BC449A

Single Bipolar Transistors Overview

The BC449A is a single NPN bipolar junction transistor manufactured by onsemi, housed in a TO-92 through-hole package. It features a maximum collector-emitter voltage of 100 V and a continuous collector current rating of 300 mA. The device has a maximum power dissipation of 625 mW and a transition frequency of 100 MHz. Minimum DC current gain (hFE) is specified at 120 under standard test conditions.

Single Bipolar Transistors Feature Summary

• High voltage capability with 100 V collector-emitter breakdown
• Moderate current handling up to 300 mA for general switching
• Standardized TO-92 through-hole mounting for easy integration

Single Bipolar Transistors Applications

• General-purpose signal amplification
• Low-power switching circuits
• Audio pre-amplifier stages

Single Bipolar Transistors Procurement Notes

Verify the manufacturer origin carefully, as the BC449A is produced by multiple vendors including NXP and onsemi. Confirm RoHS compliance status, as older batches may not meet current environmental standards. Ensure the specific hFE bin matches circuit requirements, as gain varies significantly between manufacturers.

Single Bipolar Transistors Selection Notes

Select this component when a 100 V rating is required for NPN applications. Compare against the BC449B if higher gain is needed, or the BC447A for intermediate voltage levels. Verify that the 300 mA current limit suits the load requirements without exceeding thermal constraints.

Single Bipolar Transistors Part Context

This part belongs to the BC4xx series of small-signal NPN transistors. It shares the same physical package and basic electrical structure as the BC449 and BC449B, differing primarily in gain classification and manufacturing source. It serves as a direct replacement for legacy designs using the BC449A designation.