MF72-200D7 - 200Ω 200mA Power NTC Thermistor ICL | Cantherm
MPN: MF72-200D7 ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $0.18 | $0.18 |
| 10 | $0.15 | $1.50 |
| 100 | $0.11 | $11.00 |
| 500 | $0.09 | $45.00 |
| 1,000 | $0.07 | $70.00 |
MF72-200D7 Overview
An inrush current limiter (ICL) is a type of negative-temperature-coefficient (NTC) thermistor whose resistance drops sharply as it self-heats from load current. At 25°C ambient it presents a high cold resistance that absorbs the initial charging surge of bulk capacitors, then settles to a low hot resistance that minimizes continuous power dissipation. In the system hierarchy, an ICL sits between an upstream power source (rectifier, front-end, or switching supply) and downstream bulk capacitance, functioning as a passive, self-recovering current-limiting element within circuit protection architectures.
Key features of the MF72-200D7 include 200 Ω nominal resistance at 25°C with ±20% tolerance, a steady-state current rating of 200 mA, and a hot resistance of approximately 11.65 Ω at rated current. The device is housed in a 9.0 mm radial-lead disc package with 5.00 mm lead spacing, operates from −55°C to +200°C, and is supplied in bulk packaging. Its lead-free construction complies with RoHS requirements, making it suitable for modern lead-free assembly processes.
Technically, the MF72-200D7 uses a metal-oxide ceramic body whose resistance decreases following an exponential beta curve as the device self-heats from I²R dissipation. During turn-on, the high cold resistance forces the input current through the thermistor instead of directly charging downstream capacitors, after which the lowered hot resistance keeps steady-state losses to a few hundred milliwatts. Engineers typically derate the steady-state current by 30–50% in continuous duty to keep the device below its maximum operating temperature.
Typical applications include switch-mode power supply (SMPS) input protection, DC-DC converter input stages, audio amplifier power rails, and LED driver input surge suppression where the MF72-200D7 limits the initial capacitor-charging spike that would otherwise stress rectifier diodes and fuses.
A key design trade-off is selecting the cold-resistance value: too low provides insufficient surge limiting, too high creates excessive steady-state loss. The MF72-200D7's 200 Ω cold resistance is well-matched to low-current 5–24 V supplies drawing well under 1 A continuous.
This page synthesizes distributor pricing, drop-in same-series alternatives, and practical inrush-limiting design notes that are not consolidated in the manufacturer datasheet, giving buyers and engineers a single source for parametric, application, and sourcing decisions.
Drop-in alternatives for MF72-200D7 — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
MF72-100D7
✅ Drop-In📋 Reference alternative (not in catalog)
MF72-200D9
✅ Drop-In📋 Reference alternative (not in catalog)
MF72-150D7
✅ Drop-In📋 Reference alternative (not in catalog)
MF72-200D5
✅ Drop-In📋 Reference alternative (not in catalog)
MF72-200D11
✅ Drop-In📋 Reference alternative (not in catalog)
MF72-200D7 Specifications
| Component Type | Inrush Current Limiter (ICL) / Power NTC Thermistor |
| Resistance @ 25°C | 200 Ω |
| Resistance Tolerance | ±20% |
| Steady-State Max Current | 200 mA |
| Resistance @ Rated Current (hot) | 11.65 Ω |
| Disc Diameter | 9.0 mm (0.354 in) |
| Lead Spacing | 5.00 mm (0.197 in) |
| Lead Style | Radial |
| Mounting Type | Through-Hole |
| Minimum Operating Temperature | −55°C |
| Maximum Operating Temperature | +200°C |
| Packaging | Bulk |
| Lead Free | Yes |
| RoHS Status | Compliant |
| Series | MF72 Power NTC Thermistor |
| Manufacturer | Cantherm (Canadian Thermostats & Control Devices LTD) |
MF72-200D7 Pin Configuration
| Pin 1 | Lead 1 — Radial through-hole lead, non-polarized — connect to either side of the load |
| Pin 2 | Lead 2 — Radial through-hole lead, non-polarized — connect to either side of the source |
Typical Applications
MF72-200D7 is suitable for 6 applications: Switch-Mode Power Supply (SMPS) Input Protection, DC-DC Converter Input Surge Suppression, Audio Amplifier Power Rail Soft-Start, LED Driver Input Surge Limiting, Industrial 24V Sensor & Relay Supply Protection, Telecom & Network Equipment Hot-Plug Protection.
