BE8251 Notes

LOGIC GATES

LOGIC GATES All digital systems are made from a few basic digital circuits that we call logic gates. These circuits perform the basic logic functions that we will describe in this session. The physical realization of these logic gates has changed over the years from mechanical relays to electronic vacuum tubes to transistors to integrated […]

BE8251 Notes

ASCII Character Encoding

ASCII Character Encoding ASCII Character Encoding the name ASCII is an acronym for: American Standard Code for Information Interchange. It is a character encoding standard developed several decades ago to provide a standard way for digital machines to encode characters. The ASCII code provides a mechanism for encoding alphabetic characters, numeric digits, and punctuation marks […]

BE8251 Notes

Hexadecimal Numbers

Hexadecimal Numbers In addition to binary, another number base that is commonly used in digital systems is base 16. This number system is called hexadecimal, and each digit position represents a power of 16. For any number base greater than ten, a problem occurs because there are more than ten symbols needed to represent the […]

BE8251 Notes

BIPOLAR JUNCTION TRANSISTOR

BIPOLAR JUNCTION TRANSISTOR A bipolar junction transistor is a three terminal semiconductor device in which the operation depends on the interaction of majority and minority carriers. Transistor refers to Transfer Resistor i.e., signals are transferred from low resistance circuit into high resistance circuit. BJT BIPOLAR JUNCTION TRANSISTOR consists of silicon crystal in which a layer […]

BE8251 Notes

RECTIFIERS

RECTIFIERS The rectifiers is a circuit that converts AC voltages and currents into pulsating DC voltages and currents. It consists of DC components and the unwanted ac ripple or harmonic components which can be removed by using filter circuit. Thus the output obtained will be steady DC voltage and magnitude of DC voltage can be […]

BE8251 Notes

ZENER EFFECT

ZENER EFFECT ZENER EFFECT: In a general purpose PN diode the doping is light; as a result of this the breakdown voltage is high. If a P and N region are heavily doped then the breakdown voltage can be reduced.  When the doping is heavy, even the reverse voltage is low, the electric field at barrier […]

BE8251 Notes

PN JUNCTION DIODE

PN JUNCTION DIODE PN JUNCTION DIODE: A p–n junction is formed by joining P-type and N-type semiconductors together in very close contact. The term junction refers to the boundary interface where the two regions of the semiconductor meet. Diode is a two-terminal electronic component that conducts electric current in only one direction. The crystal conducts […]