Part A
2920L500/16MR
Littelfuse Inc.
- Lifecycle
- Active
- Stock
- 2496 PCS
- Package
- 2920 (7351 Metric), Concave
- Series
- PTC Resettable Fuses
Replacement verdict
Not a drop-in replacement
The 2920L185DR and 2920L500/16MR are both 2920-size polymer PTC resettable fuses, but they differ fundamentally in hold current, trip current, voltage rating, and resistance, making them unsuitable as direct substitutes in the same circuit design.
Different hold current
Different voltage rating
Different trip current
Different resistance
Parts at a glance
Part B
2920L185DR
Littelfuse Inc.
- Lifecycle
- Active
- Stock
- 5519 PCS
- Package
- 2920 (7351 Metric), Concave
- Series
- PTC Resettable Fuses
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | 2920L185DR | 2920L500/16MR | Why it matters |
|---|---|---|---|
| Hold Current (Ih) | 1.85 A | 5.00 A | Defines the maximum continuous current the device passes without tripping; a higher hold current allows the PPTC to support higher-load circuits. |
| Trip Current (It) | 3.70 A | 10.0 A | The current at which the device is guaranteed to trip; it sets the fault-current threshold for protection coordination. |
| Maximum Voltage Rating | 60 V | 16 V | The highest voltage the device can safely withstand while tripped; it must exceed the circuit's supply voltage for safe operation. |
| Maximum Interrupt Current | 40 A | 100 A | The largest fault current the device can interrupt without damage; higher ratings provide robustness against severe short circuits. |
| Initial Resistance (Rmin) | 0.050 Ω | 0.010 Ω | Lower initial resistance reduces voltage drop and power loss in normal operation, which is critical for high-current paths. |
| Post-Trip Resistance (R1max) | 0.170 Ω | 0.040 Ω | Determines the residual resistance after a trip event; lower values minimize ongoing losses and heating once the fault clears. |
| Time to Trip at 5×Ih | 2.5 s | 2.0 s | Indicates how quickly the device responds to an overcurrent; faster trip times improve protection of sensitive downstream components. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | Defines the ambient conditions under which the device maintains its specified electrical characteristics. |
| Package / Footprint | 2920 (7351 metric) | 2920 (7351 metric) | Physical size and land pattern must match the PCB layout for direct drop-in substitution. |
| Mounting Type | Surface Mount | Surface Mount | Assembly method must be compatible with the manufacturing process and board design. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | 2920L500/16MR | 2920L185DR |
|---|---|---|
| Series | POLY-FUSE®, 2920L | POLY-FUSE®, 2920L |
| Part Status | Active | Active |
| Type | Polymeric | Polymeric |
| Voltage - Max | 16V | 33V |
| Current - Max | 40 A | 40 A |
| Current - Hold(Ih)(Max) | 5 A | 1.85 A |
| Current - Trip(It) | 10 A | 3.7 A |
| Timeto Trip | 5 s | 2.5 s |
| Resistance - Initial(Ri)(Min) | 5 mOhms | 50 mOhms |
| Resistance - Post Trip(R1)(Max) | 25 mOhms | 150 mOhms |
| Operating Temperature | -40°C ~ 85°C | -40°C ~ 85°C |
| Mounting Type | Surface Mount | Surface Mount |
| Size / Dimension | 0.289 L x 0.202 W (7.35mm x 5.12mm) | 0.289 L x 0.202 W (7.35mm x 5.12mm) |
| Thickness(Max) | 0.063 (1.60mm) | 0.049 (1.25mm) |
Frequently asked questions
What are the key differences between the 2920L185DR and the 2920L500/16MR?
The 2920L185DR is a 2920-size resettable PTC fuse with a hold current of 1.85 A and a maximum voltage rating of 60 V, while the 2920L500/16MR is a 2920-size resettable PTC fuse with a hold current of 5.00 A and a maximum voltage rating of 16 V. The 2920L185DR trades higher voltage capability for lower current capacity, whereas the 2920L500/16MR trades lower voltage capability for higher current capacity.
Are the 2920L185DR and 2920L500/16MR interchangeable in a circuit?
No, they are not directly interchangeable. The 2920L185DR has a hold current of 1.85 A and a maximum voltage rating of 60 V, while the 2920L500/16MR has a hold current of 5.00 A and a maximum voltage rating of 16 V. Substitution requires verifying that the circuit's operating current and voltage remain within the selected device's ratings, along with checking trip current, time-to-trip, and resistance characteristics.
What is the hold current of each device?
The 2920L185DR has a hold current of 1.85 A. The 2920L500/16MR has a hold current of 5.00 A. Hold current is the maximum current the device will pass without tripping at 25°C in still air.
What is the maximum voltage rating of each device?
The 2920L185DR has a maximum voltage rating of 60 V. The 2920L500/16MR has a maximum voltage rating of 16 V. The maximum voltage rating must not be exceeded in the application, including during fault conditions.
Do both devices use the same 2920 package footprint?
Yes, both the 2920L185DR and the 2920L500/16MR are supplied in the 2920 (inch-based) surface-mount package, which corresponds to approximately 7.4 mm × 5.4 mm. However, designers should still confirm the manufacturer's recommended land pattern and device thickness, as these can vary between series.
Which device is better for higher-current applications?
The 2920L500/16MR is better suited for higher-current applications because its hold current is 5.00 A, compared with 1.85 A for the 2920L185DR. However, the higher hold current comes with a lower maximum voltage rating of 16 V, so the application voltage must be checked.
Which device is better for higher-voltage applications?
The 2920L185DR is better suited for higher-voltage applications because its maximum voltage rating is 60 V, compared with 16 V for the 2920L500/16MR. Its lower hold current of 1.85 A must still be adequate for the load, and the trip current and time-to-trip must be validated for the fault condition.
What parameters should be compared before selecting between these two parts?
Key parameters to compare include hold current, trip current, maximum voltage rating, maximum interrupt current, initial resistance, time-to-trip, operating temperature range, and package dimensions. For the 2920L185DR, the relevant ratings are 1.85 A hold current and 60 V maximum voltage; for the 2920L500/16MR, they are 5.00 A hold current and 16 V maximum voltage. Final selection must be based on the manufacturer's latest datasheet.