Switch-Mode Power Supply (SMPS) Input Protection
The MF72-200D7 is placed in series between the bridge rectifier output and the bulk-input capacitor in sub-200 mA SMPS designs, where its 200 Ω cold resistance clamps the turn-on charging spike that would otherwise weld relay contacts or blow the input fuse. At 25°C the cold impedance limits peak inrush to roughly VIN/200 Ω, while its 11.65 Ω hot resistance at the 200 mA rated current keeps steady-state dissipation near 0.5 W. According to the Cantherm MF72 datasheet, this 17× hot-to-cold ratio is the design lever for sizing inrush margin vs continuous loss trade-off.
Recommended
DC-DC Converter Input Surge Suppression
In 12 V or 24 V isolated DC-DC converter front-ends drawing less than 200 mA, the MF72-200D7 protects input capacitors from the repeated inrush events that happen at every hot-plug or restart cycle. Its 9.0 mm disc body dissipates the inrush energy thermally while the radial 5.00 mm leads keep the part drop-in compatible with standard through-hole PCB layouts. Compared to a fixed resistor, the NTC's hot-resistance collapse means steady-state voltage drop stays under 2.5 V at 200 mA — a critical advantage in low-voltage rails.
Recommended
Audio Amplifier Power Rail Soft-Start
Class-A and class-AB audio amplifiers draw heavy inrush when their large power-supply bypass capacitors energize; placing an MF72-200D7 in series with the main rail limits the speaker-protect-relay stress and prevents DC-offset thumps at turn-on. Its 200 Ω cold impedance slows the rail rise to a few hundred milliseconds — slow enough to mute the amplifier's protection circuit but fast enough not to be audible. The MF72-200D7's 200 mA continuous rating matches small pre-amp and headphone-amplifier supply rails perfectly.
Recommended
LED Driver Input Surge Limiting
Constant-current LED drivers with bulk input capacitance suffer from repeated inrush each time the driver is switched on, gradually weakening the upstream fuse and bridge diodes. The MF72-200D7 in series with the LED driver's input absorbs the initial surge, with its 9.0 mm disc body spreading the heat across enough thermal mass to survive thousands of turn-on cycles. The 200 Ω cold resistance is well-matched to 12–24 V LED drivers drawing under 200 mA continuous, which is the typical envelope for under-cabinet and architectural lighting fixtures.
Recommended
Industrial 24V Sensor & Relay Supply Protection
Industrial 24 V rails feeding PLC sensor inputs, small relays, and instrumentation often suffer from capacitive-load inrush that violates IEC 61131-2 surge limits. The MF72-200D7 at the sensor-supply branch input clamps the inrush to roughly 120 mA peak (24 V / 200 Ω), well below the 2× nominal envelope that most sensor inputs tolerate. Its −55°C to +200°C operating range makes it suitable for outdoor and unconditioned-cabinet installations where ambient swings are wide.
Recommended
Telecom & Network Equipment Hot-Plug Protection
Network switches, routers, and small-cell base stations with −48 V or PoE input rails benefit from the MF72-200D7 at the front-end input stage to limit the inrush that would otherwise trip upstream OR-ing controllers. Its through-hole radial package handles the vibration and thermal-cycling stress typical of telecom enclosures, and the part's 200 mA rating matches the auxiliary-power rails used for management-Ethernet and low-power monitoring subsystems. The Cantherm MF72 family is a long-standing reference design in legacy telecom input stages.
