KBU4B Bridge Rectifier Equivalent & Substitute Parts

Part Overview

The KBU4B is a single-phase bridge rectifier manufactured by onsemi, rated for 100 V peak reverse voltage and 4 A average rectified current. This component is classified as obsolete, making equivalent and substitute parts necessary for ongoing design support and procurement continuity. Bridge rectifiers in this voltage and current class are widely used in power supply circuits, battery charging systems, and AC-to-DC conversion applications requiring through-hole mounting.

Key Parameters

Parameter	Value
Voltage - Peak Reverse (Max)	100 V
Current - Average Rectified (Io)	4 A
Voltage - Forward (Vf) (Max) @ If	1 V @ 4 A
Current - Reverse Leakage @ Vr	5 µA @ 50 V
Operating Temperature Range	-55°C ~ 150°C (TJ)
Mounting Type	Through Hole
Package / Case	4-SIP, KBU

Substitute Part Grouping Explanation

Substitution for the KBU4B is determined by the following critical parameters:

Voltage Rating: Peak reverse voltage must be 100 V or higher
Current Rating: Average rectified current must meet or exceed 4 A
Diode Type: Single-phase bridge rectifier configuration
Mounting: Through-hole package only
Package Form Factor: 4-SIP or compatible footprint (KBU or GBU)
Forward Voltage: Maximum forward voltage drop at rated current
Temperature Range: Operating temperature capability from -55°C to 150°C or better

All substitute parts listed maintain compatibility with these core electrical and mechanical specifications. Parts are grouped by manufacturer and product status to facilitate selection based on availability and compliance requirements.

Parameter Comparison

Part Number	Manufacturer	Voltage - Peak Reverse (Max)	Current - Average Rectified (Io)	Voltage - Forward (Vf) (Max) @ If	Current - Reverse Leakage @ Vr	Operating Temperature	Product Status	Inventory (Pcs)
KBU4B	onsemi	100 V	4 A	1 V @ 4 A	5 µA @ 50 V	-55°C ~ 150°C	Obsolete	1077
GBU4B	Diotec Semiconductor	100 V	2.8 A	1 V @ 4 A	5 µA @ 100 V	-50°C ~ 150°C	Active	1812
GBU401-G	Comchip Technology	100 V	4 A	1 V @ 2 A	10 µA @ 100 V	-55°C ~ 150°C	Active	896
GBU2501-G	Comchip Technology	100 V	4.2 A	1 V @ 12.5 A	10 µA @ 50 V	-55°C ~ 150°C	Active	934
GBU601-G	Comchip Technology	100 V	6 A	1 V @ 3 A	10 µA @ 100 V	-55°C ~ 150°C	Active	881
GBU801-G	Comchip Technology	100 V	8 A	1 V @ 4 A	5 µA @ 100 V	-55°C ~ 150°C	Active	2042

Engineering Selection Recommendations

GBU401-G (Comchip Technology) provides the closest electrical match to the KBU4B with identical 100 V voltage rating and 4 A current rating. This part is active in production and RoHS3 compliant, offering immediate procurement availability with 896 units in stock.

GBU2501-G (Comchip Technology) exceeds the KBU4B specifications with 4.2 A current capacity while maintaining 100 V voltage rating and the full -55°C to 150°C operating range. This part is active and RoHS3 compliant.

GBU801-G (Comchip Technology) provides higher current capacity at 8 A with 100 V voltage rating, suitable for applications requiring design margin or future current headroom. This part is active, RoHS3 compliant, and has the highest inventory availability at 2042 units.

GBU4B (Diotec Semiconductor) maintains the 100 V voltage rating and 1 V forward voltage specification. Current rating is 2.8 A, which is below the KBU4B specification and may not be suitable for full-load applications. Operating temperature range is -50°C to 150°C, which is narrower than the original part.

GBU601-G (Comchip Technology) provides 6 A current capacity with 100 V voltage rating and full temperature range compliance. This part is active and RoHS3 compliant.

All substitute parts use through-hole 4-SIP package configuration compatible with KBU4B footprints. Selection should be based on application current requirements, compliance certifications, and procurement lead times.

Frequently Asked Questions (FAQ)

Q: Can GBU4B replace KBU4B directly? A: GBU4B maintains the same voltage rating (100 V) and forward voltage specification (1 V @ 4 A). However, the average rectified current is rated at 2.8 A, which is below the KBU4B specification of 4 A. This part is suitable only for applications operating below 2.8 A continuous current.

Q: What is the difference between GBU401-G and GBU2501-G? A: Both parts are rated for 100 V and meet or exceed 4 A current requirements. GBU401-G is rated at exactly 4 A average rectified current, while GBU2501-G is rated at 4.2 A. GBU2501-G provides additional current margin. Both are active, RoHS3 compliant, and operate across the full -55°C to 150°C temperature range.

Q: Why would I select GBU801-G over GBU401-G? A: GBU801-G provides 8 A current capacity compared to GBU401-G at 4 A. Selection depends on application requirements. If the circuit requires only 4 A, GBU401-G is appropriate. If design margin or future current expansion is needed, GBU801-G provides higher capacity. Both parts are electrically compatible with the KBU4B footprint and operating temperature range.

Q: Are all substitute parts RoHS3 compliant? A: GBU4B, GBU401-G, GBU2501-G, GBU601-G, and GBU801-G are all RoHS3 compliant. The original KBU4B does not specify RoHS status.

Q: What is the package compatibility between KBU and GBU parts? A: Both KBU and GBU parts use 4-SIP through-hole package configuration. The physical footprint and pin spacing are compatible, allowing direct board-level substitution without layout modifications.

Q: Which substitute part has the best inventory availability? A: GBU801-G has the highest inventory at 2042 units in stock, followed by GBU4B at 1812 units. GBU2501-G and GBU401-G have 934 and 896 units respectively.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message