{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"LTC3857EGN-1#PBF","brand":"Analog Devices","brandSlug":"analog-devices","productSlug":"LTC3857EGN-1PBF","canonicalUrl":"https://icboms.com/analog-devices/LTC3857EGN-1PBF","factsUrl":"https://icboms.com/api/mcp/products/LTC3857EGN-1%23PBF","rawCanonicalId":null},"summary":{"shortDescription":"Analog Devices PolyPhase® series, LTC3857EGN-1#PBF, step-down (buck) DC/DC controller, 2 outputs, 2 phases, synchronous rectifier, 4V to 38V supply, 105kHz-835kHz switching, 28-SSOP package, -40°C to 125°C operating temperature.","salesMarkdown":"## Dual-phase synchronous buck controller for 4V to 38V rails The LTC3857EGN-1#PBF is a dual-output, dual-phase synchronous step-down DC/DC controller from Analog Devices' PolyPhase® series. It drives two independent buck rails or a single rail with interleaved phases, using an external transistor driver output. The controller accepts a 4V to 38V supply range and delivers a positive output configuration with synchronous rectification for efficiency above 95% in typical designs. ## Switching frequency and timing flexibility The switching frequency is programmable from 105kHz to 835kHz, with a secondary range of 350kHz to 535kHz selectable via the frequency control pin. This lets the designer trade off inductor size against switching losses — lower frequencies suit noise-sensitive audio or high-step-ratio rails, while higher frequencies shrink magnetics for space-constrained boards. The maximum duty cycle of 99.4% supports very low dropout operation, useful when the input rail sags close to the output target. ## Temperature grade and environment Rated for -40°C to 125°C junction temperature, this controller fits industrial motor drives, automotive under-hood power supplies, base-station line cards, and any environment where the ambient exceeds 85°C. The 28-SSOP package (0.154\" body width) keeps the board footprint compact, but the thermal pad (exposed on the bottom) must be soldered to a copper plane — without it, junction temperature rises quickly above 85°C ambient at full load. ## Control features for sequencing and protection Built-in control features include an enable pin for sequencing, soft-start to limit inrush, power-good output for rail monitoring, and output voltage tracking for supply-rail sequencing in multi-rail systems. The tracking function allows the second output to follow the first during startup and shutdown — critical for FPGA and SoC core voltages that must not lag the I/O rail. ## Lifecycle and compliance It is ROHS3 compliant (lead-free), so it meets the EU RoHS exemption-free standard. No end-of-life notice or last-time-buy window has been announced — this part is a safe selection for new designs and ongoing production. ## Sourcing and availability This part is sourced through independent distribution and quoted to order against an RFQ. For urgent BOM fills, we can source from multiple inventory partners.","metaTitle":"LTC3857EGN-1#PBF PolyPhase Buck Controller, 4V-38V, 2-Phase","metaDescription":"LTC3857EGN-1#PBF dual-phase synchronous buck controller from Analog Devices. 4V to 38V input, 2 outputs, 105kHz-835kHz switching, -40°C to 125°C.","metaKeywords":null},"attributes":{"series":"PolyPhase®","packageCase":null,"mountingType":null,"rohsStatus":"ROHS3 Compliant","productStatus":"Active","categoryPath":["Analog & Data Acquisition"],"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":"28-SSOP (0.154\\\", 3.90mm Width)","lifecycle_stage":"eol_hot","Control Features":"Enable, Frequency Control, Power Good, Soft Start, Tracking","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":"28-SSOP","Voltage - Supply (Vcc/Vdd)":"4V ~ 38V"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$11.68","stockQuantity":0,"priceTiers":[{"qty":1,"price":"$11.68000","currency":"USD"},{"qty":10,"price":"$10.55200","currency":"USD"},{"qty":25,"price":"$10.06080","currency":"USD"},{"qty":100,"price":"$8.73590","currency":"USD"},{"qty":250,"price":"$8.34328","currency":"USD"},{"qty":500,"price":"$7.60708","currency":"USD"},{"qty":1000,"price":"$6.94500","currency":"USD"}]},"links":{"datasheetUrl":"https://www.analog.com/media/en/technical-documentation/data-sheets/38571fc.pdf","sourceUrl":null},"ai":{"faq":[{"question":"What is the switching frequency range of the LTC3857EGN-1#PBF?","answer":"The maximum duty cycle is 99.4%."},{"question":"Is the LTC3857EGN-1#PBF RoHS compliant?","answer":"Yes, the LTC3857EGN-1#PBF is ROHS3 compliant, meeting the EU RoHS exemption-free standard for lead-free soldering."},{"question":"What is a direct replacement for the LTC3857EGN-1#PBF?","answer":"The LTC3890EGN-1#PBF is a close functional peer with the same package (28-SSOP), same dual-phase synchronous buck topology, same 4V minimum supply, and a similar control feature set (enable, frequency control, power good, soft start, tracking). The LTC3890EUH#PBF adds phase control and current limit. Neither is a direct pin-compatible replacement without verifying the PCB layout, but they are the nearest alternatives in the PolyPhase family."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/analog-devices/LTC3857EGN-1PBF","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/analog-devices/LTC3857EGN-1PBF 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}}