MF72-010D9 - 10Ω 2A Power NTC Inrush Current Limiter | Cantherm
N.º de pieza: MF72-010D9 ✓ Activo| Cant. | Precio unitario | Total |
|---|---|---|
| 1 | $0.4 | $0,40 |
| 5 | $0.39 | $1,95 |
| 10 | $0.379 | $3,79 |
| 50 | $0.319 | $15,95 |
| 100 | $0.264 | $26,40 |
| 250 | $0.24 | $60,00 |
| 500 | $0.204 | $102,00 |
| 1.000 | $0.18 | $180,00 |
| 5.000 | $0.162 | $810,00 |
MF72-010D9 Descripción general
A power NTC thermistor (Negative Temperature Coefficient thermistor) is a type of inrush current limiting device whose resistance decreases sharply as its body temperature rises. When power is first applied to a capacitive load, the cold thermistor presents a high initial resistance that absorbs the charging surge; once steady-state current flows, self-heating drives the resistance down to a low residual value, minimizing continuous power dissipation. This class of component sits within the broader hierarchy of circuit protection devices, between simple resistors and active solid-state soft-start circuits.
Key features of the MF72-010D9 include 10 ohm nominal resistance at 25 °C with ±20% tolerance, a 2 A steady-state maximum current rating, 0.458 ohm residual resistance at rated current, 11.00 mm (0.433 inch) disk diameter, and 7.50 mm (0.295 inch) lead spacing. The through-hole radial leaded package is supplied in bulk packaging. Operating principle is purely passive: the ceramic semiconductor material self-heats under load, reducing resistance to a small fraction of the cold resistance and therefore limiting continuous power loss.
Typical applications include switch-mode power supply (SMPS) input protection, AC-DC converter soft-start, motor drive inrush limiting, audio amplifier power sequencing, and battery charging systems where high peak currents could damage rectifier bridges or fuse components. The MF72 series is a long-established industry-standard form factor used globally in low-to-medium power offline power designs.
When designing with the MF72-010D9, verify that the steady-state load current never exceeds the 2 A rating once the thermistor has reached its hot equilibrium resistance. Place the device on the AC side (line or neutral) of the supply, ahead of the bulk capacitor, and ensure adequate lead-form stress relief. For higher surge energy or continuous-current applications, choose a larger diameter from the same series rather than paralleling two thermistors, which can create current-sharing instability.
Alternativas directas para MF72-010D9 — mismo encapsulado, compatible pin a pin. Se excluyen las piezas de otro encapsulado que requieren retrabajo de la PCB.
Herramienta de comparación rápida — seleccione piezas alternativas para compararlas lado a lado:
MF72-010D11
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
MF72-010D13
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
MF72-010D25
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
SL12-10009
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
B57238S0100M
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
NTC10D-9
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
MF72-010D9 Especificaciones
| Component Type | Power NTC Thermistor (Inrush Current Limiter, ICL) |
| Resistance @ 25 °C | 10 Ω |
| Tolerance | ±20% |
| Steady-State Current Max | 2 A |
| Resistance @ Max Current | 0.458 Ω |
| Diameter | 11.00 mm (0.433 in) |
| Lead Spacing | 7.50 mm (0.295 in) |
| Lead Style | Radial, through-hole |
| Packaging | Bulk |
| Operating Principle | Passive NTC self-heating resistance drop |
| Tipo de montaje | Through-Hole (THT) |
| Estado RoHS | Compliant (per distributor listings) |
| Lead Free | Yes (per distributor listings) |
| Manufacturer Series | MF72 |
| Datasheet Document Type | Cantherm MF72 Power NTC Thermistor datasheet |
Configuración de pines de MF72-010D9
| Pin 1 | Lead 1 — Input (line side, AC mains or DC+) |
| Pin 2 | Lead 2 — Output (load side, toward rectifier/bulk capacitor) |
Aplicaciones típicas
MF72-010D9 es adecuado para 6 aplicacións: Switch-Mode Power Supply (SMPS) Inrush Protection, AC-DC Converter Soft-Start, Motor Drive Inrush Limiting, Audio Amplifier Power Sequencing, Battery Charger Input Protection, Industrial Control Panel Surge Limiting.
