SF34G A0G Equivalent & Substitute Parts

Part Overview

The SF34G A0G is a general-purpose rectifier diode manufactured by Taiwan Semiconductor Corporation, rated for 200 V DC reverse voltage and 3 A average rectified current in a DO-201AD axial through-hole package. This component is classified as Active product status and is ROHS3 compliant. Equivalent and substitute parts are identified based on matching or exceeding the electrical and mechanical specifications of the original device, ensuring functional compatibility in circuit applications where this diode is specified.

Key Parameters

Parameter	Value	Unit
Voltage - DC Reverse (Vr) (Max)	200	V
Current - Average Rectified (Io)	3	A
Voltage - Forward (Vf) (Max) @ If	950 mV @ 3 A	mV
Speed	Fast Recovery ≤ 500ns, > 200mA (Io)	-
Reverse Recovery Time (trr)	35	ns
Current - Reverse Leakage @ Vr	5	µA @ 200 V
Package / Case	DO-201AD, Axial	-
Mounting Type	Through Hole	-
Operating Temperature - Junction	-55 to 150	°C
RoHS Status	ROHS3 Compliant	-

Substitute Part Grouping Explanation

Substitute parts for the SF34G A0G are grouped based on the following critical parameters that determine functional equivalence:

Primary Matching Criteria:

Voltage - DC Reverse (Vr) (Max): 200 V minimum
Current - Average Rectified (Io): 3 A minimum
Package / Case: DO-201AD, Axial (through-hole)
Mounting Type: Through Hole

Secondary Compatibility Factors:

Voltage - Forward (Vf) (Max) @ If: Comparable forward voltage drop
Speed Classification: Fast Recovery or Standard Recovery
Reverse Recovery Time (trr): Recovery characteristics
Operating Temperature Range: Junction temperature capability
RoHS Status: ROHS3 Compliant

Parts are classified into two categories: Direct Equivalents (matching all primary criteria with identical electrical performance) and Functional Substitutes (meeting or exceeding primary criteria with acceptable variations in secondary parameters).

Parameter Comparison

Part Number	Manufacturer	Vr (Max) [V]	Io [A]	Vf (Max) @ If [mV]	Speed	trr [ns]	Tj (Max) [°C]	Package
SF34G A0G	Taiwan Semiconductor Corporation	200	3	950 @ 3A	Fast Recovery ≤ 500ns	35	150	DO-201AD
1N5402-E3/54	Vishay General Semiconductor	200	3	1200 @ 3A	Standard Recovery >500ns	-	150	DO-201AD
1N5402-E3/73	Vishay General Semiconductor	200	3	1200 @ 3A	Standard Recovery >500ns	-	150	DO-201AD
BY251P-E3/54	Vishay General Semiconductor	200	3	1100 @ 3A	Standard Recovery >500ns	3000	150	DO-201AD
MUR420-E3/54	Vishay General Semiconductor	200	4	890 @ 4A	Fast Recovery ≤ 500ns	35	175	DO-201AD
MUR420-E3/73	Vishay General Semiconductor	200	4	890 @ 4A	Fast Recovery ≤ 500ns	35	175	DO-201AD
MUR420-M3/54	Vishay General Semiconductor	200	4	890 @ 4A	Fast Recovery ≤ 500ns	35	175	DO-201AD
RGP30D-E3/73	Vishay General Semiconductor	200	3	1300 @ 3A	Fast Recovery ≤ 500ns	150	175	DO-201AD
STTH302	STMicroelectronics	200	3	950 @ 3A	Fast Recovery ≤ 500ns	35	175	DO-201AD
STTH302RL	STMicroelectronics	200	3	950 @ 3A	Fast Recovery ≤ 500ns	35	175	DO-201AD

Engineering Selection Recommendations

Direct Equivalents (Identical Electrical Performance):

The STTH302 and STTH302RL from STMicroelectronics are direct equivalents to the SF34G A0G. Both devices match the 200 V reverse voltage, 3 A average rectified current, 950 mV forward voltage drop at 3 A, fast recovery speed classification, and 35 ns reverse recovery time. Both are ROHS3 compliant and rated to 175°C junction temperature, exceeding the SF34G A0G operating range. The STTH302RL variant includes a tape-and-reel packaging option.

Functional Substitutes with Higher Current Rating:

The MUR420-E3/54, MUR420-E3/73, and MUR420-M3/54 from Vishay General Semiconductor are functional substitutes rated for 4 A average rectified current, exceeding the 3 A requirement of the SF34G A0G. These devices maintain the 200 V reverse voltage, fast recovery speed classification, 35 ns reverse recovery time, and ROHS3 compliance. The higher current rating provides design margin for applications requiring increased current capacity. Junction temperature rating extends to 175°C.

