**BD139 equivalent transistor replacement**

The transistor BD139 equivalent is the topic we are going to discussing in this article, which means we need to consider the main electrical characteristics of the transistors we are suggesting.

When we consider equivalent for any component for a circuit designer or a repairing person, needs for every circuit are different which means the comparison of characteristics is important for every aspect, such as connection details, packaging, and maximum values.

**bd139 transistor equivalent**

**MJE722**

The MJE722 is the perfect replacement for BD139 because almost all the electrical characteristics and connection criteria of MJE722 and BD139 are the same.

The **collector to base voltage for MJE722 and BD139 is the same that is (80v)**, **collector to emitter voltage of MJE722 and BD139 is the same that is (80v)** and the **emitter to base voltage at MJE722 and BD139 is the same (5v)**.

Then the **collector current of both transistor MJE722 and BD139 is the same (1.5A)**, but the **peak collector current of BD139 is 3A**. And the **base current of MJE722 and BD139 is the same that is (0.5A)**.

The **pinout and package (TO-126) of both MJE722 and BD139 are the same** and the **maximum temperature of MJE722 and BD139 (150˚C) is the same**.

The **power dissipation of BD139 will be 12.5w** and **MJE722 and for 20w**.

And the **DC gain of BD139 is 25 to 250HFe** and **MJE722 is 40HFe**, the **thermal resistance of BD139 is 10˚C/W** and for **MJE722 it is 6.25˚C/W**.

The **transition frequency of BD139 is 190MHz** and for **MJE722 it is not found**.

**BD230 **

The BD230 transistor is also a good equivalent for BD139, the **pinout details, and the package of both MJE722 and BD139 is the same (TO-126)**.

The **collector to base voltage of BD139 is 80v** and for **BD230 it is 100v**, **collector to emitter voltage of BD139 and BD230 is the same (80v)** and **emitter to base voltage of both transistor BD139 and BD230 is the same (5v)**.

The **collector current of BD139 and BD230 is the same (1.5A**) and the **base current of BD139 is 0.5A and at BD230 it is 1A**.

**Power dissipation of both BD139 and BD230 transistor are the same (12.5w)**, the **DC gain of BD139 is 25 to 250HFe** and for **BD230 it is 40 to 250HFe**.

The **thermal resistance of BD139 is 10˚C/w** and on **BD230 it is not found** and the **maximum temperature of both is the same (150˚C).**

The **transition frequency at BD139 is 190MHz** and for the **BD230 transistor, it is 125MHz**.

**BD139 equivalent SMD**

The SMD version for BD139 is BCP56, the BDP951 (SOT-223), BDP953 (SOT-223), and BDP955 (SOT-223) is the equivalent for BD139 transistor.