Switch-Mode Power Supply (SMPS) Inrush Protection
The MF72-010D9 sits between the AC line and the bulk input capacitor of offline switch-mode power supplies, providing inrush current suppression during the first few power cycles. Its 10 Ω cold resistance at 25 °C limits the initial charging surge to a safe level, protecting the bridge rectifier and input fuse from peak currents that can exceed 100 A in unprotected designs. Once the bulk capacitor charges and steady-state current flows, self-heating drives the device resistance down to ~0.458 Ω, minimizing continuous conduction loss to roughly 1.83 W at the 2 A rating. Designers should size upstream fuses assuming the cold-resistance-limited inrush profile, not the steady-state current.
Recomendado
AC-DC Converter Soft-Start
In AC-DC converter front-ends from 50 W to 250 W, the MF72-010D9 provides a passive, zero-standby-power alternative to active MOSFET inrush circuits. Placed in series with the AC line ahead of the bridge rectifier, the device's 10 Ω cold resistance limits the capacitor charging spike to roughly 10-20 A even from a worst-case 264 VAC input. The ±20% tolerance on cold resistance is acceptable because the downstream bulk capacitor and bridge rectifier are typically rated for substantial surge. The purely passive design eliminates the auxiliary supply and start-up sequencing required by active limiters, reducing BOM cost and complexity for cost-sensitive consumer and industrial designs.
Recomendado
Motor Drive Inrush Limiting
Small universal motors and single-phase induction motors draw very high inrush currents at start-up, which can trip protection circuits and stress relay contacts. The MF72-010D9, connected in series with the motor supply, presents its cold 10 Ω resistance at the moment of switch-on, reducing the start-up surge by 80-90% compared to an un-protected switching event. After the motor reaches running speed and the current drops to its steady value, self-heating drops the thermistor resistance to its hot equilibrium, leaving only modest additional loss in the running motor circuit. For motor ratings above 250 W or frequent start-stop cycles, a larger-diameter MF72 variant is recommended for thermal margin.
Recomendado
Audio Amplifier Power Sequencing
Audio power amplifiers with large bulk reservoir capacitors (typically 10,000 µF and above) can demand multi-hundred-ampere inrush surges when the mains is first connected. The MF72-010D9 limits this inrush to manageable levels, protecting the amplifier's fuse and relay contacts and preventing nuisance trips of upstream breakers. The passive NTC solution is favored over relay-based pre-charge circuits in cost-sensitive consumer audio because it requires no control logic and dissipates only ~1.83 W at 2 A continuous. Place the device in series with the mains line before the toroidal transformer primary to limit the secondary-side surge as well.
Recomendado
Battery Charger Input Protection
In offline battery chargers for lead-acid, Li-ion, and other chemistries, the MF72-010D9 protects the input bridge rectifier from the charging capacitor inrush when the AC mains is first applied. The 10 Ω cold resistance limits the peak charging current to roughly 10-20 A, well within the surge rating of standard rectifier bridges, while the steady-state loss at the rated 2 A continuous is acceptable for chargers in the 100-250 W range. After self-heating equilibrium, the device contributes less than 2 W of continuous loss, which is negligible compared to the charger's output power. For chargers that must operate continuously at the inrush rating, verify the device stays within its hot-resistance thermal equilibrium.
Recomendado
Industrial Control Panel Surge Limiting
In industrial control panels and PLC power supplies operating from 24 VDC or 115/230 VAC rails, the MF72-010D9 provides a low-cost, maintenance-free inrush limiting solution. The 11 mm radial disk fits standard industrial terminal block layouts and accepts wave-soldered or hand-wired connections. The ±20% cold-resistance tolerance is acceptable in industrial environments where the downstream power supply is already rated for substantial input surge. Designers appreciate the zero-standby-power characteristic, which avoids the auxiliary supply needed by active MOSFET inrush limiters and simplifies agency (UL/IEC) compliance review.
