4448-128L - 100uH 15% High Current Molded SMT Inductor | API Delevan
MPN: 4448-128L β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $7.73 | $7.73 |
| 10 | $7.16 | $71.60 |
| 100 | $6.61 | $661.00 |
| 500 | $6.11 | $3,055.00 |
| 1,000 | $5.66 | $5,660.00 |
Drop-in alternatives for 4448-128L β same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
4448R-128L
β Drop-Inπ Reference alternative (not in catalog)
4448-128L-Q
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
4448-128L Maximum Ratings & Electrical Characteristics
| Inductance | 100 uH |
| Inductance Tolerance | 15% |
| DC Resistance (DCR) | 0.303 ohm |
| Product Type | Coupled / Fixed Power Inductor (High Current Molded SMT Toroid) |
| Family | 4448 Surface Mount High Current Power Toroids |
| Mounting Type | Surface Mount |
| Construction | Molded toroid |
| Shielding | Toroid construction (low stray flux) |
| AEC-Q100 Status | Not applicable (passive inductor) |
4448-128L standard Pin Configuration Guide
Complete pinout information for 4448-128L (standard package). Learn about pin numbering, functions, and connection diagrams. Refer to the manufacturer datasheet for exact footprint and soldering guidelines. Common applications include circuit design and PCB assembly.
No detailed pinout data available for 4448-128L.
Refer to the datasheet for full pin configuration.
Safe Operating Area (SOA) & Thermal Characteristics
No official SOA curve available for this component. Always operate within absolute maximum ratings specified in the datasheet. Ensure adequate cooling and derate as needed.
Typical Applications
4448-128L is suitable for 6 applications: Switching Power Supply Output Filtering, DC-DC Converter Energy Storage, EMI Differential-Mode Filtering, Industrial Power and Control Boards, Test and Measurement Instrumentation, Battery-Powered and Portable Power Stages.
Switching Power Supply Output Filtering
The 4448-128L's 100 uH inductance and low 0.303 ohm DCR make it well suited as an output choke in switching power supplies. In a buck or forward converter output stage, the inductor works with the output capacitor to set the LC corner frequency and smooth the switched current waveform into a low-ripple DC rail. The 15% inductance tolerance keeps the filter corner frequency consistent across production lots, which simplifies loop compensation design. The toroidal geometry confines magnetic flux inside the core, so radiated fields that could couple into nearby analog circuitry are minimized. Because the part is a molded SMT toroid, it withstands pick-and-place handling and reflow without winding deformation. Designers should verify the DC bias current against the datasheet ratings, since inductance rolls off as the core approaches saturation.
Recommended
DC-DC Converter Energy Storage
In DC-DC converters, the power inductor is the central energy-transfer element: it stores energy while the switch is on and releases it to the load during the off period. The 4448-128L's 100 uH value suits moderate-frequency converters where a larger inductance reduces ripple current at the cost of slower transient response. Its 0.303 ohm DCR keeps conduction losses bounded; as an estimate, at 1 A of average current the winding dissipates roughly 0.3 W (I^2 x R), so the thermal budget must be checked at the maximum load. The molded SMT construction supports automated assembly in volume production, and the toroid's low stray flux permits placement near control circuitry without shield cans. Always confirm the saturation current from the API Delevan 4448 series datasheet before fixing the switching frequency and current ripple ratio.
Recommended
EMI Differential-Mode Filtering
The 4448-128L functions as a differential-mode choke in EMI input and output filters, where it presents high impedance to switching-frequency ripple while passing DC load current with minimal loss. A 100 uH value combined with X- and Y-capacitors forms an effective low-pass filter that attenuates conducted emissions from switch-mode sources before they reach the mains or a backplane. The 0.303 ohm DCR limits voltage drop in the power path, an important consideration at multi-ampere loads. Because the toroid construction has little radiated leakage flux, the filter inductor can sit close to other magnetics on a crowded PCB without unintended magnetic coupling. The 15% tolerance ensures repeatable filter attenuation across production, supporting consistent EMC pre-compliance results between design and manufacturing lots.
Recommended
Industrial Power and Control Boards
Industrial control equipment places magnetics under vibration, thermal cycling, and dust exposure. The 4448-128L's molded body encapsulates the toroidal winding, protecting it from mechanical stress and contamination that could shift inductance or abrade the wire insulation. With 100 uH at 15% tolerance and 0.303 ohm DCR, it suits local power conditioning on PLC I/O cards, motor-drive auxiliary supplies, and sensor power rails where a compact SMT magnetics solution is preferred over through-hole toroids. The surface-mount format enables automated assembly and consistent solder joints across high-volume industrial production. Designers operating in high-ambient-temperature enclosures should verify the part's temperature rating and current derating from the API Delevan datasheet, since enclosure temperatures of 70 C or more reduce allowable dissipation.
