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Are resistors bipolar?
There are two major types of bipolar transistor, called PNP and NPN. A single IC can contain many thousands of bipolar transistors, along with other components such as resistors, capacitors, and diodes.
How are transistors used in logic gates?
The use of transistors for the construction of logic gates depends upon their utility as fast switches. When the base-emitter diode is turned on enough to be driven into saturation, the collector voltage with respect to the emitter may be near zero and can be used to construct gates for the TTL logic family.
What is a bipolar circuit?
[bī′pō·lər ′sər·kət] (electronics) A logic circuit in which zeros and ones are treated in a symmetric or bipolar manner, rather than by the presence or absence of a signal; for example, a balanced arrangement in a square-loop-ferrite magnetic circuit.
What are the diodes of a bipolar transistor?
The diodes marked D1 and D2, together with resistor R1, form a two-input AND function. At the input to D3, a logic 0 is represented by approximately 0.7 V, while a logic 1 is in the range 4 to 5 V. D3 increases the voltage required to turn on the transistor.
What is the role of the base resistor in a transistor?
It consists of a common-emitter stage with a base resistor connected between the base and the input voltage source. The role of the base resistor is to expand the very small transistor input voltage range (about 0.7 V) to the logical “1” level (about 3.5 V) by converting the input voltage into current.
How does a diode and transistor work in a NOR gate?
NOR Gate using Diode and Transistor (DTL) The transistor will conduct when either one or both of the inputs receive a logic 1 signal. When both inputs are logic 0, the transistor stops conducting (OFF) and all the current passes through the LED instead, hence the LED lights up.
Why are resistors important in digital logic gates?
What is important to students of digital logic is this: If no current is flowing through a resistor, the voltage at the two ends will be the same; if current is made to flow through the resistor, there will be a voltage dropacross the resistor. This is analogous to the pressure drop across the constricted pipe of Figure 1.