2N2907 PNP Transistor

• This is a Bipolar PNP transistor, having a high value of current 600mA with low voltage of 40v. The condition of being forward biased is when the base connected to the ground or having no supply on it, and as a signal is provided to base pin it goes reverse biased. The transistor is having DC current gain value of 100 to 300 which shows the amplification capacity of the transistor. As it is used for the amplification and switching. When the transistor is fully biased, it allows a maximum of 500mA current through the collector and provide a voltage (collector to emitter) of 1.6v (max.), this is the Saturation region of the transistor. While the base current is removed the transistor is in off state it’s in Cut-off region.
• When use as a switch, can be operated in saturation region and cut-off region. In PNP transistor, by default it’s in ON state, but not to be said perfectly on until the base pin is not grounded. If we provide ground to the base pin, then the transistor will be in reverse biased and said to be turn ON. If supply is provided to the base pin, it stops conducting current between emitter and collector and said to be in OFF state. For the protection of transistor, a resistance added in series with it.
• When use as a amplifier, can be operated in the active region. When its base is connected to ground, it will allow high current (600mA) to pass through collector to emitter, that’s how it amplifies the current. There are three configuration used in an amplifier circuit are common emitter, common base, common collector. This transistor is used where low power amplification is needed. It can also amplifies the power and current. Amplification factor usually determined in term of power; for calculating the current gain, we use the formula:

  Gain (hfe) = IC / IB Where, IC is the collector current and IB is the base current of the circuit.

• 2N2907 is a widely used transistor; it is the PNP complementary transistor of 2N2222
• 2N2907 Equivalent Transistors – 2N4401, 2N2905, 2N2906, 2N5763

Applications

• Where amplification of low power is needed we use this transistor.
• It can also be used in the various switching applications.
• Used for making siren or dual Led or Lamp flasher.
• Can be used in Darlington Pair.