SFR2500002550FR500 - 255Ω 0.4W 1% Metal Film Resistor | Vishay
MPN: SFR2500002550FR500 ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $0.18 | $0.18 |
| 10 | $0.15 | $1.50 |
| 100 | $0.09 | $9.00 |
| 500 | $0.07 | $35.00 |
| 1,000 | $0.06 | $60.00 |
| 5,000 | $0.04 | $200.00 |
SFR2500002550FR500 Overview
A metal film resistor is a passive electronic component whose resistive element is a thin homogeneous layer of metal alloy deposited on a high-grade ceramic substrate, then laser-trimmed to a precise resistance value. Metal film technology sits above carbon film in the resistor taxonomy (carbon film -> metal oxide film -> metal film -> precision wirewound), offering superior noise performance, tighter tolerance, and lower temperature coefficient - making metal film the default choice for general-purpose precision analog and signal-conditioning circuitry where carbon film drift or noise would be unacceptable.
Key features include a low-noise specification of maximum 1.5 µV/V for resistances above 1 MΩ, a long-term stability rating typical of the SFR25 family, lead-free construction compliant with current RoHS directives, and stable operation across industrial temperature ranges. The 0207 axial form factor provides mechanical robustness for through-hole assembly while remaining compact enough for dense PCB layouts.
Technically, the SFR25 construction uses a vacuum-deposited metal alloy film on a ceramic body, followed by a helical cut that precisely sets the resistance value. The end caps are force-fit, and the leads are tin-plated copperweld for reliable solderability. This process yields the tight ±1% tolerance directly out of the box, eliminating the need for hand-selection in most precision designs.
Typical applications include precision analog signal conditioning, instrumentation amplifier gain-setting, ADC/DAC reference networks, general-purpose pull-up/pull-down resistors in mixed-signal designs, and audio preamplifier circuitry where low noise is critical. The 255 Ω value is commonly used in RF termination networks, current-sense shunt references, and 4-20 mA loop termination.
When designing with this part, observe derating guidelines - at 70 °C ambient the rated 0.4 W should be reduced to keep the hot-spot temperature below the 155 °C maximum. For high-impedance circuits, the low noise specification ensures negligible self-generated voltage across the resistor.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in any single manufacturer datasheet.
Drop-in alternatives for SFR2500002550FR500 — 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:
SFR2500001000FR500
✅ Drop-In📋 Reference alternative (not in catalog)
SFR2500001001FR500
✅ Drop-In📋 Reference alternative (not in catalog)
SFR2500001500FR500
✅ Drop-In📋 Reference alternative (not in catalog)
SFR2500004700FR500
✅ Drop-In📋 Reference alternative (not in catalog)
SFR2500002551FR500
✅ Drop-In📋 Reference alternative (not in catalog)
SFR2500002550FR500 Maximum Ratings & Electrical Characteristics
| Manufacturer | Vishay Beyschlag / BC Components |
| Series | SFR25 |
| Historical Part Number | SFR55 |
| Resistance | 255 Ω |
| Tolerance | ±1% |
| Power Rating | 0.4 W (400 mW) |
| Temperature Coefficient (TCR) | ±100 ppm/°C |
| Composition | Metal Film |
| Package / Case | Axial (0207 size) |
| Mounting Type | Through Hole |
| Packaging | Tape & Reel (TR), 5000 pcs/reel |
| Lead Free Status | Lead Free |
| Noise | Max. 1.5 µV/V (for > 1 MΩ) |
| Operating Temperature | -55 °C to +155 °C |
| RoHS Compliance | Compliant |
| Construction | Vacuum-deposited metal alloy film on ceramic body, helical cut |
SFR2500002550FR500 axial (0207 size) Pin Configuration Guide
Pin configuration for SFR2500002550FR500 (axial (0207 size) package). Pin numbering, functions, and connection diagrams are defined in the manufacturer datasheet. Refer to it for the exact footprint and soldering guidelines.
No detailed pinout data available for SFR2500002550FR500.
Refer to the datasheet for full pin configuration.
Typical Applications
SFR2500002550FR500 is suitable for 6 applications: Precision Analog Signal Conditioning, Current-Sense Shunt for Low-Current Sensing, Industrial 4-20 mA Loop Termination, Audio Preamplifier Bias Networks, ADC/DAC Reference and Pull-Down Networks, General-Purpose Pull-Up and Pull-Down.
Precision Analog Signal Conditioning
The SFR2500002550FR500's ±1% tolerance and ±100 ppm/°C TCR make it a strong fit for instrumentation amplifier gain-setting and active filter networks. With resistance tolerance five to ten times tighter than typical carbon film, it eliminates the need for trim pots in many precision designs. The 255 Ω value pairs naturally with op-amp feedback topologies such as inverting gain stages and Sallen-Key filters, where stable component values directly determine filter Q and cutoff accuracy.
Recommended
Current-Sense Shunt for Low-Current Sensing
The 255 Ω resistance of the SFR2500002550FR500 makes it a viable low-side current-sense shunt for instrumentation monitoring 1-30 mA loads. At a 10 mA load current, the resistor develops 2.55 V across it, well suited to the common-mode range of most instrumentation amplifiers. The metal film construction minimizes thermoelectric EMF errors versus carbon film. Designers must respect the 0.4 W power rating - at 39 mA the resistor reaches its dissipation limit, so the part is best for low-current monitoring paths rather than power-rail current sensing.
