Posts Tagged ‘transistor’

What is a MOS-FET?

Monday, August 23rd, 2010

Mos-FETMOS-FET, which is an abbreviation of Metal-Oxide-Semiconductor Field Effect Transistor, is a very important kind of transistor. Many IC’s are constructed of arrays of MOS-FETS on a tiny sliver of silicon.

They are very small, easy to manufacture and many MOS-FETS consume a small amount of power making them an excellent choice for many applications.

It is the most common type of transistor available for either digital or analog circuits, replacing the bipolar transistor which was much more common in the past.

The word ‘metal’ in the name is actually now a misnomer because what was originally the gate material (often Aluminum) is now more often a layer of polysilicon (aka polycrystalline silicon).

BUZ11 – a Popular Power MOSFET

Friday, February 6th, 2009
BUZ11

BUZ11

The BUZ11 is an N-Channel enhancement mode silicon gate power field effect transistor designed for applications such as switching regulators, switching converters, motor drivers, relay drivers, and drivers for high power bipolar switchng transistors requiring high speed and low gate drive power. The BUZ11 is also used for DC-DC and DC-AC converters and in the automotive environment for injection, ABS, airbags, lampdrivers and more.

It features:

  • 33A 50V
  • Nanosecond Switching Speed
  • Linear Transfer Characteristics
  • High Input Impedance

The BUZ11 is in a TO220 package.

If you are looking at the BUZ11 with the drain (flange) at the top, the left pin is the GATE, the middle is the DRAIN, and the right lead is the SOURCE.

What is Transistor-Transistor-Logic – TTL?

Sunday, September 7th, 2008

TTL Transistor-Transistor-Logic

TTL Transistor-Transistor-Logic


TTL or Transistor-Transistor Logic is a type of digital circuit that is made from BJT or bipolar junction transistor along with resistors. Both the amplifying function and the logic gating function are carried out through transistors, thus the name transistor-transistor logic.

TTL is used for many applications like industrial controls, computers consumer electronics, test equipment, synthesizers and more. The TTL designation is also used in some places to imply ‘compatible logic levels’ even if they are not directly associated with transistor transistor logic circuits.

James Buie invented the Transistor Transistor Logic in 1961 and the first Transistor-Transistor Logic devices were made in 1963 in Sylvania. These devices were called the “Sylvania Universal High-Level Logic family” and were used within controls for the US Phoenix missile. In 1964 Texas Instruments produced ICs of 5400 series and later on, the 7400 series which made the Transistor-transistor Logic devices popular amongst electronic system designers. The 7400 series went on to become the industry standard. Many companies like AMD, Motorola, Intel, Fairchild, Siemens, National Semiconductor made compatible parts.

The TTL circuits were low cost which made them highly practical for using digital techniques in tasks which were earlier done through analog methods. One of the first computers that was built, in 1971, made use of the transistor transistor logic instead of a microprocessor chip which at that point of time was not available. With time incremental improvements in power consumption and speed were made, and the last popular series was the 74AS/ALS Advanced Schottky was made available in 1985.