Functional Substitutes with Matching Current Rating:

The 1N5402-E3/54 and 1N5402-E3/73 from Vishay General Semiconductor match the 200 V reverse voltage and 3 A current rating. These devices employ standard recovery speed classification (>500ns) and are ROHS3 compliant. Forward voltage is specified at 1200 mV at 3 A, representing a 250 mV increase compared to the SF34G A0G. These substitutes are suitable for applications where recovery speed is not a critical parameter.

The BY251P-E3/54 from Vishay General Semiconductor matches the 200 V reverse voltage and 3 A current rating with a forward voltage of 1100 mV at 3 A. This device employs standard recovery speed classification and is ROHS3 compliant.

The RGP30D-E3/73 from Vishay General Semiconductor (SUPERECTIFIER® series) matches the 200 V reverse voltage and 3 A current rating with fast recovery speed classification. Forward voltage is specified at 1300 mV at 3 A. Junction temperature rating extends to 175°C.

All substitute parts are packaged in DO-201AD axial through-hole format and are ROHS3 compliant, ensuring compatibility with existing PCB designs and regulatory requirements.

Frequently Asked Questions (FAQ)

Q: Can the MUR420 series replace the SF34G A0G in all applications?

A: The MUR420 series (MUR420-E3/54, MUR420-E3/73, MUR420-M3/54) can replace the SF34G A0G in applications where the 3 A current requirement is not exceeded. The MUR420 devices are rated for 4 A, providing design margin. Both device families share identical 200 V reverse voltage, fast recovery speed classification, and 35 ns reverse recovery time. The primary difference is the higher current rating of the MUR420 series, which does not restrict its use in 3 A circuits.

Q: What is the difference between fast recovery and standard recovery diodes?

A: Fast recovery diodes have reverse recovery times of 500 ns or less, while standard recovery diodes exceed 500 ns. The SF34G A0G is specified as fast recovery with 35 ns reverse recovery time. Standard recovery substitutes such as the 1N5402 series have recovery times exceeding 500 ns. Fast recovery diodes are preferred in high-frequency switching applications where reduced reverse recovery time minimizes switching losses and electromagnetic interference.

Q: Are the STTH302 and STTH302RL interchangeable?

A: The STTH302 and STTH302RL are electrically identical. The primary difference is packaging: STTH302 is supplied in cut tape format, while STTH302RL is supplied in tape-and-reel format. Both devices match the SF34G A0G electrical specifications and are suitable for direct replacement.

Q: Does forward voltage variation affect circuit performance?

A: Forward voltage variation affects power dissipation and voltage drop across the diode during conduction. The SF34G A0G is specified at 950 mV at 3 A. Substitutes with higher forward voltage (such as 1N5402 at 1200 mV or RGP30D at 1300 mV) will dissipate more power and produce greater voltage drop. In precision rectifier circuits or applications with tight voltage regulation requirements, forward voltage differences must be evaluated. In general power supply applications, forward voltage variations of 100-300 mV are typically acceptable.

Q: What does ROHS3 compliance indicate?

A: ROHS3 compliance indicates the device meets the Restriction of Hazardous Substances Directive 3 requirements, restricting the use of lead, mercury, cadmium, hexavalent chromium, polybrominated biphenyls, and polybrominated diphenyl ethers. All listed substitute parts are ROHS3 compliant, ensuring compatibility with environmental and regulatory standards.

Q: Can a 200 V rated diode be used in a 200 V circuit?

A: A 200 V rated diode is specified for maximum reverse voltage of 200 V. In circuit design, the peak reverse voltage must not exceed this rating. Operating at the maximum rated voltage provides no safety margin. Circuit design practice typically specifies diodes with reverse voltage ratings 25-50% higher than the maximum expected reverse voltage in the application.

Q: What is the significance of the DO-201AD package designation?

A: DO-201AD is a standardized axial through-hole package for rectifier diodes. The designation indicates a specific physical form factor with leads extending from both ends of the cylindrical body. All listed substitute parts use the DO-201AD package, ensuring mechanical compatibility with existing PCB designs and component placement equipment.

Q: How does junction temperature rating affect device selection?

A: The SF34G A0G is rated to 150°C maximum junction temperature. Most substitute parts are rated to 175°C, providing higher thermal margin. In applications where the diode operates near its maximum temperature limit, higher-rated devices provide additional safety margin. However, the actual junction temperature depends on ambient temperature, power dissipation, and thermal design of the circuit.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message