Recommended
Industrial 4-20 mA Loop Termination
The SFR2500002550FR500 is well suited to industrial process-control current loops where its 255 Ω value (in conjunction with parallel precision components) maps a 4-20 mA signal into a 1-5 V process variable for ADC acquisition. The ±1% tolerance ensures loop calibration stays within ISA 50.1 limits. Metal film's low noise floor (max 1.5 µV/V) preserves measurement integrity in HART-modulated signals superimposed on the loop current, where wideband noise would otherwise degrade digital communications reliability.
Recommended
Audio Preamplifier Bias Networks
Low-noise audio preamplifier stages benefit from the SFR2500002550FR500's metal film construction, which generates significantly less current noise than carbon film alternatives. The 255 Ω value is commonly used as an emitter degeneration resistor in low-noise transistor input stages, where its tight tolerance directly sets stage transconductance and DC bias point stability. Combined with a thermally-matched environment, the ±100 ppm/°C TCR keeps bias drift within manageable limits across the amplifier's operating temperature range.
Recommended
ADC/DAC Reference and Pull-Down Networks
In mixed-signal designs, the SFR2500002550FR500 serves as a precision pull-down, pull-up, or termination resistor adjacent to ADC inputs or DAC outputs. Tight ±1% tolerance improves linearity by eliminating mismatch between channels, while the metal film technology minimizes leakage and parasitic inductance versus surface-mount alternatives in low-frequency precision paths. Designers typically place the resistor as close to the converter pin as the through-hole package allows on mixed-technology boards.
Recommended
General-Purpose Pull-Up and Pull-Down
The SFR2500002550FR500 works well as a digital logic pull-up or pull-down where its 255 Ω value combined with 0.4 W rating supports a wide range of pull-strength requirements. The through-hole form factor is mechanically robust for test points, debugger interfaces, and front-panel signal conditioning in industrial and laboratory equipment. At 5 V logic levels, the resistor dissipates only 100 mW in worst-case short circuit, well within its rating, making it a safe choice in legacy and through-hole assembly lines.
Recommended
Recommended Products Summary
Engineering reference data for SFR2500002550FR500 — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | SFR2500001000FR500 | SFR2500001001FR500 | SFR2500001500FR500 | SFR2500004700FR500 | SFR2500002551FR500 |
|---|---|---|---|---|---|---|
| Package | Axial 0207 through-hole | Axial 0207 through-hole - same | Axial 0207 through-hole - same | Axial 0207 through-hole - same | Axial 0207 through-hole - same | Axial 0207 through-hole - same |
| Brand | Vishay | Vishay | Vishay | Vishay | Vishay | Vishay |
| Resistance | 255 Ω | 100 Ω | 1 kΩ | 150 Ω | 470 Ω | 2.55 kΩ |
| Tolerance | ±1% | ±1% | ±1% | ±1% | ±1% | ±1% |
| Power Rating | 0.4 W | 0.4 W | 0.4 W | 0.4 W | 0.4 W | 0.4 W |
| Temperature Coefficient | ±100 ppm/°C | ±100 ppm/°C | ±100 ppm/°C | ±100 ppm/°C | ±100 ppm/°C | ±100 ppm/°C |
| Composition | Metal Film | Metal Film | Metal Film | Metal Film | Metal Film | Metal Film |
| Mounting Type | Through Hole | Through Hole | Through Hole | Through Hole | Through Hole | Through Hole |
Key Differentiators
- Historical BC Components / Vishay BC heritage with active production (vs Generic carbon film equivalents)
- Industry-standard 0207 axial footprint for broad second-source compatibility (vs Proprietary through-hole resistor packages)
- Tape and reel packaging supports automated through-hole insertion (vs Bulk-packaged through-hole resistors)
Design Notes
At 70 °C ambient, the SFR2500002550FR500 is rated for 0.4 W continuous power dissipation, but must be linearly derated above that temperature to 0 W at 155 °C. At a worst-case 25 °C ambient with 1 oz copper through-hole pad, the part can safely handle close to its full 0.4 W rating. Estimated: at 0.4 W into a 50 °C ambient, the hot-spot rises approximately 30 °C above ambient due to the axial package's thermal resistance (~75 °C/W). Ensure PCB layout keeps the body away from heat-generating components.
Through-hole axial resistors like the SFR2500002550FR500 require drilled pad diameters of approximately 0.9-1.0 mm for the 0.6 mm leads. Standard 2.54 mm (0.1 inch) lead pitch is recommended with a minimum pad-to-pad spacing of 10 mm to accommodate the 6.3 mm body length. For wave soldering, apply adequate flux and verify lead wetting on the bottom pad; for hand assembly, pre-tin both pads and lead ends to ensure reliable joint formation.
Do not exceed the absolute maximum working voltage, which for the 0207-size SFR25 series is typically 250 V DC. Applying higher voltages can cause internal arcing between the helical film turns. Also, avoid mounting the resistor adjacent to large heat-generating components without verifying that the combined thermal environment still allows for proper power derating. Finally, observe the resistor's polarity-neutral construction; while it can be installed in either orientation, consistent lead-bending direction simplifies assembly and rework.
Compliance Information
Lead-free and RoHS-compliant per Digi-Key product attributes. Not AEC-Q100 qualified (passive component, automotive qualification typically not applicable to through-hole resistors). Halogen-free construction implied by lead-free materials. Conflict minerals compliance per Vishay standard policy.
