BD243B Equivalent & Substitute Parts

Part Overview

The BD243B is an NPN bipolar junction transistor manufactured by onsemi, rated for 80 V collector-emitter breakdown voltage and 6 A maximum collector current in a TO-220-3 through-hole package. This device is classified as obsolete, necessitating identification of active equivalent and substitute components for new designs and production applications. The BD243B delivers 65 W maximum power dissipation and features a minimum DC current gain of 15 at 3 A collector current and 4 V collector-emitter voltage.

Substiute Parts

BD243B

onsemiIn Stock: 2115BD243B Datasheet

Current PartRFQ

BD243CG

onsemiIn Stock: 1618BD243CG Datasheet

DirectRFQ

TIP41BG

onsemiIn Stock: 20347TIP41BG Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the BD243B is determined by electrical and mechanical parameter compatibility within the NPN bipolar transistor category. The critical parameters governing substitution are:

Electrical Parameters:

• Collector current rating (Ic Max): 6 A minimum required
• Collector-emitter breakdown voltage (Vce breakdown): 80 V minimum required
• DC current gain (hFE): 15 minimum at specified conditions
• Collector cutoff current: 700 µA maximum
• Saturation voltage characteristics

Mechanical Parameters:

• Package type: TO-220-3 through-hole configuration
• Mounting compatibility: Through-hole PCB mounting

Compliance Parameters:

• REACH compliance status
• ECCN classification
• HTSUS code alignment

The substitute parts BD243CG and TIP41BG meet or exceed the electrical specifications of the BD243B while maintaining identical package and mounting characteristics. Both substitutes are active products with current manufacturing status, addressing the obsolescence of the original BD243B.

Parameter Comparison

Engineering Selection Recommendations

BD243CG is the primary substitute for the BD243B. This part maintains identical collector current and saturation voltage specifications while providing enhanced collector-emitter breakdown voltage (100 V versus 80 V), offering improved voltage margin in circuit applications. The BD243CG is an active product with RoHS3 compliance certification, ensuring long-term availability and regulatory alignment. The extended operating temperature range (-65°C to 150°C) provides broader thermal operating capability compared to the BD243B specification.

TIP41BG serves as an alternative substitute when voltage margin is not a critical design constraint. This part matches the 80 V collector-emitter breakdown voltage and 6 A collector current of the BD243B. The TIP41BG is an active product with RoHS3 compliance and extended temperature range. However, the maximum power dissipation rating of 2 W differs significantly from the BD243B specification of 65 W, restricting its application to circuits with lower power requirements.

Both substitute parts share identical REACH compliance status, ECCN classification, and HTSUS codes with the BD243B, ensuring regulatory and trade compliance continuity.

Frequently Asked Questions (FAQ)

Q: Can BD243CG directly replace BD243B in all applications?

A: BD243CG is electrically compatible with BD243B for applications requiring up to 80 V collector-emitter voltage. The higher 100 V rating of BD243CG provides additional voltage margin without affecting lower-voltage circuit operation. Both parts maintain identical 6 A collector current, saturation voltage, and DC current gain specifications. The TO-220-3 package is identical, enabling direct PCB mounting compatibility.

Q: What is the primary difference between BD243CG and TIP41BG as BD243B substitutes?

A: The critical difference is maximum power dissipation. BD243CG maintains the 65 W power rating of BD243B, while TIP41BG is rated for 2 W maximum. For applications dissipating power levels between 2 W and 65 W, BD243CG is the appropriate selection. Both parts share identical collector current (6 A) and saturation voltage characteristics.

Q: Are there package compatibility concerns when substituting BD243B?

A: No. Both BD243CG and TIP41BG use the TO-220-3 through-hole package, identical to BD243B. PCB footprint, lead spacing, and mounting hole requirements are unchanged, enabling direct mechanical substitution without board redesign.

Q: How do the operating temperature ranges compare?

A: BD243B specifies a maximum junction temperature of 150°C without a minimum operating temperature. BD243CG and TIP41BG both specify -65°C to 150°C operating range, providing defined low-temperature performance. For applications operating below 0°C, the substitute parts offer specified performance characteristics.

Q: What regulatory compliance status applies to these substitutes?

A: All three parts—BD243B, BD243CG, and TIP41BG—share identical REACH compliance status (REACH Unaffected), ECCN classification (EAR99), and HTSUS code (8541.29.0095). Regulatory and trade compliance requirements remain unchanged when substituting these parts.

Q: Why is BD243B classified as obsolete?

A: BD243B is an obsolete product, indicating onsemi has discontinued manufacturing. BD243CG and TIP41BG are active products with current production status, ensuring availability for new designs and ongoing production requirements.