Point: Bench-measured curves and spec comparisons show where the 784770102 SMD power inductor meets high-current buck converter needs and where derating is required.
Evidence: this spec report combines datasheet fields, measured L(f), L(ID) and DCR(T) guidance.
Explanation: designers gain a reproducible test plan and pass/fail criteria to qualify the part for production.
Point: The objective is actionable data: confirm electrical curves, thermal behavior and usable continuous current for the 784770102 SMD power inductor.
Evidence: suggested long-tail keywords for traceability include “784770102 inductance vs frequency curve”, “784770102 saturation current curve”, “SMD power inductor DCR vs temperature”.
Explanation: these terms help index the CSV deliverables in the BOM.
(1) Background & Key Specifications for 784770102
Specification breakdown (part-level quick reference)
Point: A compact spec list helps engineers compare published numbers versus measured results. Evidence: typical measured/typical example values are below to convert into a formal verification table. Explanation: always replace example values with datasheet or lab-verified numbers prior to approval.
| Parameter | Example Value (typ) |
|---|---|
| Inductance nominal (µH) | 10 µH |
| Tolerance | ±20% |
| DCR (Ω) typical / max | 0.025 / 0.035 Ω |
| Rated IDC (continuous) | 10 A |
| Isat (1% L drop) | 25 A |
| SRF | ~30 MHz |
| Operating temp range | -40 °C to +125 °C |
| Package size | 10.0 × 8.0 × 4.0 mm (1008/2520 metric) |
| Mounting type | SMD, top-side reflow |
Terms & units explained for quick reading
Point: Clear metric definitions avoid misinterpretation. Evidence: DC bias describes L drop with ID; Isat is the current where L falls to a specified percent; SRF marks self-resonance where inductance becomes reactive. Explanation: check ambient temp and test frequency on datasheets before comparing to lab curves.
(2) Electrical Characteristic Curves — Inductance, Frequency & Q
Inductance vs frequency curve (what to measure and interpret)
Point: L(f) reveals usable inductance through the switching band and parasitic resonances. Evidence: measure with an impedance analyzer over kHz to tens of MHz, average multiple samples and report median curve. Explanation: identify the flat region for switching frequency and flag SRF approach where L falls rapidly.
Q factor, impedance and SRF interpretation
Point: Q and impedance separate core loss from winding loss. Evidence: derive Q = Xl / R from measured series data across frequency and identify SRF where Xl crosses capacitive behavior. Explanation: plot Q(f) and |Z|(f) to show margin between converter switching frequency and SRF for reliable operation.
(3) Current Handling: DC Bias, Saturation & Thermal Effects
Inductance vs DC current (L vs ID) and saturation curve
Point: L vs ID defines usable current range; saturation reduces inductance and increases ripple. Evidence: use stepwise DC bias (0→rated→above) with L measured at converter frequency or low test frequency, then plot %L drop vs ID. Explanation: set continuous IDC at the point where L drop remains acceptable (commonly 10–20% derating below Isat specification).
DCR, temperature coefficient and thermal derating
Point: DCR determines I²R losses which increase with temperature. Evidence: measure DCR at room temp and elevated temps (e.g., +25 °C, +85 °C) using four-wire technique, then compute I²R loss curves. Explanation: apply thermal rise tests to set continuous current derating to keep winding and core below safe limits.
(4) Measurement Methods & Test Setup (reproducibility & reporting)
Recommended equipment, fixtures and calibration notes
Point: Accurate curves require low-stray fixtures and calibration. Evidence: use an impedance analyzer or precision LCR meter, DC bias source with current sensing, and thermocouple or thermal camera for hotspot mapping. Explanation: document fixture layout, short/open calibration and sample size (≥5 parts) to quantify manufacturing variability.
Standardized test procedures & data presentation
Point: Standard steps improve reproducibility and comparison. Evidence: save raw CSV files for each sweep (frequency, L, R, phase), annotate test conditions (ambient, fixture, sample ID). Explanation: present plots with log-frequency axes for wideband data and tabulate key points (L at fsw, Isat, SRF, DCR at temp points).
(5) Application Examples & Performance Trade-offs
Buck converter case study (practical performance expectations)
Point: Use measured curves to estimate inductor loss and ripple in a synchronous buck. Evidence: calculate AC ripple L-based current ripple and I²R plus core loss estimates from measured L(f) and DCR(T). Explanation: choose part value and derated IDC so ripple, efficiency and thermal rise remain within system margins.
EMI, layout impact and interaction with capacitors
Point: Inductor selection affects EMI and decoupling needs. Evidence: minimize loop area between inductor and capacitor, use short traces and multiple vias, and select caps with low ESL near the switch node. Explanation: document placement rules and recommended via patterns in the spec report for consistent EMC performance.
(6) Design & Spec-Report Checklist — How to Present 784770102 Findings
Engineering checklist for BOM & selection
Point: A concise verification checklist speeds approval. Evidence: attach measured curves (L(f), L(ID), DCR(T), SRF), thermal images, and a verified spec table with pass/fail limits. Explanation: specify acceptance criteria for production sampling and note procurement tolerances to avoid surprise variation.
Layout, derating & replacement guidance
Point: Document layout and derating rules to preserve performance in production. Evidence: include pad dimensions, recommended clearance, continuous vs pulsed current derating percentages, and candidate alternates with margin. Explanation: maintain a controlled list of replacements with equivalence notes for long-term sourcing.
