output LDO from Texas Instruments, delivering 1 A at a regulated 9 V. Its 1 V maximum dropout at full load means the input rail must stay above 10 V to maintain regulation — a 12 V bus provides comfortable margin, but a 9.5 V supply would drop out under load. The 64 dB PSRR at 120 Hz is the figure that matters for post-rectifier filtering: it knocks down the full-wave ripple by a factor of ~1600, making this part a clean choice for analog bias rails or audio supply lines where 120 Hz hum couples into the signal path. ## Industrial temperature grade and integrated protections The protection set includes over-current, over-temperature, reverse polarity, and short-circuit shutdown, which reduces the need for external clamp diodes or current-limiting resistors on the output. The 10 mA quiescent current is typical for a 1 A LDO of this generation; it is not a micropower part, so always-on battery applications should budget for the Iq draw.","metaTitle":"LM2940SX-9.0 1A Fixed 9V LDO, TO-263, Obsolete","metaDescription":"Texas Instruments LM2940SX-9.0 positive fixed 9V LDO, 1A output, 64dB PSRR at 120Hz, -40 to 125°C.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Obsolete","categoryPath":["Analog & Data Acquisition"],"specifications":{"Mfr":"Texas Instruments","PSRR":"64dB (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":"Obsolete","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":"-40°C~125°C","Voltage - Input (Max)":"26V","Voltage Dropout (Max)":"1V @ 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)":"9V"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.icboms.com/f38d6c1a461ac905342e1b9990545fb3.pdf","sourceUrl":null,"alternativesUrl":"https://icboms.com/api/mcp/products/LM2940SX-9.0/alternatives.json"},"ai":{"faq":[{"question":"What is a drop-in replacement for LM2940SX-9.0?","answer":"No official drop-in replacement is listed on the lifecycle record. The LM2940CT is a through-hole TO-220 variant of the same base regulator family, but it is not a pin-compatible surface-mount substitute — the package and footprint differ. For a TO-263-3 (DDPAK) footprint, a designer would need to evaluate other fixed 9 V, 1 A LDOs from TI or alternate vendors, verifying pinout, dropout, and PSRR against the application requirements."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/texas-instruments/LM2940SX-9.0","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/texas-instruments/LM2940SX-9.0 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}}