VLSI stands for “very large scale integration”. This is the field which involves packing more and more logic devices into smaller and smaller areas. Thanks to VLSI, circuits that would have taken boardfuls of space can now be put into a small space few millimeters across. Digital VLSI circuits are predominantly CMOS based. Most of the VLSI circuits available in the commercial market nowadays are of the programmable type and are called programmable Logic Device is a whose logic characteristic can be changed and manipulated or stored through programming . The type of PLD is as follows:
·Programmable array logic (PAL)
·Configurable programmable logic devices (CPLD)
·Field programmable gate array ( FPGA)
Adaptive Noise cancelling is a speech-specific filtering technique to suppress additive interference. It is a sensible choice for speech-orientated devices in situations where the designer has no knowledge of the properties of interference that could potentially corrupt the input speech to a point beyond intelligibility. A good example of devices subject to such noise is mobile telephones, where the user may be communicating in a variety of environments. However, constraints appear when implementing a noise-cancelling algorithm on such a portable device, and issues of power consumption and silicon area become prominent
·Petroleum technology covers a wide range and the specific tasks of petroleum technologists are dependent on the field in which they work.
·Petroleum technologists are involved in the search of new oil-wells.
·This geological work and those involved in this field are known as geological petroleum technologists.
·In the extraction process the petroleum technologists do research on the different types of mud used to lubricate drill bits.
·Petroleum technologists are also involved in the evaluation of crude oil to determine its specific properties and classification which will, in turn, determine the refining parameters.
·Testing and evaluation of the various cuts are done by laboratory petroleum technologists during the refining process.
·Petroleum technologists are employed by Chemical Industries, in the refineries of various oil companies and other manufacturing industries, as well as in marketing sections.
·Biometrics is technology that automatically authenticates, identify, or verify an individual based on physiological or behavioural characteristics.
·This process is accomplished by using computer technology in a non-invasive way to match patterns of live individuals in real time against enrolled records.
Example:products that recognizefaces, hands, fingers, signatures, irises or irides, voices, and fingerprints.
PART OF BIOMETRICS IN VARIOUS FIELDS AND APPLICATIONS:
·Biometrics are most commonly used to enhance computer network security, protect financial transactions, safeguard international borders, control access to secured work sites, verify time and attendance, and prevent benefits fraud.
·Biometrics work well as stand-alone safeguards in many applications and complement other means of security in other applications.
·To verify e-commerce transactions, protect networksecurity, and authenticate online access, biometric technologies are particularly well suited to work in conjunction with other technologies to create a multi-layered security infrastructure
BIOMETRICS:
·The word biometrics comes from the Greek words bio and metric, meaning ``lifemeasurement''.
·By measuring something unique about an individual and using that to identify them, we can achieve a dramatic improvement in security of the key store.
·Newer biometric measurements include DNA from tissue samples, voice pattern, face pattern or even the arrangement of blood vessels in the retina or pattern of coloration in the cornea of the eye.
·The oldest and most widely accepted biometric is the fingerprint.
·The tip of every finger has a characteristic called ``friction ridges''.
·While generally similar, no two friction ridges are exactly the same.
·By imaging the ridges of the fingertips, we get the fingerprint.
SECURITY LEVEL:
·Integrating smart cards, biometrics and public key cryptography provides a solid foundation for developing secure applications and communications.
The highest level of security uses three-factor authentication:
1.Something you know (password or PIN)
2.Something you have (smart card, magnetic stripe card or a physical key)
3.Something you are (your fingerprint, retina scan or voice pattern)
AUTHENTICATION PATTERNS:
·An individual gains three-factor authentication by combining a smart card, biometric and PIN.
·If the user loses the smart card, the card is inoperable without the biometric.
·Forged fingerprints are weeded out with use of the PIN.
·In a smart-card-secure world, you are not locked into one form of authentication, such as a password or key.
BIOMETRIC SYSTEMS:
Biometric systems are :
·Automated.
·Mostly computerized systems.
·Used in Physio-biological measurements.
·Designed for detection of human body.(UNIQUE INDICATOR)
A VMOS is an enhancement MOSFET that can handle much higher drain currents than standard E-MOSFETS (Enhanced-MOSFETS). The "CURRENT" capability of a VMOS transistor results from its physical make-up or construction. The V-MOSFET has a "WIDER CHANNEL" than other E-MOSFETS. The "WIDER CHANNEL" allows a higher "DRAIN CURRENT" to be generated at a given value of Vgs or "source gate voltage" Also, another advantage of the VMOSFET is that it is not susceptible to thermal runaway. The VMOS has a positive temperature coefficient, which means that the channel resistance increases when temperature increases.
Therefore V-MOSFETS can be used in high-power applications where standard MOSFETS cannot be used.
VMOS (pronounced /ˈviːmɒs/), is an acronym for Vertical Metal Oxide Semiconductor (Transistor). Vmos is also used to describe the V-groove shape vertically cut into the substrate material metal oxide semiconductor transistor.
The "V" shape of the MOSFET's gate allows the device to deliver a higher amount of current from the source to the drain of the device. The shape of the depletion region creates a wider channel, allowing more current to flow through it.
The device was used as a power device until more suitable geometries, like the UMOS (or Trench-Gate MOS) were introduced in order to lower the maximum electric field at the top of the V shape and thus leading to higher maximum voltages than in case of the
VMOS Field Effect Transistor
VMOS field effect transistor or FET, electronics components used in many applications to give higher power performance than traditional FETs.
VMOS field effect transistors or FETs are a form of power MOSFET and these electronics components are used for a variety of applications where medium powers are required. The VMOS FET gains its name from the fact that it is "Vertical Metal Oxide Silicon". From this it can be imagined that the VMOS FET has many similarities to MOS technology, but the structure is arranged with a V-groove which also adds another dimension to the name VMOS.
When VMOS FETs were first introduced they out-performed bipolar semiconductor technology in many respects making the design of amplifiers much cheaper and easier. Since their introduction VMOS FETs have become firmly established as useful power MOSFET electronics components that can be used for a variety of power MOS applications ranging from power supply switching applications through to medium power RF amplifiers. They are also incorporated into many integrated circuits as they are able to switch very quickly.
VMOS FET structure
VMOS FETs are able to overcome many of the problems which prevented FETs being used in power applications. Their new structure enabled much higher powers to be handled than was previously possible with bipolar transistors of an equivalent size and cost.
The reason for this great improvement lies in the structure of the device. To show the advantages of a VMOS FET a traditional MOS device. Here it can be seen that the drain and source are separated by the gate. Current flows horizontally between the source and drain, controlled by the potential on the gate. As the current only flows through a relatively small area, resistance values can be high reducing the efficiency of the device.
The VMOSFET uses a different structure. The most striking point about the new device is the V groove in the structure which is the key to the operation of the device. It can be seen that the source is at the top of the device, and the drain is at the bottom. Instead of flowing horizontally as in the standard FET, current in this device flows vertically giving the device its name - Vertical Metal Oxide Silicon, VMOS.
VMOS field effect transistor structure:
The device uses two connections for the source and accordingly there is a much large area through which the current can flow. This reduces the ON resistance of the device allowing it to handle much higher powers than conventional FETs.
The gate consists of a metallised area over the V groove and this controls the current flow in the P region. As the gate is fabricated in this way it means that the device retains the exceptionally high input resistance typical of the MOS family of devices.
DEMERIT:
·Structure is more complicated than a traditional FET
