BLM21PG221SN1D - 220 Ohm 2A Ferrite Bead 0805 | Murata
Артикул: BLM21PG221SN1D ✓ Активен| Кол-во | Цена за ед. | Итого |
|---|---|---|
| 1 | $0 | $0,00 |
| 10 | $0 | $0,00 |
| 100 | $0 | $0,00 |
| 500 | $0 | $0,00 |
| 1.000 | $0 | $0,00 |
BLM21PG221SN1D Обзор
A chip ferrite bead is a passive EMI suppression component in the inductor family that behaves resistively at high frequencies while presenting near-zero impedance at DC. Unlike a conventional inductor, the BLM series is designed to function nearly as a resistor at noise frequencies, which greatly reduces the possibility of resonance and leaves signal waveforms undistorted. Within the power management signal chain, ferrite beads sit between a power source and a noise-sensitive load to attenuate conducted high-frequency noise.
Key features of the BLM21PG221SN1D include the high 2 A DC current rating for power line filtering, the low 45 mOhm DC resistance that minimizes voltage drop and power loss on supply rails, and the dense 220 ohm impedance at 100 MHz for effective suppression of radiated and conducted emissions. The nickle-barrier terminal construction provides excellent solderability and reliability in reflow assembly.
Technically, the ferrite material used in this bead has low Q characteristics, so the resistive element becomes dominant at high frequencies; the absorbed noise is dissipated as heat rather than reflected or reradiated. This is why the BLM series is preferred over wire-wound chip inductors for broadband EMI attenuation on DC power lines such as those feeding microcontrollers, PLLs, and interface ICs.
Typical applications include DC power line noise suppression for microcontroller boards, EMI countermeasures on USB and communication ports of industrial equipment, and supply-rail filtering in consumer and automotive electronics. The 0805 (2012 metric) footprint is compatible with standard pick-and-place assembly and offers a good balance of current capacity and board area.
When designing with this bead, remember that the impedance spec applies at 100 MHz; the effective attenuation depends on the source and load impedances of the filter network, and DC bias current reduces the actual impedance below the zero-bias datasheet curve. Allow margin on the 2 A rating in high-ripple environments.
This page synthesizes distributor availability, drop-in alternatives, and practical design notes not found in the manufacturer datasheet.
Аналоги без доработки для BLM21PG221SN1D — тот же корпус, pin-to-pin совместимость. Компоненты в других корпусах, требующие переработки PCB, исключены.
Инструмент быстрого сравнения — выберите альтернативные компоненты для сравнения бок о бок:
BLM21PG221SN1L
✅ Прямая замена📋 Справочный аналог (нет в каталоге)
BLM21PG221SN1
✅ Прямая замена ⚠️ Характеристики не проверены📋 Справочный аналог (нет в каталоге)
742792022
✅ Прямая замена📋 Справочный аналог (нет в каталоге)
BLM21PG221SN1D Максимальные параметры и электрические характеристики
| Impedance @ 100 MHz | 220 Ohm (25% tolerance) |
| Rated DC Current | 2 A |
| Max DC Resistance (DCR) | 45 mOhm |
| Категория | Power Line Ferrite Bead (1 line) |
| Корпус / Типоразмер | 0805 (2012 Metric) |
| Тип монтажа | Surface Mount (SMD) |
| Height (Max) | 1.05 mm |
| Size / Dimension | 2.0 mm x 1.25 mm |
| Рабочая температура | -55C to +125C |
| Filter Type | EMIFIL Chip Ferrite Bead, Inductor Type |
| Frequency Characteristic | Resistive element dominant at high frequencies |
| Terminal Finish | Ni-Sn plated electrodes |
| Test Frequency | 100 MHz |
| Tolerance | +/-25% |
| Статус RoHS | Compliant (RoHS Y per distributor data) |
| Application Domain | DC power line noise suppression / EMI countermeasures |
Конфигурация выводов BLM21PG221SN1D
| Контакт 1 | Terminal 1 — Non-polarized ferrite bead terminal; series connection in the power line |
| Контакт 2 | Terminal 2 — Non-polarized ferrite bead terminal; series connection in the power line |
Типичное применение
BLM21PG221SN1D подходит для 6 применениеs: Microcontroller Power Rail Filtering, USB Port EMI Countermeasures, Analog and Audio Signal Chain Supply Isolation, Industrial Equipment Conducted EMI Suppression, Clock and PLL Supply Noise Reduction, Consumer and Automotive Electronics Noise Filtering.
Microcontroller Power Rail Filtering
The BLM21PG221SN1D is a standard choice for cleaning supply rails feeding MCU cores, I/O banks, and on-chip oscillators. Its 220 ohm impedance at 100 MHz attenuates switching noise conducted between a shared supply and sensitive digital loads, while the 45 mOhm maximum DC resistance keeps rail droop negligible at typical MCU currents well below the 2 A rating. Placed between the regulator output and the MCU supply pin with 10 uF bulk and 100 nF local decoupling capacitors, the bead forms an effective low-pass filter for the 30 MHz to 300 MHz band where radiated emission limits apply. Because the BLM series behaves resistively at noise frequencies, it avoids resonance with decoupling capacitors that a high-Q inductor would create.
Рекомендуется
USB Port EMI Countermeasures
On USB VBUS and cable-side power lines, the BLM21PG221SN1D suppresses common-mode and conducted noise that would otherwise radiate from the cable. The 2 A current rating covers the USB 500 mA and USB 900 mA budgets with ample margin, and the low 45 mOhm DCR preserves the 5 V rail within the USB voltage-drop specification even at full load. The 220 ohm impedance at 100 MHz provides strong attenuation in the frequency range scrutinized by CISPR-style radiated emissions testing. Best practice is to place the bead immediately at the connector with a decoupling capacitor on the device side, forming a two-stage filter that also protects the downstream transceiver IC from cable-borne transients.
