How Do I Choose The Right Transistor?

Can I replace mosfet with transistor?

Since switching voltages above 5 V or up to 12 V is easily available from most digital and analogue ICs, mosfets can be quickly interfaced with any source irrespective of the load current.

So it means, in general we can easily replace a BJT with a mosfet, provided we take care of the relevant polarities..

What is Alpha DC?

Alpha (αdc): It is defined as the ratio of collector current to emitter current. `alpha_(dc)=”I”_c/”I”_E` —————–(Equation 1) Beta (βdc): It is the current gain defined as the ratio of collector current to the base current.

How much current can a Mosfet handle?

When on, the part exhibits a low resistance without any non-linear forward voltage drop as seen in bipolar transistors. Modern MOSFETs can have on resistances of less than 10 milliohms. A little math shows that this device can handle 10 amps with one watt converted into waste heat (power = current2 x resistance).

What are the two basic types of transistors?

Transistors are basically classified into two types; they are Bipolar Junction Transistors (BJT) and Field Effect Transistors (FET). The BJTs are again classified into NPN and PNP transistors. The FET transistors are classified into JFET and MOSFET.

What is current gain in a transistor?

The current gain for the common-base configuration is defined as the change in collector current divided by the change in emitter current when the base-to-collector voltage is constant. Typical common-base current gain in a well-designed bipolar transistor is very close to unity. The most useful amplifier…

Which transistor is best?

Best Transistors: BJTs#1 NPN – 2N3904. You can find most often NPN Transistors in low-side switch circuits. … #2 PNP – 2N3906. For high-side switch circuits, you need a PNP style BJT. … #3 Power – TIP120. … #4 N-Channel (Logic Level) – FQP30N06L.

Can I use any transistor?

Fortunately it is normally possible to use a replacement transistor type as there is often a considerable degree of overlap between the specifications of different types of transistor, and by looking at the basic specifications it is normally possible to choose the correct transistor replacements.

What is the symbol of Mosfet?

The line in the MOSFET symbol between the drain (D) and source (S) connections represents the transistors semiconductive channel. If this channel line is a solid unbroken line then it represents a “Depletion” (normally-ON) type MOSFET as drain current can flow with zero gate biasing potential.

How many types of transistors are there?

two typesThere are two types of transistors, which have slight differences in how they are used in a circuit. A bipolar transistor has terminals labeled base, collector, and emitter.

What do transistor numbers mean?

Its format for transistors is two letters followed by a serial number. The first letter represents the material. For instance, A means germanium and B means silicon. The second letter refers to transistor type. For instance, C means small signal and D means power.

What is current gain alpha and beta?

A transistors current gain is given the Greek symbol of Beta, ( β ). As the emitter current for a common emitter configuration is defined as Ie = Ic + Ib, the ratio of Ic/Ie is called Alpha, given the Greek symbol of α. … Typically, Beta has a value between 20 and 200 for most general purpose transistors.

What can we use instead of transistor?

The most obvious alternatives to transistors are vacuum tubes and electromechanical relays. In addition, magnetic amplifiers (magamps) are useful. Piezoelectric relays are rare. Rotating amplifiers, such as amplidyne motor-generator machines are useful at higher power levels.

What is Alpha Beta Gamma in transistor?

What are α,β and γ in a transistor ? ALPHA (α): It is a large signal current gain in common base configuration. It is the ratio of collector current (output current) to the emitter current (input current). It is a current gain in CB amplifier and it indicates that the amount of emitter current reaching to collector.

What are the transistor parameters?

The main transistor parameters are Beta, input impedance, output impedance and bandwidth. … The input and output impedance is used to fix the operating point of the transistor. And the bandwidth parameter is used to find a range of frequency in which the transistor can be used as an amplifier or for switching purpose.

What are MOSFETs used for?

MOSFET, in short, is a metal oxide semiconductor field-effect transistor used to switch or amplify voltages in circuits. Being part of the field-effect transistor family, it is a current-controlled device that is constructed with 3 terminals; Source.

How can we use a parameter to select a better transistor?

Current Gain (β) Current is the ratio of the base current to the collector current and a measure of the amplifying ability of the transistor. If you want to use the transistor as an amplifier, then choose a transistor with higher current gain.

How is a transistor connected in a circuit?

To connect the transistor as a switch in a circuit, we connect the output of the device that will switch on the transistor to the base of the transistor. The emitter will connect to ground of the circuit. And the collector will connect to the load that the transistor will turn on and the supply voltage of the circuit.