{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"LD1117V18","brand":"STMicroelectronics","brandSlug":"stmicroelectronics","productSlug":"LD1117V18","canonicalUrl":"https://icboms.com/stmicroelectronics/LD1117V18","factsUrl":"https://icboms.com/api/mcp/products/LD1117V18","rawCanonicalId":null},"summary":{"shortDescription":"STMicroelectronics LD1117V18, positive fixed LDO voltage regulator, 1.8V output, 800mA output current, 1.2V dropout max, 75dB PSRR at 120Hz, TO-220-3 through-hole package, 0°C to 125°C.","salesMarkdown":"## 1.8V fixed LDO — what it powers The STMicroelectronics LD1117V18 is a single-output, positive fixed LDO regulator delivering a 1.8V rail from a maximum 15V input. It is rated for 800mA continuous output current, with a maximum dropout voltage of 1.2V at full load — meaning the input must stay above 3.0V to maintain regulation at 800mA. The 75dB PSRR at 120Hz makes this part a candidate for powering 1.8V analog or mixed-signal rails — ADC supplies, PLL VCOs, or sensor front-ends — where line-frequency ripple rejection matters. The 10 mA quiescent current is typical for a bipolar LDO of this output capability. ## Obsolete — replacement and sourcing path For new designs, consider the LD1117 series in the same TO-220 package with a different fixed output voltage — the LD1117V33 (3.3V) or LD1117V50 (5.0V) — or look at the LD1117 adjustable version (LD1117V) if the 1.8V rail can be set with a resistor divider. None of these are drop-in replacements; the fixed output voltage is set internally. No stock-holding claim is made. The 1.2V dropout at 800mA means 0.96W dissipation at minimum headroom — more if the input is higher. Over-current and over-temperature protection are built in — the regulator folds back or shuts down if the junction exceeds the thermal limit or the output current exceeds the safe area.","metaTitle":"STMicroelectronics LD1117V18 LDO Regulator, 1.8V Fixed","metaDescription":"ST LD1117V18 positive fixed LDO regulator, 1.8V output, 800mA, 75dB PSRR at 120Hz, TO-220-3.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Obsolete","categoryPath":["Analog & Data Acquisition"],"specifications":{"Mfr":"STMicroelectronics","PSRR":"75dB (120Hz)","Series":"-","Package":"Tube","Output Type":"Fixed","Mounting Type":"Through Hole","Package / Case":"TO-220-3","Product Status":"Obsolete","lifecycle_stage":"eol_hot","Control Features":"-","Current - Output":"800mA","Base Product Number":"LD1117","Protection Features":"Over Current, Over Temperature","Number of Regulators":"1","Output Configuration":"Positive","Operating Temperature":"0°C ~ 125°C","Voltage - Input (Max)":"15V","Voltage Dropout (Max)":"1.2V @ 800mA","Voltage - Output (Max)":"-","Supplier Device Package":"TO-220","Current - Quiescent (Iq)":"10 mA","Voltage - Output (Min/Fixed)":"1.8V"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$0.8000","priceTiers":null},"links":{"datasheetUrl":"https://cdn.icboms.com/494bb92f4effb270dec91ee8a399de6d.pdf","sourceUrl":null,"alternativesUrl":"https://icboms.com/api/mcp/products/LD1117V18/alternatives.json"},"ai":{"faq":[{"question":"What is the replacement for LD1117V18?","answer":"No official direct replacement is listed. For a 1.8V fixed output in a TO-220 package, the LD1117V18 must be sourced through surplus or independent distribution. For new designs, consider the LD1117 adjustable version (LD1117V) with a resistor divider, or a different fixed-voltage variant if the rail voltage can change."},{"question":"Can I use LD1117V18 for 3.3V output?","answer":"No. The LD1117V18 has a fixed 1.8V output. It cannot be adjusted to 3.3V. For a 3.3V output, use the LD1117V33 or an adjustable LDO."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/stmicroelectronics/LD1117V18","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/stmicroelectronics/LD1117V18 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}}