{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"STTH20R04FP","brand":"STMicroelectronics","brandSlug":"stmicroelectronics","productSlug":"STTH20R04FP","canonicalUrl":"https://icboms.com/stmicroelectronics/STTH20R04FP","factsUrl":"https://icboms.com/api/mcp/products/STTH20R04FP","rawCanonicalId":null},"summary":{"shortDescription":"STMicroelectronics STTH20R04FP, Fast Recovery Diode, 400 V DC reverse voltage, 20 A average rectified current, 45 ns reverse recovery time, 1.7 V forward drop at 20 A, TO-220-2 Full Pack (TO-220FPAC), Through Hole mounting.","salesMarkdown":"The STTH20R04FP is a 400 V, 20 A fast recovery diode from STMicroelectronics, built with standard planar technology and housed in a TO-220-2 Full Pack (TO-220FPAC) through-hole package. Its 45 ns reverse recovery time places it in the ultrafast class for a 400 V part, which matters when you are cleaning up the switching node in a continuous-conduction-mode PFC boost stage or as the output rectifier in a 200–400 W flyback converter. The 45 ns trr means the diode exits conduction fast enough that the MOSFET's body diode does not take over during the dead-time — a common failure mode in hard-switched bridges that shows up as a hot MOSFET and a ringing waveform you cannot snub out. ## 20 A in TO-220FPAC — the thermal reality The 20 A average rectified current is the headline number, but the full-pack TO-220FPAC package changes the thermal game. Unlike a standard TO-220 with a metal tab, the full-pack moulding isolates the back — no insulating washer needed when bolting to a grounded heatsink, which simplifies assembly in metal-enclosure designs. The trade-off is higher junction-to-case thermal resistance. At 1.7 V forward drop at 20 A, conduction loss runs 34 W. For pulsed or lower-duty-cycle applications the margin improves. That means STMicroelectronics has ended production — no last-time-buy window remains open through the factory channel.","metaTitle":"STTH20R04FP Fast Recovery Diode, 400V 20A TO-220FPAC","metaDescription":"STTH20R04FP 400V 20A fast recovery diode in TO-220FPAC full-pack. 45 ns trr, 1.7 Vf at 20 A.","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","Technology":"Standard","Mounting Type":"Through Hole","Package / Case":"TO-220-2 Full Pack","Product Status":"Obsolete","lifecycle_stage":"eol_hot","Base Product Number":"STTH20","Capacitance @ Vr, F":"-","Supplier Device Package":"TO-220FPAC","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":"$1.9200","stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.icboms.com/0ba69a2dc459e968a8d8f04af9d077ac.pdf","sourceUrl":null},"ai":{"faq":[{"question":"Is STTH20R04FP obsolete?","answer":"Yes, the STTH20R04FP is listed as Obsolete by STMicroelectronics. Production has ended, and no factory last-time-buy is available."},{"question":"What is the equivalent of STTH20R04FP?","answer":"The STTH20R04FP is a specific full-pack variant (TO-220FPAC) of the STTH20R04 series. A direct functional equivalent in the same series would be the standard TO-220 variant (STTH20R04) or the D²PAK surface-mount variant (STTH20R04D), both of which share the same 400 V, 20 A, 45 ns trr silicon but differ in package and thermal performance. For a newer-design replacement, evaluate ST's current ultrafast diode portfolio at the same voltage and current class."},{"question":"Does STTH20R04FP require a heatsink?","answer":"At its 20 A rated current with a 1.7 V forward drop, conduction loss reaches 34 W. The TO-220FPAC full-pack package has higher thermal resistance than a standard TO-220 tab, so a heatsink is required for continuous operation at or near the rated current to keep the junction temperature within the 175°C maximum. For pulsed or lower-current applications, the thermal margin improves and a heatsink may not be necessary — calculate the junction temperature rise against your duty cycle."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/stmicroelectronics/STTH20R04FP","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/stmicroelectronics/STTH20R04FP 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}}