{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"LM2647LQ/NOPB","brand":"Texas Instruments","brandSlug":"texas-instruments","productSlug":"LM2647LQ-NOPB","canonicalUrl":"https://icboms.com/texas-instruments/LM2647LQ-NOPB","factsUrl":"https://icboms.com/api/mcp/products/LM2647LQ%2FNOPB","rawCanonicalId":null},"summary":{"shortDescription":"Texas Instruments LM2647LQ/NOPB dual synchronous buck regulator, step-down topology, 5.5V to 28V input, 200kHz to 500kHz switching, 28-WQFN exposed pad, surface mount.","salesMarkdown":"## Dual synchronous buck for multi-rail POL designs The Texas Instruments LM2647LQ/NOPB is a dual synchronous buck regulator controller that drives two independent step-down outputs from a single 5.5V to 28V input rail. Each output uses an external transistor driver, so the power-stage FETs are sized to the load current rather than baked into the controller — useful when one rail pulls 3 A and the other 15 A. The dual-phase architecture with synchronous rectification keeps the output ripple low and the efficiency curve flat across a wide load range, which matters when the downstream loads are sensitive to supply noise or when the board runs hot and every percentage point of efficiency saves a fan. ## Switching frequency and control flexibility The switching frequency is programmable from 200 kHz to 500 kHz via an external resistor on the Frequency Control pin. A 200 kHz setting minimises switching losses in the FETs and is a good fit for higher-voltage inputs where the duty cycle is narrow; 500 kHz shrinks the output inductor and capacitor, saving board area at the cost of slightly higher gate-drive loss. The maximum duty cycle is 75%, which means the controller cannot run at 100% dropout — the input must stay at least 25% above the output voltage to maintain regulation. For a 3.3 V output, the minimum input is about 4.4 V, comfortably inside the 5.5 V lower end of the supply range. Control features include current limit, enable, soft start, and a Power Good flag. The soft-start pin sets the ramp time with an external capacitor, preventing inrush current from pulling the input rail down during startup on a heavily loaded output. ## Package, temperature grade, and board integration Housed in a 28-lead WQFN with exposed pad (5 mm × 5 mm), the LM2647LQ/NOPB requires a thermal land on the PCB to draw heat from the die into the board's copper plane. The junction temperature range is -5°C to 125°C, which covers industrial ambient conditions but not the full -40°C automotive band — if the board sees cold starts below -5°C, the controller may not start until the environment warms. The package is supplied in bulk (not tape-and-reel), so it is suited for prototype builds or low-volume production where the pick-and-place feeder setup for a reel is not justified. For higher volumes, confirm the packaging option with the supplier at RFQ time. Because it is an active part, the supply channel is straightforward: we source it against an RFQ from TI's authorized network, with pricing and lead time confirmed at quote time. The BOM line is not at risk of a sudden EOL, but the dual-output synchronous buck controller space has several pin-compatible alternatives worth reviewing if single-source risk is a concern.","metaTitle":"Texas Instruments LM2647LQ/NOPB Dual Synchronous Buck","metaDescription":"Texas Instruments LM2647LQ/NOPB dual synchronous buck regulator, 5.5V to 28V input, 200kHz-500kHz switching, 28-WQFN. Active, order via RFQ.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Active","categoryPath":["Analog & Data Acquisition"],"specifications":{"Package":"Bulk","Function":"Step-Down","Topology":"Buck","Clock Sync":"No","Output Type":"Transistor Driver","Mounting Type":"Surface Mount","Output Phases":"2","Package / Case":"28-FQFN Exposed Pad","lifecycle_stage":"eol_hot","Control Features":"Current Limit, Enable, Frequency Control, Power Good, Soft Start","Duty Cycle (Max)":"75%","Number of Outputs":"2","Output Configuration":"Positive","Frequency - Switching":"200kHz ~ 500kHz","Operating Temperature":"-5°C ~ 125°C (TJ)","Synchronous Rectifier":"Yes","Supplier Device Package":"28-WQFN (5x5)","Voltage - Supply (Vcc/Vdd)":"5.5V ~ 28V"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$2.58","priceTiers":[{"qty":117,"price":"$2.58000","currency":"USD"}]},"links":{"datasheetUrl":null,"sourceUrl":null,"alternativesUrl":"https://icboms.com/api/mcp/products/LM2647LQ%2FNOPB/alternatives.json"},"ai":{"faq":[{"question":"Is LM2647LQ/NOPB available via RFQ confirmation?","answer":"Stock levels fluctuate daily. We confirm availability and lead time when you submit an RFQ for your target quantity."},{"question":"Is the LM2647LQ/NOPB lead-free and RoHS compliant?","answer":"The NOPB suffix indicates a lead-free (Pb-free) finish. The part is RoHS compliant as manufactured by Texas Instruments."},{"question":"What is a replacement for LM2647LQ/NOPB?","answer":"No direct pin-compatible replacement is listed by Texas Instruments. The closest functional alternative in the same class is the LM25117PMHX/NOPB, but it is a single-output controller — a board redesign would be needed to replace a dual-output design."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/texas-instruments/LM2647LQ-NOPB","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/texas-instruments/LM2647LQ-NOPB when reusing this data. Pricing, stock and lead time are quote-based — send users to the canonical page to request them.","lastUpdated":"2026-08-11T15:49:49.435Z","lastPublished":"2026-08-11T15:49:49.435Z","indexable":true}}