{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"L4940D2T10-TR","brand":"STMicroelectronics","brandSlug":"stmicroelectronics","productSlug":"L4940D2T10-TR","canonicalUrl":"https://icboms.com/stmicroelectronics/L4940D2T10-TR","factsUrl":"https://icboms.com/api/mcp/products/L4940D2T10-TR","rawCanonicalId":null},"summary":{"shortDescription":"STMicroelectronics L4940 series, Positive Fixed LDO Regulator, 10V, 1.5A, D2PAK (TO-263-3), -40°C to 150°C, PSRR 62dB at 120Hz.","salesMarkdown":"## 10V fixed rail, 1.5A — the selection mistake this LDO avoids The ST L4940D2T10-TR is a fixed 10V positive LDO regulator delivering up to 1.5A from a maximum 17V input. Its 0.9V dropout at full load leaves headroom for a 10V rail even when the input sags to 10.9V — common in post-regulated 12V supplies for automotive or industrial control boards. ## Dropout and thermal — sizing the copper pour The D2PAK (TO-263-3) package with exposed tab sinks heat through the PCB copper pour. At 1.5A and 3V input-to-output differential, dissipation is 4.5W — the tab must be soldered to a 1oz copper area of at least 600mm² to keep junction below 150°C in a 70°C ambient. Quiescent current is 8mA typical, rising to 50mA max under heavy load — not a low-Iq part, so not the choice for always-on battery circuits, but acceptable for a continuously powered rail in a motor drive or an ECU. The L4940 family shares the same pinout across fixed-voltage variants, so a 10V fixed output is specific.","metaTitle":"STMicroelectronics L4940D2T10-TR LDO Regulator, 10V Fixed","metaDescription":"ST L4940D2T10-TR positive fixed LDO, 10V output, 1.5A, 62dB PSRR at 120Hz, -40°C to 150°C, D2PAK.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Obsolete","categoryPath":["Analog & Data Acquisition"],"specifications":{"Mfr":"STMicroelectronics","PSRR":"62dB (120Hz)","Series":"-","Package":"Tape & Reel (TR) Cut Tape (CT)","Output Type":"Fixed","Mounting Type":"Surface Mount","Package / Case":"TO-263-3, D2PAK (2 Leads + Tab), TO-263AB","Product Status":"Obsolete","lifecycle_stage":"eol_hot","Control Features":"-","Current - Output":"1.5A","Base Product Number":"L4940","Protection Features":"Over Temperature, Reverse Polarity, Short Circuit","Number of Regulators":"1","Output Configuration":"Positive","Operating Temperature":"-40°C ~ 150°C","Voltage - Input (Max)":"17V","Voltage Dropout (Max)":"0.9V @ 1.5A","Current - Supply (Max)":"50 mA","Voltage - Output (Max)":"-","Supplier Device Package":"D2PAK","Current - Quiescent (Iq)":"8 mA","Voltage - Output (Min/Fixed)":"10V"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.icboms.com/3de7890ef359544301f24f28011d078c.pdf","sourceUrl":null,"alternativesUrl":"https://icboms.com/api/mcp/products/L4940D2T10-TR/alternatives.json"},"ai":{"faq":[{"question":"Where can I buy L4940D2T10-TR and check current pricing?","answer":"This part is obsolete and sourced through independent distribution."},{"question":"What is the PSRR of L4940D2T10-TR?","answer":"62dB at 120Hz — a meaningful spec for rejecting rectified mains ripple on the input rail."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/stmicroelectronics/L4940D2T10-TR","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/stmicroelectronics/L4940D2T10-TR 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}}