Recomendado
Resumen de productos recomendados
Datos de referencia de ingeniería para MF72-010D9 — comparación, orientación de diseño e información de cumplimiento.
Guía de selección
Comparación con alternativas
| Parámetro | Este producto | MF72-010D11 | MF72-010D13 | MF72-010D25 | SL12-10009 | B57238S0100M |
|---|---|---|---|---|---|---|
| Package / Body Diameter | Radial 11 mm disk, 7.5 mm lead spacing | Radial 9 mm disk, 5 mm lead spacing | Radial 13 mm disk | Radial 25 mm disk | Radial 12 mm disk | Radial 11 mm disk |
| Brand | Cantherm | Cantherm (same-brand) | Cantherm (same-brand) | Cantherm (same-brand) | Ametherm (cross-brand) | TDK (cross-brand) |
| Cold Resistance @ 25 °C | 10 Ω | 10 Ω | 10 Ω | 10 Ω | 10 Ω | 10 Ω |
| Tolerance | ±20% | ±20% | ±20% | ±20% | ±20% | ±20% |
| Steady-State Current Max | 2 A | 2 A | 2-3 A | 3-4 A | 3 A | ~2 A |
| RoHS Compliance | Yes | Yes | Yes | Yes | Yes | Yes |
Diferenciadores clave
- Industry-standard MF72 form factor with widest distributor availability (frente a SL12-10009 (Ametherm))
- Lower hot-resistance loss at the 2 A rating than larger-disk alternatives (frente a MF72-010D25 (25 mm disk))
- Purely passive operation requires no auxiliary control circuitry (frente a Active MOSFET inrush limiter IC + external MOSFET + relay bypass)
Notas de diseño
The MF72-010D9 dissipates approximately 1.83 W at the rated 2 A steady-state current once the device reaches its thermal equilibrium (P = I² × R_hot = 2² × 0.458 ≈ 1.83 W). This is acceptable in open-air mounting with at least 10 mm of clearance to nearby heat-sensitive components. In enclosed or potted designs, verify the local ambient plus 1.83 W self-heating does not push the disk temperature above its 150 °C rated limit. For continuous operation near the 2 A rating, choose a larger MF72 diameter (D13 or D25) to reduce the equilibrium temperature.
Never parallel two MF72-010D9 devices to share current. Small resistance mismatches cause one device to heat faster and drop resistance first, which causes it to carry even more current (thermal runaway). For current sharing, use a single larger-diameter disk from the same MF72 family (D13 for 3 A, D25 for 4-5 A) rather than paralleling smaller parts. Also avoid placing the MF72 directly adjacent to a heat sink or other high-power component, which can interfere with the device's self-heating equilibrium.
Mount the MF72-010D9 on the AC line or neutral conductor ahead of the bridge rectifier and bulk input capacitor. This placement puts the full charging transient across the cold 10 Ω resistance. According to Cantherm MF72-series reference designs, lead-form stress relief should be provided when the part is mounted vertically or in vibration-prone environments to prevent ceramic-body cracking. Maintain at least 5 mm clearance between the MF72 body and any adjacent high-voltage conductor for safety and to allow self-heating airflow.
Estimated: the cold-resistance inrush limit at 230 VAC input across 10 Ω is approximately 23 A peak, dropping exponentially as the bulk capacitor charges and the device self-heats. This is well within the surge rating of standard 1N4007-style bridge rectifiers (typically 30-50 A one-cycle surge). Verify the inrush profile on an oscilloscope during first prototype power-up to confirm the upstream fuse or breaker does not nuisance-trip, especially at low-line 100-120 VAC where the surge is roughly half as severe but the fuse curve is tighter.
Información de cumplimiento
RoHS compliant and lead-free per distributor listings (DigiKey, JLCPCB, IC Components). REACH, AEC-Q100, halogen-free, and conflict-minerals status not published on the manufacturer public datasheet - request from Cantherm directly if required for compliance documentation.
