RB751S40 Equivalent & Substitute Parts

Part Overview

The RB751S40 is a Schottky rectifier diode manufactured by onsemi, rated for 30 V DC reverse voltage and 30 mA average rectified current in a surface mount SOD-523F package. This part is classified as obsolete, making equivalent and substitute components necessary for new designs and ongoing production requirements. The RB751S40 serves applications requiring small-signal Schottky rectification with low forward voltage drop and fast switching characteristics typical of Schottky technology.

Key Parameters

Parameter	Value	Unit
Voltage - DC Reverse (Vr) (Max)	30	V
Current - Average Rectified (Io)	30	mA
Voltage - Forward (Vf) (Max) @ If	370 mV @ 1 mA	mV
Current - Reverse Leakage @ Vr	500 nA @ 10 V	nA
Technology	Schottky	—
Speed Classification	Small Signal ≤ 200mA (Io), Any Speed	—
Mounting Type	Surface Mount	—
Package / Case	SC-79, SOD-523F	—
Operating Temperature - Junction	-55 to 125	°C
Moisture Sensitivity Level (MSL)	1 (Unlimited)	—

Substitute Part Grouping Explanation

Substitution of the RB751S40 is determined by strict equivalence across the following critical parameters:

Primary Substitution Criteria:

Voltage - DC Reverse (Vr) (Max): Must equal or exceed 30 V
Current - Average Rectified (Io): Must equal or exceed 30 mA
Voltage - Forward (Vf) (Max) @ If: Must not exceed 370 mV @ 1 mA for direct equivalence
Technology: Schottky rectifier diode
Mounting Type: Surface Mount
Package / Case: SOD-523 or SOD-523F (SC-79)

Direct Equivalents maintain identical electrical ratings and packaging, differing only in product status (Active vs. Obsolete) or packaging format (Tape & Reel vs. Cut Tape).

Similar Parts exceed one or more electrical parameters (higher voltage rating or current capacity) while maintaining the same package footprint and core Schottky technology. These parts are electrically compatible in applications where the RB751S40 is specified, as they provide equal or superior performance within the same physical constraints.

Parameter Comparison

Part Number	Manufacturer	Vr (Max) [V]	Io [mA]	Vf (Max) @ If [mV]	Package	Product Status	RoHS Status
RB751S40	onsemi	30	30	370 @ 1 mA	SOD-523F	Obsolete	—
RB751S40T5G	onsemi	30	30	370 @ 1 mA	SOD-523	Active	ROHS3 Compliant
RB751S40T1G	onsemi	30	30	370 @ 1 mA	SOD-523	Active	ROHS3 Compliant
BAS581-02V-G3-08	Vishay General Semiconductor - Diodes Division	40	30	370 @ 1 mA	SOD-523	Active	ROHS3 Compliant
PMEG4002EB,115	Nexperia USA Inc.	40	200	600 @ 200 mA	SOD-523	Active	ROHS3 Compliant
PMEG4002EJ,115	Nexperia USA Inc.	40	200	600 @ 200 mA	SOD-323F	Active	ROHS3 Compliant
PMEG4005EJ,115	Nexperia USA Inc.	40	500	470 @ 500 mA	SOD-323F	Active	ROHS3 Compliant
PMEG4010CEJ,115	Nexperia USA Inc.	40	1000	570 @ 1 A	SOD-323F	Active	ROHS3 Compliant
PMEG4010EJ,115	Nexperia USA Inc.	40	1000	640 @ 1 A	SOD-323F	Active	ROHS3 Compliant
RB751S-40-TP	Micro Commercial Co	40	30	370 @ 1 mA	SOD-523	Active	ROHS3 Compliant
RB751S40,115	Nexperia USA Inc.	40	120	370 @ 1 mA	SOD-523	Active	ROHS3 Compliant

Engineering Selection Recommendations

Direct Equivalents (Recommended Primary Substitutes):

RB751S40T5G and RB751S40T1G are direct functional equivalents to the obsolete RB751S40. Both parts maintain identical electrical specifications (30 V, 30 mA, 370 mV forward voltage) and are manufactured by onsemi. Both are Active products with ROHS3 compliance. Selection between these two depends on packaging format requirements: RB751S40T5G is supplied in Tape & Reel format, while RB751S40T1G is supplied in Cut Tape & Digi-Reel format. Both operate across the extended temperature range of -55°C to 150°C, exceeding the original part's -55°C to 125°C specification.

Compatible Alternatives (Same Voltage, Same Current):

BAS581-02V-G3-08 (Vishay) provides identical 30 mA current capacity and 370 mV forward voltage at 1 mA, with a higher 40 V reverse voltage rating. This part is Active and ROHS3 compliant, supplied in SOD-523 package. The elevated voltage rating provides additional design margin without affecting circuit performance in 30 V applications.

RB751S-40-TP (Micro Commercial Co) matches the RB751S40 electrical specifications exactly (30 mA, 370 mV @ 1 mA) with a 40 V reverse voltage rating. This part is Active, ROHS3 compliant, and supplied in Tape & Reel format in SOD-523 package.

