1F3G Fast Recovery Rectifier: Specifications, Polarity and Testing

The Good-Ark 1F3G fast recovery rectifier is a single silicon diode rated at 1 A average forward rectified current and 200 V repetitive peak reverse voltage. It uses an R-1 axial package and specifies 150 ns maximum reverse recovery time under defined test conditions. The banded end identifies its cathode.

If you are identifying a part on a board, start with the marking, manufacturer and polarity. If you are choosing a replacement, add the circuit’s voltage peaks, current waveform and temperature. The short model name alone does not describe every operating limit.

Last updated: October 16, 2026

Where is the original 1F3G data sheet?

Use the document for the manufacturer of your device.

The values here refer to Good-Ark’s 1F1G through 1F7G data sheet, Rev. B, dated November 13, 2023 in its revision history. Read the 1F3G column alongside shared rows, curves and footnotes.

Search results contain several suppliers with similar part names. They can also include unhelpful cross-reference pages. Do not combine one manufacturer’s package drawing with another manufacturer’s electrical table and treat the result as one specification.

The 1F3G is a two-terminal diode, not a bridge rectifier. A packaged single-phase bridge contains four connected junctions and normally has two AC terminals plus positive and negative DC terminals. This distinction matters when identifying a component or tracing a board.

What are the Good-Ark 1F3G specifications?

Its headline ratings are 1 A, 200 V and 150 ns.

The table keeps the conditions close to the numbers. Ratings, listed electrical values and typical characteristics should not be interpreted as interchangeable kinds of guarantee.

Parameter	Published value	Condition or meaning
Repetitive reverse voltage	200 V	V_RRM blocking rating
RMS reverse voltage	140 V	Published V_RMS rating
DC blocking voltage	200 V	V_DC rating
Average rectified current	1 A	Subject to mounting and temperature
Forward surge	30 A	Single 8.3 ms half-sine on rated load
Forward drop	1.30 V	Listed at I_F = 1 A
Reverse leakage	5 μA / 100 μA	Rated reverse voltage; junction 25°C / 125°C
Maximum recovery time	150 ns	I_F = 0.5 A, I_R = 1 A, I_RR = 0.25 A
Typical capacitance	12 pF	4 V reverse bias, 1 MHz
Junction temperature	−55°C to +150°C	Rated range
Package	R-1 axial	Use the original outline drawing

The electrical table labels forward drop and reverse leakage without separate minimum/typical/maximum columns. Preserve the document’s wording instead of relabeling every electrical number as a maximum. It explicitly labels recovery time as maximum and capacitance as typical.

The mounting footnote requires the leads 9.5 mm from the case to be kept at ambient temperature. This is a stated thermal condition, not a promise that every board can carry 1 A continuously.

How do you identify the anode and cathode?

The band identifies the cathode end.

Conventional forward current flows from the anode toward the cathode. On an axial diode, the opposite end from the band is the anode. Confirm the marking against the manufacturer’s drawing and the board’s connection before installation.

A board symbol, stripe or silkscreen can help, but it should not override a verified circuit connection. Repairs sometimes involve rotated parts or ambiguous printing. Photograph the original orientation and trace where each terminal goes when necessary.

Also check the body length, diameter, lead diameter and available lead spacing. “Axial” is a package style, not a complete mechanical specification. Avoid forcing a lead into place by bending it against the body.

What does 150 ns recovery mean?

It describes a specified forward-to-reverse transition test.

A PN diode stores charge during forward conduction. When forced into reverse blocking, it can briefly conduct reverse current while that charge is removed. Vishay’s rectifier fundamentals illustrates this process.

For this 1F3G, 150 ns applies to the published test with 0.5 A forward current, 1 A reverse current and a 0.25 A recovery endpoint. It is not a universal delay at every current, voltage or temperature.

Taking 1 / 150 ns ≈ 6.67 MHz does not establish a permissible switching frequency. Converter losses and commutation stress depend on reverse-recovery charge, circuit inductance, temperature and waveform. The inverse calculation is mathematically valid but is not a device-selection rule.

The data sheet does not provide a full recovery-charge map for all operating points. For a demanding switching application, obtain suitable additional information or validate the commutation in the intended circuit.

How can you test a 1F3G with a multimeter?

Diode mode checks basic conduction, not full performance.

Remove power and discharge stored energy before resistance or diode-mode measurements. Read the meter instructions for probe polarity. With a typical digital meter, the red probe on the anode and black probe on the cathode tests forward conduction.

Reverse the probes to check the opposite direction. A basic isolated diode often conducts in one direction and appears blocking in the other. A near-short both ways suggests a fault, while an apparent open both ways requires checking contacts, meter behavior and the component.

In-circuit readings can be influenced by transformers, resistors, capacitors and other semiconductors. If the result is ambiguous, isolate a lead where appropriate and recheck. Do not condemn a part solely because a parallel circuit path changed the reading.

