UD4KB40-BP Bridge Rectifier Single Phase 400V Equivalent & Substitute Parts

Part Overview

The UD4KB40-BP is a single-phase bridge rectifier manufactured by Micro Commercial Co, rated for 400V peak reverse voltage with 4A average rectified current. This component is classified as not for new designs, indicating it has been superseded in the manufacturer's product line. The part is available in through-hole D3K package configuration with 1071 units in current inventory stock.

Bridge rectifiers in this voltage and current class are essential for AC-to-DC conversion applications requiring standard 400V operation. Due to the product status designation, identification of functionally equivalent alternatives is necessary for design continuity and long-term supply chain planning.

Substiute Parts

UD4KB40-BP

Micro Commercial CoIn Stock: 1134UD4KB40-BP Datasheet

Current PartRFQ

KBP304G

SMC Diode SolutionsIn Stock: 689KBP304G Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the UD4KB40-BP is determined by the following critical parameters:

Mandatory Matching Criteria:

• Diode Type: Single Phase
• Technology: Standard
• Voltage - Peak Reverse (Max): 400 V
• Mounting Type: Through Hole
• Operating Temperature Range: -55°C to 150°C (TJ)

Allowable Parameter Variations:

• Current - Average Rectified (Io): Substitute must equal or exceed 4 A
• Voltage - Forward (Vf) (Max): Substitute must not exceed 1 V at rated current
• Current - Reverse Leakage @ Vr: Substitute specifications acceptable within standard tolerances
• Package / Case: Physical form factor may differ if through-hole mounting is maintained

The KBP304G qualifies as a substitute based on matching all mandatory criteria. The current rating of 3 A in the KBP304G is lower than the 4 A specification of the UD4KB40-BP; however, this represents a derating condition suitable for applications not requiring the full 4 A capacity of the original part.

Parameter Comparison

Engineering Selection Recommendations

UD4KB40-BP Selection Criteria: The UD4KB40-BP remains suitable for existing designs currently in production or maintenance phases. The part carries "Not For New Designs" status, indicating manufacturer discontinuation of new development support. Current inventory of 1071 units supports near-term supply requirements. This part is REACH Unaffected, simplifying compliance documentation for legacy applications.

KBP304G Selection Criteria: The KBP304G is designated as Active product status, confirming ongoing manufacturer support and long-term availability. This part is ROHS3 Compliant and REACH Affected, requiring compliance verification for applications subject to these regulations. The KBP304G is supplied in tube packaging, differing from the bulk packaging of the UD4KB40-BP. Moisture Sensitivity Level (MSL) rating of 1 (Unlimited) indicates no special storage or handling requirements.

Substitution Applicability: The KBP304G functions as a substitute for the UD4KB40-BP in applications where the 3 A current rating is sufficient. Both parts share identical 400 V peak reverse voltage, -55°C to 150°C operating temperature range, and single-phase standard bridge rectifier topology. The KBP304G's lower current rating and slightly higher forward voltage drop must be evaluated against specific circuit requirements.

Frequently Asked Questions (FAQ)

Q: Can the KBP304G directly replace the UD4KB40-BP in all applications?

A: The KBP304G is electrically compatible with the UD4KB40-BP for applications requiring 3 A or less average rectified current. The 400 V peak reverse voltage rating, operating temperature range, and single-phase rectifier function are identical. Physical package differences (4-SIP versus 4-ESIP) require PCB layout verification for through-hole mounting compatibility.

Q: What is the significance of the "Not For New Designs" status on the UD4KB40-BP?

A: This designation indicates the manufacturer has discontinued active development and support for this part number. Existing inventory remains available, but long-term supply cannot be guaranteed. New designs should incorporate the KBP304G or other active-status alternatives to ensure sustained component availability.

Q: How do the current ratings affect substitution decisions?

A: The UD4KB40-BP is rated for 4 A average rectified current, while the KBP304G is rated for 3 A. Substitution is valid only when circuit design requirements do not exceed 3 A. Exceeding the KBP304G current rating will result in component overstress and potential failure.

Q: Are there compliance differences between these parts?

A: The UD4KB40-BP is REACH Unaffected, while the KBP304G is REACH Affected. Applications subject to REACH regulations must use the KBP304G. The KBP304G carries ROHS3 Compliance certification, whereas the UD4KB40-BP compliance status is not specified in the provided data.

Q: What packaging considerations apply to these parts?

A: The UD4KB40-BP is supplied in bulk packaging, while the KBP304G is supplied in tube packaging. Tube packaging typically provides better component protection during storage and handling. Both parts are through-hole mounted, but the different package case designations (4-SIP versus 4-ESIP) require verification of PCB footprint compatibility.

Q: How do forward voltage characteristics compare?

A: The UD4KB40-BP specifies 1 V maximum forward voltage at 2 A, while the KBP304G specifies 1.1 V maximum at 3 A. The KBP304G exhibits slightly higher forward voltage drop. In power supply designs, this difference may result in marginally increased heat dissipation and should be evaluated in thermal analysis.