What is hFE on a transistor?

What is hFE on a transistor?

hFE is an abbreviation, and it stands for “Hybrid parameter forward current gain, common emitter”, and is a measure of the DC gain of a junction transistor. So on a multimeter, it indicates a mode where the meter can measure (probably crudely), the HFE of a transistor.

What is hFE classification?

hFE is a transistor parameter that denotes its gain ratio. For example, if 200mA is produced in the collector circuit by a base current of 2mA, that transistor gain is 100. When transistors are made, production lots will have a spread, or range of hFE. Production testing sorts the hFE by “ranks.”

How is hFE calculated?

The common-emitter DC gain (base-to-collector current gain, hFE) is calculated by hFE = IC/IB with VCE at a constant voltage. hFE is also called βF, the forward DC current gain. It is often simply written as β, and is usually in the range of 10 to 500 (most often near 100). hFE is affected by temperature and current.

What causes the hFE to vary between transistors?

These large variations in the current gain: β hFE and hfe can occur between the same transistor type, between different batches and even different transistors manufactured ont he same wafer. The current gain depends on manufacturing characteristics such as the thickness of the base and the doping level.

What are the 3 leads of a transistor?

There are typically three electrical leads in a transistor, called the emitter, the collector, and the base—or, in modern switching applications, the source, the drain, and the gate.

What is HFE of BC547?

hFE. VCE=5.0V, IC=2.0mA (BC547, BC548) 110. 800.

How do I choose a transistor?

In choosing a suitable switching transistor:

  1. The transistor’s maximum collector current must be greater than the load current.
  2. The transistor’s maximum current gain must be at least 5 times the load current divided by the maximum output current from the IC.

Is HFE and HFE same?

hfe and HFE are two different, but related, characteristics of a bipolar transistor. hFE is the short circuit (vCE=0) forward current ratio (also known as h21) at a specified DC bias (which must be stated for each value of hFE). hfe is the small signal AC gain at a specified bias, and is frequency dependent.

What is the best transistor for amplifier?

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.