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Home > Products > Discrete Semiconductor Products > Diodes > Bridge Rectifiers

Taiwan Semiconductor Corporation KBU1004G

Name: KBU1004G
Brand: Taiwan Semiconductor Corporation
SKU: KBU1004G
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: KBU1004G

Manufacturer:: Taiwan Semiconductor Corporation

Category:: Bridge Rectifiers

Package:: 4-SIP, KBU

Datasheet:: KBU1004G.pdf

Description:: BRIDGE RECT 1PHASE 400V 10A KBU

Quantity:: RFQ Add To RFQ list

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Inventory:368

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Product details

Overview

KBU1004G from Taiwan Semiconductor is a 10A, 400V repetitive peak reverse voltage (V_RRM) standard bridge rectifier in KBU package, featuring glass-passivated junctions, 200A surge capability (I_FSM), and 2.2°C/W junction-to-case thermal resistance - used for AC/DC conversion in compact off-line power supplies.

For engineers reviewing the KBU1004G datasheet, KBU1004G pinout, KBU1004G application, or KBU1004G equivalent, key selection factors include its 400V V_RRM, 10A average forward current rating, 1.1V max forward voltage at 10A, UL recognition (E-326243), and RoHS-compliant matte tin-plated leads suitable for J-STD-002 soldering.

Technical Context

The KBU1004G integrates four silicon diodes in a single-phase full-wave bridge configuration with quad-terminal layout. Its glass-passivated junction ensures stable leakage performance (<5 µA at 25°C, <500 µA at 125°C) and high reliability under thermal cycling.

Designed for PCB mounting with UL 94V-0 molding compound and 0.56 N·m maximum mounting torque, it supports high-density power conversion where ambient temperature derating and I²t fusing margin (166 A²s) are critical for surge immunity in SMPS and lighting drivers.

Key Specifications

Parameter	Value and Actual Design Meaning
V_RRM	400 V - Maximum repetitive reverse voltage the device blocks without breakdown; defines usable input AC range in bridge applications.
I_F	10 A - Continuous average forward current per device; determines heatsink sizing and conduction loss in steady-state operation.
I_FSM	200 A - Non-repetitive surge current (8.3 ms half-sine); enables robust startup and fault tolerance in switch-mode supplies.
V_F @ 10A	≤1.1 V - Forward voltage drop at rated current; directly impacts conduction loss (P_cond ≈ I_F × V_F) and thermal design.
R_θJC	2.2 °C/W - Junction-to-case thermal resistance; enables accurate case temperature estimation when mounted to heatsink or PCB copper.
I²t	166 A²s - Fusing integral for short-duration overcurrent; used to coordinate with upstream fuses or circuit breakers.

Pinout & Package

Package: KBU - molded plastic case with 4 axial leads (AC1, AC2, +, −), UL 94V-0 rated, 7.2 g weight, polarity marked on top surface.

Pin/Terminal	Circuit Role	Design Meaning
AC1	AC Input Terminal 1	One of two alternating-current input connections; tied internally to cathode of D1 and anode of D2 in full-wave bridge topology.
AC2	AC Input Terminal 2	Second AC input connection; tied internally to cathode of D3 and anode of D4; forms complete bridge input pair with AC1.
+	DC Output Anode	Positive DC output node; common cathode connection of D1 and D3; delivers rectified positive voltage to load/filter capacitor.
−	DC Output Cathode	Negative DC output node; common anode connection of D2 and D4; serves as return path and ground reference for output stage.

Key Features

Feature	Design Value
Glass-passivated junction	Reduces surface leakage and improves long-term stability under humidity and bias stress, critical for industrial-grade reliability.
UL Recognized (E-326243)	Validates safety compliance for end-equipment certification in North America without requiring additional system-level testing.
Matte tin-plated leads	Ensures consistent solderability per J-STD-002, eliminating lead-free solder wetting issues in automated PCB assembly.
JESD 201 Class 1A whisker resistance	Prevents tin whisker growth under thermal cycling, mitigating risk of latent short circuits in high-reliability applications.

