TIP31 NPN Bipolar Junction Transistor Equivalent & Substitute Parts

Part Overview

The TIP31 is an NPN bipolar junction transistor manufactured by onsemi, rated for 40 V collector-emitter breakdown voltage and 3 A maximum collector current in a TO-220-3 through-hole package. The device is classified as obsolete, necessitating identification of equivalent and substitute components for ongoing design support and procurement continuity. This reference provides direct substitutes and similar alternatives that maintain functional compatibility within specified electrical and mechanical parameters.

Key Parameters

Parameter	Value	Unit
Transistor Type	NPN	—
Voltage - Collector Emitter Breakdown (Max)	40	V
Current - Collector (Ic) (Max)	3	A
Power - Max	2	W
Frequency - Transition	3	MHz
Vce Saturation (Max) @ Ib, Ic	1.2 @ 375mA, 3A	V
DC Current Gain (hFE) (Min) @ Ic, Vce	10 @ 3A, 4V	—
Operating Temperature Range	-65 to 150	°C (TJ)
Package / Case	TO-220-3	—
Mounting Type	Through Hole	—

Substitute Part Grouping Explanation

Substitution of the TIP31 is determined by strict adherence to the following electrical and mechanical parameters:

Primary Substitution Criteria:

Transistor type must be NPN
Collector-emitter breakdown voltage must be equal to or greater than 40 V
Maximum collector current must be equal to or greater than 3 A
Package type must be TO-220-3 through-hole configuration
Operating temperature range must encompass -65°C to 150°C (TJ)
Mounting type must be through-hole

Substitute Classification:

Direct Substitutes maintain identical electrical specifications and differ only in product status or compliance certifications. These parts are pin-compatible and functionally equivalent without circuit modification.

Similar Substitutes exceed the minimum electrical requirements in one or more parameters (such as voltage rating or power dissipation) while maintaining compatibility with the primary electrical and mechanical constraints. These parts are suitable for applications where the TIP31 is specified, provided the circuit design accommodates the enhanced ratings.

Parameter Comparison

Parameter	TIP31 (Main)	TIP31G (Direct)	TIP31A (Similar)
Manufacturer	onsemi	onsemi	Solid State Inc.
Transistor Type	NPN	NPN	NPN
Voltage - Collector Emitter Breakdown (Max)	40 V	40 V	60 V
Current - Collector (Ic) (Max)	3 A	3 A	3 A
Power - Max	2 W	2 W	40 W
Frequency - Transition	3 MHz	3 MHz	3 MHz
Vce Saturation (Max) @ Ib, Ic	1.2 V @ 375mA, 3A	1.2 V @ 375mA, 3A	1.2 V @ 375mA, 3A
DC Current Gain (hFE) (Min) @ Ic, Vce	10 @ 3A, 4V	10 @ 3A, 4V	25 @ 1A, 4V
Current - Collector Cutoff (Max)	300 µA	300 µA	300 µA
Operating Temperature Range	-65 to 150 °C (TJ)	-65 to 150 °C (TJ)	-65 to 150 °C (TJ)
Package / Case	TO-220-3	TO-220-3	TO-220-3
Mounting Type	Through Hole	Through Hole	Through Hole
Product Status	Obsolete	Last Time Buy	Active
RoHS Status	Non-compliant	ROHS3 Compliant	ROHS3 Compliant

Engineering Selection Recommendations

TIP31G (Direct Substitute): The TIP31G is a direct electrical equivalent manufactured by onsemi with identical voltage, current, and thermal specifications. The primary distinction is product status: TIP31G is classified as Last Time Buy, indicating limited future availability. TIP31G achieves ROHS3 compliance, addressing environmental and regulatory requirements absent in the obsolete TIP31. For applications requiring RoHS compliance or where onsemi sourcing is preferred, TIP31G is the appropriate selection.

TIP31A (Similar Substitute): The TIP31A, manufactured by Solid State Inc., exceeds the TIP31 specification in two parameters: collector-emitter breakdown voltage (60 V versus 40 V) and maximum power dissipation (40 W versus 2 W). The TIP31A maintains identical collector current (3 A), transition frequency (3 MHz), and saturation voltage characteristics. The TIP31A is classified as Active, ensuring long-term availability and supply continuity. The enhanced voltage and power ratings provide design margin for applications operating near the TIP31 limits. The TIP31A is suitable for direct substitution in circuits designed for the TIP31, with the understanding that the higher ratings do not degrade performance in the original application context.

Both substitutes maintain through-hole TO-220-3 packaging and operating temperature range compatibility with the original TIP31 specification.

Frequently Asked Questions (FAQ)

Q: Can TIP31G be used as a direct replacement for TIP31 without circuit modification?

A: Yes. TIP31G maintains identical electrical specifications for voltage, current, power, and thermal characteristics. Pin configuration and package dimensions are identical. No circuit modification is required. The primary difference is product status and RoHS compliance.

Q: What is the key difference between TIP31 and TIP31A?

A: TIP31A exceeds TIP31 specifications in collector-emitter breakdown voltage (60 V versus 40 V) and maximum power dissipation (40 W versus 2 W). Collector current, transition frequency, and saturation voltage remain identical. TIP31A is suitable for direct substitution where enhanced voltage and power margins are beneficial.

Q: Is TIP31A pin-compatible with TIP31?

A: Yes. Both devices use TO-220-3 through-hole packaging with identical pin configuration and mechanical dimensions. Direct substitution on printed circuit boards is possible without modification.

Q: Why is TIP31 classified as obsolete?

A: Product obsolescence is determined by manufacturer discontinuation. The TIP31 is no longer in active production. TIP31G (Last Time Buy) and TIP31A (Active) provide continuity for applications requiring NPN transistors with these electrical specifications.

Q: Does RoHS compliance affect electrical performance?

A: No. RoHS compliance addresses material composition and environmental standards. Electrical performance, thermal characteristics, and functional behavior remain unchanged between RoHS-compliant and non-compliant versions of equivalent parts.

Q: Can TIP31A be used in applications where TIP31 is specified if the circuit operates below 40 V?

A: Yes. TIP31A is suitable for any application where TIP31 is specified. The higher voltage rating (60 V) and power rating (40 W) do not degrade performance in circuits designed for 40 V and 2 W operation. The device operates within its safe operating area in all such applications.

Q: What is the significance of the TO-220-3 package for substitution?

A: TO-220-3 is a standardized through-hole package with three leads (collector, base, emitter). All listed substitutes use identical packaging, ensuring mechanical and electrical compatibility on printed circuit boards without modification to board layout or mounting hardware.

Q: Are there any thermal management differences between TIP31, TIP31G, and TIP31A?

A: All three devices operate across the same temperature range (-65°C to 150°C junction temperature). TIP31A has higher power dissipation capability (40 W versus 2 W), which may reduce thermal stress in high-power applications but does not affect thermal management requirements in applications designed for 2 W operation.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message