Рекомендуется
Analog and Audio Signal Chain Supply Isolation
Audio codecs, precision amplifiers, and data converters are highly sensitive to supply-borne digital noise. The BLM21PG221SN1D isolates the analog supply island from the noisy digital rail: its 220 ohm impedance at 100 MHz blocks switching-regulator ripple and clock harmonics, while the resistive-dominant characteristic dissipates the noise as heat instead of reflecting it back into the rail. With a 45 mOhm DCR, the DC voltage offset introduced into the analog rail is negligible even at hundreds of milliamps of load. Pair the bead with quality decoupling at the converter AVDD pin, and keep analog return current paths away from the digital ground to preserve the isolation benefit across the full 30 MHz to 1 GHz suppression band.
Рекомендуется
Industrial Equipment Conducted EMI Suppression
Industrial controllers, motor drives, and factory automation electronics must meet conducted emission limits on their power inputs and communication ports. The BLM21PG221SN1D is inserted in the supply lines of interface and control circuitry to attenuate noise generated by switching converters and motor commutation, with its -55C to +125C operating range supporting industrial cabinets and unconditioned environments. The 2 A rating accommodates multiple auxiliary loads behind a single bead, simplifying the EMI design. Because the bead adds no DC regulation complexity, it is often combined with a TVS diode and bulk capacitor at the entry point to build a robust, low-cost input filter stage that passes EMC pre-compliance on the first iteration.
Рекомендуется
Clock and PLL Supply Noise Reduction
Phase-locked loops, clock generators, and crystal oscillators translate supply noise directly into timing jitter, degrading high-speed serial links and ADC sampling performance. The BLM21PG221SN1D forms an RC-style low-pass filter with the PLL supply pin capacitance, using its 220 ohm impedance at 100 MHz to attenuate controller bus noise before it reaches the oscillator supply. The low 45 mOhm DC resistance ensures the clean rail stays within the PLL supply tolerance, and the resistive-dominant ferrite characteristic prevents the bead and pin capacitance from forming a resonant peak at mid-band frequencies, which is a known failure mode when high-Q inductors are used for the same purpose. Verify attenuation at the actual DC bias for jitter-critical designs.
Рекомендуется
Consumer and Automotive Electronics Noise Filtering
Set-top boxes, displays, in-vehicle infotainment, and body-control modules deploy the BLM21PG221SN1D across many rails to tame broadband noise from LCD backlights, wireless modules, and switching supplies. The 0805 (2012 metric) footprint fits dense consumer layouts and supports standard reflow assembly with Ni-Sn plated electrodes providing reliable solder joints. With the -55C to +125C temperature range and RoHS compliance, the bead suits both cost-driven consumer designs and harsher automotive cabin environments where EMC qualification of submodules is required. Murata's application guidance recommends grouping beads per functional block - radio, display, and controller - so each noisy load is filtered locally rather than at a shared, high-current point.
Рекомендуется
Сводка рекомендуемых товаров
Справочные инженерные данные для BLM21PG221SN1D — сравнение, рекомендации по проектированию и информация о соответствии.
Руководство по выбору
Сравнение с аналогами
| Параметр | Этот товар | BLM21PG221SN1L | BLM21PG221SN1 | 742792022 |
|---|---|---|---|---|
| Package | 0805 (2012 Metric) | 0805 (2012 Metric) - same | 0805 (2012 Metric) - same | 0805 (2012 Metric) - same |
| Brand | Murata Manufacturing | Murata Manufacturing | Murata Manufacturing | Wurth Elektronik |
| Drop-in Compatibility | Reference part | 100% - same electricals, same footprint | 100% - same electricals, same footprint | Same footprint; verify impedance curve |
| RoHS Compliance | Compliant | Compliant | Compliant | Compliant |
Ключевые отличия
- High current with low DCR in 0805 (против 742792022)
- Resonance-free resistive characteristic (против Generic high-Q 0805 chip inductors)
- Family packaging flexibility (против BLM21PG221SN1L)
Заметки по проектированию
Size the bead with current margin: the BLM21PG221SN1D is rated 2 A, but its 220 ohm impedance at 100 MHz is a zero-bias specification. As DC bias approaches the rating, the ferrite saturates and effective impedance drops substantially. A common rule of thumb is to select a bead rated at least twice the maximum continuous rail current so the datasheet attenuation is preserved. Also compute DC drop as I x 45 mOhm (e.g. 90 mV at 2 A) and confirm the downstream load tolerance. Source: Murata BLM21 series datasheet application guidance.
Place the BLM21PG221SN1D directly at the entry point or at the noisy load's supply pin, with the decoupling capacitor on the quiet side of the bead - not between the bead and the noise source. Keep the bead's loop area small by routing the filtered trace short and wide (0805 footprint supports 30-40 mil traces at 2 A without excessive heating). Do not route other noisy signals under or beside the bead, since the ferrite can couple magnetic field noise into the filtered node and defeat the suppression.
Do not treat the 220 ohm figure as the attenuation value: insertion loss depends on source and load impedance, roughly 20*log10(1 + Zbead/(Zsource+Zload)). Against a 1 ohm source and a decoupled load, 220 ohms yields ~47 dB of ideal attenuation at 100 MHz, but less at lower frequencies where bead impedance is small. Avoid cascading a bead with an inductive regulator output without checking for peaking; the resistive-dominant BLM ferrite minimizes this risk versus high-Q inductors, per Murata's datasheet.
Информация о соответствии
RoHS Y per distributor (PartGenie) compliance data. REACH, halogen-free, and conflict-minerals status were not stated in the verified data.