Applications

LED Driver Power Supply	Desktop PC SMPS Input Stage
Use Scenario: Converts 100–240 VAC mains to unregulated DC bus feeding PFC and DC/DC stages in constant-current LED drivers. IC Role / Device Role / Timing Role: Primary AC/DC rectification element; provides isolated, low-leakage DC input with minimal conduction loss and high surge tolerance. Use Value: 400V V_RRM safely handles 240 VAC line peaks (≈340 V) with margin; 200A I_FSM withstands inrush into bulk capacitors.	Use Scenario: Rectifies AC input before active PFC in ATX-compliant desktop power supplies operating up to 230 VAC. IC Role / Device Role / Timing Role: Off-line bridge rectifier delivering ~320 VDC to boost converter; operates continuously at 10A average current. Use Value: 2.2°C/W R_θJC enables efficient thermal transfer to chassis or heatsink; UL recognition simplifies end-product safety approval.
Industrial AC Adapter	Commercial Lighting Ballast
Use Scenario: Powers 24 VDC industrial control modules from universal 85–264 VAC input in factory environments. IC Role / Device Role / Timing Role: Main rectifier in compact, convection-cooled adapter; must survive repeated cold-start surges and ambient temperatures up to 70°C. Use Value: −55°C to +150°C operating range ensures functionality across extended temperature profiles; 166 A²s I²t supports fuse coordination.	Use Scenario: Provides DC bus for electronic ballasts driving T5/T8 fluorescent lamps or integrated LED troffers in office buildings. IC Role / Device Role / Timing Role: High-efficiency bridge rectifier in high-frequency AC/DC front-end; interfaces with EMI filter and resonant tank. Use Value: Low IR (<5 µA at 25°C) minimizes standby power loss; glass passivation maintains leakage performance over 10-year service life.

LED Driver Power Supply

Desktop PC SMPS Input Stage

Use Scenario: Converts 100–240 VAC mains to unregulated DC bus feeding PFC and DC/DC stages in constant-current LED drivers.

IC Role / Device Role / Timing Role: Primary AC/DC rectification element; provides isolated, low-leakage DC input with minimal conduction loss and high surge tolerance.

Use Value: 400V V_RRM safely handles 240 VAC line peaks (≈340 V) with margin; 200A I_FSM withstands inrush into bulk capacitors.

Use Scenario: Rectifies AC input before active PFC in ATX-compliant desktop power supplies operating up to 230 VAC.

IC Role / Device Role / Timing Role: Off-line bridge rectifier delivering ~320 VDC to boost converter; operates continuously at 10A average current.

Use Value: 2.2°C/W R_θJC enables efficient thermal transfer to chassis or heatsink; UL recognition simplifies end-product safety approval.

Industrial AC Adapter

Commercial Lighting Ballast

Use Scenario: Powers 24 VDC industrial control modules from universal 85–264 VAC input in factory environments.

IC Role / Device Role / Timing Role: Main rectifier in compact, convection-cooled adapter; must survive repeated cold-start surges and ambient temperatures up to 70°C.

Use Value: −55°C to +150°C operating range ensures functionality across extended temperature profiles; 166 A²s I²t supports fuse coordination.

Use Scenario: Provides DC bus for electronic ballasts driving T5/T8 fluorescent lamps or integrated LED troffers in office buildings.

IC Role / Device Role / Timing Role: High-efficiency bridge rectifier in high-frequency AC/DC front-end; interfaces with EMI filter and resonant tank.

Use Value: Low IR (<5 µA at 25°C) minimizes standby power loss; glass passivation maintains leakage performance over 10-year service life.

Equivalent & Alternatives

The following parts are listed as comparable options for similar bridge rectifier applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
GBU1004	Same 10A/400V rating, GBU package (larger footprint, higher R_θJA = 30°C/W), no UL recognition.	Acceptable where space permits and safety certification is handled at system level.	Choose GBU1004 only if board layout allows larger GBU outline and UL listing is not required.
W04M	4A/400V rating, smaller WOB package, lower I_FSM (60A), same KBU pinout but reduced current capacity.	Suitable for low-power adapters (<30W) where thermal budget is constrained.	Select W04M only for designs with ≤4A average load and verified surge margin; not a direct replacement for 10A use cases.

Compared with GBU1004 and W04M, the KBU1004G uniquely combines UL recognition, 10A continuous rating, and 2.2°C/W thermal resistance in the KBU outline - making it optimal for certified, thermally demanding, mid-power SMPS where reliability and regulatory compliance are non-negotiable.

