Features
Low Voltage, High Current PNP Transistor
Continuous Collector current (IC) is 500mA
Collector-Emitter voltage (VCEO) is -25 V
Collector-Base voltage (VCB0) is -40V
Emitter Base Voltage (VBE0) is -5V
Current Gain (hFE), 85 to 300
Commonly used as Class B Push-pull transistors
Available in To-92 Package

S8550 is a PNP transistor hence the collector and emitter will be left open (Reverse biased) when the base pin is held at ground and will be closed (Forward biased) when a signal is provided to base pin. It has a maximum gain value of 300; this value determines the amplification capacity of the transistor normally S8550. Since it is very high it is normally used for amplification purposes.