How do you calculate PNP base resistor?
To calculate the base resistor, subtract the B-E 0.7V from the driver voltage and divide by the base current: 4.5-0.7 = 3.8V / 400uA = ~9.5K ohms max.
How do you calculate the resistance of a transistor?
Yes the simplest method to figure out the equivalent resistance is to measure the collector voltage Vc and the emitter voltage Ve and subtract: V=Vc-Ve, and then measure the current through the collector Ic. The approximate resistance (neglecting the base current) is: R=V/Ic.
What is the formula of PNP transistor?
PNP Transistor Example Base current, IB = VB/ RB = 1.5/ (200*103) = 7.5uA. Emitter current, IE = VE/ RE = (10-2)/ (5*103) = 8/ (5*103) = 1.6mA.
How do you select a resistor for a transistor?
Choosing a transistor and base resistor for a digital IC output
- Choose the right type of transistor, NPN or PNP.
- Find out the supply voltage(s) and load properties.
- Work out the transistor properties required.
- Work out a value for the base resistor R.
- Check if you need a protection diode.
How is base voltage of a transistor calculated?
Determine the voltage drop between the collector and emitter junctions (Vce) of the transistor using the formula Vce = Vcc – IcRc, where “Vce” is the collector emitter voltage; “Vcc” is the supply voltage; and “IcRc” is the voltage drop across the base resistor (Rb).
What is the value of transistor?
Typically, Beta has a value between 20 and 200 for most general purpose transistors. So if a transistor has a Beta value of say 100, then one electron will flow from the base terminal for every 100 electrons flowing between the emitter-collector terminal.
What is the resistance of transistor?
Contact resistance in transistors is the resistance between the metal and silicon in a contact. This is due to the difference in the bandgap energies between the two materials. The closer the bandgap the less resistance.
What is PNP transistor?
The PNP transistor is a type of transistor in which one n-type material is doped with two p-type materials. It is a device that is controlled by the current. Both the emitter and collector currents were controlled by the small amount of base current. Two crystal diodes are connected back-to-back in the PNP transistor.
What is PNP transistor in chemistry?
PNP Transistors. A PNP transistor is a dual of an NPN transistor, and so they are complementary to each other. Their bias voltages and currents are in opposite directions. While current flow is because of the movement of holes in PNP transistors, it’s due to the movement of electrons in NPN transistors.
What is the formula of base voltage?
This can be done using the formula: Vcc = Vrc + Vrb + Vbe + (Ic + Ib)Rc + IbRb + Vbe, where “Vrc” is the voltage across the collector resistor; “Vrb” is the voltage across the base resistor (connected across the base) and the junction between the collector resistor and the transistor collector; and “Vbe” is the voltage …
How do you calculate emitter current of a transistor?
Calculate the emitter current, which is the current flowing from the emitter to ground. Use the formula Ie = (Vbb – Vbe)/[Rb/(Beta + 1) + Re] where Ie is the variable for the emitter current and Vbe is the base to emitter voltage. Set Vbe to 0.7 volts, which is the standard for most transistor circuits.