Availability

KBU1004G is available at Aetrix Electronics and suitable for switching mode power supplies, LED lighting drivers, and industrial AC adapters requiring stable component supply, long-lifecycle support, and traceable sourcing.

Supply support for KBU1004G includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Taiwan Semiconductor Corporation (TSC) is a vertically integrated analog and discrete semiconductor manufacturer headquartered in Hsinchu, Taiwan, serving global power, industrial, and consumer markets since 1979.

The KBU1004G belongs to TSC's standard bridge rectifier product line, engineered for cost-effective, high-reliability AC/DC front-end conversion in off-line power systems where safety certification, thermal performance, and long-term stability are essential.

FAQ

What is the maximum repetitive peak reverse voltage (V_RRM) for KBU1004G?

The KBU1004G has a V_RRM of 400 V, meaning it can reliably block up to 400 V of reverse voltage in repetitive AC cycles. This rating ensures safe operation with 230 VAC mains (peak ≈ 325 V) plus safety margin. The value is confirmed in the Absolute Maximum Ratings table of the official Taiwan Semiconductor datasheet (Version J2103) and applies specifically to the KBU1004G variant - not extrapolated from adjacent part numbers.

Does KBU1004G have UL recognition, and what is the file number?

Yes, the KBU1004G is UL Recognized under File # E-326243. This certification covers the entire KBU1001G–KBU1007G family and validates compliance with UL 60747-4 for semiconductor devices. The recognition applies to the KBU1004G as shipped, supporting faster end-product safety approvals in North American markets without requiring retesting.

What is the forward voltage drop (V_F) of KBU1004G at 10A and 25°C?

At 10A forward current and 25°C junction temperature, the KBU1004G exhibits a maximum forward voltage drop of 1.1 V per diode (i.e., 2.2 V total across the bridge). This value is specified in the Electrical Specifications table under "Forward voltage per diode" and directly impacts conduction losses and thermal design in high-current applications.

Can KBU1004G be used in place of KBU1006G in a 600V design?

No - the KBU1004G is rated for 400 V V_RRM, while the KBU1006G is rated for 800 V. Substituting KBU1004G in a 600V application risks reverse breakdown and catastrophic failure. The voltage ratings are strictly variant-specific; KBU1004G data does not extend to higher-voltage members of the family, and no derating guidance is provided in the datasheet for such use.

What is the thermal resistance from junction to case (R_θJC) for KBU1004G?

The KBU1004G has a typical junction-to-case thermal resistance (R_θJC) of 2.2°C/W, as published in the Thermal Performance section of the datasheet. This value enables precise case temperature estimation when the device is mounted to a heatsink or thermally enhanced PCB, and is critical for validating thermal margin in continuous 10A operation.

KBU1004G Specifications

Product attributes: Attribute value

Manufacturer:: Taiwan Semiconductor Corporation

Series:: -

Package/Case:: 4-SIP, KBU

Packaging:: Tray

Product Status:: Active

Diode Type:: Single Phase

Technology:: Standard

Voltage - Peak Reverse (Max):: 400 V

Current - Average Rectified (Io):: 10 A

Voltage - Forward (Vf) (Max) @ If:: 1.1 V @ 10 A

Current - Reverse Leakage @ Vr:: 5 µA @ 400 V

Operating Temperature:: -55°C ~ 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: KBU

KBU1004G FAQ

1.How can I place an order for KBU1004G through Aetrix?

Please submit a Request for Quotation (RFQ) for KBU1004G on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for KBU1004G reliable?

The price and inventory of KBU1004G are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for KBU1004G is usually 5 days.

3.What payment methods are accepted for KBU1004G?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for KBU1004G transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for KBU1004G?

KBU1004G orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your KBU1004G order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for KBU1004G?

For technical support, including KBU1004G datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your KBU1004G requirements.

6.How does Aetrix verify that KBU1004G is sourced from the original manufacturer or authorized distributors?

All KBU1004G products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that KBU1004G meets industry standards.

7.What is the process for return or replacement of KBU1004G?

All KBU1004G units undergo pre-shipment inspection (PSI). If there is an issue with KBU1004G, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The KBU1004G part is unused and in its original packaging.

Return procedure for KBU1004G:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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