FR107-B - 1A 1000V Fast Recovery Rectifier DO-41 | Rectron
MPN: FR107-B ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $0.18 | $0.18 |
| 10 | $0.14 | $1.40 |
| 100 | $0.09 | $9.00 |
| 500 | $0.07 | $35.00 |
| 1,000 | $0.05 | $50.00 |
| 5,000 | $0.04 | $200.00 |
FR107-B Overview
A fast recovery rectifier is a discrete semiconductor device designed to conduct current in one direction while switching from the conducting (forward) state to the blocking (reverse) state far faster than a standard 50 Hz rectifier. FR107-B belongs to the rectifier diode family within discrete semiconductors, sitting alongside general-purpose rectifiers (1N400x series), Schottky diodes, and ultrafast rectifiers. Its primary role is AC-to-DC conversion in switched-mode power supplies (SMPS), motor drive snubbers, and inductive load freewheel paths where the slow recovery of a 1N4007 would cause excessive switching loss or shoot-through.
Key features include a low forward voltage drop of typically 1.3 V at 1 A (max 1.7 V), a peak surge capability of 30 A for 8.3 ms half-sine pulses, glass passivated die construction, and a molded epoxy body that meets UL 94V-0 flammability. The axial lead format simplifies PCB insertion and wave-soldering on through-hole boards. Operating junction temperature spans -55C to +150C, covering industrial and automotive underhood environments.
Technically, the device uses a diffused PN junction with controlled minority carrier lifetime to achieve the 150 ns recovery specification without sacrificing surge ruggedness. The glass passivation layer eliminates surface instability and leakage drift, ensuring stable high-temperature reverse current below 5 uA at 25C and 50 uA at full rated voltage and temperature.
Typical applications include switch-mode power supply output rectifiers, DC-DC converter freewheel diodes, inverter stage snubbers, and polarity protection in industrial controls. The 1000 V rating also supports 230 VAC line-rectified rails directly without derating.
When designing with FR107-B, always verify that the switching frequency of the host converter is consistent with a 150 ns trr. Above approximately 100 kHz, an ultrafast (UF4007-class, 75 ns) or Schottky part is preferable. Reverse voltage margin of at least 20% should be applied for reliability.
This page synthesizes distributor pricing, same-brand drop-in alternatives (FR107, FR157-B), cross-brand DO-41 equivalents from Diodes Incorporated and EVVO, application guidance, and a DO-41 pinout diagram - practical engineering context not found in the bare datasheet.
Drop-in alternatives for FR107-B — 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:
FR107
✅ Drop-In📋 Reference alternative (not in catalog)
FR157-B
✅ Drop-In📋 Reference alternative (not in catalog)
FR207-B
✅ Drop-In📋 Reference alternative (not in catalog)
FR107-B
✅ Drop-In✓ In Stock
$0.04 / Unit
View Datasheet →FR107-B Maximum Ratings & Electrical Characteristics
| Manufacturer | Rectron |
| Part Number | FR107-B |
| Product Type | Fast Recovery Rectifier Diode |
| Package | DO-41 (DO-204AC) axial through-hole |
| Maximum Repetitive Peak Reverse Voltage (VRRM) | 1000 V |
| Maximum RMS Voltage (VRMS) | 700 V |
| Maximum DC Blocking Voltage (VDC) | 1000 V |
| Average Forward Rectified Current (IF(AV)) | 1.0 A at TA = 75C |
| Non-Repetitive Peak Forward Surge Current (IFSM) | 30 A (8.3 ms half-sine) |
| Maximum Forward Voltage (VF) at IF = 1 A | 1.3 V typical, 1.7 V max |
| Maximum DC Reverse Current at Rated DC Blocking Voltage | 5 uA at 25C, 50 uA at 100C |
| Reverse Recovery Time (trr) | 150 ns |
| Typical Junction Capacitance (CJ) | 15 pF at VR = 4 V, f = 1 MHz |
| Operating Junction Temperature Range | -55C to +150C |
| Storage Temperature Range | -55C to +150C |
| Mounting Type | Through-hole axial |
| Lead Finish | Tin-lead (per Rectron FR101-FR107 datasheet) |
| Body Material | Molded epoxy, UL 94V-0 flammability |
| Polarization | Cathode band marked on body |
FR107-B Pin Configuration
| Pin 1 | A (Anode) — Anode lead - unmarked end of the axial body |
| Pin 2 | K (Cathode) — Cathode lead - end nearest the polarity band printed on the body |
Typical Applications
FR107-B is suitable for 6 applications: Switch-Mode Power Supply Output Rectifier, DC-DC Converter Freewheel Diode, Inductive Load Snubber and Flyback Clamp, Bridge Rectifier Stage in Off-line Power Supplies, Battery Reverse Polarity Protection, AM/FM Radio and Audio Demodulator Signal Rectifier.
