{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"LQH43NN120K03L","brand":"Murata Electronics","brandSlug":"murata-electronics","productSlug":"LQH43NN120K03L","canonicalUrl":"https://icboms.com/murata-electronics/LQH43NN120K03L","factsUrl":"https://icboms.com/api/mcp/products/LQH43NN120K03L","rawCanonicalId":null},"summary":{"shortDescription":"Murata Electronics LQH43 series, Drum Core Wirewound Inductor, 12 µH, ±10%, 380 mA, 620 mOhm DCR, Unshielded, 1812 (4532 Metric), -40°C to 105°C.","salesMarkdown":"## 12 µH at 380 mA — DC bias and conduction loss trade-off The LQH43NN120K03L is a 12 µH unshielded wirewound inductor in the Murata LQH43 series, built on a ferrite drum core. The 380 mA current rating is the DC bias limit where the inductance typically drops by 10% — beyond this the core enters saturation and the effective inductance falls off sharply, so the design should derate to ~300 mA for a 20% margin on the bias point. The 620 mOhm maximum DCR sets the I²R conduction loss: at 380 mA the self-heating is 89 mW, which at 105°C ambient leaves roughly 15°C of temperature rise before hitting the ferrite Curie point. For a power rail filter the DCR voltage drop — 236 mV at full rated current — must be budgeted into the converter's output regulation loop. ## Q factor and self-resonant ceiling A Q of 35 at 1 MHz means the inductive reactance is 35 times the effective series resistance at that frequency — the inductor behaves as a low-loss element in resonant tank circuits or band-pass filters near 1 MHz. Above 21 MHz the self-resonant frequency the parasitic capacitance between windings dominates and the part looks capacitive; it cannot be used as an inductor above that ceiling. The unshielded construction means the external magnetic field is not contained by a ferrite shield — adjacent traces or components within ~2 mm will see eddy-current coupling. For a DC-DC converter input filter the unshielded field can inject ripple into nearby analog signal paths; a shielded variant from the same LQH43 family is the better choice when board density forces tight coupling. ## 1812 footprint and reflow integration The ferrite core is brittle; the recommended pad geometry uses a 0.5 mm solder-paste aperture reduction on each end to prevent tombstoning during reflow, and the peak reflow temperature should not exceed 260°C for 10 seconds per the Murata soldering profile. Tape-and-reel packaging (Cut Tape also available) means the part feeds into a standard 8 mm carrier tape for automated pick-and-place. The 1812 package requires a 0.5 mm nozzle for the placement head. For engine-bay deployments above 105°C ambient a higher-temperature-grade inductor from Murata's LQH series would be required.","metaTitle":"Murata LQH43NN120K03L 12 µH Unshielded Wirewound Inductor","metaDescription":"Murata LQH43NN120K03L drum core wirewound inductor, 12 µH ±10%, 380 mA, 620 mOhm DCR, unshielded, 1812 package, -40°C to 105°C.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Active","categoryPath":["Inductors & Chokes"],"specifications":{"Mfr":"Murata Electronics","Type":"Drum Core, Wirewound","Series":"LQH43","Package":"Tape & Reel (TR) Cut Tape (CT)","Ratings":"-","Q @ Freq":"35 @ 1MHz","Shielding":"Unshielded","Tolerance":"±10%","Inductance":"12 µH","Mounting Type":"Surface Mount","Package / Case":"1812 (4532 Metric)","Product Status":"Active","Material - Core":"Ferrite","lifecycle_stage":"unknown","Size / Dimension":"0.177\\\" L x 0.126\\\" W (4.50mm x 3.20mm)","Base Product Number":"LQH43NN","DC Resistance (DCR)":"620mOhm Max","Current Rating (Amps)":"380 mA","Height - Seated (Max)":"0.110\\\" (2.80mm)","Operating Temperature":"-40°C ~ 105°C","Supplier Device Package":"1812 (4532 Metric)","Frequency - Self Resonant":"21MHz","Current - Saturation (Isat)":"-","Inductance Frequency - Test":"1 MHz"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$0.2818","stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.icboms.com/d0d6b1d39c76e30b3c05600906460c39.pdf","sourceUrl":null},"ai":{"faq":[{"question":"What is the DC resistance and why does it matter?","answer":"The maximum DCR is 620 mOhm. This resistance causes I²R power loss (89 mW at rated current) and a voltage drop of 236 mV at 380 mA, which must be accounted for in the power supply regulation loop."},{"question":"What is the self-resonant frequency and how does it affect circuit design?","answer":"The self-resonant frequency is 21 MHz. Above this frequency the inductor behaves capacitively due to inter-winding capacitance, so it cannot be used as an inductor in circuits operating above 21 MHz."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/murata-electronics/LQH43NN120K03L","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/murata-electronics/LQH43NN120K03L 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}}