Recommended
Test and Measurement Instrumentation
Bench power supplies, electronic loads, and measurement instruments need power inductors that combine low DCR with predictable inductance, because both output ripple and control-loop behavior depend on the magnetics. The 4448-128L's 15% tolerance and 100 uH value let instrument designers forecast the converter ripple current and output impedance with confidence, while the 0.303 ohm DCR limits load-dependent voltage sag. The toroid's confined flux prevents magnetic coupling into high-impedance measurement front ends, preserving low-noise performance in sensitive acquisition paths. Molded SMT construction also supports compact, reflow-assembled instrument boards. For designs where measurement accuracy depends directly on supply cleanliness, pairing this inductor with a post-regulator LDO stage further suppresses switching ripple below the instrument's noise floor.
Recommended
Battery-Powered and Portable Power Stages
In battery-operated equipment, every milliohm of series resistance shortens runtime, so the 4448-128L's 0.303 ohm DCR is a meaningful efficiency parameter in the power path. Its 100 uH inductance supports converter topologies with moderate switching frequencies that favor efficiency over small size, a common trade in portable instruments and battery-backed industrial devices. The molded toroid resists the mechanical shock and vibration typical of handheld or vehicle-mounted equipment. Low stray flux also matters in portable designs where radios, sensors, and displays are packed closely around the power stage. Verify the part's current rating against the battery discharge profile, including peak inrush during power-up, using the ratings published in the API Delevan 4448 series datasheet.
Recommended
Recommended Products Summary
Engineering reference data for 4448-128L β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | 4448R-128L | 4448-128L-Q |
|---|---|---|---|
| Brand | API Delevan | API Delevan | API Delevan |
| Package | 4448 molded SMT toroid | 4448 molded SMT toroid - same | 4448 molded SMT toroid - same |
| Inductance | 100 uH | 100 uH | 100 uH |
| Inductance Tolerance | 15% | 15% | [DATA_NEEDED] |
| DC Resistance | 0.303 ohm | 0.303 ohm | [DATA_NEEDED] |
| Rated Current | [DATA_NEEDED] | [DATA_NEEDED] | [DATA_NEEDED] |
| Construction | Molded SMT toroid, high current | Molded SMT toroid, high current | Molded SMT toroid |
| Unit Price (qty 1) | $7.73 (LCSC, as of 2026-09-04) | [DATA_NEEDED] | [DATA_NEEDED] |
Key Differentiators
- Tight 15% inductance tolerance (vs generic 100 uH SMD power inductors)
- Low 0.303 ohm DCR in a molded package (vs 4448R-128L)
- Molded toroid construction with low stray flux (vs drum-core SMD inductors)
Design Notes
The 4448-128L has a DC resistance of 0.303 ohm, so conduction loss is a first-order design constraint. Estimated: at 1 A continuous the winding dissipates about 0.3 W; at 2 A it dissipates about 1.2 W, which in a small molded SMT toroid produces a significant temperature rise. Compute your I^2R loss at worst-case load, add core loss from the switching ripple, and verify the total against the datasheet current and temperature ratings before releasing the design. If the loss budget is exceeded, consider a lower-DCR part number in the 4448 family or parallel magnetics.
The 4448 footprint is a proprietary molded SMT toroid outline, not a JEDEC standard package, so create the PCB land pattern directly from the API Delevan 4448 series datasheet drawing rather than from a generic library footprint. Place the inductor so the high di/dt loop (input capacitor, switch node, inductor, output capacitor) is as short as possible. Pour a solid ground plane beneath the part for thermal spreading, but keep sensitive analog return currents out of that region to avoid magnetically induced noise pickup.
Toroid power inductors fail primarily by saturation and by thermal aging, not by open circuit. Inductance falls sharply as DC bias approaches the saturation current, which increases ripple current and can trigger overcurrent faults in the converter. Confirm the saturation current from the manufacturer datasheet, and in production do not substitute visually similar toroids with different core materials - the same 100 uH value in a different core can saturate far earlier. Also confirm RoHS status documentation before using the part in restricted-market products.
Compliance Information
Compliance status was not stated in the retrieved data. Verify RoHS/REACH status on the official API Delevan datasheet or request a material declaration from the manufacturer or distributor.
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