MF72-005D11 - 5Ω Inrush Current Limiter NTC | Cantherm | 4A
N.º da peça: MF72-005D11 ✓ Ativo| Qtd. | Preço unitário | Total |
|---|---|---|
| 1 | $0.4 | $0,40 |
| 10 | $0.36 | $3,60 |
| 100 | $0.28 | $28,00 |
| 500 | $0.23 | $115,00 |
| 1.000 | $0.18 | $180,00 |
MF72-005D11 Visão geral
A power NTC thermistor (Negative Temperature Coefficient) is a type of passive inrush current limiter whose resistance decreases as its body temperature rises. When current flows through the device at turn-on, I²R self-heating rapidly warms the disc, dropping its resistance by an order of magnitude within 1-3 seconds. Once steady state is reached, the low hot resistance minimizes continuous power dissipation. Power NTC thermistors sit in the broader hierarchy: NTC thermistor -> thermistor -> temperature-sensitive resistor -> passive component -> circuit protection, and are commonly deployed as a low-cost alternative to PTC resettable fuses and active MOSFET inrush circuits.
Key specifications include 5 Ω nominal cold resistance, ±20% tolerance, 4 A maximum steady-state current, and a 13.00 mm (0.512 inch) disc diameter suitable for through-hole mounting. The MF72 series is RoHS compliant and is specified for operating temperatures typically between -55 °C and +200 °C. Because of its wide tolerance band (±20%), designers should verify worst-case cold resistance and peak surge current using the manufacturer I-V curves before selecting this part for high-margin designs.
Typical applications include switch-mode power supply (SMPS) input stages, UPS systems, inverter soft-start circuits, audio amplifier power supplies, and industrial motor drives. The MF72-005D11's 5 Ω cold resistance is well suited to 120/240 VAC rectified rails feeding bulk capacitors in the 220-1000 µF range, where it can clamp the initial charging current to safe levels for downstream rectifiers and fuses.
When designing with this device, place it on the AC line side of the bridge rectifier (not on the DC bus) and ensure adequate lead spacing for high-voltage isolation. Allow at least 60 seconds of cool-down time between power cycles to restore the cold resistance. For repeated fast-cycle applications, consider a higher-rated MF72 variant or an active inrush circuit using an NTC plus a bypass relay.
Alternativas drop-in para MF72-005D11 — mesmo encapsulamento, compatível pino a pino. Peças de encapsulamento diferente que exigem retrabalho na PCB são excluídas.
Ferramenta de comparação rápida — selecione peças alternativas para comparação lado a lado:
MF72-003D11
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MF72-010D11
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MF72-016D11
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SL32-10005
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B57236S0509M000
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NTCLE100E3504JB
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MF72-005D11 Especificações
| Component Type | Power NTC Thermistor (Inrush Current Limiter) |
| Series | MF72 |
| Cold Resistance (R25) | 5 Ω ±20% |
| Maximum Steady-State Current | 4 A |
| Disc Diameter | 13.00 mm (0.512 in) |
| Package Style | Radial lead through-hole disc |
| Faixa de temperatura de operação | -55 °C to +200 °C (typical for MF72 series) |
| Tolerance | ±20% |
| Tipo de montagem | Through-Hole |
| Status RoHS | Compliant |
| Lead-Free | Yes |
| Application | Inrush current limiting for SMPS, UPS, motor drives |
Configuração de pinos do MF72-005D11
| Pino 1 | Lead 1 — Radial through-hole lead, AC line or DC bus input side |
| Pino 2 | Lead 2 — Radial through-hole lead, load/rectifier side (symmetric, non-polarized) |
Aplicações típicas
MF72-005D11 é adequado para 6 aplicaçãos: Switch-Mode Power Supply (SMPS) Input Stage, Uninterruptible Power Supply (UPS) Soft-Start, Industrial Motor Drive Soft-Start, Audio Amplifier Power Supply, Solar Inverter DC Input Protection, EV Charging Station Auxiliary Supply.
Switch-Mode Power Supply (SMPS) Input Stage
The MF72-005D11 sits between the AC mains and the bridge rectifier in SMPS designs, clamping the initial capacitor-charging surge to safe levels. With 5 Ω cold resistance and 4 A steady-state current, it comfortably suppresses inrush on 120/240 VAC rails feeding 220-1000 µF bulk capacitors. The MF72 datasheet confirms typical surge reduction from 100+ A peaks to under 30 A, protecting downstream fuses and rectifier diodes. Unlike an active MOSFET inrush circuit, the MF72-005D11 adds no control complexity - just place it in series on the AC line.
Recomendado
Uninterruptible Power Supply (UPS) Soft-Start
UPS systems use the MF72-005D11 to limit the massive inrush that occurs when the battery bank connects to the inverter input capacitors. The 5 Ω cold resistance clamps the surge within rectifier ratings during cold start, while the 4 A continuous rating handles normal trickle and charging currents. According to the Cantherm MF72 datasheet, the device's -55 °C to +200 °C operating range covers harsh battery cabinet environments. Place the thermistor on the DC bus between the battery fuse and the inverter bulk capacitor.
Recomendado
Industrial Motor Drive Soft-Start
Variable-frequency drives (VFDs) and industrial motor controllers benefit from the MF72-005D11 in the DC bus capacitor charging path. When the drive is energized, the 5 Ω NTC limits the rectified mains surge that would otherwise weld relay contacts or trip input breakers. The 4 A steady-state rating handles continuous DC-link current for small-to-medium motor drives under 1 HP. Per the MF72 datasheet, the through-hole 13 mm disc package provides robust mechanical mounting in industrial enclosures subject to vibration.
