FJB102 bipolar transistor — Specifications & Equivalents

About the FJB102

The FJB102 is an NPN bipolar transistor with a collector–emitter voltage (V_CEO) rating of 100 V, a continuous collector current (I_C) of 8 A and a DC current gain (h_FE) of minimum 1000. It can dissipate up to 80 W. It is supplied in the TO263 package.

At a glance

• Type: NPN bipolar transistor
• Max collector–emitter voltage (V_CEO): 100 V
• Max collector current (I_C): 8 A
• DC current gain (h_FE): minimum 1000
• Power dissipation (P_D): 80 W
• Package: TO263

Typical applications

Judging from its ratings the FJB102 is generally applied in power output and driver stages.

The quoted current gain of minimum 1000 determines the base drive needed: divide your target collector current by the minimum h_FE, not the typical figure, when sizing the base resistor.

Biasing and absolute maximum ratings

Absolute-maximum breakdown limits are V_CEO 100 V, V_CBO 100 V and V_EBO 5 V (magnitudes). The emitter–base rating is the easiest to overlook and is often only a few volts, so protect the junction against reverse drive.

Dissipation is capped at 80 W, and that figure assumes the datasheet's mounting and ambient conditions — derate it for your own thermal design.

Choosing a replacement for the FJB102

A drop-in substitute for the FJB102 must be the same NPN type and offer a collector–emitter rating of at least 100 V, a collector current rating of at least 8 A and current gain in the same ballpark as minimum 1000.

Mechanically, check the replacement against the TO263 footprint and confirm the pin order — parts sharing a package outline do not always share a pinout.

Where the application switches inductive loads or runs near the voltage limit, keep extra headroom rather than choosing a part that only just meets the original numbers.

Frequently asked questions

What is the FJB102?

The FJB102 is an NPN bipolar junction transistor (BJT). It is rated for 100 V collector-emitter and 8 A continuous collector current.

What is the maximum voltage of the FJB102?

Maximum collector-emitter voltage (Vceo) is 100 V, and collector-base (Vcbo) is 100 V.

How much current can the FJB102 handle?

Continuous collector current is rated at 8 A, with dissipation limited to 80 W.

What is the hFE of the FJB102?

DC current gain (hFE) is quoted as minimum 1000. Size base drive from the minimum value so the transistor saturates fully across production spread.

What package does the FJB102 come in?

It is listed in TO263. Verify the pinout of the specific variant, as one outline can carry different pin assignments.

What can I use to replace the FJB102?

This page lists 17 candidate equivalents matched on electrical ratings and package. Any replacement should meet or exceed the original voltage, current and dissipation figures and use a compatible drive level.