2006-09-10 02:24:08 · 3 answers · asked by nebula 1 in Science & Mathematics ➔ Engineering
It depends entirely on the circuit and what the transister is being used for. A transister may be biased 'on' or have no bias 'off' or it may even be biased 'off.'
If it is being used as a simple on/off switch, it may not be biased at all until it is turned on.
If it is being used an amplifier (other than class A), it will be biased at or near it's turn on voltage - usually around 0.4 or 0.5 volt for an NPN silicone type.
A transister in a class A amplifier will be biased 'on' all the time - approximately in the middle of its operating range. This is the most linear type of amplifier, but also the least efficient.
An integrated circuit may contain litterally millions of transisters.
There are several types of transisters (NPN, PNP, Unijuction, FET, MOSFET, etc.) and each, depending on their use in the circuit, may be biased in different ways.
2006-09-10 02:51:22 · answer #1 · answered by LeAnne 7 · 1⤊ 0⤋
Transistors are biased depend on the load ie collector current.If you are biasing an small signal input stage, collector current would be around 1mA and base bias current would be as small as a few micro ampere depend on the current gain of the transistor.As for the output transistor, depend on collector current base current should be biased accordingly depend on the amp class A, B , AB.If you are using transistor for switch there is no bias at all.
2006-09-10 21:05:42 · answer #2 · answered by dwarf 3 · 0⤊ 0⤋
It all depends on the base current and the type of transistor you are using.
2006-09-10 02:28:08 · answer #3 · answered by Anonymous · 0⤊ 0⤋