CDBMH340-G Schottky Diode Equivalent & Substitute Parts

Part Overview

The CDBMH340-G is a Schottky rectifier diode manufactured by Comchip Technology, rated for 40V DC reverse voltage with 3A average rectified current in a surface mount SOD-123T package. This component is classified as obsolete, necessitating identification of active equivalent parts for ongoing design requirements and procurement continuity. The fast recovery characteristic (≤500ns for currents >200mA) and low forward voltage drop make this diode suitable for high-frequency switching and power conversion applications.

Substiute Parts

CDBMH340-G

Comchip TechnologyIn Stock: 689CDBMH340-G Datasheet

Current PartRFQ

CDBMT240-HF

Comchip TechnologyIn Stock: 8313CDBMT240-HF Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the CDBMH340-G is determined by the following critical parameters:

Mandatory Matching Criteria:

• Voltage - DC Reverse (Vr) (Max): 40 V (exact match required)
• Technology: Schottky (defines switching characteristics)
• Mounting Type: Surface Mount (assembly compatibility)
• Operating Temperature Range: -55°C ~ 125°C (thermal envelope)

Allowable Variation Criteria:

• Current - Average Rectified (Io): Substitute must equal or exceed 3 A requirement
• Voltage - Forward (Vf) (Max): Substitute must not exceed 500 mV @ rated current
• Current - Reverse Leakage @ Vr: Substitute specification acceptable if within component class tolerances
• Package / Case: SOD-123T or compatible surface mount package (SOD-123H acceptable with mechanical verification)
• Speed: Fast Recovery characteristic maintained (≤500ns, >200mA)

The CDBMT240-HF qualifies as a substitute based on matching reverse voltage (40V), Schottky technology, fast recovery speed, surface mount configuration, and identical operating temperature range. The reduced current rating (2A vs. 3A) represents a derating condition and requires application-level verification that circuit current demands do not exceed 2A.

Parameter Comparison

Engineering Selection Recommendations

Substitution Feasibility:

The CDBMT240-HF is an active equivalent for the obsolete CDBMH340-G based on electrical parameter alignment and compliance status. Both components share identical reverse voltage rating (40V), Schottky technology, fast recovery speed, surface mount assembly type, and operating temperature range (-55°C to 125°C).

Critical Considerations:

1. Current Rating Derating: The substitute part is rated for 2A average rectified current versus the original 3A specification. Circuit designs must confirm that maximum operating current does not exceed 2A. Thermal analysis should account for the reduced current capacity.

2. Package Transition: The original CDBMH340-G uses SOD-123T packaging, while the substitute CDBMT240-HF uses SOD-123H packaging. Although both are surface mount packages, physical footprint and land pattern differences require PCB layout verification before implementation.

3. Reverse Leakage Increase: The substitute exhibits 500 µA reverse leakage at 40V compared to 200 µA for the original part. This 2.5× increase remains within acceptable Schottky diode specifications but should be evaluated in applications sensitive to leakage current (low-power standby circuits, precision analog circuits).

4. Capacitance Reduction: The substitute has lower junction capacitance (160 pF vs. 250 pF at 4V, 1MHz), which is advantageous for high-frequency switching applications and reduces switching losses.

5. Compliance and Availability: The CDBMT240-HF holds active product status with RoHS3 compliance and REACH unaffected designation, ensuring regulatory alignment and long-term procurement availability.

Frequently Asked Questions (FAQ)

Q: Can CDBMT240-HF directly replace CDBMH340-G without circuit modification?

A: Direct replacement requires verification of two conditions: (1) circuit maximum current does not exceed 2A, and (2) PCB layout accommodates SOD-123H package dimensions and land pattern. If both conditions are met, electrical substitution is valid. If circuit current exceeds 2A, the substitute is not suitable.

Q: What is the difference between SOD-123T and SOD-123H packages?

A: Both are surface mount Schottky diode packages with identical electrical performance. SOD-123T and SOD-123H differ in physical dimensions and lead configuration. PCB footprint and land pattern must be verified for compatibility. Consult package datasheets for precise dimensional specifications.

Q: Why does the substitute have higher reverse leakage current?

A: Reverse leakage current variation is inherent to Schottky diode manufacturing and technology. The 500 µA specification for CDBMT240-HF remains within acceptable limits for this component class. Applications requiring leakage current below 200 µA should evaluate this parameter against circuit requirements.

Q: Is the lower current rating (2A vs. 3A) a significant limitation?

A: The current rating reduction is significant only if the application requires sustained current above 2A. For applications operating at or below 2A, the substitute is fully adequate. Thermal design should account for the reduced current capacity to prevent device overstress.

Q: Are there compliance or regulatory differences between the two parts?

A: Both parts share identical ECCN (EAR99) and HTSUS classifications. The substitute CDBMT240-HF includes RoHS3 compliance and REACH unaffected status, providing regulatory alignment with current standards. The original CDBMH340-G compliance status is not specified in available data.

Q: What is the inventory status for these parts?

A: CDBMH340-G (obsolete) has 672 pieces in stock. CDBMT240-HF (active) has 8231 pieces available in Tape & Reel packaging, supporting sustained procurement requirements.