CSDD-25M BK Equivalent & Substitute Parts

Part Overview

The CSDD-25M BK is a Silicon Controlled Rectifier (SCR) rated for 600V off-state voltage with 25A RMS on-state current in a surface mount D2PAK package. This component is classified as obsolete, making identification of functionally equivalent alternatives essential for ongoing system support and new design implementations. The part operates across an industrial temperature range of -40°C to 125°C and features standard recovery characteristics suitable for AC switching applications.

Substiute Parts

CSDD-25M BK

Central Semiconductor CorpIn Stock: 835CSDD-25M BK Datasheet

Current PartRFQ

QJ6025NH5RP

Littelfuse Inc.In Stock: 1469QJ6025NH5RP Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the CSDD-25M BK is based on the following critical electrical and mechanical parameters:

Voltage Rating: Off-state voltage must equal or exceed 600V to maintain blocking capability in the same application circuit.

Current Rating: On-state RMS current must support minimum 25A to ensure adequate current-carrying capacity without thermal derating.

Gate Trigger Characteristics: Gate trigger voltage (Vgt) and gate trigger current (Igt) must remain within compatible ranges to ensure reliable triggering from existing gate drive circuits.

Thermal Operating Range: The substitute must operate across the required temperature envelope; extended upper temperature limits are acceptable.

Package Compatibility: Surface mount D2PAK (TO-263-3) package is mandatory for PCB layout compatibility.

Device Type: While the CSDD-25M BK is an SCR (Standard Recovery), functionally equivalent thyristor devices such as TRIACs with matching electrical specifications and package form factor are acceptable substitutes for AC switching applications where bidirectional conduction is not a circuit requirement.

Parameter Comparison

Engineering Selection Recommendations

The QJ6025NH5RP from Littelfuse Inc. is an active product substitute for the obsolete CSDD-25M BK. Both devices share identical voltage and current ratings (600V, 25A RMS) and are packaged in the same D2PAK surface mount form factor, ensuring direct PCB compatibility.

The QJ6025NH5RP offers the following advantages:

Active Product Status: Ensures long-term availability and supply chain continuity, eliminating obsolescence risk associated with the CSDD-25M BK.

Extended Temperature Range: Operating range of -40°C to 150°C exceeds the original specification of -40°C to 125°C, providing thermal margin in high-temperature environments.

RoHS3 Compliance: Meets current environmental and regulatory requirements for electronic component manufacturing and distribution.

Lower Gate Trigger Voltage: Vgt of 1.3V is lower than the original 1.5V specification, potentially reducing gate drive circuit power requirements.

Identical Moisture Sensitivity: MSL rating of 1 (Unlimited) matches the original part, maintaining equivalent handling and storage requirements.

The QJ6025NH5RP functions as a TRIAC (Alternistor - Snubberless configuration) rather than an SCR. In applications requiring unidirectional conduction only, the SCR characteristics of the original part are not essential; the TRIAC's bidirectional capability does not degrade performance in such circuits. For applications requiring strict unidirectional conduction, circuit validation is necessary to confirm TRIAC operation is acceptable.

Frequently Asked Questions (FAQ)

Q: Why is the CSDD-25M BK classified as obsolete?

A: The CSDD-25M BK is no longer manufactured by Central Semiconductor Corp. Obsolete status indicates the part is not available through standard distribution channels and future availability cannot be guaranteed.

Q: Can the QJ6025NH5RP directly replace the CSDD-25M BK on the PCB?

A: Yes. Both devices use the TO-263-3 D2PAK surface mount package with identical pinout and footprint. No PCB layout modifications are required.

Q: What is the difference between an SCR and a TRIAC?

A: An SCR (Silicon Controlled Rectifier) conducts current in one direction only (unidirectional). A TRIAC (Triode for Alternating Current) conducts in both directions (bidirectional). In circuits where unidirectional conduction is not a functional requirement, a TRIAC can substitute for an SCR without performance degradation.

Q: Are the gate trigger characteristics compatible?

A: The QJ6025NH5RP has a lower gate trigger voltage (1.3V vs. 1.5V) and higher gate trigger current (50mA vs. 30mA). Existing gate drive circuits designed for the CSDD-25M BK will reliably trigger the QJ6025NH5RP. The lower Vgt may reduce gate drive power consumption.

Q: Does the extended temperature range of the QJ6025NH5RP affect compatibility?

A: No. The extended upper temperature limit of 150°C (vs. 125°C) provides additional thermal margin and does not reduce compatibility. The lower temperature limit remains -40°C, matching the original specification.

Q: What compliance certifications apply to the QJ6025NH5RP?

A: The QJ6025NH5RP is RoHS3 compliant and REACH unaffected. Both devices carry identical ECCN (EAR99) and HTSUS (8541.30.0080) classifications.

Q: Is moisture sensitivity a concern when switching from CSDD-25M BK to QJ6025NH5RP?

A: No. Both parts carry MSL rating 1 (Unlimited), indicating no moisture sensitivity. Handling and storage requirements are identical.