Switch-Mode Power Supply Output Rectifier
The FR107-B is widely used as the output rectifier in small-to-medium switch-mode power supplies (SMPS) operating below approximately 100 kHz. Its 150 ns reverse recovery time is fast enough to avoid the cross-conduction loss and audible switching noise that plague 1N4007-class parts, while the 1 A average current comfortably handles 30-60 W converter output stages. The 1000 V reverse rating provides generous headroom for off-line flyback and forward converters fed from universal 85-265 VAC mains, where reflected voltage spikes can momentarily exceed 600 V across the output rectifier. Placed in the secondary side of a flyback transformer, the FR107-B's 1.3 V typical forward drop translates to roughly 1.3-1.5 W conduction loss at full 1 A load, so PCB copper area under the DO-41 leads becomes the primary thermal path. Engineers prefer this part over Schottky diodes when the output voltage exceeds 30-40 V, since the FR107-B's reverse leakage stays in the microamp range versus a Schottky's milliamp leakage that scales with voltage and temperature.
Recommended
DC-DC Converter Freewheel Diode
In buck, boost, and buck-boost converters the FR107-B serves as the freewheel (commutation) diode that carries inductor current when the main switch turns off. The 150 ns trr is critical here: a slow diode allows current to ramp in the wrong direction during the recovery interval, generating both conduction loss and reverse-voltage spikes that stress the switch. The 1 A average current rating handles inductor currents up to roughly 0.7 A continuous in a buck converter, or peak currents of 2-3 A in discontinuous-mode flyback at moderate duty cycles. The 1000 V reverse rating makes the FR107-B suitable for 48 V telecom bus converters, 96 V battery stacks, and any application where the switch node can ring above 100 V during turn-off. Compared to a Schottky, the FR107-B has higher forward drop but orders-of-magnitude lower reverse leakage, which matters in battery-powered systems where standby drain must be minimized. Lead bend and orientation on the PCB should keep lead length short to minimize parasitic inductance that would otherwise amplify the recovery transient.
Recommended
Inductive Load Snubber and Flyback Clamp
Relays, solenoids, motor windings, and small transformers all store magnetic energy that must be safely dissipated when the driving transistor switches off. The FR107-B is a classic choice for the flyback (freewheel) diode placed across the inductive load, conducting the kick-back current back to the supply rail and clamping the switch voltage to VCC plus one diode drop. With a 1000 V reverse rating the FR107-B tolerates the high flyback voltages generated when switching off 24 V or 48 V solenoids, and the 30 A IFSM rating absorbs the brief high-current spike when the magnetic field collapses. The 150 ns recovery is sufficient at switching frequencies up to a few kHz typical of relay and solenoid drive circuits; above 20 kHz an ultrafast part is preferable. Across small brushed DC motors in toys, appliances, and automotive accessories, the FR107-B prevents the inductive kick from destroying the driver transistor and reduces EMI by providing a controlled current path.
Recommended
Bridge Rectifier Stage in Off-line Power Supplies
Four FR107-B diodes wired as a full-wave bridge directly rectify 230 VAC mains into a DC rail for downstream filtering. With each diode rated for 1000 V VRRM, the bridge withstands the 325 V peak inverse voltage of 230 VAC mains plus transients, leaving substantial margin. The 1 A average current supports rectified output currents of roughly 0.5-0.7 A continuous after derating, sufficient for 50-100 W linear or simple switch-mode supplies. Compared to a packaged bridge rectifier module, discrete FR107-B diodes are sometimes preferred for thermal distribution: heat dissipates across four separate DO-41 bodies rather than concentrating in one block. Engineers also use the FR107-B in half-wave or voltage-doubler configurations for low-current bias supplies where cost and PCB real estate matter more than absolute efficiency. The 30 A IFSM rating survives the inrush of input filter capacitors at power-on, provided an NTC or proper fuse coordination is used.
Recommended
Battery Reverse Polarity Protection
A single FR107-B placed in series with the battery rail blocks destructive reverse-polarity connection in portable and field equipment. In forward bias it conducts with only 1.3 V drop, while in reverse bias it blocks up to 1000 V, easily surviving the reversed 6 V, 12 V, or 24 V battery connection. The 1 A rating suits handheld instruments, two-way radios, and small industrial sensors. The trade-off versus a P-channel MOSFET reverse-protection circuit is the constant 1.3 V conduction drop, which matters in low-voltage battery systems where every millivolt of drop reduces runtime. For higher-current paths above 5 A, or where dropout is unacceptable, an ideal-diode MOSFET controller is preferred. The FR107-B remains a cost-effective one-component solution where the additional dissipation is tolerable.