The meter uses a small test current. Its reading should not be compared directly with the data sheet’s 1.30 V value at 1 A. A low-current diode-mode test also cannot verify 200 V blocking, 150 ns recovery, hot leakage or surge survival.

Where can the 1F3G be considered?

Consider it where the verified electrical stresses fit.

The manufacturer lists small battery chargers and power supplies among applications for the family. A particular rectifying or inductive-current path still needs to fit the 1F3G’s voltage, current, recovery and thermal conditions.

For example, a hypothetical measured reverse peak of 170 V leaves 30 V below the 200 V rating. Whether that margin is adequate depends on tolerance, measurement uncertainty and abnormal behavior; the nominal supply alone cannot decide.

The 200 V rating is not suitable for a diode directly blocking the peak of a 230 V RMS sine wave, whose ideal peak is about 325 V before surges. Its published 140 V RMS value is also not a blanket permission to connect it to any 140 V AC topology.

What should you check before replacing it?

Match the required behavior, not only 1 A and 200 V.

Check package and polarity, maximum reverse stress, average and peak currents, surge conditions, forward loss, hot leakage and recovery test conditions. A general-purpose rectifier with similar voltage and current labels may behave differently during switching.

For a thermal illustration, assume 0.4 A average current and a constant 1.0 V forward drop. The conduction estimate is 0.4 W. If the assembly’s effective junction-to-ambient resistance were 80°C/W, the rise would be 32°C. Those assumed values are not measured 1F3G performance and omit dynamic loss.

A higher-voltage family member is not automatically equivalent. The 1F4G guide covers the 400 V member; the 1F5G guide explains a member with a different recovery-time limit.

Separate this part check from general meter instruction

The polarity and specifications above identify the 1F3G. A diode-mode reading only screens its low-current behavior; it does not verify recovery, rated blocking voltage, or high-temperature leakage. Use the general diode-mode workflow for interpreting the meter, and keep the part-specific approval checks here.

FAQs

Is the 1F3G a bridge rectifier?

No. In the referenced Good-Ark data sheet, the 1F3G is a single two-terminal fast recovery diode in an R-1 axial package. A packaged full-wave bridge has a different internal connection and terminal arrangement. Some search descriptions mix these names, so identify the original manufacturer document and physical terminals rather than treating a search-result title as a component specification.

What does the band on a 1F3G mean?

The band marks the cathode. Conventional forward current flows from the opposite anode end toward that banded cathode. Match this direction to the schematic and board connection before soldering. If printing is damaged or the board indication is ambiguous, confirm the manufacturer drawing and trace the nodes. Do not assume a plausible diode-mode reading proves the installed orientation is correct for the circuit.

Can the 1F3G carry 30 A continuously?

No. Its referenced average rectified-current rating is 1 A under stated conditions. The 30 A value describes a single 8.3 ms half-sine surge event, not continuous load or automatic approval for repeated pulses. Repetitive charging or startup requires a waveform and thermal assessment. Read the mounting note and derating information as well as the surge headline.

Can a multimeter verify its 150 ns recovery time?

No. Diode mode checks basic conduction at a small test current and can help locate certain faults. The published recovery time comes from a defined dynamic test, with specified forward current, reverse current and endpoint. A meter does not reproduce that transition. It also cannot prove rated blocking or hot leakage, and in-circuit parallel paths can affect the observed reading.

Can I replace a 1F3G with a 1F4G or 1F5G?

Possibly, if the required electrical and mechanical behavior fits. In the referenced family, the 1F4G raises the blocking rating while retaining the 150 ns maximum recovery limit; the 1F5G has a different 250 ns limit. These labels alone do not approve a substitute. Check recovery conditions, forward loss, current pulses, polarity, dimensions and installed temperature before accepting the replacement.

Why is my meter reading lower than the listed 1.30 V?

The listed forward-drop value is at 1 A, whereas a diode-mode meter normally uses a much smaller test current. Forward voltage also depends on temperature and the particular junction. The readings therefore describe different conditions. A lower meter value is not by itself a fault, but a plausible value also does not verify rated current, blocking voltage or switching performance.

Keep identification and approval separate

The marking, cathode band and meter test help identify the part and find obvious faults. Approval for use comes from the correct data sheet and the circuit conditions. Use the power rectifier selection guide when moving from identification to an actual replacement decision.

Continue through this engineering topic

For the complete selection, design, verification, and troubleshooting path, explore the Rectifier Testing Failure and Reliability.

• Practical guide: Thermal Cycling vs Power Cycling: Reading Rectifier Life Curves and the Delta-T Trade
• Practical guide: Rectifier Overheating: The Six Causes, the Evidence, and a Fix in Order
• Practical guide: Inside an ATX Power Supply: Rectifier Roles, 12 V Rails, and What Fails in a Loaded PC
• Ask Good-Ark technical support about this application