Q8008DH4TP TRIAC Alternistor 800V 8A Equivalent & Substitute Parts

Part Overview

The Q8008DH4TP is an 800V 8A TRIAC Alternistor (Snubberless) manufactured by Littelfuse Inc. in Surface Mount TO-252 (DPAK) packaging. This component is classified as Active status and is RoHS3 compliant. Substitute parts are necessary when the primary part is unavailable, when alternative packaging formats are required, or when application requirements permit operation at reduced current ratings while maintaining the same voltage class and thermal operating range.

Key Parameters

Parameter	Value
Manufacturer Part Number	Q8008DH4TP
Manufacturer	Littelfuse Inc.
Category	Thyristors
TRIAC Type	Alternistor - Snubberless
Voltage - Off State	800 V
Current - On State (It RMS) Max	8 A
Voltage - Gate Trigger (Vgt) Max	1.3 V
Current - Gate Trigger (Igt) Max	35 mA
Current - Hold (Ih) Max	35 mA
Operating Temperature Range	-40°C to 125°C (TJ)
Package / Case	TO-252-3, DPAK (2 Leads + Tab), SC-63
Mounting Type	Surface Mount
RoHS Status	RoHS3 Compliant
Product Status	Active

Substitute Part Grouping Explanation

Substitution of the Q8008DH4TP is determined by the following critical parameters:

Mandatory Compatibility Parameters:

Voltage - Off State: 800 V (all substitutes must match)
Package / Case: TO-252-3, DPAK (all substitutes must match)
Mounting Type: Surface Mount (all substitutes must match)
Operating Temperature Range: -40°C to 125°C (all substitutes must match)

Current Rating Flexibility:

Current - On State (It RMS) Max: Substitutes rated at 4 A or 8 A are acceptable. Lower current ratings (4 A) are suitable for applications not requiring the full 8 A capacity.

TRIAC Type Flexibility:

Alternistor - Snubberless, Standard, or Logic - Sensitive Gate types are acceptable based on application requirements.

Gate Trigger Parameters:

Voltage - Gate Trigger (Vgt) Max: 1.1 V to 1.3 V range acceptable
Current - Gate Trigger (Igt) Max: 5 mA to 35 mA range acceptable
Current - Hold (Ih) Max: 10 mA to 35 mA range acceptable

Packaging Format Flexibility:

Tube, Tape & Reel (TR), or Cut Tape (CT) & Digi-Reel® packaging formats are interchangeable for component selection purposes.

Parameter Comparison

Part Number	Manufacturer	TRIAC Type	Voltage - Off State	Current - On State (It RMS) Max	Vgt Max (V)	Igt Max (mA)	Ih Max (mA)	Package	Packaging Format	Product Status
Q8008DH4TP	Littelfuse Inc.	Alternistor - Snubberless	800 V	8 A	1.3	35	35	TO-252-3, DPAK	Tube	Active
MAC4DCNT4G	Littelfuse Inc.	Standard	800 V	4 A	1.3	35	35	TO-252-3, DPAK	Tape & Reel (TR)	Active
ACST210-8B	STMicroelectronics	Logic - Sensitive Gate	800 V	2 A	1.1	10	10	TO-252-3, DPAK	Tube	Active
ACST435-8B	STMicroelectronics	Standard	800 V	4 A	1.1	35	25	TO-252-3, DPAK	Tube	Active
ACST435-8BTR	STMicroelectronics	Standard	800 V	4 A	1.1	35	25	TO-252-3, DPAK	Cut Tape (CT) & Digi-Reel®	Active
T405-800B-TR	STMicroelectronics	Logic - Sensitive Gate	800 V	4 A	1.3	5	10	TO-252-3, DPAK	Cut Tape (CT) & Digi-Reel®	Active
T435-800B-TR	STMicroelectronics	Alternistor - Snubberless	800 V	4 A	1.3	35	35	TO-252-3, DPAK	Cut Tape (CT) & Digi-Reel®	Active
T810-800B-TR	STMicroelectronics	Logic - Sensitive Gate	800 V	8 A	1.3	10	15	TO-252-3, DPAK	Cut Tape (CT) & Digi-Reel®	Active
T835-800B-TR	STMicroelectronics	Alternistor - Snubberless	800 V	8 A	1.3	35	35	TO-252-3, DPAK	Tape & Reel (TR)	Active

Engineering Selection Recommendations

All listed substitute parts maintain Active product status and RoHS3 compliance, ensuring regulatory and supply chain continuity.