Higher Current Capacity Alternatives (Same Voltage, Increased Current):

RB751S40,115 (Nexperia, supplied by Nexperia USA Inc.) provides 120 mA average rectified current at the same 40 V reverse voltage and 370 mV forward voltage specification. This part is Active, ROHS3 compliant, AEC-Q100 qualified for automotive applications, and operates to 150°C maximum junction temperature.

Higher Voltage and Current Alternatives (Increased Performance):

PMEG4002EB,115, PMEG4002EJ,115, PMEG4005EJ,115, PMEG4010CEJ,115, and PMEG4010EJ,115 (all Nexperia) provide 40 V reverse voltage with current ratings of 200 mA, 500 mA, and 1 A respectively. These parts are Active, ROHS3 compliant, and suitable for applications requiring higher current capacity than the original 30 mA specification. Package options include SOD-523 and SOD-323F formats. Forward voltage specifications vary with current rating and must be evaluated against circuit requirements.

All substitute parts listed maintain Moisture Sensitivity Level 1 (Unlimited) and REACH Unaffected status consistent with the original RB751S40.

Frequently Asked Questions (FAQ)

Q: Can RB751S40T5G or RB751S40T1G be used as direct replacements for the obsolete RB751S40?

A: Yes. Both parts are manufactured by onsemi and maintain identical electrical specifications: 30 V reverse voltage, 30 mA average rectified current, and 370 mV maximum forward voltage at 1 mA. The primary difference is packaging format (Tape & Reel vs. Cut Tape) and extended operating temperature range (-55°C to 150°C vs. -55°C to 125°C). Both are Active products with ROHS3 compliance.

Q: What is the difference between SOD-523F and SOD-523 packages?

A: Both packages are SC-79 footprints suitable for surface mount assembly. The SOD-523F designation in the original RB751S40 and the SOD-523 designation in substitute parts refer to the same physical package. The parts are mechanically and electrically interchangeable on the PCB.

Q: Can I use BAS581-02V-G3-08 or RB751S-40-TP in place of RB751S40?

A: Yes. Both parts provide 30 mA current capacity and 370 mV forward voltage at 1 mA, matching the original specification. Both have 40 V reverse voltage ratings, which exceeds the original 30 V specification and provides additional design margin. Both are Active products with ROHS3 compliance and SOD-523 packaging.

Q: When should I consider higher current alternatives like PMEG4002EB,115 or PMEG4010CEJ,115?

A: Higher current alternatives are appropriate when circuit requirements exceed 30 mA or when design margin for current capacity is desired. PMEG4002EB,115 provides 200 mA capacity; PMEG4005EJ,115 provides 500 mA capacity; PMEG4010CEJ,115 and PMEG4010EJ,115 provide 1 A capacity. These parts maintain 40 V reverse voltage and are suitable for applications requiring increased rectification current. Forward voltage specifications vary with current rating and must be evaluated against circuit design parameters.

Q: Are all substitute parts ROHS3 compliant?

A: Yes. All Active substitute parts listed (RB751S40T5G, RB751S40T1G, BAS581-02V-G3-08, PMEG4002EB,115, PMEG4002EJ,115, PMEG4005EJ,115, PMEG4010CEJ,115, PMEG4010EJ,115, RB751S-40-TP, and RB751S40,115) are ROHS3 compliant. The original RB751S40 does not specify RoHS status.

Q: What is the difference between Cut Tape and Tape & Reel packaging?

A: Both formats contain the same electronic component. Cut Tape (CT) & Digi-Reel format is suitable for lower-volume applications and manual assembly processes. Tape & Reel (TR) format is optimized for high-volume automated assembly. Selection depends on production volume and assembly equipment capabilities.

Q: Can I use PMEG4002EJ,115 or PMEG4005EJ,115 if my circuit requires SOD-523 package instead of SOD-323F?

A: No. PMEG4002EJ,115 and PMEG4005EJ,115 are supplied in SOD-323F package (SC-90 footprint), which differs physically from the SOD-523 package (SC-79 footprint) of the original RB751S40. Use PMEG4002EB,115 instead, which is supplied in SOD-523 package and provides 200 mA capacity at 40 V reverse voltage.

Q: Is RB751S40,115 (Nexperia) the same as RB751S40 (onsemi)?

A: No. RB751S40,115 is manufactured by Nexperia USA Inc. and provides 120 mA average rectified current, exceeding the original onsemi RB751S40 specification of 30 mA. Both maintain 40 V reverse voltage and 370 mV forward voltage at 1 mA. RB751S40,115 is AEC-Q100 qualified for automotive applications and operates to 150°C maximum junction temperature.

Q: What is the significance of AEC-Q100 qualification on RB751S40,115?

A: AEC-Q100 qualification indicates the part meets automotive industry reliability and quality standards. This certification is relevant for applications in automotive or other high-reliability environments. Parts without this designation are suitable for general industrial and consumer applications.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message