Recommended
AM/FM Radio and Audio Demodulator Signal Rectifier
Although most often used in power circuits, the FR107-B's combination of moderate forward drop and 150 ns recovery also serves in envelope detector and AGC rectifier positions in AM and shortwave radio receivers. The 1.3 V forward drop sets the detection threshold, and the 150 ns recovery is more than fast enough for audio-bandwidth demodulation up to 20 kHz. The 1000 V reverse rating is overkill for signal-level work but provides robust protection against static discharge and stray RF pickup on long antenna leads. Designers of crystal radio sets, simple envelope detectors, and educational electronics kits have used the FR107 family for decades. The through-hole DO-41 package also makes the part convenient for breadboard and point-to-point wiring where SMD parts are awkward.
Recommended
Recommended Products Summary
Engineering reference data for FR107-B — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | FR107 | FR157-B | FR207-B | FR107-B (Diodes) |
|---|---|---|---|---|---|
| Package | DO-41 (DO-204AC) axial | DO-41 (DO-204AC) - same | DO-41 (DO-204AC) - same | DO-41 (DO-204AC) - same | DO-41 (DO-204AC) - same |
| Brand | Rectron | Rectron | Rectron | Rectron | Diodes Incorporated |
| VRRM (V) | 1000 | 1000 | 1000 | 1000 | 1000 |
| IF(AV) (A) | 1.0 | 1.0 | 1.5 | 2.0 | 1.0 |
| trr (ns) | 150 | 150 | 150 | 150 | 150 |
| IFSM (A, 8.3ms) | 30 | 30 | 50 | 60 | 30 |
| VF at 1A (V, typical) | 1.3 | 1.3 | 1.3 | 1.3 | 1.3 |
| Operating Temperature (C) | -55 to +150 | -55 to +150 | -55 to +150 | -55 to +150 | -55 to +150 |
Key Differentiators
- 1000 V reverse rating supports direct 230 VAC mains rectification (vs FR157-B)
- Bulk packaging suffix (-B) optimized for through-hole assembly (vs FR107 (Rectron, ammo pack))
- Cross-brand second source availability from Diodes Incorporated (vs FR107-B (Diodes Incorporated))
Design Notes
Estimated: at IF = 1 A continuous with VF = 1.3 V typical, the FR107-B dissipates roughly 1.3 W. The DO-41 package has no heatsink tab; thermal performance is dominated by lead length, lead bend geometry, and the copper area on the PCB. Keep axial lead length between the body and the PCB pad to under 5 mm where possible, and provide at least 50 mm^2 of 2 oz copper per lead to keep the junction below 125C. For continuous operation above 0.7 A, consider the FR157-B (1.5 A) or FR207-B (2.0 A) for additional thermal margin in the same package.
In high-frequency switching positions (SMPS freewheel, snubber) the parasitic lead inductance of the DO-41 package (typically 5-10 nH per lead) can ring with junction capacitance to produce voltage overshoot that exceeds the 1000 V rating. Bend leads as short as practical and place the diode physically close to the switching node. For switching frequencies above 100 kHz or where switch-node dV/dt exceeds 5 kV/us, an SMD package (SOD-123FL, SMA) or a part specifically designed for snubber use (ultrafast MUR120) is recommended. Source: Rectron FR101-FR107 datasheet and standard rectifier application literature.
Do not substitute a 1N4007 or other 50 Hz rectifier in any position where the FR107-B's 150 ns recovery is required - the 1N4007's ~30 us trr will cause cross-conduction loss, EMI, and possible switch transistor failure. Conversely, do not substitute the FR107-B in a position originally designed for an ultrafast rectifier (UF4007, 75 ns) above 100 kHz - the slower recovery will increase switching loss. Always verify reverse voltage margin: peak inverse voltage plus 20% transient headroom should remain below the 1000 V VRRM rating. Reverse current measurement should be performed at 25C and at maximum rated temperature to characterize leakage drift.
Compliance Information
RoHS status not explicitly confirmed in retrieved distributor data as of 2026-10-14. Rectron FR101-FR107 family datasheet indicates tin-lead finish on standard parts; check with Rectron for lead-free -LF suffix variants if RoHS is required.
