How do you select a transistor for specific operations?

How do you select a transistor for specific operations?

How to Select a Transistor – Linear/Active Operation

1. Device current gain.
2. Consider the Bandwidth and Frequency Specifications for high frequency applications.
3. Continuous Current Rating.
4. RMS Current Rating.
5. Single Pulse Peak Current.
6. Power Dissipation.
7. Collector-emitter voltage with open base (VCEO)
8. Operating Temperature Range.

What kind of transistor do I need?

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.

Does it matter what transistor i use?

General application: Although it is not always necessary to exactly match the intended purpose for the transistor, a variety of areas of its performance will be tailored to its intended applications. Possible application types may include: switching, analogue, low power, RF amplifier, low noise, etc.

How do you match transistors?

A common method of matching transistors is to use a fancy active current source to drive a stable current through the devices one at a time and to record the individual Vbe values. Then matched devices are selected based on the recorded values.

What are the specifications for switching transistors?

Saturation Characteristics

• • The input and Base are connected to VCC
• • Base-Emitter voltage VBE > 0.7v.
• • Base-Emitter junction is forward biased.
• • Base-Collector junction is forward biased.
• • Transistor is “fully-ON” ( saturation region )
• • Max Collector current flows ( IC = Vcc/RL )
• • VCE = 0 ( ideal saturation )

How do you know if a transistor is NPN or PNP?

Connect the positive lead of the multimeter to the Base (B) of the transistor and connect the negative lead to the Emitter (E) of the transistor. If it is an NPN transistor then meter should show a voltage drop between 0.45V and 0.9V. If it is a PNP transistor, then it should display see “OL” (Over Limit).

Can I replace PNP with NPN?

Generally, the PNP transistor can replace NPN transistors in most electronic circuits, the only difference is the polarities of the voltages, and the directions of the current flow. PNP transistors can also be used as switching devices and an example of a PNP transistor switch is shown below.

How do you match JFET?

Measuring JFETs

1. Get a 5 to 13 volt supply and a DC voltmeter (we used 12V)
2. Connect the +V to the Drain.
3. Connect the Gate and Source together to a 100Ω resistor.
4. Connect the other lead of the resistor to ground.
5. Measure the voltage across the resistor, which gives the Idss (1 volt = 10 mA of current)

What is meant by matched transistors?

Matched means the transistors were selected from a pile by measuring them to find the two that “match” closest for a particular variable, presumably the one you care about. However, you can never achieve identical in all parameters.