Q201E4 Equivalent & Substitute Parts

Part Overview

The Q201E4 is a standard TRIAC thyristor manufactured by Littelfuse Inc., rated for 200V off-state voltage and 1A on-state current in a TO-92 through-hole package. This component is classified as obsolete, making equivalent and substitute parts necessary for ongoing design support and production continuity. The Q201E4 operates across a temperature range of -65°C to 125°C and is ROHS3 compliant.

Substiute Parts

Q201E4

Littelfuse Inc.In Stock: 1008Q201E4 Datasheet

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Q401E4

Littelfuse Inc.In Stock: 1796Q401E4 Datasheet

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Q601E4

Littelfuse Inc.In Stock: 897Q601E4 Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution for the Q201E4 is determined by the following electrical and mechanical parameters:

• Triac Type: Standard configuration
• Current - On State (It (RMS)) (Max): 1 A (must match exactly)
• Voltage - Gate Trigger (Vgt) (Max): 1.3 V (must match exactly)
• Current - Gate Trigger (Igt) (Max): 25 mA (must match exactly)
• Current - Hold (Ih) (Max): 25 mA (must match exactly)
• Current - Non Rep. Surge 50, 60Hz (Itsm): 16.7A, 20A (must match exactly)
• Operating Temperature Range: -65°C ~ 125°C (TJ) (must match exactly)
• Mounting Type: Through Hole
• Package / Case: TO-226-3, TO-92-3 (TO-226AA)

The substitute parts Q401E4 and Q601E4 maintain identical gate trigger characteristics, hold current, surge current ratings, and operating temperature specifications. The primary difference is the off-state voltage rating, which is higher in the substitute parts (400V and 600V respectively). These higher voltage ratings provide enhanced capability for applications requiring greater voltage isolation while maintaining full compatibility with the original electrical and mechanical interface requirements.

Parameter Comparison

Engineering Selection Recommendations

The Q401E4 and Q601E4 are active product alternatives to the obsolete Q201E4. Both substitute parts maintain full electrical and mechanical compatibility with the original component specification, with the exception of increased off-state voltage ratings.

Selection between Q401E4 (400V) and Q601E4 (600V) depends on the application's voltage isolation requirements. The Q401E4 provides a direct voltage upgrade path for applications requiring 400V capability, while the Q601E4 extends voltage isolation to 600V. Both parts are ROHS3 compliant and manufactured by Littelfuse Inc., ensuring regulatory compliance and supply chain continuity.

Frequently Asked Questions (FAQ)

Q: Can Q401E4 or Q601E4 directly replace Q201E4 in existing designs?

A: Yes, both Q401E4 and Q601E4 are direct mechanical and electrical replacements for the Q201E4. The TO-92 package, gate trigger characteristics, on-state current rating, and operating temperature range are identical. The higher off-state voltage ratings in the substitute parts do not affect compatibility with existing circuit layouts or control signal requirements.

Q: What is the primary difference between Q201E4, Q401E4, and Q601E4?

A: The three parts differ only in off-state voltage rating: Q201E4 is rated for 200V, Q401E4 for 400V, and Q601E4 for 600V. All other electrical parameters, including gate trigger voltage, on-state current, hold current, and surge current ratings, are identical.

Q: Why would I choose Q401E4 or Q601E4 over the original Q201E4?

A: The Q201E4 is obsolete. Q401E4 and Q601E4 are active products with ongoing manufacturing support. Additionally, the higher voltage ratings provide enhanced capability for applications requiring greater voltage isolation margins.

Q: Are there any compatibility concerns when substituting these parts?

A: No compatibility concerns exist for the electrical interface or mechanical mounting. Both substitute parts use the identical TO-92 package and maintain the same gate trigger and control current specifications. Circuit operation remains unchanged.

Q: What certifications apply to these substitute parts?

A: Both Q401E4 and Q601E4 are ROHS3 compliant and manufactured by Littelfuse Inc., meeting the same regulatory standards as the original Q201E4.