Direct Equivalents (Same Current Rating - 8A):

T835-800B-TR (STMicroelectronics): Identical electrical specifications to Q8008DH4TP with matching Alternistor - Snubberless type, gate trigger parameters, and hold current. Available in Tape & Reel packaging.
T810-800B-TR (STMicroelectronics): Matches 8A current rating with Logic - Sensitive Gate type, lower gate trigger current (10 mA), and reduced hold current (15 mA). Suitable for applications with lower gate drive requirements.

Reduced Current Rating Substitutes (4A):

T435-800B-TR (STMicroelectronics): Alternistor - Snubberless type matching the original TRIAC classification. Identical gate trigger voltage and hold current specifications. Suitable for applications not exceeding 4A continuous current.
ACST435-8B and ACST435-8BTR (STMicroelectronics): Standard TRIAC type with lower gate trigger voltage (1.1V) and reduced hold current (25 mA). Available in both Tube and Cut Tape & Digi-Reel® formats.
MAC4DCNT4G (Littelfuse Inc.): Maintains manufacturer continuity with Standard TRIAC type and identical gate trigger parameters to the original part.

Lower Current Rating Substitutes (2A or 4A with Sensitive Gate):

T405-800B-TR (STMicroelectronics): Logic - Sensitive Gate type with 4A rating and minimal gate trigger current (5 mA). Applicable for low-power gate drive applications.
ACST210-8B (STMicroelectronics): Logic - Sensitive Gate type with 2A rating and 10 mA gate trigger current. Suitable only for applications with significantly reduced current requirements.

Frequently Asked Questions (FAQ)

Q: Can I substitute a 4A TRIAC for the 8A Q8008DH4TP? A: Yes, if your application does not require continuous current exceeding 4A. The 4A substitutes (MAC4DCNT4G, ACST435-8B, ACST435-8BTR, T435-800B-TR, T405-800B-TR) maintain the same 800V voltage rating and TO-252 DPAK package. Verify your circuit's maximum current demand before selection.

Q: What is the difference between Alternistor - Snubberless and Standard TRIAC types? A: Alternistor - Snubberless TRIACs (Q8008DH4TP, T435-800B-TR, T835-800B-TR) are optimized for operation without external snubber circuits, reducing component count. Standard TRIACs (MAC4DCNT4G, ACST435-8B, ACST435-8BTR) may require snubber networks in certain applications. Logic - Sensitive Gate types (ACST210-8B, T405-800B-TR, T810-800B-TR) feature lower gate trigger current for reduced gate drive power.

Q: Are all substitutes available in the same TO-252 DPAK package? A: Yes. All listed substitutes use the TO-252-3 DPAK (2 Leads + Tab) SC-63 package, ensuring mechanical and thermal compatibility. Packaging formats (Tube, Tape & Reel, Cut Tape & Digi-Reel®) differ but do not affect component functionality or PCB mounting.

Q: What is the operating temperature range for all substitutes? A: All substitutes operate across the same temperature range: -40°C to 125°C (TJ), matching the Q8008DH4TP specification.

Q: Can I use a substitute with lower gate trigger current (Igt)? A: Yes. Lower gate trigger current (5 mA to 10 mA in Logic - Sensitive Gate types) reduces gate drive power requirements. Ensure your gate drive circuit can supply the specified minimum current for reliable triggering. Higher gate trigger current (35 mA) provides greater noise immunity in noisy environments.

Q: Are all substitutes RoHS3 compliant? A: Yes. All listed substitute parts are RoHS3 compliant and REACH unaffected, maintaining regulatory compliance with the original Q8008DH4TP.

Q: Which substitute offers the closest electrical match to Q8008DH4TP? A: T835-800B-TR provides the closest match with identical 8A current rating, Alternistor - Snubberless type, and matching gate trigger specifications (Vgt 1.3V, Igt 35 mA, Ih 35 mA). It is available in Tape & Reel packaging format.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message