Q4008RH4 Equivalent & Substitute Parts

Part Overview

The Q4008RH4 is a Littelfuse Snubberless TRIAC Alternistor rated for 400 V off-state voltage and 8 A on-state current in a TO-220-3 through-hole package. This component is discontinued at DiGi Electronics, making equivalent substitutes necessary for ongoing design requirements and procurement. The part operates across an industrial temperature range of -40°C to 125°C and is RoHS3 compliant.

Substiute Parts

Q4008RH4

Littelfuse Inc.In Stock: 870Q4008RH4 Datasheet

Current PartRFQ

BTB08-600CWRG

STMicroelectronicsIn Stock: 1515BTB08-600CWRG Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

The BTB08-600CWRG from STMicroelectronics qualifies as a direct substitute based on the following critical parameters:

Matching Parameters:

• TRIAC Type: Alternistor - Snubberless (identical technology)
• Current - On State (It (RMS)) (Max): 8 A (identical)
• Voltage - Gate Trigger (Vgt) (Max): 1.3 V (identical)
• Current - Gate Trigger (Igt) (Max): 35 mA (identical)
• Current - Hold (Ih) (Max): 35 mA (identical)
• Operating Temperature: -40°C ~ 125°C (identical)
• Package / Case: TO-220-3 (identical)
• Mounting Type: Through Hole (identical)
• RoHS Status: RoHS3 Compliant (identical)
• MSL Rating: 1 (Unlimited) (identical)

Voltage Consideration: The BTB08-600CWRG operates at 600 V off-state voltage compared to the Q4008RH4's 400 V. This represents an uprating in voltage capability, which is acceptable for substitution in applications designed for 400 V operation, as the higher voltage rating provides additional safety margin without affecting performance in lower-voltage circuits.

Parameter Comparison

Engineering Selection Recommendations

The BTB08-600CWRG is suitable for direct substitution in applications currently using the Q4008RH4. Both components share identical electrical characteristics for gate trigger voltage, gate trigger current, hold current, on-state current rating, and operating temperature range. Both are RoHS3 compliant and packaged in TO-220-3 through-hole format.

The BTB08-600CWRG carries active product status from STMicroelectronics, ensuring ongoing availability and supply chain continuity. The 600 V off-state voltage rating of the BTB08-600CWRG exceeds the 400 V requirement of the Q4008RH4, providing additional voltage margin without performance degradation in 400 V applications.

Frequently Asked Questions (FAQ)

Q: Can the BTB08-600CWRG replace the Q4008RH4 in existing designs?

A: Yes. The BTB08-600CWRG matches all critical electrical parameters including gate trigger voltage, gate trigger current, hold current, and on-state current rating. The identical TO-220-3 package and through-hole mounting type ensure mechanical compatibility. The higher 600 V off-state voltage rating is acceptable for 400 V applications.

Q: What is the significance of the voltage difference between 400 V and 600 V?

A: The Q4008RH4 is rated for 400 V off-state voltage, while the BTB08-600CWRG is rated for 600 V. In substitution, the higher voltage rating of the BTB08-600CWRG provides additional safety margin and does not degrade performance in circuits designed for 400 V operation.

Q: Are both parts packaged identically?

A: Yes. Both the Q4008RH4 and BTB08-600CWRG use the TO-220-3 package with through-hole mounting. No PCB layout modifications are required for substitution.

Q: What is the product status difference?

A: The Q4008RH4 is discontinued at DiGi Electronics, while the BTB08-600CWRG is active at STMicroelectronics. This makes the BTB08-600CWRG the recommended choice for new procurement and long-term supply assurance.

Q: Do both parts meet the same compliance standards?

A: Yes. Both the Q4008RH4 and BTB08-600CWRG are RoHS3 compliant with MSL rating 1 (Unlimited), ensuring equivalent environmental and regulatory compliance.