2N6668 PNP Darlington Transistor Equivalent & Substitute Parts

Part Overview

The 2N6668 is a PNP Darlington bipolar junction transistor manufactured by STMicroelectronics, housed in a TO-220-3 package for through-hole mounting applications. This component is rated for 80 V collector-emitter breakdown voltage and 10 A maximum collector current, with a maximum power dissipation of 65 W. The 2N6668 is classified as obsolete, necessitating identification of functionally equivalent substitute components for ongoing design support and production requirements. Substitute parts must maintain electrical and mechanical compatibility within the specified parameter ranges.

Substiute Parts

2N6668

STMicroelectronicsIn Stock: 21152N6668 Datasheet

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BDW47G

onsemiIn Stock: 3963BDW47G Datasheet

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BDW94C

STMicroelectronicsIn Stock: 25847BDW94C Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the 2N6668 are selected based on strict electrical and mechanical parameter compatibility. The primary substitution criteria are:

1. Transistor Type: Must be PNP - Darlington configuration
2. Package / Case: Must be TO-220-3 for mechanical and thermal compatibility
3. Mounting Type: Must be Through Hole
4. Voltage Rating: Collector-emitter breakdown voltage must equal or exceed 80 V
5. Current Rating: Maximum collector current must equal or exceed 10 A
6. Power Dissipation: Maximum power rating must equal or exceed 65 W
7. DC Current Gain: Minimum hFE must meet or exceed 1000 at specified conditions
8. Vce Saturation: Must not exceed 3 V at specified base and collector currents

The identified substitute parts BDW47G and BDW94C meet these criteria with enhanced or equivalent electrical specifications and improved product status or compliance certifications.

Parameter Comparison

Engineering Selection Recommendations

BDW94C is the primary recommended substitute for the 2N6668. This component is manufactured by STMicroelectronics and maintains active product status, ensuring long-term availability and supply chain continuity. The BDW94C exceeds the electrical requirements of the 2N6668 with a 100 V collector-emitter breakdown voltage (versus 80 V), 12 A maximum collector current (versus 10 A), and 80 W power dissipation (versus 65 W). The BDW94C is ROHS3 compliant, addressing regulatory requirements that the obsolete 2N6668 does not meet. Vce saturation and DC current gain specifications are equivalent to or better than the 2N6668 at specified operating conditions.

BDW47G is an alternative substitute manufactured by onsemi. This component provides enhanced electrical specifications with 15 A maximum collector current and 85 W power dissipation. The BDW47G is ROHS3 compliant and offers an extended operating temperature range of -55°C to 150°C. However, BDW47G is classified as obsolete, which may present future availability concerns. The BDW47G is suitable for applications requiring higher current capacity or extended temperature operation.

Both substitute parts are housed in TO-220-3 packages and are compatible with through-hole mounting applications identical to the 2N6668. Selection between BDW94C and BDW47G depends on application-specific requirements for current capacity, temperature range, and supply chain longevity.

Frequently Asked Questions (FAQ)

Q: Can the BDW94C directly replace the 2N6668 in existing circuit designs?

A: Yes. The BDW94C is electrically and mechanically compatible with the 2N6668. Both components are PNP Darlington transistors in TO-220-3 packages with through-hole mounting. The BDW94C meets or exceeds all electrical specifications of the 2N6668, including voltage rating, current capacity, power dissipation, and gain characteristics. No circuit modifications are required.

Q: What is the primary advantage of BDW94C over BDW47G?

A: The BDW94C is manufactured by STMicroelectronics and maintains active product status, ensuring ongoing availability and supply chain support. The BDW47G, while offering higher current capacity (15 A versus 12 A), is classified as obsolete. For long-term production and design continuity, BDW94C is the preferred choice.

Q: Are there thermal management differences between the 2N6668 and substitute parts?

A: All three components are housed in TO-220-3 packages with identical thermal characteristics. The BDW94C and BDW47G have higher power dissipation ratings (80 W and 85 W respectively, versus 65 W for the 2N6668), allowing operation at higher power levels without exceeding junction temperature limits. Thermal management requirements depend on application-specific power dissipation, not on the component selection.

Q: Does the BDW94C meet RoHS compliance requirements?

A: Yes. The BDW94C is ROHS3 compliant, meeting current regulatory requirements for restricted substances. The 2N6668 is RoHS non-compliant. For applications subject to RoHS regulations, the BDW94C is the appropriate substitute.

Q: What is the significance of the DC Current Gain (hFE) difference between BDW94C and 2N6668?

A: The 2N6668 specifies a minimum hFE of 1000 at 5 A and 3 V. The BDW94C specifies a minimum hFE of 750 at 5 A and 3 V. Both values are within acceptable ranges for Darlington transistor applications. The lower hFE specification of BDW94C does not impact circuit functionality, as Darlington transistors inherently provide high current gain. Applications relying on specific gain characteristics should verify compatibility through circuit simulation or prototype testing.

Q: Can BDW47G be used in applications requiring extended temperature operation?

A: Yes. The BDW47G operates across a temperature range of -55°C to 150°C, compared to 150°C maximum for both the 2N6668 and BDW94C. Applications requiring operation below ambient temperature or in cold environments should specify BDW47G. However, the obsolete status of BDW47G may limit long-term availability.

Q: Are the Vce saturation characteristics of substitute parts suitable for switching applications?

A: Yes. Both BDW94C and BDW47G maintain Vce saturation of 3 V at specified base and collector currents, identical to or better than the 2N6668. These saturation characteristics are appropriate for switching and amplification applications where low saturation voltage is required for efficient power transfer.