KMB125F Equivalent & Substitute Parts

Part Overview

The KMB125F is a single-phase Schottky bridge rectifier diode manufactured by SMC Diode Solutions, rated for 1 A average rectified current at 250 V peak reverse voltage. The device is packaged in a 4-SMD Gull Wing surface mount configuration with an MBF supplier package designation. The KMB125F is classified as obsolete, necessitating identification of active equivalent components for new designs and ongoing production requirements. Substitute parts must maintain electrical compatibility across current rating, voltage specification, forward voltage characteristics, and thermal operating range while meeting modern compliance standards.

Substiute Parts

KMB125F

SMC Diode SolutionsIn Stock: 811KMB125F Datasheet

Current PartRFQ

KMB120F

SMC Diode SolutionsIn Stock: 738KMB120F Datasheet

MFR RecommendedRFQ

KMB120F

SMC Diode SolutionsIn Stock: 738KMB120F Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the KMB125F is determined by strict equivalence across the following electrical and mechanical parameters:

Critical Substitution Parameters:

• Diode Type: Single Phase (fixed requirement)
• Technology: Schottky (fixed requirement)
• Current - Average Rectified (Io): 1 A (fixed requirement)
• Mounting Type: Surface Mount (fixed requirement)
• Package / Case: 4-SMD, Gull Wing (fixed requirement)
• Supplier Device Package: MBF (fixed requirement)
• Operating Temperature Range: -55°C ~ 150°C (TJ) (fixed requirement)

Allowable Variation Parameters:

• Voltage - Peak Reverse (Max): Equal to or greater than 250 V
• Voltage - Forward (Vf) (Max) @ If: Equal to or less than 920 mV @ 1 A
• Current - Reverse Leakage @ Vr: Equal to or less than 50 µA at rated voltage

Substitute parts must satisfy all critical parameters identically and meet or exceed performance in allowable variation parameters. The KMB120F meets the fixed requirements but operates at a reduced peak reverse voltage rating of 200 V, which is below the original 250 V specification and therefore does not qualify as a direct substitute for applications requiring the full 250 V rating.

Parameter Comparison

Engineering Selection Recommendations

The KMB125F is classified as obsolete, requiring transition to active components for continued supply chain support. The KMB120F is the manufacturer-recommended substitute and carries Active product status with ROHS3 compliance certification, providing improved regulatory alignment compared to the original part.

Selection Basis:

The KMB120F maintains electrical and mechanical compatibility across all critical parameters: single-phase Schottky technology, 1 A average rectified current, identical thermal operating range, and matching 4-SMD Gull Wing surface mount package configuration. The forward voltage characteristic of the KMB120F (900 mV @ 1 A) is superior to the original specification (920 mV @ 1 A), reducing power dissipation in rectification circuits.

Voltage Rating Consideration:

The KMB120F operates at a peak reverse voltage rating of 200 V, which is 50 V lower than the KMB125F specification of 250 V. This reduced rating must be evaluated against circuit requirements. Applications operating at or below 200 V peak reverse voltage can utilize the KMB120F without derating. Applications requiring the full 250 V rating require alternative components outside the provided substitute list.

Compliance Status:

The KMB120F achieves ROHS3 compliance and maintains REACH Affected status consistent with the original part. Moisture sensitivity level remains at MSL 1 (Unlimited), preserving handling and storage requirements.

Frequently Asked Questions (FAQ)

Q: Can the KMB120F directly replace the KMB125F in all applications?

A: The KMB120F is electrically and mechanically compatible with the KMB125F across current rating, forward voltage, thermal range, and package configuration. However, the reduced peak reverse voltage rating of 200 V versus 250 V must be verified against circuit operating conditions. Direct substitution is valid only for applications operating at or below 200 V peak reverse voltage.

Q: What is the significance of the reduced voltage rating in the KMB120F?

A: The KMB120F peak reverse voltage rating of 200 V is 50 V lower than the KMB125F. This parameter defines the maximum reverse bias voltage the diode can withstand without breakdown. Applications designed for 250 V operation require verification that actual circuit peak reverse voltages do not exceed 200 V, or alternative components must be selected.

Q: Are the forward voltage characteristics of the KMB120F acceptable?

A: The KMB120F forward voltage of 900 mV @ 1 A is 20 mV lower than the KMB125F specification of 920 mV @ 1 A. This represents improved performance, reducing power dissipation and heat generation in rectification circuits. No derating or adjustment is required.

Q: Does the KMB120F maintain the same package footprint?

A: Yes. Both the KMB125F and KMB120F utilize identical 4-SMD Gull Wing surface mount packaging with MBF supplier device package designation. PCB layout and assembly processes require no modification.

Q: What compliance improvements does the KMB120F provide?

A: The KMB120F carries Active product status and ROHS3 compliance certification, providing improved long-term supply chain availability and regulatory alignment compared to the obsolete KMB125F. Both parts maintain REACH Affected status and MSL 1 moisture sensitivity level.

Q: Are there inventory considerations for the KMB120F?

A: The KMB120F is listed as Active with 727 pieces in new original stock, ensuring availability for production requirements. The KMB125F is obsolete with 715 pieces remaining in inventory, representing limited supply for legacy applications.