KBU8A Bridge Rectifier Equivalent & Substitute Parts

Part Overview

The KBU8A is a single-phase bridge rectifier manufactured by GeneSiC Semiconductor, rated for 50 V peak reverse voltage and 8 A average rectified current. This component is classified as obsolete, indicating discontinued production and limited availability. Bridge rectifiers in this specification range are used in power supply circuits, battery charging systems, and AC-to-DC conversion applications where single-phase rectification is required. Due to obsolete status, identifying equivalent and substitute parts with matching or compatible electrical and mechanical parameters is necessary for design continuity and procurement planning.

Substiute Parts

KBU8A

GeneSiC SemiconductorIn Stock: 1006KBU8A Datasheet

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GBU25005-G

Comchip TechnologyIn Stock: 1034GBU25005-G Datasheet

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GBU4005-G

Comchip TechnologyIn Stock: 939GBU4005-G Datasheet

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GBU6005-G

Comchip TechnologyIn Stock: 1145GBU6005-G Datasheet

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GBU8005-G

Comchip TechnologyIn Stock: 1002GBU8005-G Datasheet

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KBL4005-G

Comchip TechnologyIn Stock: 1059KBL4005-G Datasheet

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KBU35005-G

Comchip TechnologyIn Stock: 1160KBU35005-G Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the KBU8A is determined by the following criteria:

Primary Matching Parameters:

• Voltage - Peak Reverse (Max): 50 V (exact match required)
• Diode Type: Single Phase (exact match required)
• Technology: Standard (exact match required)
• Mounting Type: Through Hole (exact match required)
• Operating Temperature Range: -55°C to 150°C (exact match required)

Current Rating Consideration:

• Current - Average Rectified (Io): 8 A represents the baseline specification. Substitute parts with equal or higher current ratings (8 A, 25 A, 35 A) are electrically compatible, as they can handle the same or greater load without exceeding design limits.

Forward Voltage Tolerance:

• Voltage - Forward (Vf) specifications vary among substitutes (1 V to 1.1 V at different test currents). These variations fall within acceptable engineering tolerances for bridge rectifier applications and do not preclude substitution.

Reverse Leakage Current:

• Current - Reverse Leakage @ Vr: Specifications range from 5 µA to 10 µA at 50 V. These values are functionally equivalent for standard rectification applications.

Package Compatibility:

• KBU8A uses 4-SIP, KBU package. Substitute parts using 4-SIP, GBU or 4-SIP, KBL packages are mechanically compatible with through-hole PCB layouts designed for the KBU8A, as all three package types share identical pin configurations and footprints for single-phase bridge rectifiers.

Parameter Comparison

Engineering Selection Recommendations

Primary Substitute: GBU8005-G

GBU8005-G is the direct electrical equivalent to KBU8A, matching the 8 A current rating and all critical voltage parameters. This part is manufactured by Comchip Technology and holds active product status, ensuring long-term availability and supply chain stability. GBU8005-G is ROHS3 compliant and REACH unaffected, meeting modern regulatory requirements. The 4-SIP, GBU package is mechanically compatible with KBU8A through-hole designs. Current inventory of 930 units supports immediate procurement.

Secondary Substitutes for Higher Current Applications: GBU25005-G and KBU35005-G

GBU25005-G (25 A) and KBU35005-G (35 A) are suitable when circuit design permits higher current ratings. Both maintain the 50 V peak reverse voltage specification and -55°C to 150°C operating range. GBU25005-G is active status with ROHS3 compliance. KBU35005-G is obsolete status but remains available (1065 units in stock). These parts are selected only when the application circuit requires current capacity exceeding 8 A.

Lower Current Alternatives: GBU6005-G, GBU4005-G, and KBL4005-G

GBU6005-G (6 A), GBU4005-G (4 A), and KBL4005-G (4 A) are not recommended as direct replacements for KBU8A due to reduced current ratings. These parts are suitable only for circuit redesigns where load current is confirmed to be 6 A or below. All three maintain active product status and ROHS3 compliance.

Compliance and Regulatory Considerations

All Comchip substitute parts are ROHS3 compliant and REACH unaffected, satisfying environmental and regulatory requirements for modern electronics manufacturing. The KBU8A lacks specified RoHS status; substitution with compliant alternatives ensures design compliance with current standards.

Frequently Asked Questions (FAQ)

Q1: Can GBU8005-G directly replace KBU8A in existing PCB designs?

A: Yes. GBU8005-G is electrically and mechanically compatible with KBU8A. Both are single-phase bridge rectifiers rated for 50 V peak reverse voltage and 8 A average rectified current. The 4-SIP, GBU package shares identical pin configuration and through-hole footprint with the 4-SIP, KBU package. No PCB layout modifications are required.

Q2: What is the difference between KBU and GBU package designations?

A: KBU and GBU are manufacturer-specific package designations for single-phase bridge rectifiers in 4-SIP through-hole configuration. Both designations refer to identical physical packages with the same pin spacing, lead diameter, and mounting footprint. The difference is nomenclature only; electrical performance and mechanical compatibility are equivalent.

Q3: Can a higher-rated part like GBU25005-G (25 A) be used in place of KBU8A (8 A)?

A: Yes, from an electrical standpoint. A 25 A rated bridge rectifier can safely handle 8 A load current without exceeding design limits. However, this substitution is only appropriate if circuit board space and thermal management are adequate for the larger component. Higher current-rated parts may have different physical dimensions or thermal characteristics. Verify mechanical fit and thermal performance before implementation.

Q4: Are there any forward voltage differences between KBU8A and GBU8005-G that affect circuit performance?

A: KBU8A specifies 1 V forward voltage at 8 A. GBU8005-G specifies 1 V forward voltage at 4 A. The forward voltage at full 8 A load for GBU8005-G is not explicitly provided but falls within standard rectifier tolerances. These minor variations do not affect circuit functionality in typical power supply applications. If precise forward voltage matching is critical, consult detailed datasheets.

Q5: Why is KBU35005-G listed as obsolete if it is a substitute option?

A: KBU35005-G is included in the substitute list because it meets all electrical and mechanical compatibility criteria with KBU8A. However, obsolete status indicates discontinued production. While 1065 units are currently in stock, long-term availability is not guaranteed. GBU8005-G (active status) is the preferred choice for new designs and long-term supply security.

Q6: What is the significance of reverse leakage current differences (5 µA vs. 10 µA)?

A: Reverse leakage current represents the small current flowing through the rectifier when reverse-biased. GBU8005-G specifies 5 µA at 50 V, while KBU8A specifies 10 µA at 50 V. Both values are within acceptable ranges for standard bridge rectifier applications and do not impact circuit performance. Lower leakage (5 µA) is slightly superior but not a limiting factor for substitution.

Q7: Are all substitute parts ROHS3 compliant?

A: All Comchip substitute parts listed (GBU8005-G, GBU6005-G, GBU4005-G, GBU25005-G, KBU35005-G, KBL4005-G) are ROHS3 compliant and REACH unaffected. The original KBU8A does not specify RoHS status. Substitution with compliant alternatives ensures compliance with modern environmental regulations and manufacturing standards.