{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"STTH20R04W","brand":"STMicroelectronics","brandSlug":"stmicroelectronics","productSlug":"STTH20R04W","canonicalUrl":"https://icboms.com/stmicroelectronics/STTH20R04W","factsUrl":"https://icboms.com/api/mcp/products/STTH20R04W","rawCanonicalId":null},"summary":{"shortDescription":"STMicroelectronics STTH20R04W, standard fast recovery diode, 20 A average rectified, 400 V reverse voltage, 45 ns reverse recovery time, DO-247 through-hole package.","salesMarkdown":"## 20 A fast recovery in a DO-247 — switching loss anchor The STTH20R04W is a standard fast recovery diode from STMicroelectronics, rated for 20 A average rectified current at 400 V reverse voltage. Its 45 ns reverse recovery time places it in the fast-recovery class, suited for continuous-conduction-mode PFC boost stages, output rectification in medium-frequency SMPS, and freewheeling diodes in motor-drive snubbers where the switching loss budget is dominated by trr. ## 45 ns trr — snubber and switching loss trade-off A 45 ns reverse recovery time at 20 A forward current means the diode recovers fast enough to keep turn-off losses manageable in hard-switched topologies up to roughly 100 kHz, depending on the dI/dt and junction temperature. The 1.7 V forward voltage at 20 A sets the conduction loss floor: at full rated current, each device dissipates 34 W in forward conduction alone, so the DO-247 package's junction-to-case thermal impedance becomes the limiting factor for continuous duty. ## 175°C junction — thermal headroom in tight enclosures Rated for a maximum junction temperature of 175°C, the STTH20R04W can operate in elevated ambient conditions typical of enclosed power supplies and motor drives. The reverse leakage is specified at 20 µA at 400 V and 25°C, but rises exponentially with temperature — at 125°C junction the leakage can dominate the off-state loss, so the thermal design should budget for the leakage power at the expected hot-spot temperature. ## Obsolete — sourcing from surplus and independent channels STMicroelectronics lists the STTH20R04W as obsolete.","metaTitle":"STTH20R04W Fast Recovery Diode, 20 A, 400 V, 45 ns trr","metaDescription":"STTH20R04W standard fast recovery diode, 20 A average, 400 V reverse, 45 ns trr. DO-247 through-hole package.","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":"Standard","Mounting Type":"Through Hole","Package / Case":"DO-247-2 (Straight Leads)","Product Status":"Obsolete","lifecycle_stage":"eol_hot","Base Product Number":"STTH2","Capacitance @ Vr, F":"-","Supplier Device Package":"DO-247","Reverse Recovery Time (trr)":"45 ns","Current - Reverse Leakage @ Vr":"20 µA @ 400 V","Voltage - DC Reverse (Vr) (Max)":"400 V","Current - Average Rectified (Io)":"20A","Operating Temperature - Junction":"175°C(Max)","Voltage - Forward (Vf) (Max) @ If":"1.7 V @ 20 A"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.icboms.com/0ba69a2dc459e968a8d8f04af9d077ac.pdf","sourceUrl":null,"alternativesUrl":"https://icboms.com/api/mcp/products/STTH20R04W/alternatives.json"},"ai":{"faq":[{"question":"What is the replacement for STTH20R04W?","answer":"No official replacement or pin-compatible successor is recorded in the STTH20R04 product line. For a drop-in alternative, evaluate other 20 A, 400 V fast recovery diodes in a DO-247 package from the same class, but confirm the trr and Vf match your switching loss budget. Sourcing from surplus stock is the current path."},{"question":"What is STTH20R04W's reverse recovery time?","answer":"The reverse recovery time (trr) is 45 ns, measured under typical test conditions. This places it in the fast-recovery class, suitable for hard-switched PFC and SMPS output stages up to about 100 kHz."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/stmicroelectronics/STTH20R04W","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/stmicroelectronics/STTH20R04W 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}}