{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"STPS40120CTN","brand":"STMicroelectronics","brandSlug":"stmicroelectronics","productSlug":"STPS40120CTN","canonicalUrl":"https://icboms.com/stmicroelectronics/STPS40120CTN","factsUrl":"https://icboms.com/api/mcp/products/STPS40120CTN","rawCanonicalId":null},"summary":{"shortDescription":"STMicroelectronics STPS40120CTN, Schottky diode, 1 Pair Common Cathode, 120 V DC reverse, 40 A average rectified per diode, 1 V forward drop at 40 A, Fast Recovery ≤500 ns, TO-220-3 through-hole package.","salesMarkdown":"## 120 V, 40 A Schottky in a common-cathode TO-220 Each diode delivers 20 A average (Io) with a forward voltage of 1 V at the 40 A peak rating. The fast recovery characteristic (≤500 ns, >200 mA) suits it for high-frequency switching supplies and output rectification stages where Schottky's low Vf and fast turn-off reduce losses. Packaged in a TO-220-3 through-hole case (TO-220AB narrow leads), the common-cathode pair shares the center tab, simplifying layout for center-tapped secondary rectifiers or OR-ing diodes in redundant power feeds. The junction is rated to 175°C max, giving headroom for thermally demanding environments like industrial power supplies or telecom rectifiers. ST lists the STPS40120CTN as Obsolete. No last-time-buy window remains open from the factory. New production designs should migrate to a current Schottky from ST's portfolio or a pin-compatible alternative. For existing BOM lines, stock is available through independent distribution; each lot is date-code verified and quoted per RFQ. ## Forward voltage and conduction loss At 40 A forward current the STPS40120CTN drops 1 V. That 40 W peak dissipation per diode pair drives the thermal design — the TO-220 tab must be heatsinked, and the 175°C junction limit sets the allowable case temperature. For a 20 A average load per diode, the Vf will be lower (the 1 V spec is at the 40 A peak), but the thermal margin still needs checking against the heatsink's thermal resistance. ## Reverse leakage at 120 V Reverse leakage is 25 µA at 120 V, typical for a 120 V Schottky. That leakage doubles with temperature, so at high junction temperatures the standing loss in off-state can become significant in low-load or standby conditions. For always-on OR-ing applications, verify the leakage budget at the operating temperature.","metaTitle":"STPS40120CTN Schottky Dual Diode, 120 V, 40 A, TO-220-3","metaDescription":"STPS40120CTN is a 120 V, 40 A common-cathode Schottky rectifier in TO-220AB. Fast recovery ≤500 ns.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Obsolete","categoryPath":["Discrete Semiconductors"],"specifications":{"Mfr":"STMicroelectronics","Speed":"Fast Recovery =< 500ns, > 200mA (Io)","Series":"-","Package":"Tube","Diode Type":"Schottky","Mounting Type":"Through Hole","Package / Case":"TO-220-3","Product Status":"Obsolete","lifecycle_stage":"eol_hot","Base Product Number":"STPS401","Diode Configuration":"1 Pair Common Cathode","Supplier Device Package":"TO-220AB Narrow Leads","Current - Reverse Leakage @ Vr":"25 µA @ 120 V","Voltage - DC Reverse (Vr) (Max)":"120 V","Operating Temperature - Junction":"175°C(Max)","Voltage - Forward (Vf) (Max) @ If":"1 V @ 40 A","Current - Average Rectified (Io) (per Diode)":"20A"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.icboms.com/69625ccc5cf805b1e3a133f209d99dcb.pdf","sourceUrl":null,"alternativesUrl":"https://icboms.com/api/mcp/products/STPS40120CTN/alternatives.json"},"ai":{"faq":[{"question":"Is STPS40120CTN obsolete?","answer":"Yes, STMicroelectronics lists the STPS40120CTN as Obsolete. No factory last-time-buy is available; supply is through independent distribution with date-code-verified stock."},{"question":"What is the replacement for STPS40120CTN?","answer":"ST does not publish a direct successor for this obsolete part. For new designs, evaluate current 120 V common-cathode Schottky diodes in TO-220 from ST or other manufacturers. For existing BOMs, independent distribution can supply verified stock of the STPS40120CTN against an RFQ."},{"question":"What package is STPS40120CTN in?","answer":"The STPS40120CTN is in a TO-220-3 through-hole package (TO-220AB with narrow leads)."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/stmicroelectronics/STPS40120CTN","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/stmicroelectronics/STPS40120CTN when reusing this data. Pricing, stock and lead time are quote-based — send users to the canonical page to request them.","lastUpdated":"2026-07-17T19:50:00.618Z","lastPublished":"2026-07-17T19:50:00.618Z","indexable":true}}