Recommended
Recommended Products Summary
Engineering reference data for MF72-200D7 — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | MF72-100D7 | MF72-200D9 | MF72-150D7 | MF72-200D5 | MF72-200D11 |
|---|---|---|---|---|---|---|
| Brand | Cantherm | Cantherm | Cantherm | Cantherm | Cantherm | Cantherm |
| Package | Disc 9.0 mm, radial 5.00 mm lead spacing | Disc 9.0 mm, radial 5.00 mm lead spacing - same | Disc 9.0 mm, radial 5.00 mm lead spacing - same | Disc 9.0 mm, radial 5.00 mm lead spacing - same | Disc 9.0 mm, radial 5.00 mm lead spacing - same | Disc 11.0 mm, radial 7.50 mm lead spacing - larger |
| Resistance @ 25°C (cold) | 200 Ω | 100 Ω | 200 Ω | 150 Ω | 200 Ω | 200 Ω |
| Tolerance | ±20% | ±20% | ±20% | ±20% | ±20% | ±20% |
| Min Operating Temp | −55°C | −55°C | −55°C | −55°C | −55°C | −55°C |
| Max Operating Temp | +200°C | +200°C | +200°C | +200°C | +200°C | +200°C |
| RoHS / Lead Free | Yes | Yes | Yes | Yes | Yes | Yes |
Key Differentiators
- 200 Ω cold / 11.65 Ω hot resistance gives ~17× impedance collapse for efficient turn-on surge absorption (vs MF72-100D7)
- Same 9 mm body, 5.00 mm lead spacing across the D5/D7/D9 variants enables one PCB layout for the full family (vs MF72-200D5)
- D7 disc size is the sweet spot for sub-200 mA designs — smaller than D11 (higher current) but with more thermal mass than D5 (vs MF72-200D11)
Design Notes
Estimated: at the 200 mA rated steady-state current, the MF72-200D7 dissipates approximately 0.5 W (I² × R_hot = 0.2² × 11.65 = 0.47 W). With a typical 9 mm disc thermal resistance near 60 °C/W, the body rises about 28°C above ambient in free air — well within the +200°C absolute maximum. Designers should derate continuous current to 130–150 mA in enclosed housings to keep body temperature below +150°C for long-term reliability.
Estimated: inrush energy absorbed per turn-on event is roughly ½ × C × V², where C is downstream bulk capacitance and V is the rail voltage. For a 470 µF bulk cap charged to 24 V, single-event inrush energy is ~0.135 J. The MF72-200D7's 9 mm disc can absorb several joules per cycle if spaced out, but rapid hot-plug cycling (sub-second intervals) will accumulate thermal mass faster than the disc can shed it — allow at least 5 seconds between cycles in worst-case designs.
Do not place the MF72-200D7 on the low-voltage (post-regulator) side of an SMPS — its hot resistance adds unnecessary voltage drop on the output rail. Always install it on the high-voltage input side, between the bridge rectifier and the bulk-input capacitor. Also avoid mounting it adjacent to a rectifier diode or other heat source: the disc body should have at least 5 mm clearance to neighboring parts to prevent thermal coupling that raises cold-resistance values.
Bend the radial leads carefully to fit the 5.00 mm lead-spacing PCB holes; excessive lead-bend stress cracks the disc body's metallization seal. For hand-prototype builds, leave 1–2 mm of slack between the disc body and the PCB so vibration and thermal expansion do not transfer stress to the ceramic. Through-hole wave soldering at 260°C for under 5 seconds is acceptable per the Cantherm lead-free profile.
Compliance Information
RoHS compliant and lead-free per DigiKey listing and Cantherm MF72 datasheet. Reach, halogen-free, and conflict-mineral declarations available from Cantherm on standard request. AEC-Q100 not applicable — ICLs are passive circuit-protection devices, not automotive-qualified ICs.
