CDH333 TR Equivalent & Substitute Parts Reference

Part Overview

The CDH333 TR is a general-purpose rectifier diode manufactured by Central Semiconductor Corp, rated for 125 V DC reverse voltage and 200 mA average rectified current in a DO-35 through-hole package. The part is classified as obsolete, making equivalent and substitute parts necessary for ongoing design support and procurement.

General-purpose rectifier diodes in this voltage and current class are widely used in power supply circuits, signal conditioning, and protection applications. Substitutes must maintain electrical compatibility across reverse voltage, forward current capacity, and thermal characteristics while accommodating modern active product availability.

Substiute Parts

CDH333 TR

Central Semiconductor CorpIn Stock: 1091CDH333 TR Datasheet

Current PartRFQ

1N3595-1

Microchip TechnologyIn Stock: 36241N3595-1 Datasheet

MFR RecommendedRFQ

BAY135-TAP

Vishay General Semiconductor - Diodes DivisionIn Stock: 6147BAY135-TAP Datasheet

MFR RecommendedRFQ

FDH333TR

onsemiIn Stock: 168643FDH333TR Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution logic for the CDH333 TR is based on strict electrical and mechanical parameter matching within the general-purpose rectifier diode category. The following criteria determine valid substitutes:

Primary Substitution Criteria:

• Voltage - DC Reverse (Vr) (Max): Must equal or exceed 125 V
• Current - Average Rectified (Io): Must equal or exceed 200 mA
• Mounting Type: Must be Through Hole
• Package / Case: Must be DO-204AH, DO-35, or Axial equivalent
• Technology: Must be Standard (small-signal rectifier)
• Speed Classification: Must support Small Signal ≤ 200mA (Io), Any Speed

Secondary Compatibility Parameters:

• Voltage - Forward (Vf) (Max): Lower values preferred for reduced power dissipation
• Reverse Recovery Time (trr): Equivalent or faster acceptable
• Current - Reverse Leakage @ Vr: Lower values preferred for reduced standby current
• Operating Temperature - Junction: Must accommodate application thermal requirements

All three substitute parts (1N3595-1, BAY135-TAP, FDH333TR) meet the primary substitution criteria. Differences in secondary parameters reflect manufacturing variations and design optimizations across different manufacturers.

Parameter Comparison

Engineering Selection Recommendations

1N3595-1 (Microchip Technology)

The 1N3595-1 meets primary substitution criteria with 125 V reverse voltage and through-hole DO-35 packaging. However, the average rectified current rating is 150 mA, which is below the CDH333 TR specification of 200 mA. This part is suitable only for applications where the actual circuit current requirement does not exceed 150 mA. The part is active and in stock with 3543 units available. RoHS non-compliance status must be evaluated against procurement requirements. Operating temperature range is -65°C to 175°C, which is 25°C lower than the CDH333 TR maximum.

BAY135-TAP (Vishay General Semiconductor - Diodes Division)

The BAY135-TAP provides full electrical equivalence to the CDH333 TR with 125 V reverse voltage, 200 mA average rectified current, and DO-35 through-hole packaging. Forward voltage is 1 V at 30 mA, representing improved performance compared to the CDH333 TR. The part is ROHS3 compliant and active with 6090 units in stock. Packaging is supplied as Tape & Box (TB), suitable for automated assembly. Operating temperature maximum is 175°C. Reverse leakage is specified at 60 V rather than 125 V, which is a minor specification difference.

FDH333TR (onsemi)

The FDH333TR provides complete electrical and thermal equivalence to the CDH333 TR with 125 V reverse voltage, 200 mA average rectified current, identical forward voltage characteristics (1.15 V @ 300 mA), and matching reverse recovery time (3 µs). Package is DO-35 through-hole. The part is ROHS3 compliant and active with the highest inventory availability at 168620 units. Packaging is supplied as Cut Tape (CT). Operating temperature maximum is 175°C. This part represents the closest functional equivalent.

Compliance and Availability Summary:

For RoHS3-compliant applications, BAY135-TAP and FDH333TR are preferred. For applications requiring full thermal range to 200°C, none of the active substitutes match the CDH333 TR specification; design thermal derating or alternative part selection may be necessary. FDH333TR offers the best combination of electrical equivalence, compliance status, and inventory availability.

Frequently Asked Questions (FAQ)

Q: Can the 1N3595-1 be used as a direct replacement for the CDH333 TR?

A: The 1N3595-1 is not a direct replacement. While it matches the 125 V reverse voltage and DO-35 package, the average rectified current rating is 150 mA versus 200 mA for the CDH333 TR. Use only if circuit analysis confirms actual current requirements do not exceed 150 mA. Additionally, RoHS non-compliance status must be verified against procurement standards.

Q: What is the difference between BAY135-TAP and FDH333TR?

A: Both parts provide full electrical equivalence (125 V, 200 mA, DO-35). Key differences are: BAY135-TAP is supplied in Tape & Box packaging (suitable for automated assembly), while FDH333TR is supplied in Cut Tape. FDH333TR has significantly higher inventory availability (168620 vs. 6090 units). Forward voltage measurement conditions differ slightly (1 V @ 30 mA for BAY135-TAP vs. 1.15 V @ 300 mA for FDH333TR). Both are ROHS3 compliant and active products.

Q: Are all substitute parts compatible with the original PCB footprint?

A: Yes. All three substitute parts use DO-204AH (DO-35) axial through-hole packaging, which is mechanically and electrically compatible with the CDH333 TR footprint. No PCB modifications are required.

Q: What is the impact of the 25°C lower operating temperature maximum on the substitute parts?

A: The CDH333 TR specifies -65°C to 200°C junction temperature range, while active substitutes (1N3595-1, BAY135-TAP, FDH333TR) specify maximum 175°C. For applications operating near or above 175°C, design thermal analysis is required. If sustained operation above 175°C is necessary, alternative parts or thermal management modifications may be required.

Q: Which substitute part should be selected for new designs?

A: FDH333TR is recommended for new designs based on: complete electrical equivalence to CDH333 TR, ROHS3 compliance, active product status, and highest inventory availability (168620 units). BAY135-TAP is an acceptable alternative if Tape & Box packaging is preferred for automated assembly processes.

Q: Is reverse leakage specification difference between parts significant?

A: BAY135-TAP specifies reverse leakage at 60 V (3 nA), while CDH333 TR and FDH333TR specify at 125 V (3 nA). Leakage typically increases with applied voltage. The BAY135-TAP specification at lower voltage does not indicate superior performance; at 125 V, leakage would likely be higher. For applications sensitive to leakage current, FDH333TR or CDH333 TR specifications are more representative of actual operating conditions.

Q: Can these parts be used interchangeably in existing assemblies?

A: Yes, for applications where circuit current does not exceed 150 mA. For circuits designed for 200 mA operation, use only BAY135-TAP or FDH333TR. All three parts are through-hole DO-35 packages with identical mechanical compatibility. Electrical performance differences are minor and within typical circuit tolerance margins for general-purpose rectifier applications.