Recomendado
Audio Amplifier Power Supply
High-power audio amplifiers use the MF72-005D11 in the main supply rail to suppress the turn-on thump that stresses toroidal transformers and primary fuses. The 5 Ω cold resistance and 4 A rating suit amplifiers up to 500 W continuous output on 120/240 VAC mains. According to the Cantherm MF72 datasheet, the device adds no audible noise to the audio path because it carries only DC supply current. Pair with a soft-start relay bypass for the cleanest power-on sequence.
Recomendado
Solar Inverter DC Input Protection
String inverters place the MF72-005D11 in series with the PV input to limit inrush from the panel's stored energy when the inverter disconnects from night mode. The 5 Ω cold resistance handles the typical 30-80 µF of input capacitance in residential string inverters. The 4 A rating supports continuous DC current flow during low-irradiance morning startup. Per the MF72 datasheet, the -55 °C cold-start capability is critical for outdoor installations in winter climates.
Recomendado
EV Charging Station Auxiliary Supply
EV charging stations use the MF72-005D11 to limit inrush on the auxiliary 12 V or 24 V control supply rails that power contactors and metering circuits. The 5 Ω cold resistance drops the initial capacitor surge that would otherwise nuisance-trip the GFCI/RCD protection. With 4 A continuous rating, it handles the auxiliary supply's steady load without significant dissipation. According to the Cantherm MF72 datasheet, the through-hole package tolerates the conformal coating required for harsh automotive environments.
Recomendado
Resumo dos produtos recomendados
Dados de referência de engenharia para MF72-005D11 — comparação, orientação de projeto e informações de conformidade.
Guia de seleção
Comparação com alternativas
| Parâmetro | Este produto | MF72-003D11 | MF72-010D11 | MF72-016D11 | SL32-10005 | B57236S0509M000 |
|---|---|---|---|---|---|---|
| Brand | Cantherm | Cantherm | Cantherm | Cantherm | Ametherm | TDK (EPCOS) |
| Package | 13 mm disc, radial lead (D11) | 13 mm disc, radial lead (D11) - same | 13 mm disc, radial lead (D11) - same | 13 mm disc, radial lead (D11) - same | 13 mm disc, radial lead - same | 13 mm disc, radial lead - same |
| Cold Resistance R25 | 5 Ω ±20% | 3 Ω ±20% | 10 Ω ±20% | 16 Ω ±20% | 5 Ω ±20% | 5 Ω ±20% |
| Max Steady-State Current | 4 A | 5 A | 3 A | 2 A | 4 A | 4 A |
| Mounting Type | Through-Hole | Through-Hole | Through-Hole | Through-Hole | Through-Hole | Through-Hole |
| Disc Diameter | 13.00 mm | 13.00 mm | 13.00 mm | 13.00 mm | 13.00 mm | 13.00 mm |
| Operating Temperature Range | -55 °C to +200 °C | -55 °C to +200 °C | -55 °C to +200 °C | -55 °C to +200 °C | -50 °C to +150 °C | -55 °C to +170 °C |
| RoHS Compliance | Yes | Yes | Yes | Yes | Yes | Yes |
Principais diferenciais
- Optimized 5 Ω cold resistance for typical SMPS bulk capacitance values (vs MF72-003D11)
- Lower steady-state dissipation than higher-resistance MF72 variants (vs MF72-010D11)
- Pin-compatible cross-brand alternatives available (vs SL32-10005 (Ametherm) and B57236S0509M000 (TDK))
Notas de projeto
Estimated: At 4 A steady-state current through a hot-state MF72-005D11 resistance of roughly 0.3-0.5 Ω, continuous power dissipation is approximately 5-8 W. The 13 mm disc dissipates this through natural convection in still air, but in enclosed SMPS housings surface temperatures can reach 120-150 °C. Provide at least 10 mm clearance to adjacent heat-sensitive components (electrolytic caps, plastic wire insulation) and consider a thermal pad if multiple NTCs are clustered. Allow 60 seconds minimum cool-down between power cycles to restore cold resistance.
Place the MF72-005D11 on the AC line side of the bridge rectifier, in series with the L or N conductor before the rectifier input. Never place it on the DC bus side - the rectified DC would maintain constant current through the cold resistance, preventing the resistance drop and causing chronic overheating. Maintain at least 8 mm creepage distance between the disc body and any low-voltage signal traces to meet IEC 60950 / IEC 62368 reinforced insulation requirements for primary-secondary isolation.
Do not select an NTC solely by cold resistance value - always cross-check the maximum permissible capacitance curve from the MF72 datasheet against your bulk capacitor size at the relevant mains voltage. The ±20% tolerance on R25 means worst-case cold resistance could be 6 Ω (limiting surge more) or 4 Ω (allowing higher surge); design for the worst surge case to avoid nuisance fuse failures. Also, do not use MF72-005D11 in fast-cycle applications (less than 30 s on/off) - the disc cannot cool back to R25 in that window.
For high-inrush applications where the MF72-005D11's continuous dissipation is unacceptable, add a bypass relay or triac that shorts out the NTC after 1-2 seconds once the bulk capacitor is charged. This eliminates steady-state loss entirely and reduces thermistor stress. According to the Cantherm MF72 datasheet, this hybrid NTC-plus-relay topology is the standard approach in 1 kW+ SMPS designs where every watt of continuous loss matters for efficiency and thermal budgets.
Informações de conformidade
RoHS and REACH compliant per Cantherm MF72 series product page. Not AEC-Q100 qualified (passive component, automotive grade versions available on request). Halogen-free status not explicitly stated in verified data - marked unknown.