CQ92DT Equivalent & Substitute Parts

Part Overview

The CQ92DT is an internally triggered TRIAC rated for 400 V off-state voltage and 1 A on-state current in a TO-92-3 through-hole package. This component is classified as obsolete, making equivalent substitutes necessary for new designs and production continuity. The CQ92DT was manufactured by Central Semiconductor Corp and is no longer in active production, requiring engineers to identify functionally compatible alternatives that meet the same electrical and mechanical specifications.

Substiute Parts

CQ92DT

Central Semiconductor CorpIn Stock: 816CQ92DT Datasheet

Current PartRFQ

L401E3

Littelfuse Inc.In Stock: 2255L401E3 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the CQ92DT is determined by the following critical electrical and mechanical parameters:

Voltage Rating: Off-state voltage must be 400 V or greater to ensure equivalent blocking capability.

Current Rating: On-state current (It (RMS)) must be rated at 1 A or greater to handle the same load conditions.

Gate Trigger Characteristics: Gate trigger voltage (Vgt) and gate trigger current (Igt) must be compatible with existing circuit designs. The CQ92DT specifies Vgt (Max) of 2 V and Igt (Max) of 3 mA.

Hold Current: Hold current (Ih) must not exceed the circuit's capability to maintain conduction.

Package Compatibility: The substitute must use the same TO-92-3 through-hole package to ensure mechanical fit and PCB compatibility.

Operating Temperature: The substitute must support the required temperature range of -40°C to 125°C.

The L401E3 from Littelfuse Inc. meets these substitution criteria with matching voltage and current ratings, compatible gate trigger specifications, and identical through-hole packaging.

Parameter Comparison

Engineering Selection Recommendations

The L401E3 is the recommended substitute for the obsolete CQ92DT based on the following factors:

Electrical Equivalence: The L401E3 maintains the same 400 V voltage rating and 1 A current rating as the CQ92DT. The gate trigger voltage of 1.3 V (versus 2 V maximum for the CQ92DT) represents an improvement in gate sensitivity, making the L401E3 easier to trigger in existing circuits. The hold current specification of 5 mA (versus 3 mA for the CQ92DT) is within acceptable margins for most applications.

Production Status: The L401E3 is in active production with 2200 pieces in stock, ensuring long-term availability and supply chain continuity compared to the obsolete CQ92DT.

Compliance and Certifications: The L401E3 is ROHS3 compliant, meeting current environmental and regulatory requirements. Both components share the same ECCN (EAR99) and HTSUS (8541.30.0080) classifications.

Package Compatibility: Both components use the TO-92-3 through-hole package, allowing direct PCB substitution without layout modifications.

Temperature Range: The L401E3 supports an extended operating temperature range of -65°C to 125°C, providing greater flexibility for applications requiring lower temperature operation.

Frequently Asked Questions (FAQ)

Q: Can the L401E3 directly replace the CQ92DT without circuit modifications?

A: Yes. The L401E3 meets all critical electrical parameters (voltage, current, gate trigger specifications) and uses the same TO-92-3 package. Direct substitution is possible without PCB layout changes.

Q: What is the difference between "internally triggered" and "logic - sensitive gate" TRIAC types?

A: The CQ92DT is internally triggered, meaning it has built-in gate triggering circuitry. The L401E3 is a logic-sensitive gate TRIAC, which requires external gate drive signals but offers lower gate trigger voltage (1.3 V versus 2 V). Both types function as single-configuration TRIACs in the same package.

Q: Why is the L401E3's hold current (5 mA) higher than the CQ92DT's (3 mA)?

A: Hold current is the minimum current required to maintain TRIAC conduction after triggering. The L401E3's higher specification (5 mA) is still compatible with most circuit designs and does not prevent substitution. Verify that your circuit can supply this current level during normal operation.

Q: Is the L401E3's lower gate trigger voltage (1.3 V) an advantage or disadvantage?

A: Lower gate trigger voltage is an advantage. It means the L401E3 requires less gate drive voltage to switch on, making it more sensitive and easier to trigger than the CQ92DT. This improves circuit reliability and reduces gate drive component requirements.

Q: Are there any compliance differences between the CQ92DT and L401E3?

A: The L401E3 is ROHS3 compliant, meeting current environmental regulations. The CQ92DT is marked as RoHS non-compliant. For new designs and production, the L401E3 is the preferred choice to meet modern regulatory requirements.

Q: Can the L401E3 operate at lower temperatures than the CQ92DT?

A: Yes. The L401E3 supports operation down to -65°C, compared to the CQ92DT's -40°C minimum. This extended range makes the L401E3 suitable for applications requiring lower temperature performance.