{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"LTC3858EUH#PBF","brand":"Analog Devices","brandSlug":"analog-devices","productSlug":"LTC3858EUHPBF","canonicalUrl":"https://icboms.com/analog-devices/LTC3858EUHPBF","factsUrl":"https://icboms.com/api/mcp/products/LTC3858EUH%23PBF","rawCanonicalId":null},"summary":{"shortDescription":"Analog Devices LTC3858EUH#PBF, PolyPhase series, dual-output step-down DC/DC controller, buck topology, 2 phases, 105kHz-835kHz switching, 4V-38V supply, synchronous rectification, -40°C to 125°C, 32-QFN (5x5), Tube, ROHS3.","salesMarkdown":"## What this dual-phase buck controller brings to the board The LTC3858EUH#PBF is a dual-output, 2-phase step-down DC/DC controller from Analog Devices' PolyPhase series. It drives external N-channel MOSFETs in a synchronous buck topology, delivering two independent regulated rails from a single 4V to 38V input. The 2-phase architecture interleaves the switching edges, reducing input ripple current and letting you use smaller input capacitors than a single-phase controller of equivalent output current. Switching frequency is programmable from 105kHz up to 835kHz, with a separate range of 350kHz to 535kHz available through the SYNC pin — useful for locking to an external clock or staying clear of sensitive frequency bands. ## Temperature range and where it runs Rated for -40°C to 125°C junction temperature, this part handles the thermal extremes you find in outdoor telecom enclosures, motor-drive cabinets, and under-hood automotive auxiliary supplies. The 32-QFN (5x5) package with exposed pad pulls heat into the PCB copper plane — make sure your layout includes a thermal via array under the pad to keep junction temperature inside the limit at full load. ## Package and mounting Current limit, enable, frequency control, power good, and soft start are all built in. The 99.4% maximum duty cycle means the controller can run near dropout — useful when the input rail sags and you need to keep the output up. Soft start limits inrush on both channels independently; the power-good output can sequence a downstream load or drive a reset line. No clock sync pin on this variant — if you need external synchronization, the LTC3890EUH#PBF adds that feature. ## Package and mounting Surface-mount in a 32-QFN (5x5) with exposed pad. The exposed pad is the primary thermal path and also carries the ground reference — ensure your PCB footprint has a matching thermal land with at least nine vias to an internal ground plane.","metaTitle":"LTC3858EUH#PBF PolyPhase Buck Controller, 2-Phase","metaDescription":"LTC3858EUH#PBF dual-output step-down controller from Analog Devices. 2-phase PolyPhase buck, 4V-38V supply, -40°C to 125°C. Active, ROHS3.","metaKeywords":null},"attributes":{"series":"PolyPhase®","packageCase":null,"mountingType":null,"rohsStatus":"ROHS3 Compliant","productStatus":"Active","categoryPath":["DC-DC Power Modules"],"specifications":{"Series":"PolyPhase®","Package":"Tube","Function":"Step-Down","Topology":"Buck","Clock Sync":"No","Output Type":"Transistor Driver","Mounting Type":"Surface Mount","Output Phases":"2","Package / Case":"32-WFQFN Exposed Pad","lifecycle_stage":"eol_hot","Control Features":"Current Limit, Enable, Frequency Control, Power Good, Soft Start","Duty Cycle (Max)":"99.4%","Number of Outputs":"2","Output Configuration":"Positive","Frequency - Switching":"105kHz ~ 835kHz, 350kHz ~ 535kHz","Operating Temperature":"-40°C ~ 125°C (TJ)","Synchronous Rectifier":"Yes","Supplier Device Package":"32-QFN (5x5)","Voltage - Supply (Vcc/Vdd)":"4V ~ 38V"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$11.49","stockQuantity":0,"priceTiers":[{"qty":1,"price":"$11.49000","currency":"USD"},{"qty":10,"price":"$10.38000","currency":"USD"},{"qty":73,"price":"$9.89699","currency":"USD"},{"qty":146,"price":"$8.59349","currency":"USD"},{"qty":292,"price":"$8.20726","currency":"USD"},{"qty":511,"price":"$7.48309","currency":"USD"},{"qty":1022,"price":"$6.51753","currency":"USD"}]},"links":{"datasheetUrl":"https://cdn.icboms.com/a745a3e6bc4b6d841b8ac73323043b35.pdf","sourceUrl":null},"ai":{"faq":[{"question":"What is the difference between LTC3858EUH#PBF and LTC3858EUH#TRPBF?","answer":"The only difference is the shipping medium. LTC3858EUH#PBF ships in a Tube; LTC3858EUH#TRPBF ships in Tape & Reel. The silicon, package, and electrical specifications are identical. Order the #PBF suffix for prototype or low-volume builds, and the #TRPBF suffix for automated pick-and-place production."},{"question":"What are the alternatives to LTC3858EUH#PBF?","answer":"The closest functional peer is the LTC3890EUH#PBF, also a PolyPhase dual-output buck controller in the same 32-QFN (5x5) package. The LTC3890 adds phase control and tracking features but drops the maximum duty cycle to 99%. If you need external clock synchronization, the LTC3890 supports it; the LTC3858 does not. For a lower-temperature-grade option, the LTC3850EGN-1#PBF operates to 85°C ambient and has a fixed 250kHz switching frequency."},{"question":"Can LTC3858EUH#PBF be used as a drop-in replacement for LTC3858EUH?","answer":"Yes, the LTC3858EUH#PBF is the ROHS3-compliant version of the original LTC3858EUH. The electrical specifications, package, and pinout are identical. The #PBF suffix indicates lead-free (Pb-free) finish and ROHS3 compliance. No board layout changes are needed when swapping from the non-PBF variant."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/analog-devices/LTC3858EUHPBF","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/analog-devices/LTC3858EUHPBF 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}}