U3B-E3/9AT Equivalent & Substitute Parts

Part Overview

The U3B-E3/9AT is a general-purpose rectifier diode manufactured by Vishay General Semiconductor - Diodes Division. This surface mount device operates at 100 V DC reverse voltage with a 2 A average rectified current rating and features fast recovery characteristics with a 20 ns reverse recovery time. The component is housed in a DO-214AB (SMC) package and is classified as an active product with ROHS3 compliance and unlimited moisture sensitivity level (MSL 1).

Substitute parts are identified when equivalent electrical performance and mechanical compatibility can be maintained within the specified parameter ranges for this diode category.

Substiute Parts

U3B-E3/9AT

Vishay General Semiconductor - Diodes DivisionIn Stock: 824U3B-E3/9AT Datasheet

Current PartRFQ

ES3B

Taiwan Semiconductor CorporationIn Stock: 10461ES3B Datasheet

MFR RecommendedRFQ

STPS3H100U

STMicroelectronicsIn Stock: 65395STPS3H100U Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the U3B-E3/9AT are qualified based on the following criteria:

Electrical Parameter Compatibility:

• Voltage - DC Reverse (Vr) rating must equal or exceed 100 V
• Current - Average Rectified (Io) rating must equal or exceed 2 A
• Speed classification must maintain Fast Recovery characteristics (≤ 500ns, > 200mA)
• Operating temperature range must accommodate -55°C to 150°C minimum

Mechanical Compatibility:

• Surface mount mounting type required
• Package compatibility with DO-214AB (SMC) or equivalent footprint

Compliance Requirements:

• ROHS3 compliance mandatory
• MSL 1 (Unlimited) classification required

The identified substitute parts meet or exceed these parameters while maintaining functional equivalence for general-purpose rectification applications.

Parameter Comparison

Engineering Selection Recommendations

ES3B (Taiwan Semiconductor Corporation): The ES3B provides direct functional substitution with identical voltage and package specifications. This part maintains the same DO-214AB (SMC) package footprint and operating temperature range as the U3B-E3/9AT. The ES3B carries higher current capacity (3 A versus 2 A) and meets all compliance requirements including ROHS3 and MSL 1 classification. Forward voltage is marginally higher at 950 mV compared to 900 mV, and reverse recovery time is 35 ns versus 20 ns. Both parameters remain within acceptable ranges for standard rectification applications.

STPS3H100U (STMicroelectronics): The STPS3H100U is a Schottky technology diode that meets the 100 V voltage requirement and exceeds the 2 A current specification at 3 A. This part features superior reverse leakage characteristics (1 µA versus 10 µA) and lower forward voltage (840 mV versus 900 mV), resulting in reduced power dissipation. The STPS3H100U operates to 175°C maximum junction temperature, exceeding the U3B-E3/9AT specification. Package compatibility requires consideration: the STPS3H100U uses DO-214AA (SMB) package versus the DO-214AB (SMC) package of the main part. All compliance certifications are met. Selection of this part requires PCB footprint verification for the SMB package variant.

Both substitute parts maintain ROHS3 compliance, MSL 1 rating, and fast recovery speed classification required for this application category.

Frequently Asked Questions (FAQ)

Q: Can the ES3B directly replace the U3B-E3/9AT without PCB modifications?

A: Yes. The ES3B maintains identical package specifications (DO-214AB, SMC) and footprint compatibility. No PCB layout changes are required for this substitution.

Q: What is the primary difference between the ES3B and STPS3H100U substitutes?

A: The ES3B uses standard rectifier diode technology with the same DO-214AB package as the main part. The STPS3H100U employs Schottky technology in a DO-214AA (SMB) package. Schottky technology provides lower forward voltage drop and reduced reverse leakage but requires package footprint verification before implementation.

Q: Are all substitute parts ROHS3 compliant?

A: Yes. Both the ES3B and STPS3H100U carry ROHS3 compliance certification matching the U3B-E3/9AT specification.

Q: Does the higher current rating of substitute parts affect circuit operation?

A: No. Higher current ratings (3 A for both substitutes versus 2 A for the main part) provide additional design margin without affecting circuit performance. The device will operate within its rated specifications in the existing application.

Q: What packaging consideration applies to the STPS3H100U?

A: The STPS3H100U uses DO-214AA (SMB) package, which differs from the DO-214AB (SMC) package of the U3B-E3/9AT. PCB footprint compatibility must be verified before selection. The ES3B maintains identical DO-214AB (SMC) packaging for direct substitution without layout changes.

Q: How do forward voltage characteristics compare across these parts?

A: The U3B-E3/9AT specifies 900 mV maximum forward voltage at 3 A. The ES3B specifies 950 mV at 3 A. The STPS3H100U specifies 840 mV at 3 A. Lower forward voltage reduces power dissipation; higher forward voltage increases it. Selection depends on thermal design requirements.

Q: Are reverse recovery time differences significant for this application?

A: The U3B-E3/9AT specifies 20 ns reverse recovery time. The ES3B specifies 35 ns. Both remain within the fast recovery classification (≤ 500ns, > 200mA). Selection depends on switching frequency requirements; higher switching frequencies may benefit from shorter recovery times.

Q: What is the maximum operating temperature for each part?

A: The U3B-E3/9AT and ES3B both specify -55°C to 150°C junction temperature range. The STPS3H100U extends to 175°C maximum, providing additional thermal margin in high-temperature applications.