Microchip Technology, Inc. Single Bipolar Transistors 2N2221AUA

The 2N2221AUA is an NPN silicon switching transistor in a 4-pin surface mount package with a ceramic lid, rated for a collector-emitter voltage of 50 Vdc, collector current of 800 mAdc, and power dissipation of 0.5 W at +25°C. It has a thermal resistance of 210°C/W, a forward current transfer ratio ranging from 40 to 325 depending on collector current, a collector-emitter saturation voltage of 0.3 V at 150 mA collector current and 15 mA base current, and a turn-off time of 300 µs. The device is qualified to MIL-PRF-19500/255, with the collector internally connected to the case.