Content for BC549


BC549 is a NPN 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 is a low current transistor hence the maximum amount of current that could flow through the Collector pin (Ic) is 100mA, hence we cannot connect loads that consume more than 100mA and load voltage more than 30V using this transistor. BC549 has a decent gain value hfe from 420 to 800; this value determines the amplification capacity of the transistor. When this transistor is fully biased then it can allow a maximum of 100mA to flow across the collector and emitter. This stage is called Saturation Region. When base current is removed the transistor becomes fully off, this stage is called as the Cut-off Region.